Attention alters the appearance of motion coherence

Selective attention enhances visual information processing, as measured by behavioral performance and neural activity. However, little is known about its effects on subjective experience. Here, we investigated the effect of transient (exogenous) attention on the appearance of visual motion, using a psychophysical procedure that directly measures appearance and controls for response bias. Observers viewed pairs of moving dot patterns and reported the motion direction of the more coherent pattern. Directing attention (via a peripheral precue) to a stimulus location increased its perceived coherence level and improved performance on a direction discrimination task. In a control experiment, we ruled out response bias by lengthening the time interval between the cue and the stimuli, so that the effect of transient attention could no longer be exerted. Our results are consistent with those of neurophysiological studies showing that attention modulates motion processing and provide evidence of a subjective perceptual correlate of attention, with a concomitant effect on performance.     

Geometric determinants of human spatial memory

Geometric alterations to the boundaries of a virtual environment were used to investigate the representations underlying human spatial memory. Subjects encountered a cue object in a simple rectangular enclosure, with distant landmarks for orientation. After a brief delay, during which they were removed from the arena, subjects were returned to it at a new location and orientation and asked to mark the place where the cue had been. On some trials the geometry (size, aspect ratio) of the arena was varied between presentation and testing. Responses tended to lie somewhere between a location that maintained fixed distances from nearby walls and a location that maintained fixed ratios of the distances between opposing walls. The former were more common after expansions and for cued locations nearer to the edge while the latter were more common after contractions and for locations nearer to the center. The spatial distributions of responses predicted by various simple geometric models were compared to the data. The best fitting model was one derived from the response properties of 'place cells' in the rat hippocampus, which matches the 'proximities' 1/(d+c) of the cue to the four walls of the arena, where d is the distance to a wall and c is a global constant. Subjects also tended to adopt the same orientation at presentation and testing, although this was not due to using a view matching strategy, which could be ruled out in 50% of responses. Disoriented responses were most often seen where the cued location was near the center of the arena or where the long axis of a rectangular arena was changed between presentation and testing, suggesting that the geometry of the arena acts as a weak cue to orientation. Overall, the results suggest a process of visual landmark matching to determine orientation, combined with an abstract representation of the proximity of the cued location to the walls of the arena consistent with the neural representation of location in the hippocampus.     

Substance use, suicidal ideation and attempts in children and adolescents

Using data from a community sample of youth ( N = 1,458; ages 9-17), this study assessed the association between adolescent substance use/abuse and suicidal behaviors. Suicide attempts were strongly associated with alcohol abuse and dependence, followed by frequent cigarette smoking. The associations remained significant even after controlling for depression. The associations between substance use/abuse and suicidal ideation were no longer significant after controlling for depression. These findings highlight the important role that substance use plays in adolescent suicidal behaviors.     

Relations between high and low power groups: the importance of legitimacy

Using a social identity perspective, two experiments examined the effects of power and the legitimacy of power differentials on intergroup bias. In Experiment 1, 125 math-science students were led to believe that they had high or low representation in a university decision-making body relative to social-science students and that this power position was either legitimate or illegitimate. Power did not have an independent effect on bias; rather, members of both high and low power groups showed more bias when the power hierarchy was illegitimate than when it was legitimate. This effect was replicated in Experiment 2 (N = 105). In addition, Experiment 2 showed that groups located within an unfair power hierarchy expected the superordinate power body to be more discriminatory than did those who had legitimately high or low power. The results are discussed in terms of their implications for group relations.     

Children's face recognition memory: more evidence for the cross-race effect

It is well established that own-race faces are recognized more accurately than cross-race faces. However, there are mixed results regarding the developmental consistency of the cross-race effect White and Black kindergarten children, 3rd graders, and young adults viewed a Black and a White target individual. One day later, recognition memory for each target was tested with a 6-person lineup. The interaction of race of participant by race of target face on Ag scores was significant, demonstrating an overall cross-race effect. The 2nd-order interaction with age did not approach significance; for each age group, own-race identification was more accurate than cross-race identification. The age consistency of the cross-race effect in light of the significant main effect of age suggests quantitative but not qualitative differences in face memory processing at various ages. For children, as well as adults, own-race faces are recognized more accurately than cross-race faces.     

Perceptions of adulthood among Anglo and Latino parents

The transition to adulthood presupposes that a developing adolescent acquires a set of characteristics that enables him or her to perform expected adult behaviors. There is a gap in the literature in identifying these expected behaviors as they pertain to different cultural and racial groups. To fill this gap, parent-generated indicators of adulthood were studied, including the beliefs, behaviors, and attitudes that are either common or specific to Anglo and Latino parents. College students at an urban university in the Los Angeles area were recruited to enlist their parents to complete a questionnaire. Equal numbers from each ethnic group were surveyed. The results of this study indicate that Anglo participants defined adulthood in terms of independence significantly more often than Latino participants. Furthermore, Latino participants defined adulthood in terms of event-related markers, such as marriage, significantly more often than Anglo participants. This research points to the need to define adulthood in ways that reflect the ethnic diversity of the United States. The authors express their thanks to Russell Espinoza, Ileana Garoz, Anna Rivera, Sandra Samayoa, Gabriella Chavira, Maria Hernandez, Angel Lahr, and Kevin Kim for their invaluable assistance. An earlier version of this paper was presented at the 1997 meeting of the Western Psychological Association, Seattle.     

Creativity and two modes of associative fluency: Chains and stars1

The relationship between creativity and associative fluency was reexamined in light of a proposed distinction between two modes of associative fluency, chains and stars. Chained associations were defined as a series of responses, each related to the preceding one, and star associations as a series of responses, all of which are focused on the original stimulus word. An analysis of the continuous associations produced orally by 96 university students in response to a single presentation of a stimulus word indicated that they produced associations of both types interchangeably. Chain and star fluency were found to be inversely correlated at a low order, suggesting that they are two distinct associative modes. As expected, chain fluency was highly related to creativity, as measured by a Hebrew version of Mednick's Remote Associates Test while star fluency was unrelated to it. The findings were discussed in terms of Wallach's (1970) notion of attention deployment, and directions for future research were suggested.     

The acquisition of taste aversions in humans

A written questionnaire or an interview was given to 517 undergraduates concerning their acquisition of illness-induced (taste) aversions to foods and drinks. The subjects reported 415 aversions, with 65% of the subjects reporting at least one aversion. The aversions were more likely to be reported as having been formed through forward rather than simultaneous or backward conditioning, and long-delay learning was frequent. The aversions usually formed to the taste of the foods, rather than the appearance or other aspects of the foods. Extinction appeared more effective in decreasing the aversions than did forgetting. The illness responsible for the aversion's forming was usually attributed to the subsequently aversive food, but for 21% of the reported aversions subjects were sure that something else had caused their illness. Aversions were more likely to have formed to relatively less familiar and less preferred foods. Aversions were also more likely to form between the ages of 13 and 20. Generalization of the aversions to similar foods occurred in 29% of the cases. Approximately one fourth of the aversions were to alcoholic beverages. Finally, instances of aversions forming without food or drink consumption and instances of observational learning were reported. The data were quite similar to laboratory taste aversion data collected using other species and can help in optimizing taste aversion treatments of eating and drinking disorders. Taste aversions among humans are frequent and strong.