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The processing of conceptual information on spatial directions from pictorial and linguistic symbols
Acta Psychologicu 32 (1970) 346-365; 0 North-Holland P&“shing Company Not to be reproduced in any form without written permission from the publisher
THE PROCESSING
OF CONCEPTUAL
SPATIAL DIRECTIONS LINGUISTIC
INFORMATION
FROM PICTORIAL
ON
AND
SYMBOLS 1
RONALD E. SHOP. U$versiry of New Hawpsstrire, Department of Psychology, Durham, N.H. 03824, U.S.A.
AJBTRACT
An analysis w;asmade in a sample of 30 Ss of the processing of spatiai information when expressed in pictorial and linguistic (verbal) symbolic representatious. Outline drawings of arrows pointing in the directions of UC, down, right, and left were compalunded with the word names for these directions printed within the arrows. A set of predictions were confirmed including (1) that it takes more time to name the arrow directions than to read the words and (2) that an interference phenomenon can be produced using mismatched spatial symbols similar to the color-word interference phenomenon of the Stroop test. A number of lines of further investiga;ion are presented. 1.
hTRODUCTION
is the first of a series of studies on the processing of conceptual tnformation using the compounded symbolic representations paradigm. The paradigm is a broad extrapolation from the logic of the STROOP color-word test (193Sb). In the color-word test Ss are asked to name pkesical exemplars of colors under conditions where the wrong word names of colors seriously interfere with task performance. The logic of the color-word test has been extended in two ways. First, it has been extended tlo include many other type;; of cognitive elements such as number- Uters, clockfaces, spatial relationships, geometric forms, alignments, known shapes and sizes, coin colors, traffic signal light colors;, physiognomic qualities, and the numerosity of objects. Second, the number of primary scores has been increased from the standard three to eight in order to study the interference effects in both directions and to compare the influence of differing percentages of stimulus mismatching. 30 preserve normative comparability over a series of studies and -L This study was supported by Grant MH 16209-01from the National Institute This
of Mental &a&b and by CURF Grant 352 from the University of New Hampshire. I wish to thank G. A. Forsyth, L. A. Fox, and D. ‘I’.Landrigan for their helpful cummwb. Appreciation is also due to W. M. Conroy of the Computation Center, University of New Hampshire, where the statistical work was done. 346
CONCEPTUAL
INFCRMATION
ON SPATIAL
DIRECTIONS
347
across laboratories the research methodology has been formalized into the Shor cognitive elements test (SCET) with standardized psychometric features (SHOR, 1967). Lack of standardization has regrettably characterized work with the color-word test (JENSEN, 1965). The purpose of this particular investigation was to study information processing time for the basic concepts of up, down, right, and left under conditions where these four spatial concepts were represented in two quite different forms of symbols. The first form of symbol was pictorial and the second was linguistic (verbal). For the pictorial symbolization outline drawings of arrows pointing in the four spatial directions were used. For the linguistic symbolization the word names of the directions were used. In taking the SCET the S is presented with a randomized series of stimuius sheets each representing sets of either the pictorial or linguistic symbols alone or compounded together with various degrees of stimulus matching or mismatching. Compounding is accomplished by printing the word name for a spatial direction inside of the outline drawing of an arrow. The compounding may either match the word with its correct arrow direction or mismatch the word with one of the other three arrow directions. An example of a mismatched item would be an arrow pointing to the right with either the word ‘left’, ‘up’, or ‘down’ printed within it. On each trial the S is given the preparatory set either to respond to the pictorial or to the linguistic symbolic representation. The present study was designed to test the following five hypotheses: (1) Naming directions of arrows will take more time than reading the word names for directions. (2) Stimulus complexity will make the task more difficult. (3) Performance time will be a function of the number of response alternatives. (,4) It will take more time to identify the directions of right and left than of up and down. (5) The more difficult the task the steeper the slope L rlie increase in performance time as a function of stimulus complexity. IL will prove more eficienr: to elaborate on the hypotheses after presenting section 2.
2. 2.1.
hdETWOl.3
Subjects
The Ss were 30 undergraduates taking a course in introductory psychology at the University of New Hampshire. Thirteen of the Ss were male, 1‘7 were female. Ages ranged from 18 to 21 years.
348 2.2.
RONALDESHOR
Design and prxedure
Three relate3 ruinimal arrows stimulus sets selected from the SCET
were used in this study: (l) Up-down - this stimulus set includes just the directions of up and down. (2) Right-left - this includes just right and left. (3) Four way - this includes all four directions.2 For each stimulus set the procedure of the SCET specifies two task instructions (TI) combined with four levels of stimulus complexity (SC). This makes eight conditions (the eight primary scores) administered for each of the three stimulus sets to all 30 Ss. The investigation is thus a repeated measures design with three fixed factors. The two task instructions were: (1) Arrows task instructions - the S was instructed to identify (name) the directions of the arrows ignoring any embedded words. (2) Words task instructions -. the S was instructed to identify (read) the words ignoring any surrounding arrows. The four leve!c of stimulus complexity were: (1) Pure condition either 24 arrows or 24 words were placed alone on the stimulus sheet without the other type of symbol present. (2) 0% mismatched condition __all 24 items on the sheet were composed of compounded arrows and words but all were fully matched. (3) 50% mismatched condition twelve of the 24 items on the sheet were matched and 12 were mismatched. (4) 100°A mismatched condition - all 24 items on the sheet were mismatched. Stimulus sheets were composed of 24 items arranged in 4 x 4.5 cm blccks on 21.6 x 28 cm paper (4 columns x 6 rows). The S was instructed to respond first to the item in the upper left hand corner and then go down each commn in sequence. Before each trial the appropriate test booklet page was opened flat on thle desktop before the S. Prior to the experimental testing the nature of the task and the character of the stimulus materials were explained in detail to the 5’. Twelve practice trials were given, or more until the examiner felt assured that the S was able to attain good performances. Before each trial along with one of the two task instructions the S was told the stimulus set and the degree of sti~mulus complexity that he would have to deal with on the coming sheet. Pt was made clear to the S that an important part of his overall task was to pay careful 2 Wnii
arrows are outlime&awingsof arrows composed of mctangk?spointed
Contrast these with big head arrow9which ark outlineswith the Shape of oneWay trafltiesigns (‘CX3). at one end (I).
CONCEPTUAL INP0RhIATION ON SPATIALDIRECTIONS
349
attention to the i.?structions before each trial so that he couId build up a preparatory set in which all salient information was taken into account. from trial to trial. he two task instructions were alternate The S kept his eyes averted from the page while the examiner gave the instructions for that tria he S then took whatever time he needed to form his pre hen ready the S turned his eyes to the page and proceeded throqh the list of items as quickly as he could without errors. Stopwatch timing was begun when the S named the first item and was ended when he named the 24th item. As the objective was to secure time meL:surcs of rapid and error-free performances in well-prepared ss the trial was repeated if an error was made.3 The performance measure was the total time for the 24 items. The SCET incorporates a block randomizing and counterbalancing procedure in which two measures are taken for each of the eight response categories. These pairs of measures are averaged to control for progressive errors and then serve as the raw scores. Further details on test procedure and construction are avirilable in the SCET manual (Z&OR, 1967). 3. 3.1.
HYPOTHESES Hypolhesis
I
Performance time will be longer for i cntifying (naming) the directions of up, down, right, and left from outline drawings of arro’ws pointing in these directions than for identifying (reading) the printed word
names for these directions. The presumption is that for literate adults linguistic symbols are more familiar, better learned, and more freyuently used than are pictorial symbols. Children are taught from an early age to make linguistic symbolism the primary vehicle in their thinking. In f5-K theory this can be couched in terms of differential habit strengths (STROOP, 193% 3- RXSEN and ROHWER, 1966); in organismic-develiopmental theory, in terms of hierarchic integration of functions (WAPNER and KRIS, 1960; RAND et al., 1963; COMALLIet al., 196%). An alternate or concurrent interpretation is that since Ss respond by speaking words, it will take more time to name the arrow directions than to read the printed words because reading the words does not require the additional step of transformation into a linguistic form. More information processing is required to recode pictorial arrow 3 Errors were infrequent and procedures are incorporated in the SCET to minimize possible disruptive effects of errors. Errors were recorded but not aoalysed.
