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The mediating effect of learning on the interference between location and distance recall from motor short-term memory
Acta Psychologica North-Holland
153
77 (1991) 153-165
The mediating effect of learning on the interference between location and distance recall from motor short-term memory * Kuniyasu
Imanaka
Nagasaki Uniuersify, Nagasaki, Japan
Bruce Abernethy University of Queensland, Brisbane, Australia Accepted
March
1991
Two experiments were conducted within a motor short-term memory paradigm to examine the influence of shifts in starting position upon the reproduction of movement location (experiment 1) and distance (experiment 2). We assessed whether the systematic pattern of undershooting and overshooting which occurs as a function of starting position changes is a consequence of learning which proceeds throughout the course of an experiment or is rather a more fundamental property of the encoding and retrieval processing occurring within motor short-term memory. Five groups of 10 subjects were each given 20 trials within a typical motor short-term memory paradigm. Each trial involved a criterion and reproduction linear-positioning movement separated by a lo-set retention interval. The starting position for the reproduction movement was shifted by 0, 2 or 4 cm in either direction from the starting position of the criterion movement. The presentation order of the five shifts in starting position was counterbalanced among the five groups, and each group consecutively performed 4 trials per shift. Analysis of data obtained from only the starting position condition performed first by each of the subjects showed the same systematic pattern of undershooting and overshooting in movement reproduction as observed from the typical analysis based on the data obtained from all the starting position conditions. These results suggest that the systematic undershooting-overshooting pattern typically observed in motor short-term memory experiments is not a consequence of any learning which takes place during the course of the experiment and is hence not an artifact of any central tendency effects arising from exposure to a range of different movement distances and locations. Rather location-distance interference appears to result from more fundamental aspects of the encoding and retrieval of information from motor short-term memory.
* Requests for reprints should be sent to K. Imanaka, Department of Health and Physical Education, Faculty of Liberal Arts, Nagasaki University, 1-14 Bunkyo-cho, Nagasaki 852, Japan.
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Interference
A systematic pattern of undershooting and overshooting in the reproduction of linear arm positioning movements has been frequently reported in the motor short-term memory literature (Kerr 1978; Walsh 1980, 1981; Walsh and Russell 1979, 1980; Walsh et al. 1979, 1980, 1981a, b; Wrisberg et al. 1987; Wrisberg and Winter 1985). This systematic pattern is a function of the direction and amplitude of the shift in the starting position for the reproduction movement. Specifically, in reproducing the end-locution of a criterion movement, subjects tend to overshoot the desired location when the starting position of the reproduction movement is moved closer to the end-location (relative to the starting position of the criterion movement), and tend to undershoot when the starting position is displaced away from the end-location. In contrast, in reproducing a criterion movement distance, subjects tend to undershoot when the starting position is moved toward the end-location, and overshoot when the starting position is shifted away from the end-location. This finding that the response error in reproducing either end-location or distance shifts as a function of the starting position of the reproduction movement has been interpreted in terms of the influence of other cues which were supposed to be ignored during the criterion movement (e.g., Kerr 1978; Walsh et al. 1979). Specifically, information on the end-location of a criterion movement appears to bias the reproduction of distance cues toward the end-location, thereby causing undershooting and overshooting. Similarly, information on the distance moved appears to cause undershooting and overshooting in reproducing the end-location. On the basis of such observations, Walsh et al. (1979) proposed a hypothesis of interference between location and distance cues. Information on distance was hypothesised to interfere in reproducing location cues, and information on end-location was hypothesised to interfere in reproducing distance. Although the pattern of undershooting and overshooting in movement reproduction has been demonstrated through experiments involving the systematic manipulation of recall starting position (e.g., in the experiments of Walsh et al. (1979) the starting positions were shifted by either 3 or 6 cm both backward and forward of the starting position of the criterion movement), an as yet unresolved problem is whether the systematic pattern of undershooting and overshooting can be mediated by the effects of learning. Laabs (1973) has suggested that a reproduction movement is made in reference to both the memory trace of the
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actual criterion movement and to an ‘average’ referent movement that is assumed to be formed from similar movements experienced within the experimental series. Poulton (1973, 1975, 1981) has also suggested that subjects learn the middle of the range of movements they experience as the experiment proceeds, and accordingly the information on the middle of the range comes to affect the response on any given trial, causing a central tendency effect. Consequently, the results of a particular experimental condition may not be determined by that condition alone, but may also be biased by the central tendency of the preceding conditions experienced during the course of the experiment. Poulton suggests that the only way to avoid this bias by the central tendency of the set of conditions is to use only the results of the experimental condition performed first. The investigation reported here deals with the effect of learning (which is assumed to take place as the experiment proceeds) on the systematic pattern of undershooting and overshooting in reproducing movement location (experiment 1) and distance (experiment 2). If the previously observed systematic pattern of undershooting and overshooting in movement reproduction is caused by development of memory for the ‘average’ movement, or the central tendency effect, then this systematic response bias pattern should become more apparent as the experiment proceeds. If, on the other hand, the previously observed systematic undershooting-overshooting pattern in movement reproduction is caused by encoding of non-specific sources of information available in the preceding criterion movement, then this pattern should be present throughout the experiment, even in the starting position condition performed first. Such predictions were examined in the two experiments reported here. Experiment 1 Method Subjects Fifty right-handed undergraduate students aged from 18 to 20 years from Nagasaki University participated in this experiment as part of a course requirement. Subjects were randomly assigned to one of five groups, with six male and four female subjects ’ per group. All subjects were naive to the purpose of the experiment. ’ Since no sex differences have been previously reported in movement reproduction performance (Wrisberg and Winter 1985), the unequal numbers of male and female subjects is unlikely to have any influence on the outcome of the experiment.
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Apparatus
The movement apparatus (fig. 1) consisted of a pantograph made from lengths of aluminium and secured to a table at a central pivot position. Attached to either end of the pantograph was a freely rotating handle that permitted both the subject and the experimenter to make movements linked in a one-to-one correspondence. The apparatus rested on sheets of glass and was supported by a ball-bearing located beneath the subject’s handle and at the point where the lengths of the pantograph were joined. This allowed nearly frictionless movements to be made by both the subject and the experimenter. On the experimenter’s side of the apparatus, an 80-cm metal track was located in the front-parallel plane of both the subject and the experimenter. The experimenter’s handle attached to the one end of the pantograph was mounted on a small carriage which was free to move in the metal track. This small carriage was connected with a wire to a pulley system consisting of two grooved wheels attached to either end of the track. The wire ran along the track and turned around both the grooved wheels to convert a linear movement of the handle on the track to a rotary movement of the wheels in the pulley system. A rotary potentiometer was joined to the axle of one of the wheels so that the voltage output from the potentiometer was a function of the rotary movement of the wheel (i.e., linearly related to the handle position on the track). This voltage output was converted by software run on a personal computer system (NEC PC-8000) into digital data, which were recorded in a minidisk unit of the personal computer system and used as the raw data for subsequent analysis.
