Electrocortical Responses to ecologically relevant visual stimuli among professional drivers with and without cardiovascular disease

Electrocortical responses were assessed using two simulated aspects of visual signals encountered in traffic: the Glare Pressor Test (GPT) and Event-Related Potential Avoidance Task (ERPAT) among four groups of male professional drivers: 12 with ischemic heart disease (IHD), 12 hypertensives, 10 borderline hypertensives, 34 who were apparently healthy and 23 nonprofessional driver healthy control subjects. The blood pressure (BP) responses immediately after the ERPAT were also measured. There was a significant between groups effect for the amplitude of the target N2 component in the ERPAT (p=0.02), with the lowest means among the drivers with IHD and the highest among those with hypertension. Drivers with IHD also showed the highest diastolic BP reactivity to the ERPAT. Significantly more than the expected number of drivers with IHD failed to recover alpha activity after the first glare impulse of the GPT. Professional drivers who failed to recover baseline levels of alpha activity after the GPT showed a significantly smaller N2 amplitude compared to those who recovered (p=0.01). There was a positive correlation between abundance of alpha activity at rest with P300 amplitude (p=0.02). An inverse relation was found between number of work hours behind the wheel and the amplitude of the target P300 (p=0.04). Results are interpreted in light of recent advances concerning integrative mechanisms of defence versus vigilance response patterns. The findings in this study justify further applications of these psychophysiologic methods to assess the relationship between simulated signals of the work environment and mechanisms of cardiac risk in this occupational group.     

Abrupt luminance change pops out; abrupt color change does not

The present studies investigated whether an isoluminant color change pops out, indicating that it can be detected preattentively in parallel. The results of Experiment 1 show that an abrupt color change presented on an equiluminant background does not pop out. However, when the color change is accompanied by a small luminance change, it does pop out. The results of Experiment 2 show that the pop-out is fully due to the luminance change and not to the color change. The results of Experiments 3 and 4 show that the failure to find a pop-out at equiluminance cannot be attributed to the limited temporal resolution for chromatic stimuli. The results of Experiment 5 show that particular search strategies cannot be responsible for the obtained results. The results are in agreement with physiological findings regarding the parvo and magno systems.     

Legal and ethical issues in conducting research on alcohol and drug use with children: a reaction to Havey and Dodd

Although research pertaining to alcohol and drug use by children clearly is very important for our field, it also presents a number of difficult ethical and legal challenges. In this article we react to Havey and Dodd's research (1995, this issue), commenting specifically on their use of a passive consent procedure. Problems with this aspect of their methodology are reviewed in relationship to best research practices, the U.S. Constitution, case law, federal statutes, and the ethical codes of the American Psychological Association, the National Association of School Psychologists, and the American Educational Research Association.     

MENTAL PROCESSES INVOLVED IN RAPID LOGICAL REASONING

S medslund , J. Mental processes involved in rapid logical reasoning. Scand. J. Psychol ., 1968, 9, 187–205.—Approximate reaction times of adult subjects were recorded in three studies of addition and subtraction of units, and in one of transitive inference. Transformations such as from 'V has more than H' to 'H has less than V' were found to be important determinants of RT in additionlsubtraction. Under some conditions subjects preferred to combine the first two elements in a triad of operations first, under other conditions they seemed to select inversions (V + 1 & V−1) first. Symmetries (V + 1 & H +1) were apparently never preferred. All transitive tasks seemed to be converted into normal form (A>B ∓ B>CorA < B & B < C) before they were solved.     

Perceived angle of oscillatory motion

The general background of these experiments was the fact, known from e.g. trapezoidal window experiments, that rotary motion under certain conditions is perceived as oscillation. The aim was to identify the variables that determine the perceived angle of this oscillatory motion. Different shapes and different methods of generating the stimulation were used. No effect was obtained when varying the degree of trapezoidality of trapezoids, the location of the axis of rotation, the size of the stimulus pattern and the speed of the change. Both the occurrence and the perceived angle of oscillation was effected, however, by the width-height ratio of the stimulation, a decreasing ratio giving increasing occurrence of oscillation and decreasing perceived angle.     

Some relevant factors in the transfer of material from short-term to long-term memory

The relationship between short-term memory (STM) and long-term memory (LTM) for digits was investigated by means of a Hebb-type experiment, viz. a presentation of a series of nine-digit numbers, in which a certain number recurs at intervals. Improvement in performance, with regard to the critical, or recurring, number was found when the rehearsal grouping was three-three-and-three, but was absent when there were no opportunities for rehearsal or when the rehearsal strategy was grouping five-and-four or searching for systematic numbers.

However, if an overt recall response was given on each occasion the recurring number was presented, improved performance was found even with rehearsal stratgegy five-and-four.

The conclusion was drawn that rehearsal is the main transferring mechanism from STM to LTM, with the occurrence of an over recall response as a subsidiary factor.     

THE ACQUISITION OF CONSERVATION OF SUBSTANCE AND WEIGHT IN CHILDREN

S medslund , J. The acquisition of conservation of substance and weight in children. I. Introduction. Scand. J. Psychol ., 1961, 2 , 11–20.—This is the first in a series of articles concerning the problem of how children acquire the concepts of conservation of substance and weight. The four alternative interpretations of nativism, maturation theory, learning theory and equilibration theory are discussed. It is concluded that nativism and maturation theory do not account for the known facts. An important issue is whether the concepts are established by external reinforcement (learning theory) or by a process of inner equilibration, as maintained by Piaget.     

The relationship of young adolescent Children's Depression Inventory (CDI) scores to their social and cognitive functioning

The relationship of young adolescents' scores on the Children's Depression Inventory (CDI) to subjective and objective indices of their social and cognitive functioning was examined. Subjects were 89 young adolescents (11–15 years old), their parents, and their social studies teachers. The correlations of adolescents' CDI scores with recent school grades, objective ratings of overt social behavior, and measures of adolescent social and cognitive competence as perceived by the adolescent, both parents, and the teacher were examined. CDI scores were significantly and negatively correlated with school grades, behavioral ratings of positive social communication, and adolescent, mother, father, and teacher perceptions of the adolescents' social and cognitive competence. The relationship of these findings to those of other CDI validity studies is discussed.This research was supported, in part, by the William T. Grant Foundation and the University of Georgia's Institute for Behavioral Research.