Effects of pointing direction and direction predictability on event-related lateralizations of the EEG

In two experiments, we investigated hemispheric electroencephalography (EEG) differences in 9(12) healthy volunteers during pointing to lateral and central targets. The questions addressed were whether horizontal pointing direction and the predictability of pointing direction modulated hemispheric differences (event-related lateralizations of the EEG = ERLs). To vary pointing direction predictability, targets were displayed either randomly at one of nine different positions on a screen (random) or at the same horizontal position in five subsequent trials (sequenced) while vertical positions varied randomly. Event-related lateralizations (ERLs) varied with pointing direction. This was true across changes in target eccentricity and pointing distance. Foci of the ERLs were in premotor and posterior parietal cortex, which might reflect the critical involvement of these areas in the control of visually guided reaching. Direction predictability reduced the parietal and premotor ERL before pointing onset, probably reflecting a lesser effort in visuomotor transformation. Predictability also added an overlying N2pc component to the early ERL after target onset and increased direction effects during movement.     

An investigation of repetition and language processing in a case of conduction aphasia

A study is reported of a single case of conduction aphasia. A battery of tasks designed to investigate the parameters of the patient's severe repetition deficit is supplemented by tests of several language functions. The results provide extensive information on a wide range of the patient's language abilities and are used to evaluate the adequacy of four models that have been offered to account for conduction aphasia. An argument is made in support of the suggestion that the syndrome of conduction aphasia should be divided into two subgroups based on patients' ability to select and realize phonemes in speech output. It is concluded that the best explanation for the disorder of patients with repetition deficit but without significant speech output problems is the hypothesis that repetition ability is compromised by a pathological limitation of auditory-verbal short-term memory. This hypothesis is extended to account for the pattern of results obtained in the language tasks.     

Friendship Quality and Social Development

A high-quality friendship is characterized by high levels of prosocial behavior, intimacy, and other positive features, and low levels of conflicts, rivalry, and other negative features. Friendship quality has been assumed to have direct effects on many aspects of children's social development, including their self-esteem and social adjustment. Recent research suggests, however, that friendship quality affects primarily children's success in the social world of peers. Friendship quality could also have indirect effects, by magnifying or diminishing the influence of friends on each other's attitudes and behaviors. Having high-quality friendships may lessen children's tendencies to imitate the behavior of shy and withdrawn friends, but little evidence supports the hypothesis that high-quality friendships magnify friends' influence.     

Man as a Stabiliser of Systems: From Static Snapshots of Judgement Processes to Dynamic Decision Making

The feedback arrow extending from the response to the distal state in the lens model, together with Brunswik's dictum that the organism is a stabiliser of systems, implies a dynamic view of behaviour. This paper describes the main problems in the study of dynamic decision making: feedback delays and the feedback structure of the tasks. It also describes microworlds, a methodology for studying dynamic decision making in the laboratory. The results from experiments with microworlds show that subjects have problems compensating for feedback delays and side effects. These results are discussed in terms of Brunswik's distinction between perception and thinking.     

POLICY CONFLICT AS A FUNCTION OF POLICY SIMILARITY AND POLICY COMPLEXITY

B rehmer B. Policy conflict as a function of policy similarity and policy complexity. Scand. J. Psychol ., 1972, 13 , 208–221.—The experiment tests the hypotheses, derived from the results of earlier studies on policy conflict, that subjects with similar policies will decrease their agreement in a policy conflict situation, and that subjects with cognitively complex policies will decrease their agreement more than subjects with cognitively simple policies. The results support the hypotheses, and show that the decrease in agreement is due to the decrease in policy consistency which, in turn, is due to the manner in which the subjects change their policies in the conflict situation.