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D C Shapiro

Publications and source records attributed to D C Shapiro.

4 recordsLinked to original sources
PubMed1989

Summary knowledge of results for skill acquisition: support for the guidance hypothesis.

Summary knowledge of results (KR) involves the presentation KR for each of a set of trials (e.g., 10) only after the last trial in the set has been completed. Earlier, Lavery (1962) showed that, relative to providing KR after each trial, a 20-trial summary KR was detrimental to performance in a practice phase with KR present but was beneficial for a no-KR retention test. Using a relatively simple ballistic-timing task, we examined summary lengths of 1 (essentially KR after every trial), 5, 10, and 15 trials, searching for an inverted-U relationship between summary length and retention performance as predicated by a guidance hypothesis for KR. During acquisition when KR was present and being manipulated, all groups showed improvements in performance across practice, while increased summary lengths generally depressed performance. However, in a delayed no-KR retention test, there was an inverse relation between the summary length in acquisition and absolute constant error on the retention test. A guidance hypothesis is favored to explain how, relative to immediate KR, long KR summaries can provide detrimental effects in acquisition while enhancing retention performance.

Adult↗
PubMed1988

The coordination of limb movements with different kinematic patterns.

The principles underlying the coordination of limb movements with different spatiotemporal features were explored. After an initial training session in which the same unidirectional movement had to be performed with both upper limbs, subjects attempted to coordinate two different movements in a second session, i.e., the learned unidirectional movement in the left limb and a new double reversal movement in the right limb. The findings uncovered a wide variety in patterns of interlimb dependence among and within subjects, going from a high degree of dependence to relative independence. The relationship between limbs was studied by means of a detailed analysis of the displacement and acceleration patterns and the electromyographic activity of the major muscles involved. The general underlying principle that appeared to account for the diversity in movement organization was this: higher independence between limb movements is achieved when subjects initiate the movements to be coordinated successively. This asynchrony in movement onset can possibly be viewed as an attempt to safeguard against interference.

Acceleration↗
PubMed1979

Coordinating visual and kinaesthetic memory codes.

Four experiments examined the Connolly & Jones (1970) model which postulates that translation between modalities in the cross-modal paradigm occurs before storage in short-term memory. In general, the results provided no support for the translation notion. Delaying until the end of the retention interval knowledge of the reproduction mode failed to produce a matching performance decrement. Subjects were able to maintain the code of original presentation through the retention interval even when they did not expect reproduction to be in this mode. In addition, the asymmetry in the cross-modal matching of visual (V) and kinaesthetic (K) information, whereby K-V performance is more accurate than V-K performance, was found to occur only under certain visual display conditions. The implications of these findings for general models of cross-modal translation were discussed.

Cues↗