350
RONALD E. SHOR
directions into spoken words than to recode printed words into spoken words. Verbal encoding and processing is discussed in CAMPand HARGUM (1964), NEI,SSIER (1967), CLANZERand CLA.RK(1962, 1963), and SFRRLING(1963) 3.2. Hypothesis .2 Performance time will increase as a function of stimulus complexity. It is predicted that for any given stimulus set performance time will be least in the pure condition and then will be progressively higher in the 0 %, 50x, and 100 % mismatched condirions. The presumption is that the more stimulus complexity, the more the task is made difficult by interfering and competing distractions, and thus the more time it will take to process the information in it. This hypothesis is again consistent with the S-IX habit strength theory of suppression of competitive response tendencies (see especially STEINand LANCER,1966). The capacity of an individual to maintain a uniform course of action independent of intruding or interfering stimuli is seen as an important as,pect of organismic-developmental theory (COMALLIet al., 1962). 3..3. H’gothesis 3 Petionnance time will increase as a function of the number of response alternc_.ives. It is predicted that responding to all four directions in the four way stimulus set will take more time than responding to just two directions in either the up-down or the right-left stimulus sets. The presumption is that the task will become more difficult the more response alternatives which the S must keep in mind and process. GHOLSON and HOHL.E (1968b) found the number of response alternatives to be an effective independent variable in a choice RT task patterned on the color-word test. A general discussion of the relation of number of response alternatives to disjunctive reaction time and information theory is presented in MILLER(1951). 3.4. Hypothesis 4
Performance time will be longer to the sti.mulus set composed of the directions of right and left alone than to the stimulus set composed of the directions of up and down alone. The directions of up and down are presumed to be more absolute and genetically primitive than are rigbt and left. This hypothesis is consistent with GIBSON’Stheory of
CONCEPTUAL
INFOR
THON ON SPATIAL DIRECTIONS
3;5II
the primary orienting features of the terrestial environment (19156) aget’s discussion of egocentric thinking (FLAVELL, 1963). An alternate or concurrent imterp~etation is that it will take more time to say right and left because of simple word length. 3.5.
othesis 5
he larger the pure condition mean the steeper the slope of increase in performance time as a function of stimulus complexity. ‘This functional relationship is predicted because it is presumed that if a task is relatively difficult that adding stimulus complexity to it will make it become even more difficult than it would for a ta.sk which is relatively easy in its pure condition. The presumption is that a relatively easy task can bear the burdens of additional stimulus complexity with less additional disruption. Empirical predictions are presented gra.phically in fig. 1. Stimulus Sets
Task Ipgtructions
Identify (name) the Arrow Directions
,o
/,;y
/I_
Four Way
~0
Right-Left
Identify tread1 the Words t-
-0’ e--e
Up-Down
I
-e-
50%M
Pure STIMULUS
Fig. 1.
/
COMI’LEXITY
Empirical predictions from the five hypotheses. The predictions to be interpreted as ordinal relationships.
are meant
In summary, performance time will increase as a function of (1) b’esponse to arrows or words, (2) degree of stimulus complexity, (3) number of response alternatives, (4) up and dov+Fnas compared with right and left. Also predicted is (5) a functional relationship between performance
RONALD E. SHOR
352
time in the pure condition and the effect of stimulus complexity. Al,thou for sirnplicit~~drawn on the graph as equal intervals and straight lines, the predictions are meant to be interpreted as ordinal relationships.
Means and standard deviations are presented in conditions (3 x 2 x 4) are numbered ;as sequential variables. TAaLE 1
’
Means and standarddeviation. --Stimdus
set
Task inStirUCtiOIlS
Stimulus complexity
Variable number
can
SD
50% M 100% M
1 2 3 4
9.25 9.11 10.40 10.20
1.30 1.52 1.57 1.55
Pure
5
R’ords
0% M 50% M nw& RI
6 7 8
6.84 7.10 7.39 7.32
0.88 0.95 1.07 0.94
Arrows
0% M
1.54 1.42 1.75 1.92 --
AKOWS
0% M
50% M 100% M
Kigbt-ka
9
9.59
10
9.54
11 12
10.52 10.94
----
“‘FwJs
0% M 50% M 100% M
.-_
13 14 I5 16
7.84 8.04 8.28 8.06
-----
Pure hOWS
Four way Words
0% M 50’s M lO&,~ M -Pure 0% M 50% M 100% M
1.oa 11.16 1.13 1.02 __--
17 18 19 20
11.49 10.63 12.47 13.30
21 22 23 24
7.71 8.13 8.37 8.32
--
1.69 1.92 2.27 2.14 0.94 1.05 1.13 1.08
2
2 1 5
1
4 4
‘ure 0%
4
1 3 7 5
3
2 3 7 6 6 5 1
so%loo%
5
6
7
Words 8
TAm.E2
Right-left
v
2 5 5 7 6 4 1
1 5 6 8 4 6
2 f 2 6 8 7 2 2
2 4 3 6 5 7 1 2 4 12 7 7
1 5 9 9 6
14
2 8 6 9 5
15
1 4 18 10 5
16
50% mO%
Words
Lure Qo/;, 50% loo% Pure 0%
AbOWS
Frequency distributions.
E 5 7 6 5 3 3
17
2 1 5 5 6 4 5 2
18
1 4 3 6 4 3 4 4 1
19
Arrows
f 1 8 3 2 5 5 4
20
8
5 5
3 1
2 4 11
3
4 9
2
4 4 8
354
RONALD E. SHOR
There are high correlations between the means and the standard deviations.
The coefficient is 0.59 for the 12 variables under the words TT, WV for the 12 variables mder the arrows TI, and 0.96 over all. Frequency distributiom are presented in table 2. Ah distributions appear approximately normal but a moderate amount of positive skew is commonly seen in those variables where a large proportion of the scores are close to the lower bound. The analysis of variance summary table is presented in table 3. TABIE 3 Analysis of varianw summary table. SOlUCe
Sub&cts
Stimulus complexity SC x ss Ta;ik instructions TI X ss Stimulus sets Setsx ss SC x TI SC x TI x 5’s SC X sets SC x sets x ss -l-IX&S TrX!set3XSS scxTIxse!s SC
x
Total
TI x
Set!3 :< 6%
df
29 3 87 1 29 2 58 3 87 6 174 2 58 6 174 719
VE 32.35 44.41 0.64 1447.68 6.54 155.63 0.87 20.36 0.70 2.04 0.27 49.00 0.77 2.06 0.22
F
P
-
-
69.4 221.4 -* 179.0 29.0 7.6 63.7 9.0 -
< 8.001 _< 3.001 .< 0.001 -< 0.001 < 0.001 < 0.001 < 6.001 -
-
All main effects and first and second order interactions are significant beyond the 0.001 ‘levci.Because of the large interactions and the systematic heterogeneity of variance the a.nalysis was broken down into separate comparisons between pairs of variables using the non-parametric Wilcoxon T test.4 The means are displayed graphically in fig. 2. 4 1%~objection can be raised that the probability values should be corrected to take account of multiple tests, even though the tests run to evaluate the hypotheses were only a restricted set of comparisons among the possible combinations of pairs of . The argumentdces not have practical relevancy in this particular study, however, because of the extremely small probabiliiy values which will be reported.
CONCEPTUAL
INFORMATION
ON SPATIAL Q~RECTI~NS
_
%timulus Sets
Four
355
Task Inotruetians
---I i-- Arrows
way
Right-Left
1 I
Up-Down _J
-0.--M--_=~-.---,~-~ -
b--
/
___---*--_
-
-.
-
-*-
O---
Pure
&M STIMULUS
Fig. 2.
Findings pertinent
50%H
---mm.*
’
Fmr Way Right -Left---I--
Words
Up - Down -I
100% M
COMPLEXITY
Graphic display of the means.
to the five hypotheses are as fellows: Hypothesis I. It was predicted that it would take more time to identify (name) directions of arrows tha to identify (read) word names of directions. All twelve of the counterpart mean differences under the arrows and words TI are statistically significant beyond the 0.0001 levrl. Even the difference between the very lowest arrows TI mean (0% up-down) and the highest words TI m,ean (50% four way) among the entire set is significant (p < 0,001 level). These findings are a powerful confirmation of the first hypothesis. Hypothesis 2. It was predicted that performance time would mcrease as a function of SC. Probability values for each comparison among the pzlrs of means pertinent to this hynothesis are presented in table 4. To illustrate, the corxztly predicted increase of the 50% mismatched condition mean over the pure condition mean for the up-down stimulus set under the arrows TI is significant beyond the 0.0001 level. Twenty-nine of the 36 mean differences (81%) are in the predicted direction. Of the 29 correctly predicted direct ions of mean differences only SWO failed to achieve significance at the 0.05 level. Of the seven comparisons with mean differences in the direction 0pposit.e to prediction only two are significant. Thus, of the 29 significant differences, 27 were
RONALD E. SHOR
355
TABLE 4
W&axon T probability values for each comparison among pairs of means pertinent to hypothesis 2 Mea.. +nces in the direction opposite to prediction are indiated by a square surrounding the p
values.
Y
0% M
Words T1[ 50% M 100% < 0.
II-
t&-down
Pure
j
O%M
1
10748j
SO%M/
-
50%
i
Bn:
< 0.01
< o.ooo1
< o.ooo1
-
< 0.01
-
-
-
-
< 0.001
-
-
-___
Fourway
Pure 0% M 50%Mj
< o.oum < 0.0: --
1-1 (
-
< O.oool
< o.ooo1
-
1
-.-.-
----
Pure
0% M
< 0.ooo1
_.-~.-_-..___I_.
---I----Right-left
< o.ooo1
0.08
< 0.
-
< 0.01 -
-I-
- .__.
< 0.001
< 0.001
1
<
0.02
-__..--.---__.
