Y haplogroups and aggressive behavior in a Pakistani ethnic group

Studies show that personality dimensions such as aggression are influenced by genetic factors and that allelic variants located on the Y chromosome influence such behavior. We investigated polymorphisms on the male-specific region of the human Y chromosome in 156 unrelated males from the same ethnic background, who were administered the Punjabi translation of the Buss and Perry Aggression Questionnaire that measures four aspects that constitute aggressive behavior, i.e. physical aggression, verbal aggression, anger, and hostility. A value of .85 for Cronbach's coefficient alpha indicates considerable internal consistency and suggests that the psychometric properties of the aggression questionnaire can be adapted for the Pakistani population. A mean score+/-SD of 69.70+/-19.95 was obtained for the questionnaire. Each individual was genotyped following a phylogenetic hierarchical approach to define evolutionary Y haplogroups. Five Y haplogroups that are commonly found in Eurasia and Pakistan comprised 87% (n=136) of the population sample, with one haplogroup, R1a1, constituting 55% of the sampled population. A comparison of the total and four subscale mean scores across the five common Y haplogroups that were present at a frequency > or =3% in this ethnic group revealed no overall significant differences. However, effect-size comparisons allowed us to detect an association of the haplogroups R2 (Cohen's d statistic=.448-.732) and R1a1 (d=.107-.448) with lower self-reported aggression mean scores in this population.     

Timing and stiffness in speech motor control of stuttering and nonstuttering adults

Twelve stutterers and 12 nonstutterers were investigated in order to measure speech movements of the jaw. They spoke the nonsense word /papapas/ with stress on either the first or second syllable and with three speech rates (fast, moderate, and slow). During these trials, jaw movements were analyzed with a selspot-like optical tracking system. It was shown that stutters and nonstutterers applied the same strategies for realizing jaw movements of accented and unaccented syllables. The first strategy (stiffness variation) was used to achieve fast jaw movements while the second strategy (timing) was used in order to realize jaw movements for accented syllables. These results were taken as evidence for the assumption that, in general, stutterers and nonstutterers used the same control strategies when speaking fluently. However, it was also evident that stutterers produced lengthened jaw opening and closing durations as well as reduced peak velocities and maximal opening and closing displacements. This deviating movement pattern was supposed to reflect motor compensations necessary to achieve fluent speech rather than anomalies of the speech neuromotor system.     

Acquired stuttering as a forerunner of motor-neuron disease

A case of acquired stuttering that included repetitions, blocks, prolongations, fillers, and, later on, also synkinesias is reported. This stutter turned out to be the forerunner of a motor-neuron disease.     

Learning categories by touch: On the development of holistic and analytic processing

The development of holistic and analytic processing often studied in the visual domain was investigated in haptics. Children 3 to 9 years of age and adults had to categorize haptic exemplars that varied systematically in four attributes (size, shape, surface texture, and weight). The subjects could learn the categories either analytically--that is, by focusing on a single attribute--or holistically--that is, in terms of overall similarity. The data show that even the youngest children learned the haptic categories far more often in an analytic mode than in a holistic mode. Nevertheless, an age trend was observed, referring to the attributes that the analytic learners used for their categorization. The children preferred substance-related attributes, especially surface texture, whereas the adults preferred structure-related attributes, especially shape. Thus, it appears that analytic and/or holistic processing in category learning develops in a similar manner in the visual and haptic domains.     

From rocks to graphs — the shaping of phenomena

Assuming an essential difference between scientific data and phenomena, this paper argues for the view that we have to understand how empirical findings get transformed into scientific phenomena. The work of scientists is seen as largely consisting in constructing these phenomena which are then utilized in more abstract theories. It is claimed that these matters are of importance for discussions of theory choice and progress in science. A case study is presented as a starting point: paleomagnetism and the use of paleomagnetic data in early discussions of continental drift. Some general features of this study are presented in formalized language. It is suggested that the presentation given is particularly suited for a semantic conception of theories. Even though the construction of scientific phenomena is the main topic of this paper, the view presented here is more adapted to realism than social constructivism.     

Semantic components in children's errors with pronouns

In the presence of the experimenter and two dolls, children were asked to respond to sentences containing pronous which required distinctions to be made on the basis of person, number, and gender, such as “Point tomy (your, his, her, our, their) feet.” Errors tended to maintain distinctions; for example,we was treated as if it meantI (maintaining first person) orthey (maintaining plural) more often than could be accounted for by a response-bias model. Furthermore, there were consistent individual differences in the kinds of distinctions that were difficult; some subjects has more trouble with number, others with person. These findings support the notion that errors made during acquisition result from dropping only part of the correct meaning, and they suggest that individuals may differ in the relative strengths of different components.     

THE ATTRACTIVENESS OF UNCERTAINTY

E ckblad G udrun . The attractiveness of uncertainty. III. Attractiveness of patterns in a guessing game. Scand. J. Psychol ., 1972, 13 , 292–305.—Visual displays, each consisting of three successive patterns of varying complexity and predictability, were presented as a guessing game to five groups of subjects. Six predictions about the development of task attractiveness over time were derived from the general hypothesis of an inverted U-shaped relationship between task attractiveness and the level of subjective uncertainty induced by the task. All predictions were confirmed.     

The use of computer graphics animation in motion perception research

The advantages and limitations of using computer-animated stimuli in studying motion perception are discussed. Most current programs of motion perception research could not be pursued without the use of computer graphics animation. Computer-generated displays afford latitudes of freedom and control that are almost impossible to attain through conventional methods. There are, however, limitations to this presentational medium. At present, computer-generated displays present simplified approximations of the dynamics in natural events. We know very little about how the differences between natural events and computer simulations influence perceptual processing. In practice, we tend to assume that the differences are irrelevant to the questions under study and that findings with computer-generated stimuli will generalize to natural events.     

Interval timing with gaps: gap ambiguity as an alternative to temporal decay

C. V. Buhusi, D. Perera, and W. H. Meck (2005) proposed a hypothesis of timing in rats to account for the results of experiments that have used the peak procedure with gaps. According to this hypothesis, the introduction of a gap causes the animal's memory for the pregap interval to passively decay (subjectively shorten) in direct proportion to the duration and salience of the gap. Thus, animals should pause with short, nonsalient gaps but should reset their clock with longer, salient gaps. The present authors suggest that the ambiguity of the gap (i.e., the similarity between the gap and the intertrial interval in both appearance and relative duration) causes the animal to actively reset the clock and prevents adequate assessments of the fate of timed intervals prior to the gap. Furthermore, when the intertrial interval is discriminable from the gap, the evidence suggests that timed intervals prior to the gap are not lost but are retained in memory.