Basic-level visual similarity and category specificity

The role of visual crowding in category deficits has been widely discussed (e.g.,;; ). Most studies have measured overlap at the superordinate level (compare different examples of 'animal') rather than at the basic level (compare different examples of 'dog'). In this study, we therefore derived two measures of basic-level overlap for a range of categories. The first was a computational measure generated by a self-organising neural network trained to process pictures of living and non-living things; the second was a rating of perceived visual similarity generated by human subjects to the item names. The computational measure indicated that the pattern of crowded/uncrowded does not honour a living/non-living distinction. Nevertheless, different superordinates showed varied degrees of basic-level overlap, suggesting that specific token choice affects some superordinates more than others e.g., individual fruit and vegetable tokens show greater variability than any other items, while tools and vehicles produce more reliable or overlapping basic-level visual representations. Finally, subject ratings correlated significantly with the computational measures indicating that the neural model represents structural properties of the objects that are psychologically meaningful.     

Recombinative generalization of within-syllable units in nonreading adults with mental retardation

Two adults with mental retardation demonstrated the recombination of within-syllable units (onsets and rimes) using a spoken-to-printed-word matching-to-sample (MTS) procedure. Further testing with 1 participant showed comprehension of the printed words. Printed-word naming was minimal before, but greater after, comprehension tests. The findings suggest that these procedures hold promise for further basic and applied analyses of word-attack skills.     

Missing the mark: effects of time and causal attributions on goal revision in response to goal-performance discrepancies

In an attempt to extend past goal setting research, the present study examined the influence of goal-performance discrepancies (GPDs), causal attributions, and temporal factors on the process of dynamic self-regulation. Goal revision processes were examined longitudinally in a sample of 100 varsity-level college track and field athletes over the course of an 8-week competitive season. The results indicate that an individual's GPD significantly predicted the amount of goal revision engaged in by the athletes, such that participants were more likely to lower their competition (proximal) and season (distal) goals when they failed to reach these goals and their respective GPDs were large. However, as hypothesized, this relationship was moderated by stability attributions and the temporal location of the individual with respect to the time period allotted for goal attainment. Implications for future research in the area of goal setting and dynamic self-regulation are discussed.     

Stereotypes as dominant responses: on the "social facilitation" of prejudice in anticipated public contexts

This article challenges the highly intuitive assumption that prejudice should be less likely in public compared with private settings. It proposes that stereotypes may be conceptualized as a type of dominant response (C. L. Hull, 1943; R. B. Zajonc, 1965) whose expression may be enhanced in public settings, especially among individuals high in social anxiety. Support was found for this framework in an impression formation paradigm (Experiment 1) and in a speeded task designed to measure stereotypic errors in perceptual identification (Experiment 2). Use of the process dissociation procedure (B. K. Payne, L. L. Jacoby, & A. J. Lambert, in press) demonstrated that these effects were due to decreases in cognitive control rather than increases in stereotype accessibility. The findings highlight a heretofore unknown and ironic consequence of anticipated public settings: Warning people that others may be privy to their responses may actually increase prejudice among the very people who are most worried about doing the wrong thing in public.     

Eye movements and picture processing during recognition

Eye movements were monitored during a recognition memory test of previously studied pictures of full-color scenes. The test scenes were identical to the originals, had an object deleted from them, or included a new object substituted for an original object. In contrast to a prior report (Parker, 1978), we found no evidence that object deletions or substitutions could be recognized on the basis of information acquired from the visual periphery. Deletions were difficult to recognize peripherally, and the eyes were not attracted to them. Overall, the amplitude of the average saccade to the critical object during the memory test was less than 4.5 degrees of visual angle in all conditions and averaged 4.1 degrees across conditions. We conclude that information about object presence and identity in a scene is limited to a relatively small region around the current fixation point.     

Sociotropy and autonomy: an examination of interpersonal and work adjustment

One-hundred and sixty-five undergraduate students completed measures of sociotropy, autonomy, and adjustment. Autonomy was associated with poor social adjustment but was not associated with work role adjustment. Sociotropy failed to evidence a significant relation with work role or social adjustment. In past research, autonomy has primarily been theorized to contribute to depression when achievement needs are not met. Our results raise the possibility that autonomy may be linked to depression through the pathway of low social support and interpersonal difficulties. In addition, the results suggest that sociotropic individuals may not have objectively poor social adjustment despite their concerns regarding this area. Likewise, autonomous individuals may not have better or worse work adjustment despite their efforts to achieve.     

Incremental exercise, plasma concentrations of catecholamines, reaction time, and motor time during performance of a noncompatible choice response time task

The primary purpose was to examine the effect of incremental exercise on a noncompatible response time task. Participants (N=9) undertook a 4-choice noncompatible response time task under 3 conditions, following rest and during exercise at 70% and 100% of their maximum power output. Reaction and movement times were the dependent variables. Maximum power output had been previously established on an incremental test to exhaustion. A repeated-measures multivariate analysis of variance yielded a significant effect of exercise intensity on the task, observation of the separate univariate repeated-measures analyses of variance showed that only movement time was significantly affected. Post hoc Tukey tests indicated movement time during maximal intensity exercise was significantly faster than in the other two conditions. The secondary purpose of the study was to assess whether increases in plasma concentrations of adrenaline and nor-adrenaline during exercise and power output would act as predictor variables of reaction and movement times during exercise. Catecholamine concentrations were based on venous blood samples taken during the maximum power output test. None of the variables were significant predictors of reaction time. Only power output was a significant predictor of movement time (R2 = .24). There was little support for the notion that peripheral concentrations of catecholamines directly induce a central nervous system response.     

Common features of fluency-evoking conditions studied in stuttering subjects and controls: an H(2)15O PET study

We used H(2)15O PET to characterize the common features of two successful but markedly different fluency-evoking conditions -- paced speech and singing -- in order to identify brain mechanisms that enable fluent speech in people who stutter. To do so, we compared responses under fluency-evoking conditions with responses elicited by tasks that typically elicit dysfluent speech (quantifying the degree of stuttering and using this measure as a confounding covariate in our analyses). We evaluated task-related activations in both stuttering subjects and age- and gender-matched controls. Areas that were either uniquely activated during fluency-evoking conditions, or in which the magnitude of activation was significantly greater during fluency-evoking than dysfluency-evoking tasks included auditory association areas that process speech and voice and motor regions related to control of the larynx and oral articulators. This suggests that a common fluency-evoking mechanism might relate to more effective coupling of auditory and motor systems -- that is, more efficient self-monitoring, allowing motor areas to more effectively modify speech. These effects were seen in both PWS and controls, suggesting that they are due to the sensorimotor or cognitive demands of the fluency-evoking tasks themselves. While responses seen in both groups were bilateral, however, the fluency-evoking tasks elicited more robust activation of auditory and motor regions within the left hemisphere of stuttering subjects, suggesting a role for the left hemisphere in compensatory processes that enable fluency. EDUCATIONAL OBJECTIVES: The reader will learn about and be able to: (1) compare brain activation patterns under fluency- and dysfluency-evoking conditions in stuttering and control subjects; (2) appraise the common features, both central and peripheral, of fluency-evoking conditions; and (3) discuss ways in which neuroimaging methods can be used to understand the pathophysiology of stuttering.