An observed short-term motor memory effect for isometric force emission

Contrary to an earlier study, the accuracy of isometric force production is shown to fall under the influence of short-term motor memory, and in a manner quite similar to that previously observed for linear and rotary movement. Four paid male high school seniors pulled on a control stick with one of four designated target force bands. The target ranges were randomly varied in one phase of the experiment, and were the same for a series of consecutive responses in another. A red light came on after each response, and remained on for one of four durations; subjects were instructed not to respond while the light was on. Key variables accounting for the positive findings in the present experiment appear to be the availability of repetition (or massing), and the utilization of appropriate concurrent motor cues which are not supported by correlated visual cues.     

Signaling and affective functions of conditioned aversive stimuli in an appetitive choice discrimination: US intensity effects

Different groups of rats received Pavlovian aversive conditioning in which US-shock intensity (0.25–1.0 mA) and CS-US correlation (+, 0, ?) were factorially varied. Then, the CS was administered for each group contingent upon the reinforced response in an appetitive choice discrimination. Absolute and ratio measures of speed of running in the presence of the CS showed that, at the start of discrimination training, CS+ suppressed and CS- facilitated performance. However, later in training but prior to any evidence of choice learning, these speed effects reversed, with the magnitude of both the initial and reversed effects being a positive function of US intensity. Consistent with the reversal of speeds, associative (choice) measures showed that CS+ facilitated and CS- retarded discrimination learning relative to CSo and, within limits, these effects were also amplified by stronger USs. The findings suggest that a CS has both affective (motivational) and signaling (associative) functions and that both are influenced by US intensity; however, the CS's affective property is rapidly extinguished in the presence of a hedonicly different reinforcer, while leaving the CS's signaling property largely intact. Hence, the CS functions as a transformed signal for the new (appetitive) reinforcer and facilitates or retards learning by mediating the reinforcer's presence (CS+) or absence (CS-).     

A minicomputer system for recording the dynamic properties of individual operant responses

A PDP-12 is used to conduct operant experiments in which peak force, duration, time integral of force, and interresponse time may each serve as the criterion response property for reinforcement, and all four properties are simultaneously recorded as dependent variables. Calibration, acquisition and control, and data analysis programs are described.     

Power and speed components of individual differences in letter matching

Several previous studies have reported a correlation (typically around −.30) between standardized verbal ability test scores and name identity minus physical identity reaction times (NI-PI) in a letter-matching task. This correlation has usually been thought to reflect the mutual dependence of both measures on long-term memory access time. The present research was designed to assess Carroll's (1981) suggestions that: (a) NI — PI may not be the optimal formula for predicting standardized test scores from letter matching data, and (b) NI — PI may actually be related to the speed rather than the power component of standardized tests. Fifty-one subjects previously tested with a standardized reading test participated in letter-matching and word-reading tasks. The latter tasks required subjects to read words and specially constructed pseudowords. Power and speed measures were derived from the word-reading tasks and the standardized test on theoretical grounds (and supported by a principal components analysis). The results supported both of Carroll's contentions. NI — PI reaction time was related more to speed than power and the NI — PI statistic (as usually used) was not the optimum formula for predicting standardized test scores.     

Effects of parent enhancement therapy on the treatment outcome and generalization of a parent training program

The purpose of the present study was to examine the effectiveness of parent enhancement training in facilitating treatment and maintenance effects of a parent training program. Seventeen mothers and their clinic-referred noncompliant children were assigned to either a parent training alone group or a parent training plus parent enhancement therapy group. Fifteen mothers and their nonclinic children served as a quasi-control group. All clinic-referred mother-child dyads were treated individually by teaching the mother to reward compliance and other prosocial behavior and to use time-out for noncompliance. In addition, mothers in the parent training plus parent enhancement group also received treatment related to the following areas: parent's perception of their child's behavior, parent's personal adjustment, parent's marital adjustment, and parent's extrafamilial relationships. Assessment consisted of four home observations by independent observers prior to treatment, after treatment, and at a 2-month follow-up. The data indicated that the parent training plus parent enhancement therapy was more effective than parent training alone in changing child deviant behavior at posttreatment and in maintaining child compliance, child deviant behavior, parental rewards and parent contingent attention at follow-up. The control group did not change over the three assessment periods.     

Case studies of cognitive precocity: The role of exogenous and endogenous stimulation in early mental development

Case studies of the highly successful socialization commonly evident in the development of mentally precocious children may furnish an excellent source of heuristic information on how early experience contributes to development, without down-grading our understanding of how phenotypical development is jointly determined by the cumulative interactions of genotypical and experiential processes. Both the investigation and case study literature on bright children suggest that exceptional early abilities typically flourish in highly intellectual families who early involve their children in rational communication with adults and who intensively stimulate them cognitively during early development. Two general parental strategies emerge from the case studies, one following deliberate, systematic instruction, commonly involving play, and the other applying stimulation incidentally to intensive, continuing interaction between caregiver and child. Both strategies appear to be highly flexible, interactive, and child-oriented, however, and both overlap in many ways, drawing on combinations of similar specific techniques and following a similar sequence in which interactions become increasingly, but never totally, endogenously regulated, as the child masters in exceptional ways high level sybmbolic skills (especially reading but often writing and math), complex problem solving skills, and vast bodies of knowledge. Much of the difference between the strategies can be attributed to differences in parental belief systems that alternatively stress hereditarian or environmental bases for development.     

A review of functional assessment use in data-based intervention studies

We reviewed the extent and variety of functional assessment procedures used in behavioral intervention studies. The contents of six research journals dating from 1986 to 1992 were searched for articles describing single-subject intervention studies that targeted problematic social behaviors. Articles meeting this initial criteria were examined to determine if a functional assessment was conducted. If so, the various procedures comprising the functional assessment, types of interventions conducted, and demographic characteristics of study participants were recorded for each study. Results are compared to similar reviews of research dating from 1980–1985. Potential reasons for the paucity of studies incorporating functional assessment procedures are discussed. Finally, directions for future research and applied practice are provided.     

Hemispheric contributions to the integration of visual and auditory information in speech perception

Differential hemispheric contributions to the perceptual phenomenon known as theMcGurk effect were examined in normal subjects, I callosotomy patient, and 4 patients with intractable epilepsy. Twenty-five right-handed subjects were more likely to demonstrate an influence of a mouthed ward on identification of a dubbed acoustic word when the speaker’s fag vase lateralized to the LVF as compared with the RVF. In contrast, display of printed response alternatives in the RVF elicited a greater percentage of McGurk responses than display in the LVF. Visual field differences were absent in a group of 15 left-handed subjects. These results suggest that in right-handers, the two hemispheres may make distinct contributions to the McGurk effect. The callosotomy patient demonstrated reliable McGurk effects, but at a lower rate than the normal subjects and the epileptic control subjects. These data support the view that both the right and left hemisphere can make significant contributions to the McGurk effect.     

Three measurement problems

The aim of this essay is to distinguish and analyze several difficulties confronting attempts to reconcile the fundamental quantum mechanical dynamics with Born's rule. It is shown that many of the proposed accounts of measurement fail at least one of the problems. In particular, only collapse theories and hidden variables theories have a chance of succeeding, and, of the latter, the modal interpretations fail. Any real solution demands new physics.