EXPERIMENTER
SUBJECT
Fig. 1. Movement apparatus
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Task Blindfolded subjects were required to make a self-paced preselected criterion movement and then to reproduce the end-location of this criterion movement. All criterion movements were performed by the subjects with the right hand from a O-cm position to a preselected end-location. The O-cm position was defined between the midline of the subject’s body and the left armpit. The preselection of end-location was required to be in a range of approximately 20 to 30 cm to the right of the O-cm position. The reproduction movements were made with the right hand in a left-to-right direction from a new starting position, which was determined by the experimenter at a position shifted by 0, 2, or 4 cm in either direction from the O-cm position. Four consecutive trials, each including a set of criterion and reproduction movements, were given for each shift in the starting position. Each subject thus performed five sets of four consecutive trials, for a total of 20 trials per subject. A lo-see retention interval was allowed between the criterion and reproduction movements, and each trial was separated by a 20-set intertrial interval. Each shift in the starting position (or each set of four trials) constituted one block. Design Two independent variables, the group (groups 1 to 5) and the shift in starting position (-4, -2, 0, + 2, and +4 cm), were used in this study. For the manipulation of the starting position, a positive sign indicated a shift in the starting position to the right of the O-cm position and a negative sign a shift to the left. The five groups differed in the presentation order of the five starting positions for the reproduction movement. The presentation order was counterbalanced among groups using a 5 x 5 Latin square, as shown in table 1, and all subjects within a group performed trials with the same specific order of presentation of the starting position for the reproduction movements. Data analysis Three dependent variables, constant error (CE), variable error (VE), and absolute error (AE), were analysed using two one-way analyses of variance. In the first, the independent variable of shift in starting position was tested using a repeated-measures
Table 1 Presentation
order for the shift in starting
position
(cm) for blocks of four trials in experiment
Trial block 1
2
3
4
5
-4 -2
-2
+4 -4 -2 0 +2
0 +2 +4 -4 -2
+2 +4 -4 -2 0
Group 1 2 3 4 5
0 +2 +4
0 +2 +4 -4
1.
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interference
model, based on the scores from all five blocks of trials for all five groups. The purpose of this analysis was to ascertain whether the previously observed systematic pattern of undershooting and overshooting in reproducing end-location arose in this experiment as well. If the pattern arose, then a second analysis of starting position effects could be meaningfully undertaken. If the normally observed systematic pattern of undershooting and overshooting in reproducing end-location is a consequence of the central tendency effect or ‘average’ movement, this systematic pattern should not arise at the first block. This is because, the central tendency effect or ‘average’ movement has to be gradually learned, as the experiment proceeds, from the experience of all the sets of starting position conditions (Poulton 1981). The second analysis tested the starting position effect using a betweensubjects design based on the error scores of only the first block of trials. If the previously observed systematic pattern of undershooting and overshooting in movement reproduction occurs at the first block (remembering that within the first block each subject experiences only one shift in starting position), it could then be demonstrated that the systematic response bias pattern is not a consequence of learning effects, such as the central tendency or ‘averaging’ effect. Procedure
On entering the laboratory, the subject was seated in front of the pantograph (which was hidden from view by an opaque sheet) and was told the purpose and procedure of the experiment. Then the subject was asked to put on headphones and a blindfold. The headphones emitted white noise during the experiment to eliminate any auditory cues. A practice session was held to familiarise the subject with the target area - that area was 20-30 cm to the right of the O-cm position to which the subject’s preselections of end-location were to be made. The experimenter instructed the subject to grasp the handle located at the O-cm position with the right hand, and the experimenter moved the handle to the right by 20 cm from the O-cm position, to the left margin of the target area. In a similar way, the experimenter showed the subject the right margin of the target area (30 cm from the O-cm position). In the practice session, the subject was asked to preselect an end-location within the target area, and then to move the handle from the O-cm position to the preselected end-location. The practice was continued until the subject was able to consecutively make at least four appropriate preselections, terminating within the target area. After the practice session, the subject was informed that starting positions for both the criterion and reproduction movements would not be fixed. Then the experiment was conducted as follows. The experimenter placed the handle at the O-cm position and then gave the command ‘select’. The subject accordingly mentally preselected an end-location and then made a left-to-right criterion movement in a smooth, continuous motion to this preselected position. This position was held for about 2 set, and then the subject returned his hand to his lap. During the lo-set retention interval, the experimenter replaced the handle at a new starting position for the next reproduction movement. Upon hearing a lOOO-Hz tone, the subject grasped the handle and attempted to reproduce the end-location of the criterion movement. The trials were separated by a 20-set intertrial interval, and after that, a 300-Hz tone indicated to the experimenter that it was time to give instructions for the next trial set.
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K. Imanaka, B. Abernerhy / Range effects in location-distance interference Results and Discussion Criterion
movements
Mean preselected end-locations over all groups were 24.3, 24.0, 23.1, 23.6, and 23.6 cm for the first to fifth blocks, respectively. Analysis of variance for the mean preselected end-locations showed no significant effect for blocks ( I&s6 < 1.0). Mean variabilities of the preselections over all groups were 14.8, 15.4, 14.2, 15.8, and 14.0 mm for the first to fifth blocks, respectively. Analysis of variance for the mean variabilities also showed no significant differences across blocks (&a6 < 1.0). These results indicate that both the mean selection and the variability of the end-location were not different for the five trial blocks. Reproduction
movements
Means and standard deviations of CE, VE and AE scores calculated first block alone and across all blocks are presented in table 2.
for both the
The first analysis was made on the data from all five blocks. Analysis of all blocks. Analyses of variance were calculated for CE, VE and AE scores, using a repeated-measures model. For CE scores, the main effect for shift in starting position was significant 4,96 = 45.37, p < 0.001). Trend analysis revealed significant effects for the linear $ 1,49= 90.32, p < 0.001) the cubic ( Fr,49 = 4.96, p < 0.03) and the quartic ( F,,49 = 5.68, p < 0.02) components while the quadratic component ( FI,49 = 1.94, p > 0.1) was not significant. These results show the linear component to be the most dominant. The main effect for shift in starting position was not significant for VE ( F4,196 = 1.65, p > 0.1) whereas it was significant for AE scores ( F4,196 = 5.02, p < 0.002). Trend
Table 2 Mean errors and standard deviations (mm) from each starting the first block in experiment Starting
positions
position
for all blocks and for only
1.