-._
< o.ooot
< o.ooo1
-
< 0.01
< 0.05
-
-
czl 0.38
--
in the correctly predicted
These finding:, are a strong general ~~firm=itIcn of the hypothesis. A striking exception is that there was a significant decrease in the 0 % mismatched condition mean as compared with its counterpart pure condition mean in the four way stimulus set under the arrows TI (p c 0.001). A similar pattern of decrease can be observed in comparing these two means in the other two stimulus sets, but lt.he d;+rsnces are not significant. Hypohses 3 and 4. As these two hypotheses refer to comparisons between the stimulus sets they may conveniently be treateLI together. It was prledicted that performance time would increase as a function of the number of response alternatives. It was predicted that performance time would be less for the up-down than for the right-left stimulus set. Probability values for each comparison among .;he pairs of means &%in~& to these hypotheses are presented in table 5. Most of the mean differences are significant beyond the 0.0001 level and all but one are in the predicted direction. However, all four of the comparisons between right-left and four way under the words T1[ are insignificant and two of the four comparisons between up-do-vn and right-left under the arrows TI are ins&t&ant. Despite the few direction.
TABLE
5
ilcoxon
test probability values for es& comparison among pairs of means pertinent to hypotheses 3 and 4. The one mean difference in the direction opposite to prediction is indicated by a. square surroufiding the p value.
right-left
Words
< 0.0801
< 0.0001
< 0.0001
< 0.0001
Up-down vs. four w!ay
Arrows Words
< 0.0901 --: 0.0001
(1.0.0001 < 0.0001
< 0.0001 < o.a91
< 0.0001 < 0.0001
<
< ~~.rSOOl < 0.0001 0% 0.45
Arrows Words
j
.-r:C!.OOOl 0.06
discrepancies the findings are a strong general confirmation of the two hygotheses. H_ypothesis 5. It was predicted that the higher the pure condition mean the steeper would be the slope of increase in performance time over the pure condition mean as 2a unction of SC. By inspection of fig. 2 it can be observed that this redicted relationship did appear to occur but not in a uniform way. The three lowest pure condition means all show about the same pattern of increase due to SC. The next two higher pure sbDndition means show larger increases than the first three, but do nclt appear to differ between themselves. The highest pure condition mean doles show the largest amount of increase. Another way to express these: observations is that the means appears to show less increase as a functi.on of SIC under the words TI than under the arrows Tl. The average increase: from pwre to 100% under the arrows TI is 1.44 sec. ; under the words TI is 8.68 sec. As the 100% mismatched condition is specified as representing the largest amount of stimulus complexity, the difference between the pure and the 100 “/ misnlatched condition score was select ?d as the index of slope. This inderc. uses only the extremes of stimulus complexity and ignores the two intermediate conditions. A one-way analysis of variance was performed on the six slopes (F- 16.2, L/I= 5/145, p < 0.001 level) and Dancan’s multiple range test was used to separate the differences between the means. The findings are presented in t&k 6.
RONAP.1, E. SHOR
358
TABLE6 Differences be&veen the six slopes. The means of the slopes are arranged on the table from smallest to largest. Any two means not underlined by the same line are si:gnificantly different beyond the 0.05 level of confidence, Stimulus sets
Right-left Up-down Four way Up-down Right-left Four way Words
Words
Words
Arrows
Arrows
Arrows
Ranks of size of pure condition means
3
1
2
4
5
6
Means of slopes (KMy0 mismatched minus pure condition)
0.22
0.48
0.61
0.95
1.35
1.81
Task instructions
R&&s of Duncan’s multiple range test (0.05 level)
Mot every mean difference is significant, but in each instance where it is, the difference is in the predicted direction.5 4.1.
Currelational informution
The matrix of iotercorrelations is presented in table 7. The correlations range from 0.36 to 0.93 and the median coefficient is 0.70. A principal components factor analysis was performed on this n~trix. Two factors emerged with eigenvalues set at limits of 1.0. The unrctated and rotated factor loadings are presented in table 8. The totaf percenr;sge of variance accounted for by the two factors extracted was 83:<. The percentage of accountable variance for the two rotated factors is 53 and 47% respectively. A graphic presentation of the varimax rotation is given in fig. 3. While all 24 variables have positive loadings on both factors, there 5 It can be argued that a more sahent index of increase due to SC would be to take the difference between the pure and the larger of either t& 50 y0 or 100‘% m condition score. A parallel analysis was made using this alternate index. The Duncan’s test results were the same with the excseption that the slopes for the r;ecoad and fourth ranked purr, condition means ds differ significantly. A trend analysis for linearity based on orthogonal components might suggest itself here but as predict only ordinal relationshu’ps it was not deemed appropriate. thehvpo
atrix of intercorrelations. lkcimal points are omitted.
I - 1 _-_I_2 3 1
_
4
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 ----. -___ -____ _- .___- .- ..._
68 81 ?2 65 75 74 69 79 74 74 78 67 82 76 73 80 64 $0 74 69 65 65 71
2 68 69 3 $1 69 4 I 72 72 84 5 65 57 57 6 75 60 66 7 74 64 63 8 69 50 60 9 79 63 78 10 74 85 74 11 74 65 83 12 78 68 76 13 68 59 67 14 82 67 76 15 76 56 67 16 73 63 62 17 80 65 80 18 64 $4 70 19 80 62 86 74 52 77 20 69 55 62 21 65 43 59 22 65 46 57 23 71 47 60 24
72 84 46 60 62 59 75 69 82 79 62 62 63 59 76 66 81 75 61 50 51 49
57 64 57 66 63 46 60 62 92 $8 92 e 92 $8 92 $5 90 93 63 73 67 66 69 69 64 72 68 60 71 66 87 87 84 92 92, 92 $7 91 92 89 93 90 59 63 62 55 511 56 52 61 56 41 4!) 42 :!I6 86 90 “18 83 79 ‘18 80 82 ‘99 83 83
50 60 59 85 90 93 69 60 69 64 83 87 89 88 55 42 56 40 88 $0 80 78
63 78 75 63 73 67 69 80 88 89 68 75 77 71 86 73 83 75 69 70 66 58
85 74 68 66 69 69 60 80 77 82 64 76 68 71 74 $5 77 58 62 62 56 55
65 83 $2 64 72 68 69 88 77 90 73 75 71 7:5 $3 7G 84 78 68 70 68 55
68 76 79 60 71 66 Cd $9 82 90 63 70 73 67 84 71 83 79 66 67 65 54
59 67 62 87 87 84 33 68 64 73 63 89 92 91 65 56 63 Pl 80 71 74 71
67 76 62 92 92 92 87 75 76 75 70 89 90 93 71 64 68 56 88 81 78 83
56 67 63 87 91 92 $9 77 68 78 73 92 90 92 72 58 68 55 $7 82 86 80
63 62 59 89 93 90 88 71 71 73 67 91 93 92 62 55 57 47 84 79 78 78
65 $0 76 59 63 62 55 86 74 $3 84 65 71 72 62 77 88 85 69 59 63 56
$4 70 66 55 51 56 42 73 85 70 71 56 64 58 55 77 66 56 59 51 52 43
62 86 81 52 61 56 56 83 77 84 83 63 69 68 57 88 66 $9 58 55 53 53
52 77 75 41 49 42 4C 75 68 78 79 51 56 55 47 85 66 89 50 43 41 36
55 43 62 59 61 50 86 78 $6 $3 90 79 88 $0 6E( 70 62 62 68 70 66 67 80 71 89 81 87 82 84 79 69’ 59 59 51 58 55 SO 43 -.. 85 85 85 93 84 87
is an. unambiguous clustering of the variables taken under the two TIs with each of the two factors. 5,
DISCUSSION
While exceptions in a few comparisons were noted the five hypotheses were confirmed. It takes less time to read the names of directions than to name the directions of arrows; stimulus complexity - i.e., compounding and mismatching - is an effective variable; number of response a.lternatives is an effective variable; it is easier to identify up and down than right and left; and the more difficult the task in its pure form the more difficult it becomes when stimulus complexity is added to it. This is the first study to demonstrate that an interference phenomenon
46 57 51 78 $0 82 80 66 56 68 65 74 78 86 78 63 52 53 41 $5 93 8S
47 60 49 79 $3 83 78 58 55 55 54 71 83 80 78 56 42 53 36 $4 87 $5 -
RONALD E. SHOR
360
TABLE 8
Unrotated and rotated factor lo; dings. Principal components 1 87 74 84 78 85 91 90 86
2 -16 -28 -34 -39 38 31 33 38
Verimax rotated I
2
h2
53 35 39 31
71 71 82 82
78 63 81 77
89 87 88 89
30 39 37 31
88 92 91 88
47 41 47 42
79 77 79 82
84 78 85 85
79 83 84 86
43 49 46 39
81 93 92 90
37 29 30 14
84 79 88 90
85 70 86 82
85 84 84 86
38 33 32 26
87 80 801 801
__~_II_-I_I_
Pure 0% 50 “/o 100%
9 10 12
88 84 88 86
Pure 0% 50% 100%
13 14 i5 16
87 94 93 90
Pure 0% 50 % 100%
17 18 i9 :?o
85 75 82 71
Pure
21 22 23 24
88 83 83 80
0% 50% 100%
11
-26 -28 -26 -32 23 20 24 31 -37 -38 --46 -56 30 33 34 40
can b;;. produced using mismatched spatial symbols similar to the irnterfmence phenomenon of the Stroop color-word test. In several prior investigations the Stroop test was altered to include other co,@itive eIements besides colors and words. LANGER and Rosa BERG(1966; STEIN and LANGER,1966) studied the inkrference effect using ‘phonic symbols’ instead of color names, SMITHand BORG(1964)
CONCEPTUAL INFORI’VIATION OF SPATIALDIR:ECTIONS
361
used shades of brightness rather than hues, SANTOSTEFANO and PALEY (1964) used pictures of correctly colored fruit with distracting pictures of objects printed nearby. Investigators have compared reading names with naming common objects (STROOP, 1938) and geometric forms (GHOLSON and ONLE,1968a), but interference conditions were not used.
