Indecision on decisional separability

The theoretical framework of General Recognition Theory (GRT; Ashby & Townsend, Psychological Review, 93, 154-179, 1986) coupled with the empirical analysis tools of Multidimensional Signal Detection Analysis (MSDA; Kadlec & Townsend, Multidimensional models of perception and recognition, pp. 181-228, 1992) have become one important method for assessing dimensional interactions in perceptual decision-making. In this article, we critically examine MSDA and characterize cases where it is unable to discriminate two kinds of dimensional interactions: perceptual separability and decisional separability. We performed simulations with known instances of violations of perceptual or decisional separability, applied MSDA to the data generated by these simulations, and evaluated MSDA on its ability to accurately characterize the perceptual versus decisional source of these simulated dimensional interactions. Critical cases of violations of perceptual separability are often mischaracterized by MSDA as violations of decisional separability.     

Posture-related affordances guide attacks in basketball

Objectives

The purpose of this study was to investigate the decision made by the attacker to drive to the left or right of the defender.

Method

Participants were 32 novice and intermediate basketball players who were assigned the role of attacker or defender in a one-on-one subphase. We manipulated the defender’s posture and measured both the postures of defenders and attackers and the ensuing decision on drive direction.

Results

As hypothesized, the posture of defenders guided the decision behavior of the attacker. Both novice and intermediate attackers made the same affordance-based decision by driving to the side of the defender’s most advanced foot, but only when the distance between attacker and defender was small. Moreover, novice attackers conveyed postural information regarding their upcoming drive direction while intermediate attackers were better able to conceal this information.

Conclusions

These results lend further support to the notion of information-based control of interpersonal actions in sport contexts.     

Interpersonal distance regulates functional grouping tendencies of agents in team sports

The authors examined whether, similar to collective agent behaviors in complex, biological systems (e.g., schools of fish and colonies of ants), performers in team sports displayed functional coordination tendencies, based on local interaction rules during performance. To investigate this issue, they used videogrammetry and digitizing procedures to observe interpersonal interactions in common 4 versus 2 + 2 subphases of the team sport of rugby union, involving 16 participants aged between 16 and 17 years of age. They observed pattern-forming dynamics in attacking subunits (n = 4 players) attempting to penetrate 2 defensive lines (n = 2 players in each). Data showed that within each attacking subunit, the 4 players displayed emergent functional grouping tendencies that differed between the 2 defensive lines. Results confirmed that grouping tendencies in attacking subunits of team games are sensitive to different task constraints, such as relative positioning to nearest defenders. It was concluded that running correlations were particularly useful for measuring the level of interpersonal coordination in functional grouping tendencies within attacking subunits.     

Sorting food labels and describing properties of categories: stability of results between and within subjects

The purpose of this research is to improve understanding of the consistency of the categorization process in cognitive psychology. To investigate the temporal stability of the categorization process between and within subjects, 100 participants (M = 22.1 yr., SD = 2.1) were required to sort 65 food labels into groups and to explain their grouping. The sorting and property generation of food labels were compared by conducting two sessions (with a 15-day interval) to assess within-subject variability. Two groups of participants were compared to assess between-subjects variability. The results from the sorting task showed excellent stability between and within subjects. Conversely, the property generation task showed high variability. It is concluded that the tasks involved different types of knowledge. The sorting task appeared to generate good agreement and to involve more stable knowledge. The task of producing properties may involve other mechanisms. This paper discusses the results in light of cognitive and pragmatic theories.     

Utility of a statistical model of cognitive styles in attention deficit hyperactivity disorder

The purpose of this study was to determine the best statistical model of cognitive styles, based on the MFFT-20, CEFT and Stroop tests to predict attention deficit hyperactivity disorder (ADHD), analyzing the validity of the model for the diagnosis of the disease. We studied 100 ADHD cases (DSM-IV criteria) and 100 controls, age ranging between 7 and 11 years. Controls were randomly recruited and matched in age, gender and sociodemographic area with ADHD cases. On average, ADHD cases showed more impulsiveness (d: 1.28), less cognitive flexibility (d: 0.91) and more field dependence (d: 1.62) than controls. The logistic regression model that predicts ADHD best is made up of age, CEFT, MFFT-20 and Stroop tests and the formula derived from the model shows 85% sensitivity and 85% specificity for ADHD, regarding the DSM-IV criteria as the standard. The statistical model of cognitive styles presents valid indicators to diagnose ADHD, contributing to an increase in the objectivity of its analysis.     

The costs of switching attentional sets

People prioritize those aspects of the visual environment that match their attentional set. In the present study, we investigated whether switching from one attentional set to another is associated with a cost. We asked observers to sequentially saccade toward two color-defined targets, one on the left side of the display, the other on the right, each among a set of heterogeneously colored distractors. The targets were of the same color (no attentional set switch required) or of different colors (switch of attentional sets necessary), with each color consistently tied to a side, to allow observers to maximally prepare for the switch. We found that saccades were less accurate and slower in the switch condition than in the no-switch condition. Furthermore, whenever one of the distractors had the color associated with the other attentional set, a substantial proportion of saccades did not end on the target, but on this distractor. A time course analysis revealed that this distractor preference turned into a target preference after about 250-300 ms, suggesting that this is the time required to switch attentional sets.