VE
CE
AE
Mean
SD
Mean
SD
10.00 1.53 6.93 8.51 10.97
10.1 11.7 10.3 11.6 10.7
4.74 4.91 3.81 5.88 4.64
13.1 12.9 10.4 12.6 14.9
6.80 5.20 3.99 5.13 6.57
5.09 9.05 9.15 6.23 11.35
10.8 11.4 8.6 11.7 10.2
4.79 4.44 2.81 7.51 4.58
13.0 12.9 10.2 11.7 15.8
4.44 3.72 5.01 7.05 7.83
Mean
SD
- 7.1 - 7.3 0.2 4.3 9.0
-8.2 -7.2 1.6 5.0 10.2
All blocks -4cm -2 0 +2 +4 The first block -4cm -2 0 +2 +4
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analysis on the AE scores revealed significant effects for the quadratic (Ft.+ = 15.46, The linear ( FI,49 = 1.13, p < 0.001) and the quartic ( FtT4s = 6.66, p < 0.02) components. p > 0.2) and the cubic ( F,.49 = 1.39, p > 0.2) components were not significant. This trend analysis indicates that accuracy is a U-shaped function of the starting position. This seems to reflect the systematic pattern of response bias evident in the CE scores. These results therefore indicated that the systematic pattern of undershooting and overshooting in reproducing end-location observed in other studies was also clearly present in this data and that AE also reflected this systematic response bias. On the basis of these results, a second analysis was then justified using the data from the first block and a between-subjects analysis of variance model.
Analysis of the first block only. Analysis of variance of CE scores for the first block only showed a significant main effect for shift in starting position ( F4,45 = 7.87, p c 0.001). Trend analysis on the CE scores revealed only a significant effect for the linear component ( F,,45 = 30.16, p -C 0.001). The quadratic ( Fl,45 -C 1.0) the cubic were all not significant. These (Ft.45 < l.O), and the quartic ( F,.45 c 1.0) components analyses clearly revealed that the previously observed pattern of undershooting and overshooting in reproducing end-location which holds across all blocks was present even at the first block. The main effect for shift in starting position was not significant for VE ( F4,45 i 1.0) nor for AE ( F4h.45 = 1.11, p > 0.3). Although significant starting position effects were obtained for AE in the all-blocks analysis (based on 50 observations per shift in starting position) and not the first-block analysis (based only on 10 observations per shift in starting position), direct comparison of the two analyses is not justified and indeed may be misleading. The mean values for AE are similar between the first block and all blocks (see table 2), suggesting that reproduction accuracy (in terms of AE) is probably effectively unchanged throughout the duration of the experiment.
Experiment 2
Experiment 2 replicated reproduction of movement
the purpose and design of experiment distance rather than end-location.
1 but focussed
on the
Method Fifty right-handed undergraduate students aged from 18 to 20 years from Nagasaki University participated as part of a course requirement. Subjects were randomly assigned to one of five groups, with six male and four female subjects per group. None of these students had participated in experiment 1, and all were kept naive as to the purpose of the experiment. Apparatus, design, data analysis and procedures were the same as those used in experiment 1, with the exception that subjects were required to reproduce the distance moved on the criterion movement rather than end-location.
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Results and Discussion Criterion movements Mean preselected distances over all groups were 24.9, 24.5, 24.6, 24.5, and 24.5 cm for the first to fifth blocks, respectively. Analysis of variance for the mean distance showed no significant effect for blocks ( F4,196-C 1.0). Mean variabilities of the preselections over all groups were 19.7, 17.8, 15.2, 14.9, and 16.5 mm for the first to fifth blocks, respectively. Analysis of the variability of the preselections also showed no significant inter-block differences ( F4,196= 1.90, p > 0.1). These results indicated that both the mean preselection and the variability of the preselected distance did not differ across the five blocks of trials. Reproduction
movements
Means and standard deviations of CE, VE, and AE scores calculated for both the first block alone and across all five blocks are presented in table 3. Analysis of all blocks. The first analysis was made on the data from all five blocks. For CE scores, the main effect for shift in starting position was significant ( F4,196= 26.42, p < 0.001). Trend analysis on the CE scores revealed significant effects for the linear ( Fl.49 = 42.09, p -C 0.001) and the cubic ( Fl,49 = 13.99, p < 0.001) components. The quadratic ( Fl ,49 < 1.0) and the quartic ( Fl,49 = 2.95, p > 0.05) components were not significant. The trend analysis indicated that the linear component was the most dominant, with the non-linear data at -4 and +4 cm being the probable cause of the significant cubic component.
Table 3 Mean errors and standard deviations(mm) from each starting position for all blocks and for only the first block in experiment 2. Starting positions All blocks -4cm -2 0 +2 +4 The first block -4cm -2 0 +2 +4
VE
CE Mean
AE
SD
Mean
SD
Mean
SD
9.6 10.6 1.1 -4.5 - 5.7
13.75 13.02 9.24 10.17 13.82
14.1 14.0 13.7 14.6 13.7
6.05 6.23 6.63 7.10 6.46
18.0 18.2 14.0 15.6 17.3
8.63 8.10 6.30 6.14 7.04
10.9 13.0 1.4 -4.9 - 10.7
11.26 10.70 6.94 8.98 12.36
13.9 13.0 14.8 14.2 13.9
6.79 5.14 4.45 8.84 6.01
18.1 16.8 14.4 14.3 17.4
8.31 7.82 4.31 7.49 7.78
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The main effect for shift in starting position was not significant for VE ( F4,,9h < 1 .O) whereas it was significant for AE (F 4,196 = 3.66, p < 0.01). Trend analysis on the AE scores revealed significant effects for the quadratic ( F,.49 = 6.57, p < 0.02) and the quartic ( F,,49 = 6.36, p < 0.02) components, while the linear ( F,,49 = 1.49, p > 0.2) and the cubic ( F,,49 = 2.18, p > 0.1) components were not significant. This trend analysis showed that AE was generally a U-shaped function of starting position change. The AE scores at each starting position therefore appear to reflect the systematic pattern of response bias in CE scores. These results indicate that the normally observed systematic pattern of undershooting and overshooting in reproducing movement distance was again clearly apparent in this experiment. On the basis of these results the data from the first block was then analysed in a between-subjects model.
