Tactual learning and cross-modal transfer of an oddity problem in young children

JOURNAI

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PSYCHOLOGY

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Tactual Learning and Cross-Modal Transfer Problem in Young Children J. M. TELLEVIK.

S. KREI
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INTRODUCTION A simple oddity problem is a task in which two elements are identical and one different with respect to some attribute or dimension. In order to solve an oddity problem the sub.ject must respond to a relationship among stimuli rather than to specific cues. Oddity problem learning in young children has rarely been studied outside the visual modality. Very little is therefore known about childrens‘ ability to solve tactually presented oddity problems and about tmnsfer of oddity learning across the visual and the tactual modality. Tyrell (1974). however. reported cross-modal transfer of oddity lexning in Xyear-old children. One group received visual oddity training and a tactual transfer test: a second group was trained tactually and tested visually. Thia

project

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supported

by the NOI-wegian

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for Kesexch

on Mental

WC thank PHI- Stene and Nina Winger for as\i\t;rnce with collection gratefully acknowledge the aa\ihtance of two reviewer\ for- comment\ article. Keque\t\ for reprint\ should he xldre\srd to S. Krckling. Department University of Trondheim, N-7055 Dragvoll. NOI.M:LL..

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His results demonstrated transfer effects across modalities in &year-old children much to the same extent as previously shown for college students (Tyrell, 1967). Cross-modal transfer in younger children assessed by performance on simple oddity tasks has not been studied. In the present work we report results on tactual oddity problem learning in 3- to S-year-old children. We also address the question whether such learning transfers across the visual and the tactual modalities. EXPERIMENT 1 The purpose of this experiment was twofold: First, we wanted to study the development of tactual oddity learning: second, we wanted to know whether oddity learning transferred cross-modally.

Slrbjects. Children (N = 354) from kindergarten and public schools participated in the experiment. The students were divided in six age groups. The mean chronological age (CA), age range, and number of subjects in each group were: CA 3.5 (3.2-3.9). N = 30: CA 4.5 (4.04.9). N = 56: CA 5.4 (5.1-5.8). N = 68: CA 6.3 (6.0-6.71, I%’ = 36: CA 7.6 (7.0-7.9), N = 36: CA 8.7 (X.1-9.4), N = 1X. MuteriuIs. Oddity tasks were constructed from stimuli consisting of five distinct geometrical forms (triangle, circle, square, rectangle, and hexagon) made from plastic. Measures were taken to ensure that the tactual stimulus objects had the same thickness, texture, and weight. Ptwccd~rw. The odd relation was on the same dimension (form) in training and transfer tasks. Subjects were randomly assigned in two groups. One group was given visual oddity training and subsequently tested on a series of tactual oddity tasks: the other group received tactual oddity training and was tested on visual oddity tasks. Hence, crossmodal transfer was studied by comparing scores within modalities but across groups (Ellis, 1970: Murdock. 1957). This design is not a clean one. since the assessment of transfer strictly requires a control group in which irrelevant experience is acquired in the first modality prior to second-modality testing (Bryant. 196X). As shown by Tyrell (1974). however, performance in tactual oddity tasks following visual discrimination training and performance in visual oddity tasks following tactual diacrimination training were not different from performance in an oddity task within that modality without previous training. Hence, nonspecific transfer effects would seem to be negligible in oddity learning tasks. Nevertheless, in order to reduce any “warm-up” or general transfer effects we gave all subjects match-to-sample tasks prior to the oddity training session. The match-to-sample tasks consisted of five visual match to tact& sample trials. On visual sample trials the duration of the stimulus