Arrows
m
.6----IT-.7
.9
TI
+1.0
FACTOR 2
Fig. 3. Verimax rotated factor analysis.
The purpose of the present line of investigation is to make a systematic experimental analysis of the processing of information when expressed in different symbolic representations. Although a number of investigators have suggested that the color-word interference e:ffect wou1.d be an interesting phenomenon to study in its own right (THURSTONE and MELLINGER,195.3; JENSENand ROHWER,1966; UNDERWOOD,1966) there has been little attempt to make a systematic analysis or to provide basic norms. Xotable exceptions are the study of psychometric properties by JENSEN(1965), the semantic gradient study by KLEIN(4964), and the studies following Klein’s lead (SCHILLER,1966; BAKANand ALPERSON,1967; SCHEIB~ et al., 1967; ZIEKand WEISS,1968). Klein demonstrated a semantio gradient of the capacity of different kinds of words
362
RONALDE.SHOR
to interfere with color naming. From least to most interfering these were: (1) nonsense syilables, (2) rare words, (3) common words, (4) color-re?&.ed words, (5) distant color names, and (6) actual color names as used in the common versions of the Stroop test. Tt would be interesting to apply Klein’s paradigm to compounded spatial symbols. The correlation of 0.96 between mean performance time and the variability of the .sc#ores(the standard deviations) is a striking finding. This is not just a random Increase in variability. The median intercorrelation. of 0.70 indicate:j t:hat the relative positions of the & remain moderately stable. These Sndings mean that individual differences increase systematically as I function of the average difficulty of the task - i.e., as the task on tht average becomes more difficult iI becomes more difii::& for some Ss than for others. In more succinct language, the End.ings mean that the slope of the gradient of difficulty varies for different Ss. Studies on individual differences are needed to see what other psychologifcal characteristics relate to these findings. The methodology of the present investigation based on the SCET uses a global performance measure of total time to process 24 times. This measure is convenient and simple but : t provides no way to analyze the processing of single stimulus items w %ch is also of interest. The tachistoscopi’c presentation and choice re;action time method of GHOLSON and HOHLE (1968b) could profitably be: adopted to that end. In post-experimental inquiries severa. Ss reported that it seemed intuitively easier to name the arrow directions in the 100% than iri the 50% mismatched condition because when words were known to be all wrong they could be ignored more easily. While the empiricai findings do not confirm this subjective impression, the increase of the 100% over the 50;;/, mismatched condition means is by no means so strong and uniform that the impression is implausible. In more intensive study of this issue it may become useful to introduce a number of intermediate percentages besides 50% and not tell Ss the percentages of mismatching. It is important to draw attention again to the fact that in this study stimulus sheets were presented on a flat Ljesktop. This means that the directions of up and down were deflned from the coordinates of a sheet of ,paper and not in relation to the orientation of gravity and the geographic environment. It will be interesting in subsequent studies to compare arbitrary frames of reference with geographic coordinates. Although the hypothesis was confirmed that in general performance
CONCEPTUAL INFORMATION ON SPATIAL DIRECTIONS
363
time increases as a function of SC, performance time was actually less in all three 0% mismatched conditions under t arrows TI that in : pure conditions. ‘While only one of these three reversals y significant, exceptions which appear to follow a are worthy of attention. It is plausible that the reversals occurred because it is hard to keep i’rom taking advantage of easily discerned corrzct information when it is known to be correct. Intrtispective report would seem to bear out this interpretation. In the post-experimental inquiries many SS reported that it was very difficult to ignore the correct word information when trying to name the arrow directions. Recall that in this condition the Ss are expressly tcbld before the trial that the words and arrows will all be correctly matched. Arrows known to be correct do not appear to help in reading words, however, probably because it is already much easier to read words than to name arrows. It would seem worthwhile to evaluate this mterpretation in subsequent studies by hypothesizing that performance time in the 0% mismatched condition is a function not only of SC (hypothesis 2) but also of an inability to ignore easily identified correct information when it is known to be correct. This condition is the special case where the inability to ignore the correct information can mean an inability not to take advantage of it. It is plausible that this interpretation has relevance for the SO’% mismatched condition also, but whether the correct information proves a help or a. hindrance in that context is as noted atili uncertain. The method of statistical analysis adopted concentrated on the proportion of significant individual mean comparisons in the predicted direction. This method af analysis, while cogent, does not imply that interaction information is with.out interest. The complex interactions found underscore the virtue o,f the SCET in expanding the number of primary scores to help encompass the complexity of the phenomenon and in standardizing the conditions of testing. One of the interpretations offered to account for the advantage of readinp words over naming arrows was tha.t there are fewer coding steps in transforming written words into spoken words than in transforming positional arrow directions into spoken words. On this interpretation, if the response mode were chang,ed. from the present spoken linguistic response to a motoric positional resl>onse by using a faur-way toggle switch then there should be fewer coding steps when transforming positional arrow directions into positional motor response than when transforming written words into positional motor responses. The
364 prediction
RONALD E.
SHOR
is that with a positional response mode the functions would
reverse - iz., it would take less time to identify (respond motoricaily to) the arrow directions than to identify (respond motorically to) the gxd names for directions. A study is currently in progress to evaluate this predkfion. REFERENCES BAKAN,P.and B. ALPE!RSON, 1967. Pronounceability, attensity, and interference in the color-word test. Amer. J. Psychol. 80, 416-420. C,uln; D. S. and E. R. HARCUM,1964. Visual pattern perception with varied fixation locus aud response recording. Percept. Mot. Skills IS, 283-296. COMALLI, P. E., S. WAPNERand H. WERNER,1962. Interference effects of Stroop color-word test in childhood, adulthood, and aging. J. genet. psychol. 1 47-53. Fx ~.VELL, J. H., 1963. The developmental psychology of Jean Piaget. Princeton: Van Nostrand. GHOUON, E!. and R. H. HOHJX,1968a. Verbal reaction times to hues vs. hue names and forms vs. form names. Percept. & Psychophys. 3, 191-196. and 1968b. C!noice reaction times to dues printed ,in conflicting blue names add nonsense wo&. J. exp. Psychol. 76, 413-418. Gmscq J. J., 1966 The senses considered as percqtual systems, New York: Houghton Mitihn. GLANZER,M. and W, H. CLARK,1962. Accuracy of perceptual recall : an analysis of organization. J. verb. Learn. verb. Behav. 1, 289-299. and 1963. The verbal loop hypothesis: binary numibers. J. verb. Learn. verb. ‘Behav. 2, 301-309. JENSEN,A. R., 1965. Scoring the Stroop test. Acta Psychol. 24, 398-408. and W. D. ROHWER,1966. The Stroop color-word test: a review. Acta Psychoi. 25, 36-93. Km, 6. S., 196-t. smantic power measured through interference of words with color-naming. Amer. J. Psychol. 77, 576-588. LAK~ER,J. and B. 6. ROSENBERG, 1966. Symbolic meaning and color naming. J. Per. sot. Psychol. 4, 364-372. M~LER, G. A., 1951. Language and communication. New York: McGraw-Hill. NErssur, U., 1967. Cognitive psychology. New York: Appleton-Century-Crofts. RAZZ, G., S. WAGNER,H. WERNER and J. H. MCFARLAND, 1963. Age differences in performance on the Stroop color--word test. J. Pers. :)I, 534-558. SA~TBSIEFANO, S. and E. .PALEY, 1964. Development of cognitive controls in children. Child Developm. 39, 939-949. Scr-zm~, K., P. R, SHAVERand S. C. CARRIER.1967. Color association values and response interference on variants of the Stroop test. Acta Psychol. 26, 286-295. SCULLER,P. H., 1966. Developmental study of color-word interference. J. exp. Psychol. 72, 105-108.
TlOM ON S
DIMCTlONS
365
SHOR,R. E., 1967. The Shor cognitive elements test: a manual. Durham, N.II.: Symbolic Processes horstory. s 5 G. J. W. and G. A. V. BORG,1964. prcblem of retesting in the serial color-word test. Psychol. Res. Bu G., 1963. A model for visual memory tasks. urn. Factors 5, 19-31. B. and J. LANORR, 1966. The relation of covert gnitive interference in the color-phonetic symbol test to crsonality characteristics and adjr.stment. J. Pers. STROOP,J. R., 1935a. Th is of Ligon’s theory. A4ner. J. Psy:hol. 35b. Studies of interference in serial verbal reactions. J. exp, Psychol. , I 1938. Factors affecting speed in serial verbal reactions. Psychoi. THURSTONE, L. ,d. and J. J. ELLINGBR, 1953. The Stroop test. Chapel Mill, N.C.: The Psychometric Laboratory, University of North Carolina, ho. 3. UNDBRWOOD,B. J., 1966. Experimental psychology. Second edition. New York: Appleton-Century-Crofts. WAPNER,S. and D. M. I&us, 1960. Effects of lysergic acid diethylamide, and differences between normals and schizophrenics on the Stroop color-word test J. Neuropsychiat. 2, 76-81. ZEIK,J. and S. J. WEISS,1968. Stimulus meaningfulness and sex as factors in interference on color-word lists. Paper read at the Eastern Psychological Association Conventicn.