of the first block on&. Analysis of variance on the CE scores for the first block only showed a significant main effect for shift in starting position ( F4,45 = 8.79, p < 0.001). Follow-up trend analysis revealed only a significant effect for the linear component ( F,,45 = 32.04, p < 0.001). The quadratic ( F,,45 -C 1.0) the cubic ( F,,45 = 1.73. p > 0.1). and the quartic ( F,,45 < 1.0) components were all not significant. The main effect for shift in starting position was not significant for VE ( F4,45 -C 1.0) nor for AE ( F4.45 -=c1.0). These analyses clearly indicate that the previously observed systematic pattern of undershooting and overshooting in reproducing movement distance is present even at the first block of trials. Comparison of the starting position effects on AE between the all-blocks analysis and the first-block analysis again reveals some differences. However, consideration of the mean AE data calculated for all blocks and for the first block alone (table 3) shows few differences of any substance arguing against reproduction accuracy being enhanced by learning processes occurring throughout the duration of the experiment. Analysis
General discussion The results from both experiments indicate that the pattern of undershooting and overshooting in movement reproduction arises even at the first block of the experiment, and the CE scores show that there are essentially no differences in the general pattern of undershooting and overshooting between the first block and the whole experiment. It is concluded accordingly that the systematic pattern of undershooting and overshooting in movement reproduction is not a consequence of any central tendency effect or ‘average’ movement learned during the course of the experiment. The response bias patterns appear more likely to be caused by short-term retention of non-specific cues (i.e., the
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distance moved on the criterion movement in reproducing the end-location and the end-location of the criterion movement in reproducing movement distance) as concluded in earlier studies (e.g., Kerr 1978; Walsh et al. 1979). The effect of the shift in starting position on AE scores was found to be significant for the data obtained across all blocks, but not for the data obtained only from the first block. However, the mean AE scores of the first block appeared to be very similar to those for all blocks. This suggests that reproduction accuracy in terms of AE varies little between the first block and all blocks. Although some learning effect on reproduction accuracy (in terms of AE) has been demonstrated in some other studies (e.g., Colley and Kitchen, 1983; Gentile and Nemetz, 1978) and has been suggested to mediate reproduction performance (Poulton, 1973, 1975, 1981), this type of learning effect seems to have little or no influence on the systematic pattern of undershooting and overshooting in movement reproduction as revealed in the CE analyses. Rather, the effect of short-term retention of the non-specific cues available during the criterion movement is probably the main cause of these characteristic response biases. The systematic pattern of undershooting and overshooting in movement reproduction has been interpreted by Kerr (1978) and Walsh (1980, 1981; Walsh and Russell 1979, 1980; Walsh et al. 1979, 1980, 1981b) in terms of the processing of inappropriate information which is not specified to be reproduced, namely, distance information when reproducing end-location and information on end-location when reproducing distance. This interpretation has already been confirmed by directly manipulating the availability of the inappropriate information during criterion movements (Imanaka 1989). On the basis of both these earlier findings and the current results the conclusion that the interference between movement location and distance information occurs within processes intrinsic to the encoding and retrieval of information from motor short-term memory appears warranted. However, the underlying causes of the location-distance interference are still far from clear. It appears important therefore that future investigations should focus more on the underlying mechanisms, such as the role of central and peripheral sources in causing the location-distance interference, rather than simply re-describing the already well documented characteristics of the location-distance interference (e.g., Ashby et al. 1980, 1982; Kerr 1978; Marteniuk and Roy 1972;
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Shibayama 1983; Stelmach berg and Winter 1985).
/ Range elfects in location-distance
and Kelso 1973; Walsh
interference
et al. 1979; Wris-
References Ashby, A., C. Shea and R.M. Howard, 1980. Short-term memory for kinesthetic movement information: Influence of location cues on recall of distance. Perceptual and Motor Skills 51, 403-406. Ashby, A., C.H. Shea and H. Tolson, 1982. Memory characteristics of two dimensional movement information. Research Quarterly for Exercise and Sport 53, 93-100. Colley, A. and S. Kitchen, 1983. Criterion movements in motor short-term memory experiments. Acta Psychologica 53, 119-128. Gentile, A.M. and K. Nemetz, 1978. Repetition effects: A methodological issue in motor short-term memory. Journal of Motor Behavior 10, 37-44. Imanaka, K., 1989. Effect of starting position on reproduction of movement: Further evidence of interference between location and distance information. Perceptual and Motor Skills 68, 423-434. Kerr, B., 1978. The effect of invalid task parameters on short-term motor memory. Journal of Motor Behavior, 10, 261-273. Laabs, G.J., 1973. Retention characteristics of different reproduction cues in motor short-term memory. Journal of Experimental Psychology 100, 168-177. Marteniuk, R.G. and E.A. Roy, 1972. The codability of kinesthetic location and distance information. Acta Psychologica 36, 471-479. Poulton, E.C., 1973. Unwanted range effects from using within-subject experimental designs. Psychological Bulletin 80, 113-121. Poulton, E.C., 1975. Range effects in experiments on people. American Journal of Psychology 88, 3-32. Poulton, E.C., 1981. ‘Human manual control’. In: V.B. Brooks (ed.), Handbook of physiology: Section 1. The nervous system, Vol. 2. Bethesda, MD: American Physiological Society. pp. 1337-1389. Shibayama. K., 1983. [Location and distance cues of motor space in movement reproduction.] The Japanese Journal of Psychology 54, 321-324. (English summary). Stelmach, G.E. and J.A.S. Kelso, 1973. Distance and location cues in short-term motor memory. Perceptual and Motor Skills 37, 403-406. Walsh, W.D., 1980. Interference in recall of movement terminal location and distance. Unpublished doctoral dissertation, University of Queensland, Australia. Walsh, W.D., 1981. Memory for preselected and constrained short movements. Research Quarterly for Exercise and Sport 52, 368-379. Walsh, W.D. and D.G. Russell, 1979. Memory for movement location and distance: Starting position and retention interval effects. Journal of Human Movement Studies 5, 68-76. Walsh, W.D. and D.G. Russell, 1980. Memory for preselected slow movements: Evidence for integration of location and distance. Journal of Human Movement Studies 6, 95-105. Walsh. W.D., D.G. Russell and J. Boustead, 1981a. Memory for movement cues: Angle of approach, terminal location and distance. Journal of Human Movement Studies 7, 108-123. Walsh, W.D., D.G. Russell and B. Crassini, 1981b. Interference effects in recalling movements. British Journal of Psychology 72, 287-298. Walsh, W.D., D.G. Russell and K. Imanaka, 1980. Memory for movement: Interaction of location and distance cues and imagery ability. Acta Psychologica 44, 117-130.
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/ Range effects in location-distance
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Walsh, W.D., D.G. Russell, K. Imanaka and B. James, 1979. Memory for constrained and preselected movement location and distance: Effects of starting position and length. Journal of Motor Behavior 11, 201-214. Wrisberg, C.A., D.G. Millslagle and E.S. Schliesman, 1987. Reproducing the endpoint of a positioning movement: A further test of the influence of start location. Journal of Human Movement Studies 13, 391-398. Wrisberg, C.A. and T.P. Winter, 1985. Reproducing the end location of a positioning movement: The long and short of it. Journal of Motor Behavior 17, 242-254.
