Age influences domestic dog cognitive performance independent of average breed lifespan

Animal Cognition - Across mammals, increased body size is positively associated with lifespan. However, within species, this relationship is inverted. This is well illustrated in dogs (Canis...     

Where and when to look: Sequential effects at the millisecond level

Attention, Perception, & Psychophysics - Learning and imitating a complex motor action requires to visually follow complex movements, but conscious perception seems too slow for such tasks....     

Testosterone and cortisol responses to competitive fighting in human males: A pilot study

Serum testosterone and cortisol levels were measured by radioimmunoassay in 14 young male judo competitors, in samples taken 10 minutes before and 45 minutes after two different procedures. The first involved physical exercise and the second competitive fighting. Both procedures were of 5 minutes duration and sessions took place at the same time (between 10:00 A.M. and 12:00 P.M. local time) but on different days. Comparing the two situations over all subjects revealed that testosterone increased after exercise and decreased slightly after Competition. Between subject comparisons suggested that contrary to previous claims, winning or losing did not significantly change the testosterone and cortisol levels. Comparisons of subjects who were members of the Regional Team with individuals who were not part of that group confirmed that members increased their testosterone levels after competition, whereas the nonmembers showed a significant decrease. Moreover, success of the individuals, in their sporting record, correlated positively and significantly with the changes of testosterone observed during the competition. These preliminary results suggest that previous personal experience of success can influence the pattern of the psychoendocrine response to a contest situation.     

The structure of language abilities at 4 years: a twin study

Normal language development was studied in 310 pairs of 4-year-old twins born in the United Kingdom in 1994. Twins were assessed individually in their homes on a diverse battery of language and nonverbal measures. Rotated factor analyses indicated the presence of a general Language factor (L) as well as a general Nonverbal (NV) factor. Moderate genetic influence was found for both L and NV abilities. Bivariate genetic analysis estimated a genetic correlation of .63 between L and NV abilities, implying that over half of the genetic influence on L overlaps with genetic influence on NV. These results suggest that at age 4, genetic influences on individual differences in language overlap substantially with genetic influences on individual differences in other cognitive abilities, although perhaps less so than later in development.     

Behavioral consequences of fluctuating group success: an internet study of soccer-team fans

The authors tested the hypothesis that fans of a sports team avoid private contact with their team when it is unsuccessful (cutting off reflected failure, or CORF), whereas fans actively seek private contact with their team when it is successful (basking in reflected glory, or BIRG). During the 2nd half of the 1999-2000 soccer season, the authors registered the number of visitors who had surfed the Web sites of 16 Belgian and 18 Dutch 1st-division teams on the 1st working day following a championship game. The authors obtained 586 valid measurements, which were transformed into z scores for each team separately. In line with the hypothesis, there were significantly more visitors after the teams won (BIRG) than after they lost (CORF). The effects of game outcome were not mediated by pregame expectations or by the size of the wins or losses.     

Deformation of the useful visual field with state of vigilance,task priority,and central task complexity

In a dual-task situation, peripheral perception can deteriorate due to different variables related to the experimental situation, such as central task complexity and the relative priority given to the two tasks. Recent studies have also shown that individual characteristics (such as the state of vigilance) can alter the useful visual field. The ability to perceive signals presented at different places in the visual field decreases in situations that lead to episodes of low vigilance. In Exp. 1, 27 subjects (18-29 years) had to perform a monotonous and prolonged dual-monitoring task involving central and peripheral vision. The test was carried out with two different sets of instructions regarding priority: the more important task was either the central task or the peripheral one. In Exp. 2, 18 subjects (18-30 years) performed the same test, but this time with two levels of complexity of the central task, either a simple monitoring activity or the same monitoring task coupled with a counting activity. Elliptical interpolation of the data enabled assessment of the deformation of the useful visual field in both experiments. The analysis of the parameters of the elliptical model indicated that the useful visual field mainly shrinks on the vertical axis, as the individual becomes drowsy. The useful visual field also shrinks on the horizontal axis when the peripheral task has priority and the monitoring activity is prolonged, or when the central task is complex.     

Unrealistic optimism and perceived control: role of personal competence

This work analyzed the effects of unrealistic optimism in the interaction between the emotional valence of future events, the perception of control over these events, and the person with whom one compares oneself. It was hypothesized that, if the person of comparison is judged as very competent, a pessimistic bias should be produced. Likelihood of four different types of events (positive and controllable, positive and uncontrollable, negative and controllable, and negative and uncontrollable) were rated by 133 university students (22 men and 111 women) for themselves, for an average student, for their best friend, and for a bright friend. A pessimistic bias was observed on the relative likelihood of the events when the comparison was made between oneself and a competent and bright friend, when events were perceived as controllable, especially positive ones. Not enough is known, however, to provide meaningful interpretation at present; that must await further data and theoretical development.     

The competition-among-relations-in-nominals theory of conceptual combination: implications for stimulus class formation and class expansion

One way in which new concepts are added to the conceptual system is through conceptual combination. The competition-among-relations-in-nominals (CARIN) theory (Gagné & Shoben, 1997) proposes that conceptual combination involves specifying a thematic relation (e.g., noun MADE OF modifier) to link the constituent concepts (e.g., chocolate and bee). This theory claims that relations have different strengths for various concepts that correspond to how often a modifier and relation have been paired in previous encounters with combined concepts and that this relational knowledge strongly affects the ease with which combined concepts can be formed. A mathematical model that incorporates key claims of the theory is presented, and empirical findings that are relevant to evaluating the CARIN theory are reviewed. The parallels between the CARIN theory and approaches to stimulus class formation are also discussed.