Obsessive-compulsive personality disorder and behavioral disinhibition

Although obsessive-compulsive personality disorder (OCPD) is an Axis II diagnosis that is not commonly associated with behavioral disinhibition, the literature contains reports of occasional explosive aggressive outbursts. Existing explanations of OCPD etiology do not address the coexistence of compulsive and impulsive features witnessed in some subpopulations of patients. In this study, the authors present a compensatory theory of OCPD in an effort to explain clinical observations of an unexpectedly large number of OCPD diagnoses among patients clinic referred and self-referred for aggression problems.     

Sun compass orientation in seed-caching corvids: its role in spatial memory

The role of sun compass orientation in spatial memory of Clark’s nutcrackers, Nucifraga columbiana, and pinyon jays, Gymnorhinus cyanocephalus, was studied in a series of cache recovery experiments. Birds were tested in an octagonal outdoor aviary with sand-filled cups inserted in the floor. For caching, only 12 such cups in a 90° sector were available, while for recovery 4–7 days later all 48 cups in the entire aviary were open. In control tests, the birds concentrated their search activity in the sector where they had cached. When their internal clock was shifted 6 h between caching and recovery, pinyon jays shifted their search activity to the 90° adjacent sector, as predicted if the sun compass was used. Clark’s nutcrackers did not respond to the first clock-shift; however, they, too, shifted their search activity after a second clock-shift back to normal. This suggests that the sun compass is a component of spatial memory in both species. Clark’s nutcrackers, however, seem to rely on their sun compass to a lesser degree than pinyon jays or the previously studied scrub jays. A comparison of the findings indicates that the role of the sun in spatial memory might reflect differences in habitat and ecology of the three corvid species. Received: 18 February 1999 / Accepted after revision: 17 September 1999     

Effects of search cost on foraging and feeding: a three-component chain analysis

An experiment determined whether pigeons minimize number of key pecks per food delivery and maintain their baseline intake of food while key pecking on a three-component chain schedule. Pigeons at either 80% or 100% body weight obtained all their food during baseline and contingency sessions. During baseline sessions, pecks on the left and center keys had no consequences; each peck on the right key activated the feeder. During contingency sessions, pigeons key pecked on a three-component chain schedule simulating components of a foraging chain. In the search component either 3, 9 or 15 key pecks (varied parametrically across blocks of sessions) on the left key produced a stimulus on the middle key, indicating an encounter with either the low-cost prey (3 key pecks) or an equally probable high-cost prey (21 key pecks). In the procurement component the pigeon pecked either: (a) the left key once, thus returning to the search component, or (b) the middle key either 3 or 21 times, which activated the right response key. In the handling component one peck on the right key operated the feeder. The pigeons always procured the low-cost prey and minimized the number of key pecks per hopper by procuring the high-cost prey when the search-cost ratio was high (15 key pecks) but not when it was low (3 key pecks). All pigeons maintained their baselines of eating during contingency sessions by key pecking more frequently and eating more efficiently. The 80% body-weight birds produced higher overall rates of key pecking and eating. These results have implications for ecological theories of optimal foraging and for psychological theories of learned performance.     

Responding to negative social identity: a taxonomy of identity management strategies

Taken from literature on social identity theory and social comparison theory, 12 strategies of identity management were identified as possible responses to negative social identity. A taxonomy with two orthogonal axes is proposed as theoretical organization of these diverse strategies. While the first axis considers responses as being either individual or collective, the second axis refers to the distinction between behaviours and cognitions. It is assumed that the German unification process implied a lower status position of East Germans relative to West Germans on relevant comparison dimensions, and that East Germans have to deal with this threat to their identity. Hence, data of an East German sample are used to empirically systematize identity management strategies, and, thus, to test the proposed taxonomy. Results support the expected four-factor solution only for those strategies taken from social identity theory, while the responses derived from social comparison research build a fifth factor. In addition, the empirical assignments of strategies to cells of the taxonomy are only partly in line with the expected pattern. The empirical findings suggest some clarification and modifications of the proposed response taxonomy. The most important refers to a re-interpretation of the taxonomy's first axis, which now differentiates between responses according to the specific changes of the comparison parameters they imply. © 1998 John Wiley & Sons, Ltd.     

Reliability estimates for the immediate and delayed memory tasks

The Immediate and Delayed Memory Tasks are variations of the Continuous Performance Test. While previous research with the tasks has focused on group performance across multiple blocks and sessions, reliability estimates have not been established. We estimated reliability (1) between blocks of a single testing session (N=106), (2) across four sessions within a single testing day (N=20), and (3) across sessions on four consecutive testing days (N=20). Analyses indicated that the primary variable of interest, i.e., commission of errors, showed acceptable reliability within and across testing periods.     

Temporal stability of the Wisconsin Card Sorting Test in a chronic traumatic brain injury sample

The aim of the present study was to investigate the temporal stability of the Wisconsin Card Sorting Test (WCST) in a clinical population with documented brain pathology, stable cognitive deficits, and for whom repeated testing is common: chronic severe traumatic brain injury (TBI). Participants were 34 patients at least 1 year post severe TBI living at a large residential rehabilitation facility. The WCST was administered in standard fashion with both the standard and 64-card versions scored. All derived scores with norms were examined. Results indicated acceptable temporal stability of most scores for both the standard and short WCST, although the stability of the WCST-64 was poorer than for the standard WCST. Three sets of significant change indices are provided for clinical use.     

What We Owe to the Global Poor

This essay defends an account of the duties to the global poor that is informed by the empirical question of what makes countries rich or poor, and that tends to be broadly in agreement with John Rawlss account in The Law of Peoples. I begin by introducing the debate about the sources of growth and explore its implications for duties towards the poor. Next I explore whether (and deny that) there are any further-reaching duties towards the poor. Finally, I ask about the moral foundations for the duties to the poor of the sort that earlier parts argue there are.     

Rare targets are rarely missed in correctable search

Failing to find a tumor in an x-ray scan or a gun in an airport baggage screening can have dire consequences, making it fundamentally important to elucidate the mechanisms that hinder performance in such visual searches. Recent laboratory work has indicated that low target prevalence can lead to disturbingly high miss rates in visual search. Here, however, we demonstrate that misses in low-prevalence searches can be readily abated. When targets are rarely present, observers adapt by responding more quickly, and miss rates are high. Critically, though, these misses are often due to response-execution errors, not perceptual or identification errors: Observers know a target was present, but just respond too quickly. When provided an opportunity to correct their last response, observers can catch their mistakes. Thus, low target prevalence may not be a generalizable cause of high miss rates in visual search.     

Visual attention as a predictor of on-road driving performance of older drivers

With increasing numbers of older drivers on Australian roads, it is important to determine the functional abilities most closely related to driving ability among older adults. To this end, 90 drivers aged from 60 to 91 completed a battery of psychological, visual, physical and cognitive tests, and a standardised on-road driving test. A computerised test of visual attention, devised specifically for the study, was the best predictor of on-road driving performance. Other abilities that made independent contributions to the prediction of driving performance were contrast sensitivity and visuospatial memory. These functional abilities provided a better prediction of driving performance than chronological age, reinforcing the argument that drivers should only have their driving tested when their functional abilities decline, rather than when they reach a particular age.