Object-based attention: strength of object representation and attentional guidance

Two or more features belonging to a single object are identified more quickly and more accurately than are features belonging to different objects--a finding attributed to sensory enhancement of all features belonging to an attended or selected object. However, several recent studies have suggested that this "single-object advantage" may be a product of probabilistic and configural strategic prioritizations rather than of object-based perceptual enhancement per se, challenging the underlying mechanism that is thought to give rise to object-based attention. In the present article, we further explore constraints on the mechanisms of object-based selection by examining the contribution of the strength of object representations to the single-object advantage. We manipulated factors such as exposure duration (i.e., preview time) and salience of configuration (i.e., objects). Varying preview time changes the magnitude of the object-based effect, so that if there is ample time to establish an object representation (i.e., preview time of 1,000 msec), then both probability and configuration (i.e., objects) guide attentional selection. If, however, insufficient time is provided to establish a robust object-based representation, then only probabilities guide attentional selection. Interestingly, at a short preview time of 200 msec, when the two objects were sufficiently different from each other (i.e., different colors), both configuration and probability guided attention selection. These results suggest that object-based effects can be explained both in terms of strength of object representations (established at longer exposure durations and by pictorial cues) and probabilistic contingencies in the visual environment.     

The space of an object: object attention alters the spatial gradient in the surround

Although object-based attention enhances perceptual processing of information appearing within the boundaries of a selected object, little is known about the consequences for information in the object's surround. The authors show that distance from an attended object's center of mass determines reaction time (RT) to targets in the surround. Of 2 targets in the surround, both equidistant from a cue, the target closer to the center of mass was detected faster. Moreover, RT was shown to be a linear function of distance from the center of mass of a fixed, attended object, and changes to the shape of the object and its center of mass predictably altered RT. Object-based attention leads to a pattern of facilitation in the surround that may contribute to the organization of visual scenes.     

The Kosovar sponsoring experience in Northern Alberta

We examine the experiences of sponsors who assisted Kosovar refugees in Northern Alberta. Although the sponsors of the Kosovars did not provide basic financial support to the refugees, many found their role to be onerous, particularly in terms of emotional investment and demands on their time. They would have liked more opportunity to debrief and to have contact with other experienced sponsors. Some of the sponsors' initial expectations of the Kosovars were at odds with reality; conversely, many sponsors felt that the refugees had unrealistic expectations of them and of life in Canada. Recommendations are made for future sponsoring arrangements.     

Morningness-eveningness, use of stimulants, and minor psychiatric disorders among undergraduate students

Morningness–eveningness dimension in humans have been indicated to influence social behavior and individual health. The aim of the present study was to investigate the association of the morningness–eveningness dimension with behavioral and health aspects in a sample of undergraduate students. We assessed demographic data; the Pittsburgh Sleep Quality Index was used to evaluate sleep quality; the Morningness/Eveningness Questionnaire to determine morningness–eveningness, and the Self‐Reporting Questionnaire to assess minor psychiatric disorders. A total of 372 students (66.7% females), on average 21.6 years old, participated in this study. Among them, 92.2% did not smoke, 58.9% engaged in physical activities, and 19.7% were night‐shift workers. In regard to morningness–eveningness, 55.9% of the participants were intermediate between evening (39.5%) and morning (4.6%) types. Poor sleep quality (OR = 1.89), minor psychiatric disorders (OR = 1.92), and tobacco consumption (OR = 3.65) predominated among evening types. Evening types were predominantly males (OR = 1.72). This study suggests that evening types are more vulnerable to sleep and psychiatric disturbances, and tend to smoke more than morning types.     

Exposure to maternal vs. paternal partner violence,PTSD, and aggression in adolescent girls and boys

Adolescents who witness interparental violence (IPV) are at increased risk for perpetrating aggressive acts. They are also at risk for post‐traumatic stress disorder (PTSD). In this study, we examined the relation between exposure to maternal vs. paternal physical IPV and adolescent girls' and boys' aggressive behavior toward mothers, fathers, friends, and romantic partners. We also assessed the influence of PTSD (as assessed by the Diagnostic Interview for Children and Adolescents‐IV (DICA‐IV)) on the relation between exposure to IPV and aggressive behavior. Participants were 63 girls and 49 boys, ages 13–18, consecutively admitted to a youth correctional facility or assessment facility designated to serve aggressive and delinquent youth. Structural equation modeling was used to estimate unique relations between exposure to maternal vs. paternal IPV and youth aggression in relationships. Girls who observed their mothers' aggressive behavior toward partners were significantly more aggressive toward friends. Similarly, boys who witnessed their fathers' aggression were significantly more aggressive toward friends. Adolescent girls and boys who observed aggression by mothers toward partners reported significantly higher levels of aggression toward their romantic partners. Approximately one third of our sample met PTSD criteria; the relation between exposure to parental IPV and aggression was stronger for individuals who met criteria for PTSD. The implications of understanding the relations between parents' and their daughters' and sons' use of aggression are discussed within the context of providing support for families in breaking intergenerational patterns of violence and aggression. Aggr. Behav. 32:385–395, 2006. © 2006 Wiley‐Liss, Inc.     

The roles of static depth information and object-image relative motion in perception of heading

In a series of 6 experiments, two hypotheses were tested: that nominal heading perception is determined by the relative motion of images of objects positioned at different depths (R. F. Wang & J. E. Cutting, 1999) and that static depth information contributes to this determination. By manipulating static depth information while holding retinal-image motion constant during simulated self-movement, the authors found that static depth information played a role in determining perceived heading. Some support was also found for the involvement of R. F. Wang and J. E. Cutting's (1999) categories of object-image relative motion in determining perceived heading. However, results suggested an unexpected functional dominance of information about heading relative to apparently near objects.     

The role of context on strategic actions in Mastermind

When inexperienced solvers play consecutive Mastermind games, they begin to use a strategy in which specific hypothetical types are offered in response to specific feedback types, a strategy known as the modal hypothesis strategy. When participants who had learned that strategy were shifted onto Mastermind games whose code format was different from, and easier than, that they had experienced, their use of the strategy was degraded despite their familiarity and experience in dealing with the specific feedback types occurring in the new code. The results suggest that the use of a domain-specific strategy is at least somewhat influenced by the match between the context in which the strategy has been acquired and the context in which it is being put to use.     

Selective attention to the parts of an object

Recent empirical results suggest that there is a decrement in dividing attention between two objects in a scene compared with focusing attention on a single object. However, objects can be made of individual parts. Is there a decrement for dividing attention across different parts of a single object? We addressed this question in two experiments. In Experiment 1, we demonstrated that attention can exhibit part-based selection—that is, the subjects were more accurate in reporting two attributes from the same part of an object than they were in reporting attributes from different parts of an object. In Experiment 2, we demonstrated that part-based attentional decrements occurred simultaneously with object-based attentional decrements. The results from Experiment 2 demonstrated that part-based attention is evident at the same time as objects are processed as coherent wholes. Our results imply that there is an attentional mechanism that can select either objects or their parts.