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The mediating effect of learning on the interference between location and distance recall from motor short-term memory * Kuniyasu
Imanaka
Nagasaki Uniuersify, Nagasaki, Japan
Bruce Abernethy University of Queensland, Brisbane, Australia Accepted
March
1991
Two experiments were conducted within a motor short-term memory paradigm to examine the influence of shifts in starting position upon the reproduction of movement location (experiment 1) and distance (experiment 2). We assessed whether the systematic pattern of undershooting and overshooting which occurs as a function of starting position changes is a consequence of learning which proceeds throughout the course of an experiment or is rather a more fundamental property of the encoding and retrieval processing occurring within motor short-term memory. Five groups of 10 subjects were each given 20 trials within a typical motor short-term memory paradigm. Each trial involved a criterion and reproduction linear-positioning movement separated by a lo-set retention interval. The starting position for the reproduction movement was shifted by 0, 2 or 4 cm in either direction from the starting position of the criterion movement. The presentation order of the five shifts in starting position was counterbalanced among the five groups, and each group consecutively performed 4 trials per shift. Analysis of data obtained from only the starting position condition performed first by each of the subjects showed the same systematic pattern of undershooting and overshooting in movement reproduction as observed from the typical analysis based on the data obtained from all the starting position conditions. These results suggest that the systematic undershooting-overshooting pattern typically observed in motor short-term memory experiments is not a consequence of any learning which takes place during the course of the experiment and is hence not an artifact of any central tendency effects arising from exposure to a range of different movement distances and locations. Rather location-distance interference appears to result from more fundamental aspects of the encoding and retrieval of information from motor short-term memory.
* Requests for reprints should be sent to K. Imanaka, Department of Health and Physical Education, Faculty of Liberal Arts, Nagasaki University, 1-14 Bunkyo-cho, Nagasaki 852, Japan.
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Interference
A systematic pattern of undershooting and overshooting in the reproduction of linear arm positioning movements has been frequently reported in the motor short-term memory literature (Kerr 1978; Walsh 1980, 1981; Walsh and Russell 1979, 1980; Walsh et al. 1979, 1980, 1981a, b; Wrisberg et al. 1987; Wrisberg and Winter 1985). This systematic pattern is a function of the direction and amplitude of the shift in the starting position for the reproduction movement. Specifically, in reproducing the end-locution of a criterion movement, subjects tend to overshoot the desired location when the starting position of the reproduction movement is moved closer to the end-location (relative to the starting position of the criterion movement), and tend to undershoot when the starting position is displaced away from the end-location. In contrast, in reproducing a criterion movement distance, subjects tend to undershoot when the starting position is moved toward the end-location, and overshoot when the starting position is shifted away from the end-location. This finding that the response error in reproducing either end-location or distance shifts as a function of the starting position of the reproduction movement has been interpreted in terms of the influence of other cues which were supposed to be ignored during the criterion movement (e.g., Kerr 1978; Walsh et al. 1979). Specifically, information on the end-location of a criterion movement appears to bias the reproduction of distance cues toward the end-location, thereby causing undershooting and overshooting. Similarly, information on the distance moved appears to cause undershooting and overshooting in reproducing the end-location. On the basis of such observations, Walsh et al. (1979) proposed a hypothesis of interference between location and distance cues. Information on distance was hypothesised to interfere in reproducing location cues, and information on end-location was hypothesised to interfere in reproducing distance. Although the pattern of undershooting and overshooting in movement reproduction has been demonstrated through experiments involving the systematic manipulation of recall starting position (e.g., in the experiments of Walsh et al. (1979) the starting positions were shifted by either 3 or 6 cm both backward and forward of the starting position of the criterion movement), an as yet unresolved problem is whether the systematic pattern of undershooting and overshooting can be mediated by the effects of learning. Laabs (1973) has suggested that a reproduction movement is made in reference to both the memory trace of the
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actual criterion movement and to an ‘average’ referent movement that is assumed to be formed from similar movements experienced within the experimental series. Poulton (1973, 1975, 1981) has also suggested that subjects learn the middle of the range of movements they experience as the experiment proceeds, and accordingly the information on the middle of the range comes to affect the response on any given trial, causing a central tendency effect. Consequently, the results of a particular experimental condition may not be determined by that condition alone, but may also be biased by the central tendency of the preceding conditions experienced during the course of the experiment. Poulton suggests that the only way to avoid this bias by the central tendency of the set of conditions is to use only the results of the experimental condition performed first. The investigation reported here deals with the effect of learning (which is assumed to take place as the experiment proceeds) on the systematic pattern of undershooting and overshooting in reproducing movement location (experiment 1) and distance (experiment 2). If the previously observed systematic pattern of undershooting and overshooting in movement reproduction is caused by development of memory for the ‘average’ movement, or the central tendency effect, then this systematic response bias pattern should become more apparent as the experiment proceeds. If, on the other hand, the previously observed systematic undershooting-overshooting pattern in movement reproduction is caused by encoding of non-specific sources of information available in the preceding criterion movement, then this pattern should be present throughout the experiment, even in the starting position condition performed first. Such predictions were examined in the two experiments reported here. Experiment 1 Method Subjects Fifty right-handed undergraduate students aged from 18 to 20 years from Nagasaki University participated in this experiment as part of a course requirement. Subjects were randomly assigned to one of five groups, with six male and four female subjects ’ per group. All subjects were naive to the purpose of the experiment. ’ Since no sex differences have been previously reported in movement reproduction performance (Wrisberg and Winter 1985), the unequal numbers of male and female subjects is unlikely to have any influence on the outcome of the experiment.
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Apparatus
The movement apparatus (fig. 1) consisted of a pantograph made from lengths of aluminium and secured to a table at a central pivot position. Attached to either end of the pantograph was a freely rotating handle that permitted both the subject and the experimenter to make movements linked in a one-to-one correspondence. The apparatus rested on sheets of glass and was supported by a ball-bearing located beneath the subject’s handle and at the point where the lengths of the pantograph were joined. This allowed nearly frictionless movements to be made by both the subject and the experimenter. On the experimenter’s side of the apparatus, an 80-cm metal track was located in the front-parallel plane of both the subject and the experimenter. The experimenter’s handle attached to the one end of the pantograph was mounted on a small carriage which was free to move in the metal track. This small carriage was connected with a wire to a pulley system consisting of two grooved wheels attached to either end of the track. The wire ran along the track and turned around both the grooved wheels to convert a linear movement of the handle on the track to a rotary movement of the wheels in the pulley system. A rotary potentiometer was joined to the axle of one of the wheels so that the voltage output from the potentiometer was a function of the rotary movement of the wheel (i.e., linearly related to the handle position on the track). This voltage output was converted by software run on a personal computer system (NEC PC-8000) into digital data, which were recorded in a minidisk unit of the personal computer system and used as the raw data for subsequent analysis.
