Hand Skill Asymmetry in Professional Musicians

Hand skill asymmetry on two handedness tasks was examined in consistent right-handed musicians and nonmusicians as well as mixed-handed and consistent left-handed nonmusicians. Musicians, although demonstrating right-hand superiority, revealed a lesser degree of hand skill asymmetry than consistent right-handed nonmusicians. Increased left-hand skill in musicians accounted for their reduced asymmetry. Musicians predominantly playing keyboard instruments demonstrated superior tapping performance than musicians playing predominantly string instruments, although they did not differ with respect to hand skill asymmetry. Since the diminished tapping asymmetry in musicians was related to early commencement but not duration of musical training, results are interpreted as an adaptation process due to performance requirements interacting with cerebral maturation during childhood.     

Changes of Cingulothalamic Topographic Excitation Patterns and Avoidance Response Incubation over Time Following Initial Discriminative Conditioning in Rabbits

Neurons in particular layers of cingulate cortex and in limbic thalamic nuclei exhibit peak firing rates in response to a positive conditional stimulus (CS+) in particular stages of discriminative learning. A given area is maximally activated by the CS+ in the initial, an intermediate, or a late stage of behavioral acquisition, and activation in all of the areas diminishes as training continues after the peak of activation occurs. Thus, the topographic distribution of activation in these areas depends on the stage of behavioral acquisition. The present study determined whether the acquisition-related changes of the topographic distributions of peak firing rates in CS-elicited activity are driven exclusively by the repetition of conditioning trials (i.e., practice) or may occur as well with the passage of time, similar to putative processes of memory consolidation. Multiunit activity was recorded in cingulate cortex and in the anterior dorsal (AD), anterior ventral (AV), and medial dorsal (MD) thalamic nuclei as rabbits learned to step in response to a warning tone (CS+) to prevent a scheduled foot-shock, and to ignore a different tone (CS-) not predictive of foot-shock. The rabbits received two training sessions, S1 and S2. S2 followed S1 immediately in one group of rabbits and after 48 h in a different group. Significant neuronal discharge increments occurred from S1 to S2 in the 48-h group but not in the 0-h group, for the areas (posterior cingulate cortex, AV thalamic nucleus) that previously showed only late-stage activation. Significant discharge increments occurred from S1 to S2 in the 0-h group but not in the 48-h group in areas (anterior cingulate cortex, the AD, and MD thalamic nuclei) that previously exhibited early stage activation. These results indicate that the trial-driven topographic distribution changes also occur with the passage of time after limited initial training. It is suggested that the trial-driven and time-related changes may have a common functional relevance concerning memory consolidation.     

Neonatal finger and arm movements as determined by a social and an object context

What kind of hand and finger movements are newborn infants preoccupied with, and how are these movements organized and controlled? These questions were studied in two experiments under three conditions: a social condition, in which the mother (in expt 1) or the experimenter (in expt 2) sat face to face with the infant; an object condition, in which a ball moving slowly and irregularly was presented to the infant; and a baseline condition (in expt 1) without ball or mother present. The size of the ball and the distance to it was chosen so that it approximately corresponded to the visual angle of the head of the model. Twenty-six neonates participated in the study ranging from 2 to 6 days of age at the time of observation. All infants were in an alert, optimal awake state during the experiments. The infants' finger movements were scored from video recordings. The result revealed a large variety of relatively independent finger movements. It was found that finger movements differed both in quantity and quality between the three conditions. There were many more finger movements in the social condition than in the object and baseline conditions. In addition, there were relatively more transitional finger movements and flexions of the hand in the social condition, and relatively more thumb-index finger activity and extensions of the hand in the object condition. Finally, the arms were more often forward extended in the object condition than in the social condition. The results support the notion that neonates show different modes of functioning towards people and objects.     

THE INFLUENCE OF ALCOHOL ON THE DETECTION OF LIGHT SIGNALS IN DIFFERENT PARTS OF THE VISUAL FIELD

6 subjects performed 12 times each a signal detection task lasting 40 minutes in parallel with a simple tracking task. They reported every 2nd second whether or not a signal was given in any one of 10 widely spaced locations. 0.5 or 1.0 ml alcohol/kg body weight (or no alcohol) was given 35–25 minutes prior to the task. Hit rate ( HR ) covaried with tracking efficiency; FAR was uniformly low. Variation in signal probability had no effect. Alcohol had a strong and uniform effect on 3 "experienced" subjects, reducing HR for all signals and producing a funneling effect, but had little effect on the performance of 3 "inexperienced" subjects. Motivational variables which may account for the individual differences are discussed.     

Sex differences in dealing with bureaucracy

The present study set out to test the popular stereotype of male communicative dominance in the context of dealing with bureaucracy. The study examined the responses of male and female officials of various bureaucratic organizations to different persuasive appeals activated by male and female clients. Log-linear analysis was used to reveal the relationships between sex composition of client-official dyads and outcome across types of organizations and types of persuasive appeal. Findings indicate that the sex of the client and the official significantly affected the outcome only when the type of appeal was taken into account. Although male and female clients did not differ in rates of successful outcome, males were more persuasive when using stronger (i.e., normative) appeals, and females were more effective when applying weaker (i.e., altruistic) appeals. The results demonstrate that no simple answer can be found to the old issue of sex-bound persuasiveness. The answer is highly dependent on a combination of contextual aspects, communicative tactics, and measures of response.This research was supported by the Research Authority of the University of Haifa. The author wishes to thank the late Joseph Shepher, Marilyn Safir, Maya Weinberg, and Brenda Danet and an anonymous reviewer for their helpful comments on an earlier version of this article, and to acknowledge the contribution of Henry Lever in providing the MULTC program.     

Minority influence and psycho-social identity

Social influence mechanisms are considered as also relevant to intergroup dynamics. In a social influence situation, approaching or retreating from the source's position also involves accepting or rejecting psycho-social identification with the source, implicating self-attribution of the set of characteristics stereotypical of the category or categories to which the source belongs. This conception allows one to account for some of the difficulties encountered by minorities in their attempts to diffuse innovations. An experiment illustrates this conception of influence. It is shown that the influence of a minority is greater when subjects are led to believe that they have in common with the minority numerous category memberships (five out of eight presented) than when they think they share fewer (one out of eight). The difference between these two inductions is, as expected, revealed to be most marked when the source is rigid and for those subjects displaying opinions already relatively close to those of the source and for whom therefore the matter of psycho-social identification is more salient.     

Visual perception of motion in depth: Application of a vector model to three-dot motion patterns

The aim of the present study was to identify spatial properties of three-dot motion patterns yielding perceived motion in depth. A proposed vector model analyzed each pattern in terms of common and relative motion components of the moving parts. The dots moved in straight paths in a frontoparallel plane. The Ss reported verbally what they perceived. The common motion did not affect the kénd of perceived event (translation or rotation in depth). Relative motions toward or away from a common point, i.e. concurrent motions, yielded perceived translatory motion in depth. Parallel relative motions toward or away from a common line generally yielded perceived rotation in depth. Complex motion patterns, consisting of concurrent and parallel relative motion components combined, evoked simultaneously perceived translation and rotation in depth under certain phase conditions of the components. Some limitations of the model were discussed and suggestions made to widen its generality.