Learning the invariants of a perceptual motor skill

The concept of invariant relative timing has typically been associated with the concept of a generalized motor programme. The present study approaches the phenomenon of invariant relative timing from the perspective of learning. The underlying question of concern for this study was, "What is learned." The specific question was whether relative timing is one of the essential properties of movement that is learned during skill acquisition. In the present experiment, subjects were given extensive practice in learning to track and reproduce a criterion waveform using a joystick control for their response. In order to test whether subjects learn the relative timing of a movement, they were transferred to tracking waveforms that were identical to the criterion in terms of relative timing, but different in terms of absolute timing. Measurements were taken on all waveforms in two conditions: (a) in a pursuit tracking condition where subjects were temporally constrained by the stimulus, and (b) in a reproduction condition where subjects' timing was not constrained. The outcome from both conditions gives support to the idea that humans learn invariant relative timing during the acquisition of a motor skill.     

Spatial representation of a two-dimensional pattern

The purpose of this study was (a) to determine if vision and kinesthesis contribute differentially to the coding of a specific two-dimensional pattern and (b) to identify the effect of repetition on the spatial representation of this pattern. The reproductions of a specific pattern presented visually were compared with those of a pattern presented kinesthetically. The results showed that vision and kinesthesis had contributed equally to the coding of the directional components of the pattern. However, there was dominance of visual information over kinesthetic information when coding the distance between the intersecting points of the pattern, especially at the beginning of the process. Generally speaking, the visual or kinesthetic repetition, or both, have increased favourably the precision with which a specific pattern was reproduced in distance and direction.     

Assertiveness, social support, and psychological adjustment following spinal cord injury.

Tested predictions that assertiveness and social support would be significantly predictive of psychological adjustment. Furthermore, it was anticipated that assertiveness and certain types of social relationships would differentially interact to predict adjustment, since positive and negative effects of both variables have been noted in prior research. Trained raters interviewed 156 persons receiving either in-patient or out-patient care for cord injuries and administered measures of assertiveness, social support, depression and psychosocial impairment. Persons who reported a keen sense of responsibility for the welfare of another reported more depression and impairment. Persons reporting higher levels of support facilitating social integration and reassuring personal worth were less depressed. Several significant interactions between assertiveness and different social support relationships revealed beneficial and deleterious effects on depressive behavior and impairment secondary to the disability. Results are discussed as they advance theoretical understanding of the effects of assertiveness and social support. Implications for discriminate cue learning in assertion training for persons with physical disability are proposed.     

Anxiety induced by cardiac perceptions in patients with panic attacks: a field study

In panic disorder bodily sensations appear to play an important role as a trigger for anxiety. In our psychophysiological model of panic attacks we postulate the following vicious circle: individuals with panic attacks perceive even quite small increases in heart rate and interpret these changes as being catastrophic. This elicits anxiety and a further increase in heart rate. To evaluate this model we conducted a field study of 28 subjects with panic attacks and 20 healthy controls. A 24 hr ambulatory ECG was recorded and the subjects were instructed to report any cardiac perceptions during this period and to rate the anxiety elicited by these perceptions. The incidence of cardiac perceptions was about the same in both groups, but only subjects with panic attacks reported anxiety associated with such perceptions. Analysis of the ECGs revealed that in both groups heart rate accelerations preceded cardiac perceptions. Following cardiac perceptions, the healthy controls showed a heart rate deceleration, whereas the subjects with panic attacks had a further acceleration. This heart rate increase after cardiac perceptions was positively related to the level of anxiety elicited by the perceptions. These results provide clear evidence in support of the vicious circle model of panic attacks.     

Cognitive therapy. A 30-year retrospective

Several lines of investigation have evolved from the initial cognitive model of depression and other disorders. A large number of studies have tested the cognitive model using both clinical and laboratory-based strategies. In general, studies that most closely approximate the clinical conditions from which the theory was derived are supportive of the cognitive model of depression. Studies of anxiety and panic, although fewer, generally support the cognitive model of anxiety and panic. The application to the treatment of clinical problems has been promising and supports the concept of cognitive specificity. The cognitive therapy of depression has led to the utilization of specific cognitive strategies based on the specific conceptualizations of a given disorder to a wide variety of disorders. Study of abnormal reactions has also provided clues to the cognitive structure of normal reactions.     

