Slow brain potentials in the CNV-paradigm

Slow brain potentials were recorded during the foreperiod of a reaction time task, and the effects of instructions governing the trade-off between speed and accuracy were investigated. One brain potential, a slow negative shift preceding S₂, was largely attenuated under accuracy instructions. It is suggested that this shift is dependent on a motor response and that its amplitude reflects the level of motor preparation. Two other brain potentials, a slow positive and a slow negative wave, seem to depend on the psychological properties of S₁. Enhanced amplitudes were found, when S₁ provides information, besides its warning function.     

Attention demands of movements as a function of their duration and velocity

The attention demands of initiating and controlling discrete movements were examined as a function of their movement time (MT) and average movement velocity. Experiment 1 showed that the attention required to execute a movement decreased as MT decreased, although Experiment 2 through independently manipulating MT and movement velocity, revealed that movement velocity is the key determiner of attention demands rather than MT. The attention demands of preparing a high velocity movement are greater than during its execution with the reverse being the case for relatively slow velocity movements. The results are compatible with the view that it is the initiation of error corrections that are attention demanding (Keele 1973).     

Optic array determinants of apparent distance and size in pictures

This study explored whether special mechanisms are operative in picture perception to correct for the distortion that occurs when pictures are viewed from the wrong station point. Five photographs were taken of a layout composed of two same-sized dolls positioned at different distances on a flat untextured ground. Perspective differences existed between the photographs as a function of varying the distance of the camera to the layout. Each picture was viewed from five station points along the normal by 12 adults who estimated the relative magnitude of the depth interval between the dolls and judged whether the rear doll was objectively smaller, larger, or the same size as the front doll. No evidence was found of a compensation mechanism operating to stabilize the pictured layout. Distance and size judgments were affected in a manner that was consistent with what would occur if an actual layout and the conditions under which it were viewed were similarly transformed.     

Social workers in schools - the teachers' response

73 teachers who had participated in a school-based social work scheme completed a questionnaire which recorded their attitudes to the programme. All the teachers had been directly involved in consultations about pupil management with six specially trained social workers. The response of the teachers suggest that even with a limited amount of contact, social workers can make a positive contribution to teacher practice. The personal characteristics of the teachers did not appear to affect their responses.     

APGA Members in Retirement and Their Advice to the Rest of Us

Retired and emeritus members of APGA answered a survey on their lives in retirement, their recommendations to APGA concerning activities for retired members, their suggestions for training programs in geriatric counseling, and their advice to younger counselors on planning for retirement. The results indicate most retired counselors are financially comfortable and continue to lead happy and productive lives in retirement. In their recommendations the counselors emphasized the need to remain active and stressed the importance of planning well in advance of actual retirement. They had many specific suggestions for APGA programming.     

An animal model of the hyperactive-child syndrome suitable for the study of the effects of food additives

This report describes the use of an animal model for testing the relationship between the effects of ingesting food additives and hyperactivity. Telomian × beagle hybrid dogs were chosen as subjects because this breed has been observed to exhibit behavior seen as analogous to the hyperactivity of children. Two studies were conducted by adding or deleting butylated hydroxyanisole and Food, Drug, and Cosmetic red dye number 40 to the diet of each dog. A test of sitting was performed to measure the level of activity. While a relationship was not observed between the ingestion of the additive and the level of activity, several issues pertaining to the use of the animal model became apparent. These issues and the use of animals for future research in this area are discussed.     

Meaning-dependent ratings of imagery,age of acquisition,familiarity, and concreteness for 387 ambiguous words

The problem of word ambiguity has generally been overlooked in compiling lists of words measured on various attributes. In this study, rating measures were obtained on the meanings of 387 words, the ambiguity of which had been established empirically. Imagery, age-of-acquisition, concreteness, and familiarity ratings are reported for each meaning, together with an index of meaning dominance. The results suggest that the most dominant meanings tend to be the most imageable, concrete, familiar, and earliest acquired. Generally satisfactory correlations with other norms were obtained.     

A mutual inductance shocker

A simple dc shock-generating device is described. The principle of operation relies upon the mutual inductance effect between the primary and secondary coils of a transformer.     

The effects of delayed and displaced visual feedback on motor control

Developments in television technology have made possible new approaches to the study of the role of visual feedback in motor control. In two experiments using a special videodisc recording and playback system, the effects of delaying for 66 msec a subject's view of his own hand during a target-directed movement was investigated. The observed effects of such visually delayed feedback compared to spatially distorted feedback produced by prisms led to three major conclusions: (a) despite the behavioral similarity (overshooting) induced by the two kinds of altered feedback, the role of each in the visual-motor control loop is different; (b) adaptation to and the after effect of the two kinds of altered feedback are based on different control mechanisms (c) the processing and use of visual information in hand control requires less time than previous experiments have indicated.