Response selection and initiation in speeded reactions: a pupillometric analysis

Three studies are described in which the task-evoked pupillary response is recorded during simple and disjunctive reactions in order to examine its contribution as a measure of the motoric and cognitive aspects of performance in these tasks. In simple reactions a pupillary dilation began about 1.5 sec before the imperative stimulus and peaked about 1 sec after the stimulus. The rate of dilation was inversely related to the interstimulus interval. In disjunctive reactions, both "Go" and "No-Go" responses elicited significant dilations but the No-Go dilation was smaller than the Go dilation. When the response was delayed 2.5 sec after the discrimination stimulus, the dilation to both Go and No-Go responses was much reduced. The pupillary response related to response selection was estimated at 55% of that associated with motor preparation and execution. The probability of responding was found to affect the amplitude of the dilation to No-Go responses but not that to Go responses. The data point to a significant contribution of preparatory motor processing in No-Go reactions and to an overlap between decisional and motoric processing in disjunctive reactions.     

Detection and recognition: Concurrent processes in perception

In two experiments, event-related brain potentials (ERPs) were recorded while subjects performed a simultaneous detection and recognition task. Ten subjects listened to pure tones in noise and reported both whether a target tone had occurred (using a four-category confidence rating scale) and whether the target was one of two (Experiment 1) or four (Experiment 2) tones differing in frequency. The amplitudes of three ERP components were found to be differentially related to detection and recognition performance. The early N100 component varied with processing related only to detection, while the late P300 varied with both detection and recognition, and a later slow positive shift varied only with recognition and not with detection. While the latenciee of both N100 and P300 increased for less confident target detections, there were no differences in the latencies of these ERP components between correctly and incorrectly identiffed targets. Recognition performance was above the level expected by chance even when subjects reported that no target had been presented. The results indicate that brain potential components can be used to disclose temporal features of the processing of a stimulus by the nervous system and support the view that detection and recognition are partially independent, concurrent processes in perception.     

Reaction Time of Healthy Older Adults Is Reduced While Walking Fast

Attentional requirements of walking at various speeds in older adults were examined. Twenty healthy older adults (69.9?±?2.77?years; 8 males) were asked to walk a distance of 10?m at a self-selected speed as well as 30% quicker and 30% slower. Concurrently, reaction time (RT) was evaluated by having participants respond as fast as possible to randomly presented auditory stimuli. Results reveal that an accelerated walking speed generated faster RT than slow and self-selected speeds, while no difference was found between the latter. Faster RTs during an accelerated walking speed may have been precipitated by the reduced equilibrium demands of the task.     

On the subject of homosexuality: What Freud said

The article explores Freud's writing on homosexuality, from his early hypotheses, expressed in his letters to Fleiss to his last observations in The Outline of Psychoanalysis, published in 1940 after his death. We trace the continuities as well as changes in his thinking, and have organized the paper conceptually, under the headings: 1) Bisexuality 2) Narcissism and Object choice, 3) On Normality and Pathology, and 4) The Quantitative factor and Aggression. We show that Freud was the first to confirm the existence of homosexualities, that he offers no black and white solution to the question of normality and pathology, although he contributes to the understanding of the vehemence that surrounds the subject, and that, in the considerable body of work, he has offered a rich and varied foundation for further thinking on the subject.     

Anatomic Magnetic Resonance Imaging of the Developing Child and Adolescent Brain and Effects of Genetic Variation

Magnetic resonance imaging studies have begun to map effects of genetic variation on trajectories of brain development. Longitudinal studies of children and adolescents demonstrate a general pattern of childhood peaks of gray matter followed by adolescent declines, functional and structural increases in connectivity and integrative processing, and a changing balance between limbic/subcortical and frontal lobe functions, which extends well into young adulthood. Twin studies have demonstrated that genetic factors are responsible for a significant amount of variation in pediatric brain morphometry. Longitudinal studies have shown specific genetic polymorphisms affect rates of cortical changes associated with maturation. Although over-interpretation and premature application of neuroimaging findings for diagnostic purposes remains a risk, converging data from multiple imaging modalities is beginning to elucidate the influences of genetic factors on brain development and implications of maturational changes for cognition, emotion, and behavior.     

Passion for Driving and Aggressive Driving Behavior: A Look at Their Relationship

The purpose of the present research was to investigate the relationship between passion for driving and aggressive driving behavior in 3 studies. Study 1 examined the association between passion and aggressive driving behavior in a sample of undergraduate students. Results showed that an obsessive passion for driving was associated with aggressive driving behavior, while harmonious passion was not. Study 2 replicated these results with an ecologically valid sample of community‐dwelling drivers. Finally, Study 3 replicated the results obtained in Studies 1 and 2 in a laboratory setting using a driving simulator under controlled frustrating driving situations with judges' assessment of aggressive driving behavior. Study 3 also showed that the emotion of anger mediated the obsessive‐passion/aggressive‐driving‐behavior relationship.     

Sex,sex roles,and response styles for negative affect: Selectivity in a free recall task

Study 1 examined how responses to negative affect may be influenced by sex differences in response styles [S. Nolen-Hoeksema (1987), “Sex Differences in Unipolar Depression: Evidence and Theory,” Psychological Bulletin, Vol. 101, pp. 259–282] and situational norms. Male and female experimental subjects were led to experience negative affect by reading and rating sad stories, and were then given either nonnormative or normative feedback. Nonnormative subjects were informed that their story ratings were more negative than other participants' ratings. Normative subjects were informed that their ratings were similar to others' ratings. For nonnormative subjects, men recalled less negative material than women, suggesting that response styles are most apparent when negative affect is considered inappropriate. As both sex and sex role orientation are predictive of response styles, Study 2 examined the hypothesis that both sex and sex role orientation are predictive of recall in a manner similar to sex in Study 1. Male and female subjects high and low in masculinity and femininity were assigned to negative-nonnormative and neutral affect conditions. In addition to a marginally significant sex effect consistent with Study 1, results revealed that high-masculinity individuals tended to recall more positive material in the negative-nonnormative condition than in the neutral affect condition. In contrast, low-masculinity individuals recalled less positive material in the negative-nonnormative condition than in the neutral affect condition. The implications of this research for the impact of negative affect on recall are addressed.