Kuniyasu Imanaka

Interference between location and distance information in motor short-term memory: The respective roles of direct kinesthetic signals and abstract codes

Interference between location and distance information in motor short-term memory has been hypothesized on the basis of the systematic pattern of undershooting and overshooting in movement reproduction that occurs when the starting position for reproduction movements is shifted. To determine the possible contribution of limb-specific kinesthetic information to this systematic undershooting-overshooting pattern, we compared the reproduction of linear arm positioning movements performed under either same-limb or switched-limb conditions. Ten subjects were assigned to either a location or distance cue condition, and each subject completed a total of 40 trials, 20 under same-limb and 20 under switched-limb conditions. Each trial consisted of criterion and reproduction movements, separated by a 10-s retention interval. The starting position for the reproduction movement was shifted by 0, 2, or 4 cm in either direction from that of the criterion movement. The systematic undershooting-overshooting pattern, which occurs when either the movement location or distance is reproduced, arose under both the same-limb and switched-limb conditions, suggesting that the primary cause of the location-distance interference is not limb-specific kinesthetic information. Rather, more abstract information in the form of a conceptual memory code appears to be the probable cause of the location distance interference phenomenon.

Effect of Starting Position on Reproduction of Movement: Further Evidence of Interference between Location and Distance Information

Two experiments done with a short-term memory paradigm examined the influence of shifts in the starting position on the reproduction of kinesthetic location (Exp. 1) and on distance cues (Exp. 2). We assessed possible causes of the systematic pattern of undershooting and overshooting as related to the shift in the starting position. In each experiment, two groups of 10 students were given 25 trials, and each had criterion and reproduction tasks involving linear-positioning movements with a 10-sec. retention interval. Each experiment had two independent variables, the group of subjects and the shift in the starting position. The two groups differed in the possible sources of information, the distance moved (Exp. 1) or the end-location (Exp. 2), which were assumed to cause undershooting and overshooting during reproduction. Analysis showed that the information about the distance moved may produce undershooting and overshooting in reproduction of the end-location (Exp. 1). Also, the information about the end-location may produce undershooting and overshooting in reproduction of the distance moved (Exp. 2). The findings were further evidence of interference between location and distance cues in motor short-term memory.

The mediating effect of learning on the interference between location and distance recall from motor short-term memory

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 10-sec 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.

Cortical Facilitation during Motor Imagery of Wrist Flexion-Extension Oscillatory Movements at Different Forearm Positions: TMS Study

RESULTS The investigation shows that the social situation in families where are children with developmental disorders is more complicated when the question is about the accessibility to rehabilitation services. The investigation data present evidence about a very great difference in parents’ understanding about the accessibility to rehabilitation services, aims and possibilities. The investigation data about the Quality of Life confi rm the records by other authors that usually children themselves evaluate their Quality of Life comparatively higher that their family members. CONCLUSIONS 1. The primary questionnaire shows that it is necessary to carry out further investigations about the social situation and Quality of Life in families with children who have developmental disorders. 2. It is a need to ensure a more determined selection of these children for rehabilitation services and give more information for the whole society on these issues.