Visual Search for Conjunctions of Motion and Form: The Efficiency of Attention to Static versus Moving Items Depends on Practice

Visual search for some motion-form conjunctions can be performed in parallel. Yet, if the target is easy to discriminate from the nontargets (target line tilted 45 from the vertical), search can be easier for a moving than for a stationary target. Driver and McLeod (1992; Berger & McLeod, 1996) took this asymmetry to argue that gross aspects of form discrimination are performed within a motion filter thatrepresents only the moving items, whereas discrimination of stationary items (and all fine discrimination) relies on a static form system. However, recent (unsuccessful) attempts to replicate the asymmetry (Muller & Found, 1996; Muller & Maxwell, 1994) suggested that it may occur only early during task performance, due to participants having difficulty keeping the moving items out of the search for a stationary target (but not vice versa). This was confirmed by the present study, which investigated the effects of practice on search among the moving and stationary subset of items. The results suggest that attention to the stationary subsetis difficultinitially because participants cannotefficiently compensate for the natural bias of the motion filter to pass the moving items (rather than filter them out). This ability improves with practice. Thus, there is no fixed limit to performance with stationary targets and, consequently, no need to assume that any form discrimination is performed within the motion filter.     

Limitations of perceptual segmentation on contextual cueing in visual search

In visual search, detection of a target in a repeated layout is faster than search within a novel arrangement, demonstrating that contextual invariances can implicitly guide attention to the target location (“contextual cueing”; Chun & Jiang, 1998). Here, we investigated how display segmentation processes influence contextual cueing. Seven experiments showed that grouping by colour and by size can considerably reduce contextual cueing. However, selectively attending to a relevant subgroup of items (that contains the target) preserved context-based learning effects. Finally, the reduction of contextual cueing by means of grouping affected both the latent learning and the recall of display layouts. In sum, all experiments show an influence of grouping on contextual cueing. This influence is larger for variations of spatial (as compared to surface) features and is consistent with the view that learning of contextual relations critically interferes with processes that segment a display into segregated groups of items.     

At one with our actions,but at two with our bodies

Jennifer Hornsby's account of human action frees us from the temptation to think of the person who acts as ‘doing’ the events that are her actions, and thereby removes much of the allure of ‘agent causation’. But her account is spoiled by the claim that physical actions are ‘tryings’ that cause bodily movements. It would be better to think of physical actions and bodily movements as identical; but Hornsby refuses to do this, seemingly because she thinks that to do so would be to endorse the so–called ‘standard causal story’. But Hornsby misses a possibility here, for we can insist on this identity claim without endorsing the standard story if we embrace an account which parallels the disjunctive account in the philosophy of perception. This will leave us with a picture of physical action that saves the insights of Hornsby's account without succumbing to its distortions.     

Temporal Passage and Kant's Second Analogy

In this essay I address the question of the reality of temporal passage through a discussion of some of the implications of Kant's reasoning concerning the necessary conditions of objective judgement. Some theorists have claimed that the attribution of non-relational temporal properties to objects and events represents a conceptual confusion, or 'category mistake'. By means of an examination of Kant's Second Analogy, and a comparison between that argument and Cassam's recent exploration of an argument regarding the necessity of the conceptualisation of ourselves as spatially located, I draw out a consequence of Kant's argument: namely, that the representation of temporal becoming is a necessary condition of objective judgement and an a priori element in the representation of objects of experience. I finish by explaining why this would show that the attribution of temporal becoming to objects and events cannot be described as a category mistake.     

A meta‐analysis of serotonin metabolite 5‐HIAA and antisocial behavior

During the past 25 years, researchers have examined the relationship between neurochemical variables and antisocial behavior in human adults, but none has been studied more intensely than the serotonin metabolite 5‐hydroxyindoleacetic acid (5‐HIAA). The goal of the current study was to employ meta‐analytic procedures to quantitatively evaluate selected evidence on the relationship between 5‐HIAA and antisocial behavior. It was expected that antisocial groups would show reduced cerebrospinal fluid 5‐HIAA compared with non–antisocial groups. This study also aimed to assess moderators that could influence the relationship between 5‐HIAA and antisociality. An electronic search and strict inclusion criteria identified 20 reports used in this meta‐analysis. Results showed a significant overall mean effect size (ES = –.45, P < .05) in the direction of lowered 5‐HIAA in antisocial vs. non–antisocial groups. A significant moderating effect for age indicated that groups comprised of antisocial individuals younger than 30 years exhibited larger negative effect sizes (ES = –1.37, P < .05) than groups with older subjects (ES = –.31, P < .05). There were no moderating effects for gender, target of violence, history of suicide, and alcoholism. Age effects may help explain age‐related declines in crime. The fact that effects did not differ based on other moderating variables supports models of reduced serotonin in antisocial individuals, regardless of type of crime or psychiatric problems. Aggr. Behav. 28:299–316, 2002. © 2002 Wiley‐Liss, Inc.     