EXPERIMENTER
SUBJECT
Fig. 1. Movement apparatus
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Task Blindfolded subjects were required to make a self-paced preselected criterion movement and then to reproduce the end-location of this criterion movement. All criterion movements were performed by the subjects with the right hand from a O-cm position to a preselected end-location. The O-cm position was defined between the midline of the subject’s body and the left armpit. The preselection of end-location was required to be in a range of approximately 20 to 30 cm to the right of the O-cm position. The reproduction movements were made with the right hand in a left-to-right direction from a new starting position, which was determined by the experimenter at a position shifted by 0, 2, or 4 cm in either direction from the O-cm position. Four consecutive trials, each including a set of criterion and reproduction movements, were given for each shift in the starting position. Each subject thus performed five sets of four consecutive trials, for a total of 20 trials per subject. A lo-see retention interval was allowed between the criterion and reproduction movements, and each trial was separated by a 20-set intertrial interval. Each shift in the starting position (or each set of four trials) constituted one block. Design Two independent variables, the group (groups 1 to 5) and the shift in starting position (-4, -2, 0, + 2, and +4 cm), were used in this study. For the manipulation of the starting position, a positive sign indicated a shift in the starting position to the right of the O-cm position and a negative sign a shift to the left. The five groups differed in the presentation order of the five starting positions for the reproduction movement. The presentation order was counterbalanced among groups using a 5 x 5 Latin square, as shown in table 1, and all subjects within a group performed trials with the same specific order of presentation of the starting position for the reproduction movements. Data analysis Three dependent variables, constant error (CE), variable error (VE), and absolute error (AE), were analysed using two one-way analyses of variance. In the first, the independent variable of shift in starting position was tested using a repeated-measures
Table 1 Presentation
order for the shift in starting
position
(cm) for blocks of four trials in experiment
Trial block 1
2
3
4
5
-4 -2
-2
+4 -4 -2 0 +2
0 +2 +4 -4 -2
+2 +4 -4 -2 0
Group 1 2 3 4 5
0 +2 +4
0 +2 +4 -4
1.
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interference
model, based on the scores from all five blocks of trials for all five groups. The purpose of this analysis was to ascertain whether the previously observed systematic pattern of undershooting and overshooting in reproducing end-location arose in this experiment as well. If the pattern arose, then a second analysis of starting position effects could be meaningfully undertaken. If the normally observed systematic pattern of undershooting and overshooting in reproducing end-location is a consequence of the central tendency effect or ‘average’ movement, this systematic pattern should not arise at the first block. This is because, the central tendency effect or ‘average’ movement has to be gradually learned, as the experiment proceeds, from the experience of all the sets of starting position conditions (Poulton 1981). The second analysis tested the starting position effect using a betweensubjects design based on the error scores of only the first block of trials. If the previously observed systematic pattern of undershooting and overshooting in movement reproduction occurs at the first block (remembering that within the first block each subject experiences only one shift in starting position), it could then be demonstrated that the systematic response bias pattern is not a consequence of learning effects, such as the central tendency or ‘averaging’ effect. Procedure
On entering the laboratory, the subject was seated in front of the pantograph (which was hidden from view by an opaque sheet) and was told the purpose and procedure of the experiment. Then the subject was asked to put on headphones and a blindfold. The headphones emitted white noise during the experiment to eliminate any auditory cues. A practice session was held to familiarise the subject with the target area - that area was 20-30 cm to the right of the O-cm position to which the subject’s preselections of end-location were to be made. The experimenter instructed the subject to grasp the handle located at the O-cm position with the right hand, and the experimenter moved the handle to the right by 20 cm from the O-cm position, to the left margin of the target area. In a similar way, the experimenter showed the subject the right margin of the target area (30 cm from the O-cm position). In the practice session, the subject was asked to preselect an end-location within the target area, and then to move the handle from the O-cm position to the preselected end-location. The practice was continued until the subject was able to consecutively make at least four appropriate preselections, terminating within the target area. After the practice session, the subject was informed that starting positions for both the criterion and reproduction movements would not be fixed. Then the experiment was conducted as follows. The experimenter placed the handle at the O-cm position and then gave the command ‘select’. The subject accordingly mentally preselected an end-location and then made a left-to-right criterion movement in a smooth, continuous motion to this preselected position. This position was held for about 2 set, and then the subject returned his hand to his lap. During the lo-set retention interval, the experimenter replaced the handle at a new starting position for the next reproduction movement. Upon hearing a lOOO-Hz tone, the subject grasped the handle and attempted to reproduce the end-location of the criterion movement. The trials were separated by a 20-set intertrial interval, and after that, a 300-Hz tone indicated to the experimenter that it was time to give instructions for the next trial set.
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K. Imanaka, B. Abernerhy / Range effects in location-distance interference Results and Discussion Criterion
movements
Mean preselected end-locations over all groups were 24.3, 24.0, 23.1, 23.6, and 23.6 cm for the first to fifth blocks, respectively. Analysis of variance for the mean preselected end-locations showed no significant effect for blocks ( I&s6 < 1.0). Mean variabilities of the preselections over all groups were 14.8, 15.4, 14.2, 15.8, and 14.0 mm for the first to fifth blocks, respectively. Analysis of variance for the mean variabilities also showed no significant differences across blocks (&a6 < 1.0). These results indicate that both the mean selection and the variability of the end-location were not different for the five trial blocks. Reproduction
movements
Means and standard deviations of CE, VE and AE scores calculated first block alone and across all blocks are presented in table 2.
for both the
The first analysis was made on the data from all five blocks. Analysis of all blocks. Analyses of variance were calculated for CE, VE and AE scores, using a repeated-measures model. For CE scores, the main effect for shift in starting position was significant 4,96 = 45.37, p < 0.001). Trend analysis revealed significant effects for the linear $ 1,49= 90.32, p < 0.001) the cubic ( Fr,49 = 4.96, p < 0.03) and the quartic ( F,,49 = 5.68, p < 0.02) components while the quadratic component ( FI,49 = 1.94, p > 0.1) was not significant. These results show the linear component to be the most dominant. The main effect for shift in starting position was not significant for VE ( F4,196 = 1.65, p > 0.1) whereas it was significant for AE scores ( F4,196 = 5.02, p < 0.002). Trend
Table 2 Mean errors and standard deviations (mm) from each starting the first block in experiment Starting
positions
position
for all blocks and for only
1.
