Search results for "SYSTEMS"
showing 10 items of 11952 documents
Both contextual regularity and selective attention affect the reduction of precision‐weighted prediction errors but in distinct manners
2020
Predictive coding model of perception postulates that the primary objective of the brain is to infer the causes of sensory inputs by reducing prediction errors (i.e., the discrepancy between expected and actual information). Moreover, prediction errors are weighted by their precision (i.e., inverse variance), which quantifies the degree of certainty about the variables. There is accumulating evidence that the reduction of precision-weighted prediction errors can be affected by contextual regularity (as an external factor) and selective attention (as an internal factor). However, it is unclear whether the two factors function together or separately. Here we used electroencephalography (EEG) …
Effect of Practice, Mapping, Stimulus and Size on String Matching
1987
The same-different discrepancy on a matching task on which the subject had to determine the number of common elements (physically identical and appearing in the same position) between two strings of size 1 to 4 was investigated. Manipulated also were the type of presentation (fixed or varied sets), amount of practice (four blocks), and type of stimulus (letters, words). Reaction times for pure positive responses (all same at each level) were faster than negative responses (all different), confirming the usual discrepancy shown in previous studies. The discrepancy was smaller for well-learned sets (fixed sets) and for words, indicating the development of a comparison process based on global…
Anticipatory cortisol, testosterone and psychological responses to judo competition in young men.
2003
This study compares the anticipatory hormonal and psychological responses of 17 male judo players to an official competition with the data obtained during eight resting sessions carried out at the same time of day, throughout an entire sports season. Testosterone (T) and cortisol (C) levels were determined 1 h and 30 min before competition, and mood, anxiety and expectancies were also evaluated. C levels and anxiety scores were concurrently higher before the contest than in resting conditions; however, non-significant correlations between them were found. The anticipatory T response was not significant for the whole group. However, one group of subjects did display T increases, higher C lev…
Causal attribution and psychobiological response to competition in young men.
2016
Abstract A contribution to a special issue on Hormones and Human Competition. Psychoneuroendocrine effects of competition have been widely accepted as a clear example of the relationship between androgens and aggressive/dominant behavior in humans. However, results about the effects of competitive outcomes are quite heterogeneous, suggesting that personal and contextual factors play a moderating role in this relationship. To further explore these dimensions, we aimed to examine (i) the effect of competition and its outcome on the psychobiological response to a laboratory competition in young men, and (ii) the moderating role of some cognitive dimensions such as causal attributions. To do so…
Numerical relations and skill level constrain co-adaptive behaviors of agents in sports teams.
2014
Similar to other complex systems in nature (e.g., a hunting pack, flocks of birds), sports teams have been modeled as social neurobiological systems in which interpersonal coordination tendencies of agents underpin team swarming behaviors. Swarming is seen as the result of agent co-adaptation to ecological constraints of performance environments by collectively perceiving specific possibilities for action (affordances for self and shared affordances). A major principle of invasion team sports assumed to promote effective performance is to outnumber the opposition (creation of numerical overloads) during different performance phases (attack and defense) in spatial regions adjacent to the bal…
Testosterone, Cortisol, and Mood in a Sports Team Competition
1999
In 1 humans, hormonal responses to winning/losing and their relationships to mood and status change have mostly been examined in individual athletic competitions. In this study, the salivary testosterone (T) and cortisol (C) and mood responses to a real match between two professional basketball teams were investigated. Data about individuals’ contributions to outcome, performance appraisal, and attribution of outcome to internal/external factors were also collected. Results did not show statistically significant different T and C responses depending on the outcome. Negative mood was significantly enhanced, especially in the losers, while winners showed a better appraisal of team performance…
Predictor variables for a 100-km race time in male ultra-marathoners.
2010
In 169 male 100-km ultra-marathoners, the variables of anthropometry, training, and prerace experience, in order to predict race time, were investigated. In the bivariate analysis, age ( r = .24), body mass ( r = .20), Body Mass Index ( r = .29), circumference of upper arm ( r = .26), percent body fat (r = .45), mean weekly running hours ( r = –.21), mean weekly running kilometers ( r = –.43), mean speed in training ( r = –.56), personal best time in a marathon ( r = .65), the number of finished 100-km ultra-runs ( r = .24), and the personal best time in a 100-km ultra-run ( r = .72) were associated with race time. Stepwise multiple regression showed that training speed ( p < .0001), me…
Relationships between recall of perceived exertion and blood lactate concentration in a judo competition
2001
Relationships between perceived exertion and blood lactate have usually been studied in laboratory or training contexts but not in competition, the most important setting in which sports performance is evaluated. The purpose of this study was to examine the relationships between psychological and physiological indices of the physical effort in a competition setting, taking into account the duration of effort. For this, we employed two Ratings of Perceived Exertion (RPE and CR-10) and lactic acid plasma concentration as a biological marker of the effort performed. 13 male judo fighters who participated in a sports club competition provided capillary blood samples to assay lactate concentrat…
More on magnitude of priming in implicit memory tasks.
2002
The effects of word frequency, length of the word, and type of word Fragment in a fragment-completion test were investigated with 57 undergraduate students, 19–22 years. Priming with better performance on studied than on nonstudied words in this task was greater for low frequency words than for high frequency words and greater for fragments without the first letter than for fragments with the first letter. It was inferred that characteristics of fragments should be considered in any implicit memory task when the magnitude of priming is of interest. In general, word fragment-completion processes appear to be based on sources of information available in visual identification tasks.
Facilitating Effect of Natural Frequencies: Size Does Not Matter
2009
The question of whether humans are able to work in a Bayesian way is currently a topic of substantial investigation. An important finding, reported by Gigerenzer and Hoffrage in 1995 is that Bayesian reasoning is facilitated when the information format corresponds to natural frequencies. The present concern was whether the facilitating effect of frequencies persists when natural frequencies relate to samples which are not convenient multiples of 10. 150 undergraduates participated as volunteers (42 men, 108 women; M age = 23 yr.). Analysis showed the effect of natural frequency formats was not dependent on size of reference class. Theoretical and practical implications are discussed.