THE PROCESSING
OF CONCEPTUAL
SPATIAL DIRECTIONS LINGUISTIC
INFORMATION
FROM PICTORIAL
ON
AND
SYMBOLS 1
RONALD E. SHOP. U$versiry of New Hawpsstrire, Department of Psychology, Durham, N.H. 03824, U.S.A.
AJBTRACT
An analysis w;asmade in a sample of 30 Ss of the processing of spatiai information when expressed in pictorial and linguistic (verbal) symbolic representatious. Outline drawings of arrows pointing in the directions of UC, down, right, and left were compalunded with the word names for these directions printed within the arrows. A set of predictions were confirmed including (1) that it takes more time to name the arrow directions than to read the words and (2) that an interference phenomenon can be produced using mismatched spatial symbols similar to the color-word interference phenomenon of the Stroop test. A number of lines of further investiga;ion are presented. 1.
hTRODUCTION
is the first of a series of studies on the processing of conceptual tnformation using the compounded symbolic representations paradigm. The paradigm is a broad extrapolation from the logic of the STROOP color-word test (193Sb). In the color-word test Ss are asked to name pkesical exemplars of colors under conditions where the wrong word names of colors seriously interfere with task performance. The logic of the color-word test has been extended in two ways. First, it has been extended tlo include many other type;; of cognitive elements such as number- Uters, clockfaces, spatial relationships, geometric forms, alignments, known shapes and sizes, coin colors, traffic signal light colors;, physiognomic qualities, and the numerosity of objects. Second, the number of primary scores has been increased from the standard three to eight in order to study the interference effects in both directions and to compare the influence of differing percentages of stimulus mismatching. 30 preserve normative comparability over a series of studies and -L This study was supported by Grant MH 16209-01from the National Institute This
of Mental &a&b and by CURF Grant 352 from the University of New Hampshire. I wish to thank G. A. Forsyth, L. A. Fox, and D. ‘I’.Landrigan for their helpful cummwb. Appreciation is also due to W. M. Conroy of the Computation Center, University of New Hampshire, where the statistical work was done. 346
CONCEPTUAL
INFCRMATION
ON SPATIAL
DIRECTIONS
347
across laboratories the research methodology has been formalized into the Shor cognitive elements test (SCET) with standardized psychometric features (SHOR, 1967). Lack of standardization has regrettably characterized work with the color-word test (JENSEN, 1965). The purpose of this particular investigation was to study information processing time for the basic concepts of up, down, right, and left under conditions where these four spatial concepts were represented in two quite different forms of symbols. The first form of symbol was pictorial and the second was linguistic (verbal). For the pictorial symbolization outline drawings of arrows pointing in the four spatial directions were used. For the linguistic symbolization the word names of the directions were used. In taking the SCET the S is presented with a randomized series of stimuius sheets each representing sets of either the pictorial or linguistic symbols alone or compounded together with various degrees of stimulus matching or mismatching. Compounding is accomplished by printing the word name for a spatial direction inside of the outline drawing of an arrow. The compounding may either match the word with its correct arrow direction or mismatch the word with one of the other three arrow directions. An example of a mismatched item would be an arrow pointing to the right with either the word ‘left’, ‘up’, or ‘down’ printed within it. On each trial the S is given the preparatory set either to respond to the pictorial or to the linguistic symbolic representation. The present study was designed to test the following five hypotheses: (1) Naming directions of arrows will take more time than reading the word names for directions. (2) Stimulus complexity will make the task more difficult. (3) Performance time will be a function of the number of response alternatives. (,4) It will take more time to identify the directions of right and left than of up and down. (5) The more difficult the task the steeper the slope L rlie increase in performance time as a function of stimulus complexity. IL will prove more eficienr: to elaborate on the hypotheses after presenting section 2.
2. 2.1.
hdETWOl.3
Subjects
The Ss were 30 undergraduates taking a course in introductory psychology at the University of New Hampshire. Thirteen of the Ss were male, 1‘7 were female. Ages ranged from 18 to 21 years.
348 2.2.
RONALDESHOR
Design and prxedure
Three relate3 ruinimal arrows stimulus sets selected from the SCET
were used in this study: (l) Up-down - this stimulus set includes just the directions of up and down. (2) Right-left - this includes just right and left. (3) Four way - this includes all four directions.2 For each stimulus set the procedure of the SCET specifies two task instructions (TI) combined with four levels of stimulus complexity (SC). This makes eight conditions (the eight primary scores) administered for each of the three stimulus sets to all 30 Ss. The investigation is thus a repeated measures design with three fixed factors. The two task instructions were: (1) Arrows task instructions - the S was instructed to identify (name) the directions of the arrows ignoring any embedded words. (2) Words task instructions -. the S was instructed to identify (read) the words ignoring any surrounding arrows. The four leve!c of stimulus complexity were: (1) Pure condition either 24 arrows or 24 words were placed alone on the stimulus sheet without the other type of symbol present. (2) 0% mismatched condition __all 24 items on the sheet were composed of compounded arrows and words but all were fully matched. (3) 50% mismatched condition twelve of the 24 items on the sheet were matched and 12 were mismatched. (4) 100°A mismatched condition - all 24 items on the sheet were mismatched. Stimulus sheets were composed of 24 items arranged in 4 x 4.5 cm blccks on 21.6 x 28 cm paper (4 columns x 6 rows). The S was instructed to respond first to the item in the upper left hand corner and then go down each commn in sequence. Before each trial the appropriate test booklet page was opened flat on thle desktop before the S. Prior to the experimental testing the nature of the task and the character of the stimulus materials were explained in detail to the 5’. Twelve practice trials were given, or more until the examiner felt assured that the S was able to attain good performances. Before each trial along with one of the two task instructions the S was told the stimulus set and the degree of sti~mulus complexity that he would have to deal with on the coming sheet. Pt was made clear to the S that an important part of his overall task was to pay careful 2 Wnii
arrows are outlime&awingsof arrows composed of mctangk?spointed
Contrast these with big head arrow9which ark outlineswith the Shape of oneWay trafltiesigns (‘CX3). at one end (I).
CONCEPTUAL INP0RhIATION ON SPATIALDIRECTIONS
349
attention to the i.?structions before each trial so that he couId build up a preparatory set in which all salient information was taken into account. from trial to trial. he two task instructions were alternate The S kept his eyes averted from the page while the examiner gave the instructions for that tria he S then took whatever time he needed to form his pre hen ready the S turned his eyes to the page and proceeded throqh the list of items as quickly as he could without errors. Stopwatch timing was begun when the S named the first item and was ended when he named the 24th item. As the objective was to secure time meL:surcs of rapid and error-free performances in well-prepared ss the trial was repeated if an error was made.3 The performance measure was the total time for the 24 items. The SCET incorporates a block randomizing and counterbalancing procedure in which two measures are taken for each of the eight response categories. These pairs of measures are averaged to control for progressive errors and then serve as the raw scores. Further details on test procedure and construction are avirilable in the SCET manual (Z&OR, 1967). 3. 3.1.
HYPOTHESES Hypolhesis
I
Performance time will be longer for i cntifying (naming) the directions of up, down, right, and left from outline drawings of arro’ws pointing in these directions than for identifying (reading) the printed word
names for these directions. The presumption is that for literate adults linguistic symbols are more familiar, better learned, and more freyuently used than are pictorial symbols. Children are taught from an early age to make linguistic symbolism the primary vehicle in their thinking. In f5-K theory this can be couched in terms of differential habit strengths (STROOP, 193% 3- RXSEN and ROHWER, 1966); in organismic-develiopmental theory, in terms of hierarchic integration of functions (WAPNER and KRIS, 1960; RAND et al., 1963; COMALLIet al., 196%). An alternate or concurrent interpretation is that since Ss respond by speaking words, it will take more time to name the arrow directions than to read the printed words because reading the words does not require the additional step of transformation into a linguistic form. More information processing is required to recode pictorial arrow 3 Errors were infrequent and procedures are incorporated in the SCET to minimize possible disruptive effects of errors. Errors were recorded but not aoalysed.