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presentation was 5 s and on tactual sample trials the stimuli were presented for 10 s. The stimuli were the same as those used in the oddity tasks. The matching tasks therefore also served the purpose of familiarizing the subjects with the stimuli in both modalities as well as training the subjects to attend to the form dimension. Furthermore. we felt that it there were modality differences in discriminability then visual matching to tactual samples should differ in error level from tactual matching to visual samples, and consequently give important clues as to whether any differences in visual and tactual oddity task performance could be due to modality differences in discriminability. In the oddity tasks a combination of one odd and two identical forms arranged in a row was presented on every trial. The stimulus objects were presented in front of the subject; the visual forms were facing the subject at eye level at I m distance: the tactual forms were arranged in a row on a horizontal tray. The position of the odd form was changed on every trial, and repetitions of any given combination of forms were kept at a minimum during a session. Subjects were instructed that three objects would be presented at a time. and that upon presentation of the visual task they should look carefully at the objects and upon presentation of the tactual task they should explore the ob.jects with both hands. They were further told that they were going to play ;t game in which they should try to guess which one of three objects the experimenter was thinking of. first playing the game for a while by looking and thereaftet playing the same game by touching (visual training group) or first by touching and then by looking (tactual training group). All intertrial intervals were about I5 s. which was also the interval between the training and the transfer phases. The visual stimuli were exposed for 5 s, and the subjects were required to identify the ob.ject they thought uas correct by pointing. The tactual stimuli were exposed for IO S. and the subjects were required to pick up the ob.ject they thought was correct. The v)isual objects werejust beyond the subject’s reach. whereas the tuctual ob.jcct\ were hidden from view. Different exposure times were used to compensate for the relatively slower tactmn ~1s comp;~red IO visual euplor;ttiun. TO avoid biased effects in performance due to differences in spatial orientation (Shepard Rr Metzler. 1971 ), the tactual stimulus ob.jectx were locked in a fixed orientation to make certain that the orientation of the stimulus forms was kept constant during tactual exploration. Also the visual forms had the same orientation throughout the experiment. Verbal reinforcement was given for correct responses to the odd stimuli: for wrong responses the next oddity task was presented without correction. Both training and transfer trials were terminated when the subjects either reached the criterion (four successive correct responses) or a maximum of 25 trials.

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Data from all age groups are presented, but the data on X-year-olds were excluded from the statistical analysis due to a ceiling effect. Figure IA shows the percentage of sub.jects who solved the oddity problem during visual (circles) and tactual (squares) training sessions. The curves were fitted by a cubic spline approximation (Reinsch. 1967). All X-yearolds and nearly all 7-year-olds solved the visual oddity problem, which agrees well with previous studies (e.g., Gollin & Shirk, 1966: Lipsitt & Serunian, 1963; Porter. 1965). The percentage of solvers for children 3to 6-years-old is generally above that reported in several previous studies. as shown in the review by House, Brown, and Scott (1974). One reason for this discrepancy could be that in our study the match-to-sample procedure served to focus the childrens’ attention on the form attribute. This “tuning-in” on the oddity task vehicle dimension would make younger children less likely to ignore the relational cue (Reese. 1968). The percentage of solvers on both visual and tactual problems increased with age (~‘(4. N = 226) = 2X.60. p c: .Ol). but the frequency of solvers on tactual problems lagged behind that of visual problems (x1( I. IV =