VE
CE
AE
Mean
SD
Mean
SD
10.00 1.53 6.93 8.51 10.97
10.1 11.7 10.3 11.6 10.7
4.74 4.91 3.81 5.88 4.64
13.1 12.9 10.4 12.6 14.9
6.80 5.20 3.99 5.13 6.57
5.09 9.05 9.15 6.23 11.35
10.8 11.4 8.6 11.7 10.2
4.79 4.44 2.81 7.51 4.58
13.0 12.9 10.2 11.7 15.8
4.44 3.72 5.01 7.05 7.83
Mean
SD
- 7.1 - 7.3 0.2 4.3 9.0
-8.2 -7.2 1.6 5.0 10.2
All blocks -4cm -2 0 +2 +4 The first block -4cm -2 0 +2 +4
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analysis on the AE scores revealed significant effects for the quadratic (Ft.+ = 15.46, The linear ( FI,49 = 1.13, p < 0.001) and the quartic ( FtT4s = 6.66, p < 0.02) components. p > 0.2) and the cubic ( F,.49 = 1.39, p > 0.2) components were not significant. This trend analysis indicates that accuracy is a U-shaped function of the starting position. This seems to reflect the systematic pattern of response bias evident in the CE scores. These results therefore indicated that the systematic pattern of undershooting and overshooting in reproducing end-location observed in other studies was also clearly present in this data and that AE also reflected this systematic response bias. On the basis of these results, a second analysis was then justified using the data from the first block and a between-subjects analysis of variance model.
Analysis of the first block only. Analysis of variance of CE scores for the first block only showed a significant main effect for shift in starting position ( F4,45 = 7.87, p c 0.001). Trend analysis on the CE scores revealed only a significant effect for the linear component ( F,,45 = 30.16, p -C 0.001). The quadratic ( Fl,45 -C 1.0) the cubic were all not significant. These (Ft.45 < l.O), and the quartic ( F,.45 c 1.0) components analyses clearly revealed that the previously observed pattern of undershooting and overshooting in reproducing end-location which holds across all blocks was present even at the first block. The main effect for shift in starting position was not significant for VE ( F4,45 i 1.0) nor for AE ( F4h.45 = 1.11, p > 0.3). Although significant starting position effects were obtained for AE in the all-blocks analysis (based on 50 observations per shift in starting position) and not the first-block analysis (based only on 10 observations per shift in starting position), direct comparison of the two analyses is not justified and indeed may be misleading. The mean values for AE are similar between the first block and all blocks (see table 2), suggesting that reproduction accuracy (in terms of AE) is probably effectively unchanged throughout the duration of the experiment.
Experiment 2
Experiment 2 replicated reproduction of movement
the purpose and design of experiment distance rather than end-location.
1 but focussed
on the
Method Fifty right-handed undergraduate students aged from 18 to 20 years from Nagasaki University participated as part of a course requirement. Subjects were randomly assigned to one of five groups, with six male and four female subjects per group. None of these students had participated in experiment 1, and all were kept naive as to the purpose of the experiment. Apparatus, design, data analysis and procedures were the same as those used in experiment 1, with the exception that subjects were required to reproduce the distance moved on the criterion movement rather than end-location.
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Results and Discussion Criterion movements Mean preselected distances over all groups were 24.9, 24.5, 24.6, 24.5, and 24.5 cm for the first to fifth blocks, respectively. Analysis of variance for the mean distance showed no significant effect for blocks ( F4,196-C 1.0). Mean variabilities of the preselections over all groups were 19.7, 17.8, 15.2, 14.9, and 16.5 mm for the first to fifth blocks, respectively. Analysis of the variability of the preselections also showed no significant inter-block differences ( F4,196= 1.90, p > 0.1). These results indicated that both the mean preselection and the variability of the preselected distance did not differ across the five blocks of trials. Reproduction
movements
Means and standard deviations of CE, VE, and AE scores calculated for both the first block alone and across all five blocks are presented in table 3. Analysis of all blocks. The first analysis was made on the data from all five blocks. For CE scores, the main effect for shift in starting position was significant ( F4,196= 26.42, p < 0.001). Trend analysis on the CE scores revealed significant effects for the linear ( Fl.49 = 42.09, p -C 0.001) and the cubic ( Fl,49 = 13.99, p < 0.001) components. The quadratic ( Fl ,49 < 1.0) and the quartic ( Fl,49 = 2.95, p > 0.05) components were not significant. The trend analysis indicated that the linear component was the most dominant, with the non-linear data at -4 and +4 cm being the probable cause of the significant cubic component.
Table 3 Mean errors and standard deviations(mm) from each starting position for all blocks and for only the first block in experiment 2. Starting positions All blocks -4cm -2 0 +2 +4 The first block -4cm -2 0 +2 +4
VE
CE Mean
AE
SD
Mean
SD
Mean
SD
9.6 10.6 1.1 -4.5 - 5.7
13.75 13.02 9.24 10.17 13.82
14.1 14.0 13.7 14.6 13.7
6.05 6.23 6.63 7.10 6.46
18.0 18.2 14.0 15.6 17.3
8.63 8.10 6.30 6.14 7.04
10.9 13.0 1.4 -4.9 - 10.7
11.26 10.70 6.94 8.98 12.36
13.9 13.0 14.8 14.2 13.9
6.79 5.14 4.45 8.84 6.01
18.1 16.8 14.4 14.3 17.4
8.31 7.82 4.31 7.49 7.78
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The main effect for shift in starting position was not significant for VE ( F4,,9h < 1 .O) whereas it was significant for AE (F 4,196 = 3.66, p < 0.01). Trend analysis on the AE scores revealed significant effects for the quadratic ( F,.49 = 6.57, p < 0.02) and the quartic ( F,,49 = 6.36, p < 0.02) components, while the linear ( F,,49 = 1.49, p > 0.2) and the cubic ( F,,49 = 2.18, p > 0.1) components were not significant. This trend analysis showed that AE was generally a U-shaped function of starting position change. The AE scores at each starting position therefore appear to reflect the systematic pattern of response bias in CE scores. These results indicate that the normally observed systematic pattern of undershooting and overshooting in reproducing movement distance was again clearly apparent in this experiment. On the basis of these results the data from the first block was then analysed in a between-subjects model.
