Multiple cue use and integration in pigeons (<Emphasis Type="Italic">Columba livia</Emphasis>)

Encoding multiple cues can improve the accuracy and reliability of navigation and goal localization. Problems may arise, however, if one cue is displaced and provides information which conflicts with other cues. Here we investigated how pigeons cope with cue conflict by training them to locate a goal relative to two landmarks and then varying the amount of conflict between the landmarks. When the amount of conflict was small, pigeons tended to integrate both cues in their search patterns. When the amount of conflict was large, however, pigeons used information from both cues independently. This context-dependent strategy for resolving spatial cue conflict agrees with Bayes optimal calculations for using information from multiple sources.     

Ethnicity-Related Sources of Stress and Their Effects on Well-Being

Early research on ethnicity focused on the stereotyped thinking, prejudiced attitudes, and discriminatory actions of Euro-Americans. Minority-group members were viewed largely as passive targets of these negative reactions, with low self-esteem studied as the main psychological outcome. By contrast, recent research has increasingly made explicit use of stress theory in emphasizing the perspectives and experiences of minority-group members. Several ethnicity-related stressors have been identified, and it has been found that individuals cope with these threats in an active, purposeful manner. In this article, we focus on ethnicity-related stress stemming from discrimination, from stereotypes, and from conformity pressure arising from one's own ethnic group. We discuss theory and review research in which examination of ethnicity-related outcomes has extended beyond self-esteem to include psychological and physical well-being.     

The Effect of External and Internal Focus of Attention on Gait Variability in Older Adults

Internal focus of attention on a movement or focusing on an external target are both strategies that can affect motor performance. The authors explored whether manipulating subjects' focus of attention while walking would alter gait variability, a measure reflecting consistency of gait and associated with the risk of falling in older adults. Twenty community-living older adults participated in the study and were tested while focusing their attention on (a) gait consistency (internal focus) or (b) metronome beats (external focus). In both conditions gait variability increased (i.e., worsened p < .05) or did not change. No benefit was found in instructing subjects to focus on gait consistency or metronome beats. Such instructions may actually have distracted and interfered with the execution of gait.     

The effect of arm crossing on persistence and performance

Two experiments investigated the hypothesis that arm crossing serves as a proprioceptive cue for perseverance within achievement settings. Experiment 1 found that inducing participants to cross their arms led to greater persistence on an unsolvable anagram. Experiment 2 revealed that arm crossing led to better performance on solvable anagrams, and that this effect was mediated by greater persistence. No differences in comfort, instruction adherence, or mood were observed between the arms crossed and control conditions, and participants appeared to be unaware of the effect of arm crossing on their behavior. Implications of the findings are discussed in terms of the interplay between proprioceptive cues and contextual meaning. Copyright © 2007 John Wiley & Sons, Ltd.     

Online control of discrete action following visual perturbation

We examined the spatial and temporal limitations of the visual corrective process in goal-directed aiming, as well as gender differences in online control. An initial experiment was conducted to test the utility of a monocular switch procedure as a method of rapidly introducing a visual perturbation. The results revealed minimal effect of the monocular switch on movement time and the endpoint error. Following this control experiment, prismatic displacement was introduced at the initiation of and during the movement. In the third experiment, the prism was presented prior to movement initiation, and then removed at the beginning of or during the movement. Movement trajectories were most influenced by the early presentation and removal of the prism, and female performance was significantly more affected by both perturbations than male performance.     

Dynamic action units slip in speech production errors

In the past, the nature of the compositional units proposed for spoken language has largely diverged from the types of control units pursued in the domains of other skilled motor tasks. A classic source of evidence as to the units structuring speech has been patterns observed in speech errors--"slips of the tongue". The present study reports, for the first time, on kinematic data from tongue and lip movements during speech errors elicited in the laboratory using a repetition task. Our data are consistent with the hypothesis that speech production results from the assembly of dynamically defined action units--gestures--in a linguistically structured environment. The experimental results support both the presence of gestural units and the dynamical properties of these units and their coordination. This study of speech articulation shows that it is possible to develop a principled account of spoken language within a more general theory of action.     

The effects of reinforcer magnitude on timing in rats

The relation between reinforcer magnitude and timing behavior was studied using a peak procedure. Four rats received multiple consecutive sessions with both low and high levels of brain stimulation reward (BSR). Rats paused longer and had later start times during sessions when their responses were reinforced with low-magnitude BSR. When estimated by a symmetric Gaussian function, peak times also were earlier; when estimated by a better-fitting asymmetric Gaussian function or by analyzing individual trials, however, these peak-time changes were determined to reflect a mixture of large effects of BSR on start times and no effect on stop times. These results pose a significant dilemma for three major theories of timing (SET, MTS, and BeT), which all predict no effects for chronic manipulations of reinforcer magnitude. We conclude that increased reinforcer magnitude influences timing in two ways: through larger immediate after-effects that delay responding and through anticipatory effects that elicit earlier responding.     

The Pathoplastic Relationship Between Interpersonal Problems and Fear of Failure

ABSTRACT This study advances the understanding of fear of failure (FF), a dispositional avoidance-oriented achievement motive, by employing interpersonal classification techniques to groups of individuals who fear failure in order to examine the pathoplastic relations between FF and interpersonal problems. Shame-based FF is thought to be related to the self-regulation strategies of appeasement and aggression, and these strategies are hypothesized to be associated with the interpersonal problems of Nonassertiveness and Vindictiveness, respectively. Using 2 independent samples ( n s=60 and 38) reporting high FF, interpersonal profiles were examined for the groups in their entirety and for cluster solutions within the larger samples. Results demonstrated that individuals high in FF exhibited 1 of 2 prototypical interpersonal profiles associated with Domineering/Vindictive or Nonassertive/Exploitable problems that correspond with the hypothesized aggression and appeasement regulation strategies. Consistent with the concept of pathoplasticity, these differences were not better accounted for by demographic, affective, motivational, personality, or attachment style characteristics of the samples.     

Methodological and dispositional predictors of congruence between implicit and explicit need for achievement

In this research, the authors questioned the statistical independence of implicit and explicit motives. Their first aim was to identify a methodological factor that may have weakened implicit-explicit motive correlations in past research. Their second aim was to identify personality traits that moderate implicit-explicit motive congruence. They found that implicit and explicit need for achievement (nAch) are significantly correlated, but only if the implicit and explicit measures are matched in content. Three traits were found to uniquely moderate the relationship between implicit and explicit nAch: private body consciousness, self-monitoring, and preference for consistency. These findings indicate that implicit and explicit nAch are systematically related and suggest that some individuals may use implicit nAch as a foundation for the development of explicit nAch.