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226) = 6. I I, p < .OS). The solvers by age by modality interaction was not significant. Thus, the percentage of children who solved the oddity problem increased with age, but tactual presentation made the oddity problem more difficult to solve than did visual presentation. Because the subjects were randomly assigned to the visual or the tactual condition upon appearance, these modality differences could not be due to differences between groups rather than between modalities. Furthermore a similar modality dependent difference was reported by Tyrell ( 1974) on a double stimulus oddity problem in &-year-old children. It also seems unlikely that modality differences in form discriminability could have contributed to the effect. If different form discriminability in the respective modalities were responsible for the modality differences in learning, then match-to-sample performance should also depend on mode of presentation. That is, more errors should tend IO occur when one out of three tactual ob.jects (tactual sample) had to be chosen than in tasks where only a single tactual object was present. Thih was examined by comparing error frequencies obtained by visual sample to that of tactual sample presentation for the match-to-sample data (Fig. I B). Due to a ceiling effect the data from 7-year-olds were also excluded. No difference (x2( I, N = 190) = 0.018) wa:, found between the two conditions. suggesting that the visually and tactually presented forms \ve LIX~ were equal with respect to discriminability. The absence of a difference does not of course imply that children have the hame discrimination acuteness in the two modalities. only that the stimuli we used were no challenge in either modality. Although precautions were taken to compensate for the relative slo\\ne\\ of tactual exploration, the oddity data showed that visual presentation was superior to tactual presentation. It could he argued that despite the longer period allowed for tactual exploration. there may have been ;I duration of presentation effect, given that the whole of e;lch form COLIIC~ be instantaneously perceived visually, but only progressively perceived tactually. This is not very likely, however: first. because the stimultrx forms were geometrically distinct and very easy to discriminate: \ecc)nd. because the subjects were given ample opportunity to hecome familiar with the tactual forms during the match-to-sample procedure: and finallq~. because we never observed that any \ub.ject needed more than IO \ to decide which tact& form to pick up during the match-to-sample procedure. Furthermore. since the tactual forms had the same thickness. texture. and weight. any irrelevant distracting cues during tactual presentation were eliminated. Our results therefore suggest that when the stimuli are visual rather than tactual. children are more adept at encoding the stimulus invariances or relational propertiea that arc neccsaary in order to respond consistently to an oddity relation.

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In order to analyze the results in terms of number of trials to criterion nonsolvers were given an arbitrary score of 25. Figures IC and ID show the mean number of trials that were necessary in order to reach criterion performance (excluding the criterion run) on visual and tactual oddity tasks for training (open symbols) and transfer (filled symbols) conditions. Visual training and transfer criterion scores performances were more or less similar (Fig. lC), whereas the tactual transfer performance differed from that of tactual training (Fig. ID). This suggests that tactual oddity training had no effect on subsequent visual oddity problem solving, whereas visual oddity training made subsequent tactual oddity learning easier. The criterion scores were analyzed by a three-way Group x Task x Age ANOVA in accordance with the Type III design (Lindquist, 1953). where Task refers to training versus transfer condition. However, since the Group factor contains the Task x Modality interaction the output of the analysis should be interpreted in terms of the Type IV design (Reese, 1987). Group and Age are between-subjects variables whereas Task is a within-subjects variable. In this analysis the effect of modality comes out as the Group x Task interaction. A significant Age effect was found, t;(4. 216) = 20.46. p < ,001. which means that the number of trials to criterion decreased with age in all conditions. The Task effect was also significant. F(1. 716) = 32.80. p r ,001: the mean of the transfer scores (9.38) was below that of the training scores (11.59). Furthermore. the Group x Task interaction (modality) effect was significant, F(l. 116) = 14.95. p < .OOl; i.e.. the mean of the tact& scores (17.31) was higher than the mean of visual scores (9.66). None of the interactions with Age were significant. The Task x Modality interaction (Group) was significant. F( 1, 316) = 6.06. I> < .05, which reflected the fact that the mean tactual training criterion score (15.08) was high compared to the tactual transfer (c).53), visual training (10.09). and visual transfer (9 .13) scores. This was further corroborated by an analysis of between-subjects simple effects. which showed that the effect of modality within the training tasks was significant. F( 1. 116) = 16.48, p < ,001. but not within the transfer tasks; that the effect of task within the tactual modality was significant, F( I. 216) = --. ‘? 00 . I, < ,001. whereas the effect within the visual modality was not significant. Hence, the analysis of variance supports the conclusion that a crossmodal effect existed for the visual-to-tactual condition since visual oddity experience caused a significant change in the tactual criterion scores (from 15.08 to 9.53). whereas only an insignificant difference in visual criterion scores (from 10.09 to 9 .13) was found in the tactual-to-visual condition. The reason for this unidirectional transfer effect might be that the amount of training needed for the relational response to reach asymptote