350
RONALD E. SHOR
directions into spoken words than to recode printed words into spoken words. Verbal encoding and processing is discussed in CAMPand HARGUM (1964), NEI,SSIER (1967), CLANZERand CLA.RK(1962, 1963), and SFRRLING(1963) 3.2. Hypothesis .2 Performance time will increase as a function of stimulus complexity. It is predicted that for any given stimulus set performance time will be least in the pure condition and then will be progressively higher in the 0 %, 50x, and 100 % mismatched condirions. The presumption is that the more stimulus complexity, the more the task is made difficult by interfering and competing distractions, and thus the more time it will take to process the information in it. This hypothesis is again consistent with the S-IX habit strength theory of suppression of competitive response tendencies (see especially STEINand LANCER,1966). The capacity of an individual to maintain a uniform course of action independent of intruding or interfering stimuli is seen as an important as,pect of organismic-developmental theory (COMALLIet al., 1962). 3..3. H’gothesis 3 Petionnance time will increase as a function of the number of response alternc_.ives. It is predicted that responding to all four directions in the four way stimulus set will take more time than responding to just two directions in either the up-down or the right-left stimulus sets. The presumption is that the task will become more difficult the more response alternatives which the S must keep in mind and process. GHOLSON and HOHL.E (1968b) found the number of response alternatives to be an effective independent variable in a choice RT task patterned on the color-word test. A general discussion of the relation of number of response alternatives to disjunctive reaction time and information theory is presented in MILLER(1951). 3.4. Hypothesis 4
Performance time will be longer to the sti.mulus set composed of the directions of right and left alone than to the stimulus set composed of the directions of up and down alone. The directions of up and down are presumed to be more absolute and genetically primitive than are rigbt and left. This hypothesis is consistent with GIBSON’Stheory of
CONCEPTUAL
INFOR
THON ON SPATIAL DIRECTIONS
3;5II
the primary orienting features of the terrestial environment (19156) aget’s discussion of egocentric thinking (FLAVELL, 1963). An alternate or concurrent imterp~etation is that it will take more time to say right and left because of simple word length. 3.5.
othesis 5
he larger the pure condition mean the steeper the slope of increase in performance time as a function of stimulus complexity. ‘This functional relationship is predicted because it is presumed that if a task is relatively difficult that adding stimulus complexity to it will make it become even more difficult than it would for a ta.sk which is relatively easy in its pure condition. The presumption is that a relatively easy task can bear the burdens of additional stimulus complexity with less additional disruption. Empirical predictions are presented gra.phically in fig. 1. Stimulus Sets
Task Ipgtructions
Identify (name) the Arrow Directions
,o
/,;y
/I_
Four Way
~0
Right-Left
Identify tread1 the Words t-
-0’ e--e
Up-Down
I
-e-
50%M
Pure STIMULUS
Fig. 1.
/
COMI’LEXITY
Empirical predictions from the five hypotheses. The predictions to be interpreted as ordinal relationships.
are meant
In summary, performance time will increase as a function of (1) b’esponse to arrows or words, (2) degree of stimulus complexity, (3) number of response alternatives, (4) up and dov+Fnas compared with right and left. Also predicted is (5) a functional relationship between performance
RONALD E. SHOR
352
time in the pure condition and the effect of stimulus complexity. Al,thou for sirnplicit~~drawn on the graph as equal intervals and straight lines, the predictions are meant to be interpreted as ordinal relationships.
Means and standard deviations are presented in conditions (3 x 2 x 4) are numbered ;as sequential variables. TAaLE 1
’
Means and standarddeviation. --Stimdus
set
Task inStirUCtiOIlS
Stimulus complexity
Variable number
can
SD
50% M 100% M
1 2 3 4
9.25 9.11 10.40 10.20
1.30 1.52 1.57 1.55
Pure
5
R’ords
0% M 50% M nw& RI
6 7 8
6.84 7.10 7.39 7.32
0.88 0.95 1.07 0.94
Arrows
0% M
1.54 1.42 1.75 1.92 --
AKOWS
0% M
50% M 100% M
Kigbt-ka
9
9.59
10
9.54
11 12
10.52 10.94
----
“‘FwJs
0% M 50% M 100% M
.-_
13 14 I5 16
7.84 8.04 8.28 8.06
-----
Pure hOWS
Four way Words
0% M 50’s M lO&,~ M -Pure 0% M 50% M 100% M
1.oa 11.16 1.13 1.02 __--
17 18 19 20
11.49 10.63 12.47 13.30
21 22 23 24
7.71 8.13 8.37 8.32
--
1.69 1.92 2.27 2.14 0.94 1.05 1.13 1.08
2
2 1 5
1
4 4
‘ure 0%
4
1 3 7 5
3
2 3 7 6 6 5 1
so%loo%
5
6
7
Words 8
TAm.E2
Right-left
v
2 5 5 7 6 4 1
1 5 6 8 4 6
2 f 2 6 8 7 2 2
2 4 3 6 5 7 1 2 4 12 7 7
1 5 9 9 6
14
2 8 6 9 5
15
1 4 18 10 5
16
50% mO%
Words
Lure Qo/;, 50% loo% Pure 0%
AbOWS
Frequency distributions.
E 5 7 6 5 3 3
17
2 1 5 5 6 4 5 2
18
1 4 3 6 4 3 4 4 1
19
Arrows
f 1 8 3 2 5 5 4
20
8
5 5
3 1
2 4 11
3
4 9
2
4 4 8
354
RONALD E. SHOR
There are high correlations between the means and the standard deviations.
The coefficient is 0.59 for the 12 variables under the words TT, WV for the 12 variables mder the arrows TI, and 0.96 over all. Frequency distributiom are presented in table 2. Ah distributions appear approximately normal but a moderate amount of positive skew is commonly seen in those variables where a large proportion of the scores are close to the lower bound. The analysis of variance summary table is presented in table 3. TABIE 3 Analysis of varianw summary table. SOlUCe
Sub&cts
Stimulus complexity SC x ss Ta;ik instructions TI X ss Stimulus sets Setsx ss SC x TI SC x TI x 5’s SC X sets SC x sets x ss -l-IX&S TrX!set3XSS scxTIxse!s SC
x
Total
TI x
Set!3 :< 6%
df
29 3 87 1 29 2 58 3 87 6 174 2 58 6 174 719
VE 32.35 44.41 0.64 1447.68 6.54 155.63 0.87 20.36 0.70 2.04 0.27 49.00 0.77 2.06 0.22
F
P
-
-
69.4 221.4 -* 179.0 29.0 7.6 63.7 9.0 -
< 8.001 _< 3.001 .< 0.001 -< 0.001 < 0.001 < 0.001 < 6.001 -
-
All main effects and first and second order interactions are significant beyond the 0.001 ‘levci.Because of the large interactions and the systematic heterogeneity of variance the a.nalysis was broken down into separate comparisons between pairs of variables using the non-parametric Wilcoxon T test.4 The means are displayed graphically in fig. 2. 4 1%~objection can be raised that the probability values should be corrected to take account of multiple tests, even though the tests run to evaluate the hypotheses were only a restricted set of comparisons among the possible combinations of pairs of . The argumentdces not have practical relevancy in this particular study, however, because of the extremely small probabiliiy values which will be reported.
CONCEPTUAL
INFORMATION
ON SPATIAL Q~RECTI~NS
_
%timulus Sets
Four
355
Task Inotruetians
---I i-- Arrows
way
Right-Left
1 I
Up-Down _J
-0.--M--_=~-.---,~-~ -
b--
/
___---*--_
-
-.
-
-*-
O---
Pure
&M STIMULUS
Fig. 2.
Findings pertinent
50%H
---mm.*
’
Fmr Way Right -Left---I--
Words
Up - Down -I
100% M
COMPLEXITY
Graphic display of the means.
to the five hypotheses are as fellows: Hypothesis I. It was predicted that it would take more time to identify (name) directions of arrows tha to identify (read) word names of directions. All twelve of the counterpart mean differences under the arrows and words TI are statistically significant beyond the 0.0001 levrl. Even the difference between the very lowest arrows TI mean (0% up-down) and the highest words TI m,ean (50% four way) among the entire set is significant (p < 0,001 level). These findings are a powerful confirmation of the first hypothesis. Hypothesis 2. It was predicted that performance time would mcrease as a function of SC. Probability values for each comparison among the pzlrs of means pertinent to this hynothesis are presented in table 4. To illustrate, the corxztly predicted increase of the 50% mismatched condition mean over the pure condition mean for the up-down stimulus set under the arrows TI is significant beyond the 0.0001 level. Twenty-nine of the 36 mean differences (81%) are in the predicted direction. Of the 29 correctly predicted direct ions of mean differences only SWO failed to achieve significance at the 0.05 level. Of the seven comparisons with mean differences in the direction 0pposit.e to prediction only two are significant. Thus, of the 29 significant differences, 27 were
RONALD E. SHOR
355
TABLE 4
W&axon T probability values for each comparison among pairs of means pertinent to hypothesis 2 Mea.. +nces in the direction opposite to prediction are indiated by a square surrounding the p
values.
Y
0% M
Words T1[ 50% M 100% < 0.
II-
t&-down
Pure
j
O%M
1
10748j
SO%M/
-
50%
i
Bn:
< 0.01
< o.ooo1
< o.ooo1
-
< 0.01
-
-
-
-
< 0.001
-
-
-___
Fourway
Pure 0% M 50%Mj
< o.oum < 0.0: --
1-1 (
-
< O.oool
< o.ooo1
-
1
-.-.-
----
Pure
0% M
< 0.ooo1
_.-~.-_-..___I_.
---I----Right-left
< o.ooo1
0.08
< 0.
-
< 0.01 -
-I-
- .__.
< 0.001
< 0.001
1
<
0.02
-__..--.---__.
-._
< o.ooot
< o.ooo1
-
< 0.01
< 0.05
-
-
czl 0.38
--
in the correctly predicted
These finding:, are a strong general ~~firm=itIcn of the hypothesis. A striking exception is that there was a significant decrease in the 0 % mismatched condition mean as compared with its counterpart pure condition mean in the four way stimulus set under the arrows TI (p c 0.001). A similar pattern of decrease can be observed in comparing these two means in the other two stimulus sets, but lt.he d;+rsnces are not significant. Hypohses 3 and 4. As these two hypotheses refer to comparisons between the stimulus sets they may conveniently be treateLI together. It was prledicted that performance time would increase as a function of the number of response alternatives. It was predicted that performance time would be less for the up-down than for the right-left stimulus set. Probability values for each comparison among .;he pairs of means &%in~& to these hypotheses are presented in table 5. Most of the mean differences are significant beyond the 0.0001 level and all but one are in the predicted direction. However, all four of the comparisons between right-left and four way under the words T1[ are insignificant and two of the four comparisons between up-do-vn and right-left under the arrows TI are ins&t&ant. Despite the few direction.