Do personality factors predict job satisfaction?

Two studies investigated the relationships between personality traits and aspects of job satisfaction. In Study 1, job applicants (n=250) completed the Eysenck Personality Profiler and the Work Values Questionnaire (WVQ), which requires respondents to rate various work-related facets according to the extent to which they contribute to their job satisfaction. These facets were combined into two composites (hygiene and motivator) based on previous research. The three personality superfactors accounted for a small percentage of the variance in importance ratings (about 5%). In Study 2, employees (n=82) completed a measure of the ‘Big Five’ personality traits and the Job Satisfaction Questionnaire (JSQ), which assesses both what respondents consider as important in their work environment as well as their satisfaction with their current job. Importance ratings were again combined into two composites while job satisfaction ratings were factor analyzed and three factors, differentiated along hygiene versus motivator lines, emerged. Personality traits again accounted for a small percentage of the total variance both in importance ratings and in levels of job satisfaction. It is concluded that personality does not have a strong or consistent influence either on what individuals perceive as important in their work environment or on their levels of job satisfaction.     

White Racism and Suboptimal Psychological Functioning Among White Americans: Implications for Counseling and Prejudice Prevention

This study examined the causal relationships between anxiety, racism, and self‐esteem in a sample of White graduate and undergraduate students (N = 169). The results indicated that level of anxiety had a direct effect on anti‐Black attitudes, which, in turn, had a direct effect on self‐esteem. Implications for counseling interventions aimed at preventing prejudice among Whites are discussed. Este estudio examinó las relaciones causales entre la ansiedad, el racismo, y el auto‐estima en un grupo de estudiantes graduados y estudiantes de bachillerato Blancos (N = 169). Los resultados indicaron que el nivel de ansiedad tuvo un efecto directo en las actitudes anti‐Negras, que en torno tuvo un efecto directo en el auto‐estima. Las implicaciones para las intervenciones de consejería dirigidas a prevenir el prejuicio entre los Blancos son discutidas.     

Heart Rate Changes Accompanying Jaw Movement Pavlovian Conditioning in Rabbits: Concomitant Blood Pressure Adjustments and Effects of Peripheral Autonomic Blockade

Two experiments were conducted to ascertain the cardiovascular accompaniments of differential Pavlovian jaw movement (JM) conditioning. The first examined the blood pressure (BP) changes that accompany the tachycardiac conditioned responses (CRs) associated with JM conditioning. The BP response in all instances consisted of a depressor response that was greater to the reinforced CS+ than CS-, although the magnitude of the CR was quite small. The second experiment determined the effects of peripheral autonomic antagonists on the cardiac accelerations associated with JM conditioning. It was found that the peripheral vagal antagonist methyl scopolamine completely abolished responses to both CS+ and CS-, whereas atenolol, a beta adrenergic antagonist, augmented the response, compared to saline control injections. The JM responses were also affected by the autonomic blockades, with minimal responding occurring in the scopolamine group but slightly more JM CRs in the atenolol group, compared to saline control animals. These results suggest that the major cardiovascular response to an appetitive stimulus, which evokes JM conditioning, consists of cardiac accelerations with the BP depressor responses playing a minimal, if any, role. Moreover, these conditioned cardiac increases appear to be due solely to the release of vagal inhibition.     

Modulation of cognitive flexibility by hunger and desire

Knowing when to persevere with a plan and knowing when to ditch it and change strategy is highly adaptive and breaks down in several frontal and striatal disorders. Cognitive flexibility is also susceptible to tonic influences of neuromodulators (such as dopamine) and so may be influenced by everyday fluctuations in processes known to depend upon them (such as motivation). The current study employed an attentional shifting paradigm to examine the influence of changes in food-related motivational state in healthy volunteers. Hunger was induced through fasting (physiological manipulation) or through the presentation of appetitive food cues prior to testing (desire manipulation). The desire manipulation produced a stronger effect than fasting by inducing errors when participants were attempting to shift. The results suggest that everyday fluctuations in appetite and desire can produce a significant impact on cognition, highlighting implications for our understanding of excessive motivational control including maladaptive eating behaviour.