Learning and memory of field independent-dependent individuals

It has been proposed that field-independent and field-dependent learners differ more in the processes they use than in the effectiveness of their learning or retention. The present article discusses alternative explanations which emphasize developmental differences and differences in efficiency of performance between field-independent and field-dependent learners. Review of the concept learning literature and some new data suggested that the greater effectiveness of field-independent learners was related to memory efficiency and the ability to conduct combinatorial analysis. Research concerning short-term memory and free recall was also examined. High information load, greater interference potential, and less subjective organization were suggested as factors which contribute to the less efficient memory of field-dependent learners.     

The consistent acceleration of lifted objects: implications for kinesthetic illusions and the perception of weight

In examining films of lifting movements in a study of the size-weight illusion (Davis & Roberts, 1976) a consistency was noted in the values obtained for the maximum accelerations of the objects lifted. While at first surprising, this finding can be embedded significantly in theories relating to kinesthetic illusions and the perception of weight and to theories on the control of general physical movement. This study was designed to confirm its existence. Twenty-four subjects were filmed lifting four objects differing in size, shape, substance, color, and weight. The film was analyzed frame-by-frame and the data were subjected to a two-way analysis of variance. Subjects, while differing from one another, were consistent in the maximum accelerations they applied to the three heaviest of the four objects. The accelerations of the lightest object differed significantly from the accelerations of the other three, but it seems likely that this was due to the experimental task itself.     

Group aversion by imaginal, vicarious and shared recipient-observer shocks

Sixty college students completed waiting control or alternative group aversion conditions, matched for severity and chronicity of nail-biting. Treatments spanned four sessions. Imaginai aversion (covert sensitization) clients visualized shocks to themselves. Vicarious aversion clients observed shocks to a trained model. A ‘hotseat’ format randomized a few actual shocks to each client with observing peers shocked on remaining trials. The predominant pattern of outcome and subjective impact results was as follows: Hotseat consistently best; vicarious typically second; imaginal usually third; controls worst. Clinical and conceptual issues are raised.     

Reading and cognitive capacity usage: Adjunct question effects

Cognitive capacity usage during reading was measured in two experiments. During reading of a 27-page passage on marine biology, text-relevant inserted questions, irrelevant questions, or no questions were answered by undergraduates. Cognitive capacity usage increased when text-relevant questions began but not when irrelevant questions began or when no questions were given. The increase in cognitive capacity usage was largest on pages immediately following questions. Cognitive capacity is used in the elaborative stages of text processing.     

Psychophysics of key-peck duration in the pigeon

The duration of the pigeon's key peck was differentially reinforced in either a trials or a free-operant procedure. Mean emitted peck duration was a power function of the duration required for food delivery to occur. The exponents of the power function differed considerably from those observed in earlier research involving longer duration responses in pigeons and other species. The coefficients of variation also did not correspond with those of the earlier research on other responses, nor did consideration of the durations actually reinforced resolve the differences. Duration was neither a function of response rate nor of intermittency of reinforcement. Key-peck duration was changed in an orderly way by differential reinforcement. However, it appeared to be more strongly determined by its duration in the absence of differential reinforcement than were longer duration responses.     

Clustering in the output of behavior

Pigeons exposed to fixed-interval schedules of 3, 5, 15, 40, and 120 minutes all maintained considerable variability in daily response rates for as many as 104 sessions. However, variations did not occur at random. Instead, rate in a session appeared dependent on those occurring previously. The series displayed a wave-like form arising because a group of high rates was followed by a group of low rates and vice versa. These sequential relations produced a curve having irregular periodicity, sometimes superimposed on a declining or rising linear trend. Whether grouping of response rates stemmed from experimental or extra-experimental sources was not determined. If the phenomenon was either totally or partially produced by the schedule itself, it suggests that response rate is determined by a combination of positive and negative feedback. Control by factors extrinisic to the experiment itself implies that response rate may be influenced by some rhythmic physiological process.     

Conditioned fear extinction and reinstatement in a human fear-potentiated startle paradigm

The purpose of this study was to analyze fear extinction and reinstatement in humans using fear-potentiated startle. Participants were fear conditioned using a simple discrimination procedure with colored lights as the conditioned stimuli (CSs) and an airblast to the throat as the unconditioned stimulus (US). Participants were extinguished 24 h after fear conditioning. Upon presentation of unsignaled USs after extinction, participants displayed significant fear reinstatement. In summary, these procedures produced robust fear-potentiated startle, significant CS+/CS- discrimination, within-session extinction, and significant reinstatement. This is the first demonstration of fear extinction and reinstatement in humans using startle measures.     

Changing perspectives on the benefits of newborn screening

The likelihood of benefit is fundamental to decision making about newborn screening. But benefit is construed in different ways by different stakeholders. This article begins with a review of benefit as considered historically by various expert panels and organizations. We then show how 78 conditions fared when experts recently rated them on benefit using a scoring system recommended by a task force of the American College of Medical Genetics. Finally, we analyze how benefit is reflected in the public comments submitted in response to the ACMG report. Results show that benefit has been and remains a core consideration for screening decisions. Historically the focus has been on improved physical health as a result of medical treatment; however, in only 4 of the 78 conditions rated does newborn screening prevent all negative consequences. In fact the majority of both core conditions (51.7%) and secondary targets (87.5%) recommended in the ACMG report were rated as having treatments that prevented only some negative consequences. All conditions rated had perceived benefits for family and society, but currently no conditions are screened on the basis of family or societal benefits alone. No agreed-upon threshold exists for what would be considered meaningful benefit, and stakeholder groups differ in their perceptions of benefit. We conclude by suggesting several key research studies needed to further inform public policy.     

An evaluation of the response modulation hypothesis in relation to attention-deficit/hyperactivity disorder

Several hypotheses related to Newman's (e.g., Patterson & Newman, 1993) response modulation hypothesis were examined among adolescents with attention-deficit/hyperactivity disorder (ADHD; n=18) and normal controls (n=23). Consistent with predictions, youth with ADHD committed more passive avoidance errors (PAEs) than controls during the latter trials of a computerized go/no go task with mixed incentives, and this effect remained significant or marginally significant even after common variance associated with variables that covary with ADHD (i.e., IQ, oppositional-defiant/conduct disorder [ODD/CD] symptoms, anxious/depressed mood) was removed. While a moderate inverse association was observed between PAE frequency and the amount of time spent viewing response feedback following punishment, both categorical (diagnostic) and dimensional analyses of ADHD symptomatology indicated that ADHD and reflection on punishment feedback are uniquely associated with PAE commission. Findings from this study are discussed in relation to models of disinhibition applicable to youth with ADHD.