TABLE
5
ilcoxon
test probability values for es& comparison among pairs of means pertinent to hypotheses 3 and 4. The one mean difference in the direction opposite to prediction is indicated by a. square surroufiding the p value.
right-left
Words
< 0.0801
< 0.0001
< 0.0001
< 0.0001
Up-down vs. four w!ay
Arrows Words
< 0.0901 --: 0.0001
(1.0.0001 < 0.0001
< 0.0001 < o.a91
< 0.0001 < 0.0001
<
< ~~.rSOOl < 0.0001 0% 0.45
Arrows Words
j
.-r:C!.OOOl 0.06
discrepancies the findings are a strong general confirmation of the two hygotheses. H_ypothesis 5. It was predicted that the higher the pure condition mean the steeper would be the slope of increase in performance time over the pure condition mean as 2a unction of SC. By inspection of fig. 2 it can be observed that this redicted relationship did appear to occur but not in a uniform way. The three lowest pure condition means all show about the same pattern of increase due to SC. The next two higher pure sbDndition means show larger increases than the first three, but do nclt appear to differ between themselves. The highest pure condition mean doles show the largest amount of increase. Another way to express these: observations is that the means appears to show less increase as a functi.on of SIC under the words TI than under the arrows Tl. The average increase: from pwre to 100% under the arrows TI is 1.44 sec. ; under the words TI is 8.68 sec. As the 100% mismatched condition is specified as representing the largest amount of stimulus complexity, the difference between the pure and the 100 “/ misnlatched condition score was select ?d as the index of slope. This inderc. uses only the extremes of stimulus complexity and ignores the two intermediate conditions. A one-way analysis of variance was performed on the six slopes (F- 16.2, L/I= 5/145, p < 0.001 level) and Dancan’s multiple range test was used to separate the differences between the means. The findings are presented in t&k 6.
RONAP.1, E. SHOR
358
TABLE6 Differences be&veen the six slopes. The means of the slopes are arranged on the table from smallest to largest. Any two means not underlined by the same line are si:gnificantly different beyond the 0.05 level of confidence, Stimulus sets
Right-left Up-down Four way Up-down Right-left Four way Words
Words
Words
Arrows
Arrows
Arrows
Ranks of size of pure condition means
3
1
2
4
5
6
Means of slopes (KMy0 mismatched minus pure condition)
0.22
0.48
0.61
0.95
1.35
1.81
Task instructions
R&&s of Duncan’s multiple range test (0.05 level)
Mot every mean difference is significant, but in each instance where it is, the difference is in the predicted direction.5 4.1.
Currelational informution
The matrix of iotercorrelations is presented in table 7. The correlations range from 0.36 to 0.93 and the median coefficient is 0.70. A principal components factor analysis was performed on this n~trix. Two factors emerged with eigenvalues set at limits of 1.0. The unrctated and rotated factor loadings are presented in table 8. The totaf percenr;sge of variance accounted for by the two factors extracted was 83:<. The percentage of accountable variance for the two rotated factors is 53 and 47% respectively. A graphic presentation of the varimax rotation is given in fig. 3. While all 24 variables have positive loadings on both factors, there 5 It can be argued that a more sahent index of increase due to SC would be to take the difference between the pure and the larger of either t& 50 y0 or 100‘% m condition score. A parallel analysis was made using this alternate index. The Duncan’s test results were the same with the excseption that the slopes for the r;ecoad and fourth ranked purr, condition means ds differ significantly. A trend analysis for linearity based on orthogonal components might suggest itself here but as predict only ordinal relationshu’ps it was not deemed appropriate. thehvpo
atrix of intercorrelations. lkcimal points are omitted.
I - 1 _-_I_2 3 1
_
4
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 ----. -___ -____ _- .___- .- ..._
68 81 ?2 65 75 74 69 79 74 74 78 67 82 76 73 80 64 $0 74 69 65 65 71
2 68 69 3 $1 69 4 I 72 72 84 5 65 57 57 6 75 60 66 7 74 64 63 8 69 50 60 9 79 63 78 10 74 85 74 11 74 65 83 12 78 68 76 13 68 59 67 14 82 67 76 15 76 56 67 16 73 63 62 17 80 65 80 18 64 $4 70 19 80 62 86 74 52 77 20 69 55 62 21 65 43 59 22 65 46 57 23 71 47 60 24
72 84 46 60 62 59 75 69 82 79 62 62 63 59 76 66 81 75 61 50 51 49
57 64 57 66 63 46 60 62 92 $8 92 e 92 $8 92 $5 90 93 63 73 67 66 69 69 64 72 68 60 71 66 87 87 84 92 92, 92 $7 91 92 89 93 90 59 63 62 55 511 56 52 61 56 41 4!) 42 :!I6 86 90 “18 83 79 ‘18 80 82 ‘99 83 83
50 60 59 85 90 93 69 60 69 64 83 87 89 88 55 42 56 40 88 $0 80 78
63 78 75 63 73 67 69 80 88 89 68 75 77 71 86 73 83 75 69 70 66 58
85 74 68 66 69 69 60 80 77 82 64 76 68 71 74 $5 77 58 62 62 56 55
65 83 $2 64 72 68 69 88 77 90 73 75 71 7:5 $3 7G 84 78 68 70 68 55
68 76 79 60 71 66 Cd $9 82 90 63 70 73 67 84 71 83 79 66 67 65 54
59 67 62 87 87 84 33 68 64 73 63 89 92 91 65 56 63 Pl 80 71 74 71
67 76 62 92 92 92 87 75 76 75 70 89 90 93 71 64 68 56 88 81 78 83
56 67 63 87 91 92 $9 77 68 78 73 92 90 92 72 58 68 55 $7 82 86 80
63 62 59 89 93 90 88 71 71 73 67 91 93 92 62 55 57 47 84 79 78 78
65 $0 76 59 63 62 55 86 74 $3 84 65 71 72 62 77 88 85 69 59 63 56
$4 70 66 55 51 56 42 73 85 70 71 56 64 58 55 77 66 56 59 51 52 43
62 86 81 52 61 56 56 83 77 84 83 63 69 68 57 88 66 $9 58 55 53 53
52 77 75 41 49 42 4C 75 68 78 79 51 56 55 47 85 66 89 50 43 41 36
55 43 62 59 61 50 86 78 $6 $3 90 79 88 $0 6E( 70 62 62 68 70 66 67 80 71 89 81 87 82 84 79 69’ 59 59 51 58 55 SO 43 -.. 85 85 85 93 84 87
is an. unambiguous clustering of the variables taken under the two TIs with each of the two factors. 5,
DISCUSSION
While exceptions in a few comparisons were noted the five hypotheses were confirmed. It takes less time to read the names of directions than to name the directions of arrows; stimulus complexity - i.e., compounding and mismatching - is an effective variable; number of response a.lternatives is an effective variable; it is easier to identify up and down than right and left; and the more difficult the task in its pure form the more difficult it becomes when stimulus complexity is added to it. This is the first study to demonstrate that an interference phenomenon
46 57 51 78 $0 82 80 66 56 68 65 74 78 86 78 63 52 53 41 $5 93 8S
47 60 49 79 $3 83 78 58 55 55 54 71 83 80 78 56 42 53 36 $4 87 $5 -
RONALD E. SHOR
360
TABLE 8
Unrotated and rotated factor lo; dings. Principal components 1 87 74 84 78 85 91 90 86
2 -16 -28 -34 -39 38 31 33 38
Verimax rotated I
2
h2
53 35 39 31
71 71 82 82
78 63 81 77
89 87 88 89
30 39 37 31
88 92 91 88
47 41 47 42
79 77 79 82
84 78 85 85
79 83 84 86
43 49 46 39
81 93 92 90
37 29 30 14
84 79 88 90
85 70 86 82
85 84 84 86
38 33 32 26
87 80 801 801
__~_II_-I_I_
Pure 0% 50 “/o 100%
9 10 12
88 84 88 86
Pure 0% 50% 100%
13 14 i5 16
87 94 93 90
Pure 0% 50 % 100%
17 18 i9 :?o
85 75 82 71
Pure
21 22 23 24
88 83 83 80
0% 50% 100%
11
-26 -28 -26 -32 23 20 24 31 -37 -38 --46 -56 30 33 34 40
can b;;. produced using mismatched spatial symbols similar to the irnterfmence phenomenon of the Stroop color-word test. In several prior investigations the Stroop test was altered to include other co,@itive eIements besides colors and words. LANGER and Rosa BERG(1966; STEIN and LANGER,1966) studied the inkrference effect using ‘phonic symbols’ instead of color names, SMITHand BORG(1964)
CONCEPTUAL INFORI’VIATION OF SPATIALDIR:ECTIONS
361
used shades of brightness rather than hues, SANTOSTEFANO and PALEY (1964) used pictures of correctly colored fruit with distracting pictures of objects printed nearby. Investigators have compared reading names with naming common objects (STROOP, 1938) and geometric forms (GHOLSON and ONLE,1968a), but interference conditions were not used.