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is modality dependent. Although both visual and tactual training conditions were more or less equated and training trials were run to the same criterion in both modalities. differences between the two modes of presentation might still exist with respect to the post-training availability of the oddity concept. That is. operationally mastering the criterion of four successive correct responses could nevertheless reflect different levels of learning: barely mastering the problem tactually and skillfully mastering the problem visually. This could especially be the case when a weak criterion is used, whereas the tactual skill gained during the additional criterion runs by using a stronger criterion would tend to null out any differences. Consequently, running tactual oddity training to a higher criterion should increase tactual-to-visual transfer. EXPERIMENT

2

In this experiment we investigated whether the transfer asymmetry found in Experiment 1 might reflect modality-dependent differences in post-training availability of the oddity concept. To t-educe such ditferences between the two modes of presentation a stronger criterion was used for the tactual training prior to tests for transfer on visually presented oddity tasks.

Slrbjec,t.s. Kindergarten children (N = 40). mean CA 4.6 yrs, age range 4.0-4.9 years, participated in the experiment. Mutrricrls. Materials were the same as in Experiment I. Pwc~cdrlw. For 30 of the subjects the amount of tactual oddity training was increased: Wrong responses were gently corrected and presentation of the next trial was postponed until the subject had made a correct choice: furthermore, tactual training trials were run until the sub,ject made 8 successively correct responses without correction. The other half of the subjects (N = 20) were given only visual oddity tasks. Apart from these modifications the method was the same as in the previous experiment: i.e.,

the

criterion

on

visual

were given match-to-sample

tasks

remained

unchanged

and

all

subjects

trials.

The stronger criterion applied to the tactual training phase increased subsequent visual oddity performance. When number of trials to criterion on visual transfer tests after the increased tactual training were compared to number of trials to criterion on the visual training performance, a significant tactual-to-visual transfer effect was found (Mann-Whitney U test. : = 2.64. p < .OOZ), strongly suggesting that the unidirectional transfer effect found in Experiment I reflected methodological factor% rather than inherent properties of mechanisms mediating cross-modal

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transfer. Thus, the results from both experiments taken together demonstrated the presence of bidirectional transfer effects between the tactual and the visual modality in children 4 years of age. The fact that no tactual-to-visual transfer occurred in Experiment 1, components but did occur in Experiment 9, also suggests that nonspecific of training; i.e.. factors not specific to oddity learning per se. were negligible. DISCUSSION Our results demonstrated that oddity-problem performance in both the tactual and the visual modality was dependent on age. showing a gradual increase with age. The growth in visual performance. however, began earlier than tactual. This could mean that visual processing is more effective for encoding relational stimulus properties. Thus. vision might be superior in perceptual tasks requiring the subject to attend to relational or amodal stimulus properties compared to the somatosensory system. It has been suggested that younger children operate in a perceptual mode of processing in oddity problem situations whereas older children operate in a conceptual mode (Gollin 8.z Saravo. 1971: Gollin & Schadler. 1972: Schadler, 1973). A related point of view was held by Inhelder and Piaget ( 1964) suggesting that young children are likely to solve the oddity problem by singling out the odd stimulus through “perceptual contrast by success” whereas older children tend to rely on the discovery and understanding of a rule. The perceptual mode is context-specific in contrast to the conceptual mode which is context-nonspecific (e.g.. Gollin & Schadler. 1973). Consequently. in young children little cross-modal transfer would occur since learning of a visual oddity relation would be confined to a visual context and vice versa for a tactual oddity relation. OLIIresults are not consistent with this assumption. however. The fact that both visual-to-tactual and tactual-to-visual cross-modal transfer occurred in children 4 years of age demonstrated that oddity learning in young children is not confined to a specific modality-labeled perceptual context. In contrast to this dual-process model. one might conceive of an oddity relation as an invariant amodal feature (Gibson. 1969, 1983) common to both the visual and the tactual mode of stimulation. According to this assumption oddity learning would depend on a single process rather than on qualitatively different mechanisms during development. Our results on cross-modal transfer are consistent with this view. REFERENCES

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