Kinematic information feedback for learning a rapid arm movement

The experiments reported examine the notion that knowledge of results (KR) about the outcome of a response does not provide the necessary information for optimizing performance in many skilled activities. The effect of traditional KR was contrasted with various kinematic feedback parameters in the acquisition of a single degree of freedom response requiring the minimization of movement time. Experiment 1 showed that the presentation of discrete kinematic information feedback (peak accelaration, time to peak accelaration, and velocity at the target location) did not facilitate performance over movement-time KR. Experiment 2 revealed that presentation of a computer generated velocity-time representation of the movement as terminal information feedback improved performance over movement-time KR. This facilitation occured even without knowledge of the kinematics for optimal performance. The findings suggest that the task criterion specifies the appropriate information feedback for skill learning in that the information feedback must match the constraints imposed upon response output.     

A trilevel approach to motivators for retraining

A three-level taxonomy of the reasons for vocational retraining is proposed. The compliance level is characterized by the necessity of immediate acquisition of a profession. At the identification level retraining is motivated by the need for a satisfying self-definition through the profession. With the internalization level the profession is chosen to suit one's capabilities and self-fulfillment. Participants in retraining programs filled out the following questionnaires: locus of control, vocational maturity attitudes, level of motivation for retraining, evaluation of the retraining program, and new job satisfaction. Internalization level motivators positively correlated with internal locus of control and vocational maturity attitudes. No such correlations were found for identification or compliance level. Subjects who retrained because of high compliance motivation were less satisfied by the programs, more inclined to drop out, and less apt to seek employment in jobs for which they had retrained than those high on the other levels of motivation. No difference in job satisfaction was determined for those who did work in the new profession.     

Mothers' responses to the cries of normal and premature infants as a function of the birth status of their own child

Mothers of premature and full-term infants viewed and heard videotapes of premature and full-term infants. The onset of crying by both infants elicited physiological arousal (evident in blood pressure, skin conductance, and heart rate increases) in the adults. The mothers of premature infants responded with especially marked arousal to the infants' cries. These mothers also reported that they were more attentive and alert while the infant was crying. The subjects responded similarly to the cries of full-term and premature infants. Mothers who described their own baby as easy exhibited a lower increase in diastolic blood pressure and heart rate, and reported being more alert, attentive, and willing to interact with the stimulus babies than those whose own baby appeared “difficult.”     

Language in a congenitally acallosal brain

A case of complete callosal agenesis shows two limitations of cognitive development. The first, a discrete loss of syntactic-pragmatic function within the language domain, may or may not be associated with anomalous cerebral lateralization of speech and language; its neural basis is unknown. The second deficit, an inability to identify free-field or dichotic speech sounds with overlapping temporal-acoustic properties, appears due to a nonlinguistic limitation of the acallosal brain, the inability to suppress ipsilateral information.     

Voice initiation and termination time in stuttering and nonstuttering children

Voice initiation time (VIT) and voice termination time (VTT) was measured in seven stuttering and eight nonstuttering children ranging in age from 4 yr, 6 mo to 6 yr, 10 mo. The experimental task was the production of /a/ in response to a 1000-Hz pure tone. Voice initiation time was defined as the period of time elapsing between the onset of the auditory stimulus and the onset of the subject's response of /a/, as displayed on an oscilloscope. Voice termination time was defined as the latency between termination of the stimulus tone and the point at which the oscilloscopic signal decreased by 90%. No statistically significant differences were found between the two groups with respect to either VIT or VTT. In addition, no apparent relationships were present among VIT, VTT, or stuttering severity.     

Short-term memory deficits in reading disabled children,in the absence of opportunity for rehearsal strategies

Two groups of reading-disabled (RD) children were compared with controls (age- and IQ-matched competent readers), on a serial running memory task. The unknown (to the subject) length of the serial lists coupled with high rates of presentation, made it impossible for the children to use systematic rehearsal strategies in this task. Both groups of RD children performed reliably worse than their controls. From the data, it is argued that the short-term memory deficits exhibited by the RD children should not be attributed to an inability to rehearse, nor to an inability to encode (recognize) items, but rather to an inability to encode serial items in the form of serial phonological patterns.     

An analysis of speech perception in word deafness

A patient with a rather pure word deafness showed extreme suppression of right ear signals under dichotic conditions, suggesting that speech signals were being processed in the right hemisphere. Systematic errors in the identification and discrimination of natural and synthetic stop consonants further indicated that speech sounds were not being processed in the normal manner. Auditory comprehension improved considerably however, when the range of speech stimuli was limited by contextual constraints. Possible implications for the mechanism of word deafness are discussed.