Arrows
m
.6----IT-.7
.9
TI
+1.0
FACTOR 2
Fig. 3. Verimax rotated factor analysis.
The purpose of the present line of investigation is to make a systematic experimental analysis of the processing of information when expressed in different symbolic representations. Although a number of investigators have suggested that the color-word interference e:ffect wou1.d be an interesting phenomenon to study in its own right (THURSTONE and MELLINGER,195.3; JENSENand ROHWER,1966; UNDERWOOD,1966) there has been little attempt to make a systematic analysis or to provide basic norms. Xotable exceptions are the study of psychometric properties by JENSEN(1965), the semantic gradient study by KLEIN(4964), and the studies following Klein’s lead (SCHILLER,1966; BAKANand ALPERSON,1967; SCHEIB~ et al., 1967; ZIEKand WEISS,1968). Klein demonstrated a semantio gradient of the capacity of different kinds of words
362
RONALDE.SHOR
to interfere with color naming. From least to most interfering these were: (1) nonsense syilables, (2) rare words, (3) common words, (4) color-re?&.ed words, (5) distant color names, and (6) actual color names as used in the common versions of the Stroop test. Tt would be interesting to apply Klein’s paradigm to compounded spatial symbols. The correlation of 0.96 between mean performance time and the variability of the .sc#ores(the standard deviations) is a striking finding. This is not just a random Increase in variability. The median intercorrelation. of 0.70 indicate:j t:hat the relative positions of the & remain moderately stable. These Sndings mean that individual differences increase systematically as I function of the average difficulty of the task - i.e., as the task on tht average becomes more difficult iI becomes more difii::& for some Ss than for others. In more succinct language, the End.ings mean that the slope of the gradient of difficulty varies for different Ss. Studies on individual differences are needed to see what other psychologifcal characteristics relate to these findings. The methodology of the present investigation based on the SCET uses a global performance measure of total time to process 24 times. This measure is convenient and simple but : t provides no way to analyze the processing of single stimulus items w %ch is also of interest. The tachistoscopi’c presentation and choice re;action time method of GHOLSON and HOHLE (1968b) could profitably be: adopted to that end. In post-experimental inquiries severa. Ss reported that it seemed intuitively easier to name the arrow directions in the 100% than iri the 50% mismatched condition because when words were known to be all wrong they could be ignored more easily. While the empiricai findings do not confirm this subjective impression, the increase of the 100% over the 50;;/, mismatched condition means is by no means so strong and uniform that the impression is implausible. In more intensive study of this issue it may become useful to introduce a number of intermediate percentages besides 50% and not tell Ss the percentages of mismatching. It is important to draw attention again to the fact that in this study stimulus sheets were presented on a flat Ljesktop. This means that the directions of up and down were deflned from the coordinates of a sheet of ,paper and not in relation to the orientation of gravity and the geographic environment. It will be interesting in subsequent studies to compare arbitrary frames of reference with geographic coordinates. Although the hypothesis was confirmed that in general performance
CONCEPTUAL INFORMATION ON SPATIAL DIRECTIONS
363
time increases as a function of SC, performance time was actually less in all three 0% mismatched conditions under t arrows TI that in : pure conditions. ‘While only one of these three reversals y significant, exceptions which appear to follow a are worthy of attention. It is plausible that the reversals occurred because it is hard to keep i’rom taking advantage of easily discerned corrzct information when it is known to be correct. Intrtispective report would seem to bear out this interpretation. In the post-experimental inquiries many SS reported that it was very difficult to ignore the correct word information when trying to name the arrow directions. Recall that in this condition the Ss are expressly tcbld before the trial that the words and arrows will all be correctly matched. Arrows known to be correct do not appear to help in reading words, however, probably because it is already much easier to read words than to name arrows. It would seem worthwhile to evaluate this mterpretation in subsequent studies by hypothesizing that performance time in the 0% mismatched condition is a function not only of SC (hypothesis 2) but also of an inability to ignore easily identified correct information when it is known to be correct. This condition is the special case where the inability to ignore the correct information can mean an inability not to take advantage of it. It is plausible that this interpretation has relevance for the SO’% mismatched condition also, but whether the correct information proves a help or a. hindrance in that context is as noted atili uncertain. The method of statistical analysis adopted concentrated on the proportion of significant individual mean comparisons in the predicted direction. This method af analysis, while cogent, does not imply that interaction information is with.out interest. The complex interactions found underscore the virtue o,f the SCET in expanding the number of primary scores to help encompass the complexity of the phenomenon and in standardizing the conditions of testing. One of the interpretations offered to account for the advantage of readinp words over naming arrows was tha.t there are fewer coding steps in transforming written words into spoken words than in transforming positional arrow directions into spoken words. On this interpretation, if the response mode were chang,ed. from the present spoken linguistic response to a motoric positional resl>onse by using a faur-way toggle switch then there should be fewer coding steps when transforming positional arrow directions into positional motor response than when transforming written words into positional motor responses. The
364 prediction
RONALD E.
SHOR
is that with a positional response mode the functions would
reverse - iz., it would take less time to identify (respond motoricaily to) the arrow directions than to identify (respond motorically to) the gxd names for directions. A study is currently in progress to evaluate this predkfion. REFERENCES BAKAN,P.and B. ALPE!RSON, 1967. Pronounceability, attensity, and interference in the color-word test. Amer. J. Psychol. 80, 416-420. C,uln; D. S. and E. R. HARCUM,1964. Visual pattern perception with varied fixation locus aud response recording. Percept. Mot. Skills IS, 283-296. COMALLI, P. E., S. WAPNERand H. WERNER,1962. Interference effects of Stroop color-word test in childhood, adulthood, and aging. J. genet. psychol. 1 47-53. Fx ~.VELL, J. H., 1963. The developmental psychology of Jean Piaget. Princeton: Van Nostrand. GHOUON, E!. and R. H. HOHJX,1968a. Verbal reaction times to hues vs. hue names and forms vs. form names. Percept. & Psychophys. 3, 191-196. and 1968b. C!noice reaction times to dues printed ,in conflicting blue names add nonsense wo&. J. exp. Psychol. 76, 413-418. Gmscq J. J., 1966 The senses considered as percqtual systems, New York: Houghton Mitihn. GLANZER,M. and W, H. CLARK,1962. Accuracy of perceptual recall : an analysis of organization. J. verb. Learn. verb. Behav. 1, 289-299. and 1963. The verbal loop hypothesis: binary numibers. J. verb. Learn. verb. ‘Behav. 2, 301-309. JENSEN,A. R., 1965. Scoring the Stroop test. Acta Psychol. 24, 398-408. and W. D. ROHWER,1966. The Stroop color-word test: a review. Acta Psychoi. 25, 36-93. Km, 6. S., 196-t. smantic power measured through interference of words with color-naming. Amer. J. Psychol. 77, 576-588. LAK~ER,J. and B. 6. ROSENBERG, 1966. Symbolic meaning and color naming. J. Per. sot. Psychol. 4, 364-372. M~LER, G. A., 1951. Language and communication. New York: McGraw-Hill. NErssur, U., 1967. Cognitive psychology. New York: Appleton-Century-Crofts. RAZZ, G., S. WAGNER,H. WERNER and J. H. MCFARLAND, 1963. Age differences in performance on the Stroop color--word test. J. Pers. :)I, 534-558. SA~TBSIEFANO, S. and E. .PALEY, 1964. Development of cognitive controls in children. Child Developm. 39, 939-949. Scr-zm~, K., P. R, SHAVERand S. C. CARRIER.1967. Color association values and response interference on variants of the Stroop test. Acta Psychol. 26, 286-295. SCULLER,P. H., 1966. Developmental study of color-word interference. J. exp. Psychol. 72, 105-108.
TlOM ON S
DIMCTlONS
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SHOR,R. E., 1967. The Shor cognitive elements test: a manual. Durham, N.II.: Symbolic Processes horstory. s 5 G. J. W. and G. A. V. BORG,1964. prcblem of retesting in the serial color-word test. Psychol. Res. Bu G., 1963. A model for visual memory tasks. urn. Factors 5, 19-31. B. and J. LANORR, 1966. The relation of covert gnitive interference in the color-phonetic symbol test to crsonality characteristics and adjr.stment. J. Pers. STROOP,J. R., 1935a. Th is of Ligon’s theory. A4ner. J. Psy:hol. 35b. Studies of interference in serial verbal reactions. J. exp, Psychol. , I 1938. Factors affecting speed in serial verbal reactions. Psychoi. THURSTONE, L. ,d. and J. J. ELLINGBR, 1953. The Stroop test. Chapel Mill, N.C.: The Psychometric Laboratory, University of North Carolina, ho. 3. UNDBRWOOD,B. J., 1966. Experimental psychology. Second edition. New York: Appleton-Century-Crofts. WAPNER,S. and D. M. I&us, 1960. Effects of lysergic acid diethylamide, and differences between normals and schizophrenics on the Stroop color-word test J. Neuropsychiat. 2, 76-81. ZEIK,J. and S. J. WEISS,1968. Stimulus meaningfulness and sex as factors in interference on color-word lists. Paper read at the Eastern Psychological Association Conventicn.