Adolescent Smoking Behavior and the Recognition of Cigarette Advertisements1

In a study designed to assess the relationship between smoking status and correct identification of cigarette brands, junior high school students from two schools viewed cigarette and automobile advertisements with brand and model identification deleted. Results showed that adolescents with higher ad recognition scores were more likely to smoke cigarettes. In addition, a relationship was found between age and correct identification of cigarette advertisements, with older students identifying more ads correctly than younger students. No significant effects emerged for identification of automobile advertisements except for sex, with boys identifying more advertisements than girls. Additional findings indicated that even “experimental” smokers, who smoked as little as once per year, recognized significantly more cigarette advertisements than nonsmokers. These and other results are discussed in terms of their implications for prevention and policy issues. It is argued that society's allowance of printed cigarette advertising overlooks adolescents' heightened vulnerability to the kinds of appeals used in cigarette advertisements. Present policy also overlooks adolescents' relative unresponsiveness to the health risk information required in cigarette advertisements.     

Black Students' Reactions to Feedback Conveyed by White and Black Teachers1

The present investigation examined some processes mediating self-fulfilling prophecies among black students. Specifically, we hypothesized that feedback conveyed by black and white teachers would differentially influence black students' perceptions of how the teacher viewed their success/failure, effort, ability, luck and task difficulty. In addition, we hypothesized that negative feedback would affect perceptions of evaluations differently than positive feedback. Ninety black undergraduates participated in an experiment in which a black or white teacher (confederate) expressed one of five evaluative feedback responses to a student's score on an analogies test. The results provided partial support for the first hypothesis: black female students perceived white teachers as assessing their performance less positively: that is, they perceived them to underestimate their ability and the difficulty of the task. Negative feedback also led students to believe the teacher held an unfavorable but inaccurate impression of their ability and effort, and that the teacher underestimated the difficulty of the task. These findings suggest that black students—black females in particular—may assume that white teachers hold less favorable assessments of them than black teachers and all students may be sensitive to negative evaluations.     

After-contraction phenomenon: influences on performance and learning

Three experiments investigated the influence of an after-contraction phenomenon on the performance and learning of a dynamic force-production task. The after-contraction effect refers to an involuntary potentiation (induced by a sustained precontraction) that is thought to summate with voluntary motor commands to bias subsequent responding. The precontraction involved a brief (20 s) static contraction. The subsequent influence of the precontraction on a dynamic force-production task was assessed. Experiments 1 and 2 were aimed at demonstrating the direct impact of the precontraction intensity on the magnitude and decay of the after-contraction effect. The results indicated that as the intensity of the precontraction increased, the magnitude of the induced bias increased. In Experiment 3, the indirect influence on subsequent retention of varying the precontraction intensity during acquisition was investigated. The results indicated that the performance of subjects experiencing varying precontraction intensities during acquisition was inferior to that of subjects experiencing a constant precontraction intensity, but the performance of the varied precontraction intensities group was superior on the test of retention. It is noted that the paradoxical reversal from acquisition to retention is similar to that found in contextual interference experiments and may arise from similar mechanisms.     

Classifying by dimensions and reading: a comparison of the auditory and visual modalities

Children have difficulty learning to read alphabetic writing systems, in part, because they have difficulty segmenting spoken language into phonemes. Young children also have difficulty attending to the individual dimensions of visual objects. Thus, children's early difficulty in reading may be one sign of a general inability to selectively attend to the parts of any perceptual wholes. To explore this notion, children in kindergarten through fourth grade (Experiments 1, 3, and 4) and adults (Experiment 2) classified triads of spoken syllables and triads of visual objects. Classifying speech by common parts was positively related to reading and spelling ability (Experiments 1 and 4), but usually not to classifying visual stimuli by common parts under free classification instructions (Experiments 1 through 3). However, classification was more consistent across the visual and auditory modalities when the children were told to classify based on a shared constituent (Experiment 4). Regardless of instructions, performance on the visual tasks did not usually relate to reading and spelling skill. The ability to attend selectively to phonemes seems to be a "special" skill--one which may require specific experiences with language, such as those involved in learning to read an alphabetic writing system.     

Naming speed deficits in reading disability: multiple measures of a singular process

Speed of word identification is important in the theories of reading proposed by La Berge and Samuels (1974) and Perfetti (1985), and is substantially correlated with reading skill. However, there is controversy about whether disabled readers have a speed deficit that is restricted to the identification of printed words, or if instead, they have a more general speed deficit in retrieving names of even single digits. To investigate this issue, poor and average readers (N = 43) in grade 2 were assessed on several indices of speed of digit and letter naming, using both continuous-list and discrete-trial methodologies. MANCOVA indicated clear effects of reader group on discrete-trial latencies, as well as an interaction between reader group and the speed with which to-be-named items were presented. A series of hierarchical regression analyses explored the amount of shared variance between various measures of digit naming speed and five indices of reading skill. Latency for word identification shares considerable variance with latency for digit naming, and, in general, accounts for the shared variance of naming speed and several other measures of reading skill. Naming speed contributed variance in reading skill. Naming speed contributed variance in reading skill independently of measures of phonological awareness.