of the first block on&. Analysis of variance on the CE scores for the first block only showed a significant main effect for shift in starting position ( F4,45 = 8.79, p < 0.001). Follow-up trend analysis revealed only a significant effect for the linear component ( F,,45 = 32.04, p < 0.001). The quadratic ( F,,45 -C 1.0) the cubic ( F,,45 = 1.73. p > 0.1). and the quartic ( F,,45 < 1.0) components were all not significant. The main effect for shift in starting position was not significant for VE ( F4,45 -C 1.0) nor for AE ( F4.45 -=c1.0). These analyses clearly indicate that the previously observed systematic pattern of undershooting and overshooting in reproducing movement distance is present even at the first block of trials. Comparison of the starting position effects on AE between the all-blocks analysis and the first-block analysis again reveals some differences. However, consideration of the mean AE data calculated for all blocks and for the first block alone (table 3) shows few differences of any substance arguing against reproduction accuracy being enhanced by learning processes occurring throughout the duration of the experiment. Analysis
General discussion The results from both experiments indicate that the pattern of undershooting and overshooting in movement reproduction arises even at the first block of the experiment, and the CE scores show that there are essentially no differences in the general pattern of undershooting and overshooting between the first block and the whole experiment. It is concluded accordingly that the systematic pattern of undershooting and overshooting in movement reproduction is not a consequence of any central tendency effect or ‘average’ movement learned during the course of the experiment. The response bias patterns appear more likely to be caused by short-term retention of non-specific cues (i.e., the
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distance moved on the criterion movement in reproducing the end-location and the end-location of the criterion movement in reproducing movement distance) as concluded in earlier studies (e.g., Kerr 1978; Walsh et al. 1979). The effect of the shift in starting position on AE scores was found to be significant for the data obtained across all blocks, but not for the data obtained only from the first block. However, the mean AE scores of the first block appeared to be very similar to those for all blocks. This suggests that reproduction accuracy in terms of AE varies little between the first block and all blocks. Although some learning effect on reproduction accuracy (in terms of AE) has been demonstrated in some other studies (e.g., Colley and Kitchen, 1983; Gentile and Nemetz, 1978) and has been suggested to mediate reproduction performance (Poulton, 1973, 1975, 1981), this type of learning effect seems to have little or no influence on the systematic pattern of undershooting and overshooting in movement reproduction as revealed in the CE analyses. Rather, the effect of short-term retention of the non-specific cues available during the criterion movement is probably the main cause of these characteristic response biases. The systematic pattern of undershooting and overshooting in movement reproduction has been interpreted by Kerr (1978) and Walsh (1980, 1981; Walsh and Russell 1979, 1980; Walsh et al. 1979, 1980, 1981b) in terms of the processing of inappropriate information which is not specified to be reproduced, namely, distance information when reproducing end-location and information on end-location when reproducing distance. This interpretation has already been confirmed by directly manipulating the availability of the inappropriate information during criterion movements (Imanaka 1989). On the basis of both these earlier findings and the current results the conclusion that the interference between movement location and distance information occurs within processes intrinsic to the encoding and retrieval of information from motor short-term memory appears warranted. However, the underlying causes of the location-distance interference are still far from clear. It appears important therefore that future investigations should focus more on the underlying mechanisms, such as the role of central and peripheral sources in causing the location-distance interference, rather than simply re-describing the already well documented characteristics of the location-distance interference (e.g., Ashby et al. 1980, 1982; Kerr 1978; Marteniuk and Roy 1972;
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Shibayama 1983; Stelmach berg and Winter 1985).
/ Range elfects in location-distance
and Kelso 1973; Walsh
interference
et al. 1979; Wris-
References Ashby, A., C. Shea and R.M. Howard, 1980. Short-term memory for kinesthetic movement information: Influence of location cues on recall of distance. Perceptual and Motor Skills 51, 403-406. Ashby, A., C.H. Shea and H. Tolson, 1982. Memory characteristics of two dimensional movement information. Research Quarterly for Exercise and Sport 53, 93-100. Colley, A. and S. Kitchen, 1983. Criterion movements in motor short-term memory experiments. Acta Psychologica 53, 119-128. Gentile, A.M. and K. Nemetz, 1978. Repetition effects: A methodological issue in motor short-term memory. Journal of Motor Behavior 10, 37-44. Imanaka, K., 1989. Effect of starting position on reproduction of movement: Further evidence of interference between location and distance information. Perceptual and Motor Skills 68, 423-434. Kerr, B., 1978. The effect of invalid task parameters on short-term motor memory. Journal of Motor Behavior, 10, 261-273. Laabs, G.J., 1973. Retention characteristics of different reproduction cues in motor short-term memory. Journal of Experimental Psychology 100, 168-177. Marteniuk, R.G. and E.A. Roy, 1972. The codability of kinesthetic location and distance information. Acta Psychologica 36, 471-479. Poulton, E.C., 1973. Unwanted range effects from using within-subject experimental designs. Psychological Bulletin 80, 113-121. Poulton, E.C., 1975. Range effects in experiments on people. American Journal of Psychology 88, 3-32. Poulton, E.C., 1981. ‘Human manual control’. In: V.B. Brooks (ed.), Handbook of physiology: Section 1. The nervous system, Vol. 2. Bethesda, MD: American Physiological Society. pp. 1337-1389. Shibayama. K., 1983. [Location and distance cues of motor space in movement reproduction.] The Japanese Journal of Psychology 54, 321-324. (English summary). Stelmach, G.E. and J.A.S. Kelso, 1973. Distance and location cues in short-term motor memory. Perceptual and Motor Skills 37, 403-406. Walsh, W.D., 1980. Interference in recall of movement terminal location and distance. Unpublished doctoral dissertation, University of Queensland, Australia. Walsh, W.D., 1981. Memory for preselected and constrained short movements. Research Quarterly for Exercise and Sport 52, 368-379. Walsh, W.D. and D.G. Russell, 1979. Memory for movement location and distance: Starting position and retention interval effects. Journal of Human Movement Studies 5, 68-76. Walsh, W.D. and D.G. Russell, 1980. Memory for preselected slow movements: Evidence for integration of location and distance. Journal of Human Movement Studies 6, 95-105. Walsh. W.D., D.G. Russell and J. Boustead, 1981a. Memory for movement cues: Angle of approach, terminal location and distance. Journal of Human Movement Studies 7, 108-123. Walsh, W.D., D.G. Russell and B. Crassini, 1981b. Interference effects in recalling movements. British Journal of Psychology 72, 287-298. Walsh, W.D., D.G. Russell and K. Imanaka, 1980. Memory for movement: Interaction of location and distance cues and imagery ability. Acta Psychologica 44, 117-130.
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B. Abernethy
/ Range effects in location-distance
interference
165
Walsh, W.D., D.G. Russell, K. Imanaka and B. James, 1979. Memory for constrained and preselected movement location and distance: Effects of starting position and length. Journal of Motor Behavior 11, 201-214. Wrisberg, C.A., D.G. Millslagle and E.S. Schliesman, 1987. Reproducing the endpoint of a positioning movement: A further test of the influence of start location. Journal of Human Movement Studies 13, 391-398. Wrisberg, C.A. and T.P. Winter, 1985. Reproducing the end location of a positioning movement: The long and short of it. Journal of Motor Behavior 17, 242-254.