Absence of an interaction between navigational strategies based on local and distal landmarks

In 3 experiments, rats were required to escape from a Morris pool by swimming to a submerged platform that was located at the apex of a notional, equilateral triangle with 2 different landmarks occupying the corners at the base. Training for 1 group was always conducted in view of the landmarks surrounding the pool and with the triangular array in a fixed orientation. Subjects could therefore identify the direction of the platform from a single landmark within the pool by reference to cues outside the pool or to the other landmark within the pool. Both strategies were used, and the results from additional groups revealed that the first of these strategies did not affect the acquisition of the second one.     

Transfer of spatial behavior between different environments: implications for theories of spatial learning and for the role of the hippocampus in spatial learning

In 3 experiments, rats were required to find a submerged platform located in 1 corner of an arena that had 2 long and 2 short sides; they were then trained to find the platform in a new arena that also had 2 long and 2 short sides but a different overall shape. The platform in the new arena was easier to find if it was in a corner that was geometrically equivalent, rather than the mirror image, of the corner where it had previously been located. The final experiment revealed that hippocampal lesions impaired rats' ability to find the platform in these arenas. The results suggest that rats did not use the overall shape of the arena to locate the platform but relied on more local cues and that the hippocampus plays a role in navigation based on these cues.     

Nikāmakarma: how desireless need one be?1

In the Bhagavadgītā K a advises Arjuna to act without desire. He also describes the nikāmakarmin as possessed of perfect equanimity. Some scholars have argued that K a's advice is a contradiction. Because action requires desire, desireless action is impossible. Others have claimed that this fact only suggests that K a's prohibition is against a subset of desires and not desire as a whole. These ‘subset’ positions, however, are not consistent with the equanimity requirement. The conclusion that K a's advice is a contradiction can be avoided however. The word ‘desire’ in English is ambiguous. In one sense it means ‘whatever motivated’, and in another sense it means a ‘desire proper’ in contrast to beliefs and other mental states. If it is possible that not only desires proper motivate, then it is possible to act desirelessly in this sense. This distinction, I will argue, makes the best sense of K a's advice.     

Relational integration, inhibition, and analogical reasoning in older adults

The difficulty of reasoning tasks depends on their relational complexity, which increases with the number of relations that must be considered simultaneously to make an inference, and on the number of irrelevant items that must be inhibited. The authors examined the ability of younger and older adults to integrate multiple relations and inhibit irrelevant stimuli. Young adults performed well at all but the highest level of relational complexity, whereas older adults performed poorly even at a medium level of relational complexity, especially when irrelevant information was presented. Simulations based on a neurocomputational model of analogical reasoning, Learning and Inference with Schemas and Analogies (LISA), suggest that the observed decline in reasoning performance may be explained by a decline in attention and inhibitory functions in older adults.     

Personality characteristics of partner violent men: a Q-sort approach

Our objective was to develop a personality profile of men who are violent toward their partners. A total of 52 experienced clinicians described either a current male patient who was violent toward his partner (and only toward his partner) or who was maritally distressed but nonviolent using the Shedler-Westen Assessment Procedure-200 (SWAP-200), a Q-sort instrument designed to harness the judgments of clinicians. Partner-violent patients showed significantly higher scores on the SWAP-200 antisocial and borderline personality disorder scales. In contrast, patients who were maritally distressed evidenced higher scores on the SWAP-200 obsessive, avoidant, and high-functioning depressive scales. The men who were violent toward their partners were more antisocial and emotionally dysregulated, which is consistent with theory, and less obsessive, which has not been theoretically explored. The groups did not differ on theoretically important dimensions of personality including paranoid, dependent, and hostile features.     

What's in a (neutral) face? Personality disorders, attachment styles, and the appraisal of ambiguous social cues

Attachment theory suggests that borderline, avoidant, and schizoid personality disorders are differentially associated with anxious and avoidant attachment styles. The variations of insecure attachment in these disorders, in turn, might influence how others are perceived or appraised. To test these ideas, 176 college students completed questionnaires measuring attachment styles and personality disorder features, and each rated 10 emotionally neutral faces on 18 bipolar appraisal dimensions. As expected, borderline personality was associated with anxious attachment, avoidant personality was associated with anxious and avoidant attachment, and schizoid personality was weakly associated only with avoidant attachment. Furthermore, path analyses showed that borderline and avoidant personality features were associated with anxious attachment, which in turn related to negative face appraisals (e.g., tendencies to rate faces as less friendly and more rejecting). Discussion highlights the potential of simultaneously studying biases in social information processing and attachment disturbances among individuals with personality disorders.     

Borderline psychopathology in the first-degree relatives of borderline and axis II comparison probands

The purpose of this study was to assess the prevalence of each of the nine DSM criteria for borderline personality disorder and the prevalence of the disorder itself in the first-degree relatives of borderline probands and Axis II comparison subjects. Four hundred and forty-five inpatients were interviewed about familial borderline psychopathology using the Revised Family History Questionnaire--a semistructured interview of demonstrated reliability. Of these 445 subjects, 341 met both DIB-R and DSM-III-R criteria for BPD and 104 met DSM-III-R criteria for another type of personality disorder (and neither criteria set for BPD). The psychopathology of 1,580 first-degree relatives of borderline probands and 472 relatives of Axis II comparison subjects was assessed. Both DSM-III-R and DSM-IV BPD were found to be more common among the relatives of borderline than Axis II comparison probands. However, five of the criteria for BPD (inappropriate anger, affective instability, paranoia/dissociation, general impulsivity, and intense, unstable relationships) and all four sectors of borderline psychopathology (affect, cognition, impulsivity, and interpersonal relationships) were found to be both more common and discriminating than the BPD diagnosis itself. Taken together, the results of this study suggest that the subsyndromal phenomenology of BPD may be more common than the borderline diagnosis itself.     

Resolution of conflicts between internal and external information sources on a time reproduction task: the role of perceived information reliability and attributional style

Erroneous knowledge of results (KR) that conflicts with other internal or external information sources is preferentially used and misguides performance on motor and mental timing tasks. Buekers et al. [J. Motor Behavior 26 (1994) 27] hypothesized that KR is used preferentially because participants deem it to be the most reliable information source. We tested this hypothesis in two experiments. We manipulated subjective reliability of information and information content and demonstrated that both reliability and content are assessed and used. In a third experiment we examined whether attributional style affected the use of internal and external information. While KR was present, attributional style was unrelated to performance. However, when erroneous KR was withdrawn, participants who scored high in internal attributional style or high in controllability showed more accurate performance. Whereas evaluation of information quality is explicit, information provided by the KR, whether accurate or not, may influence both implicit and explicit aspects of the tasks.     

Amplitude scaling in a bimanual circle-drawing task: pattern switching and end-effector variability

The authors manipulated movement amplitude in a bimanual circle-tracing task performed by 11 participants. With pacing frequency fixed, the systematic increase and decrease of circle diameter within a trial induced phase transitions from the asymmetric (33% of trials) to the symmetric bimanual circle-tracing pattern; the transitions resulted from a loss of stability in the asymmetric pattern. Tracing frequency varied inversely with circle diameter so that end-effector variability was minimized in a set of self-paced trials in which the circle diameter in a trial was fixed. In the amplitude-scaling trials, end-effector variability varied directly with circle diameter, a consistent speed-accuracy tradeoff. The results support the conclusion that movement amplitude is a nonspecific control parameter. The findings are discussed with reference to several factors, e.g., tactile feedback, the recruitment and suppression of biomechanical degrees of freedom, and the role those factors may play in stabilizing bimanual coordination patterns