Response Selection Contributes to the Preparation Cost for Bimanual Asymmetric Movements

Movement preparation of bimanual asymmetric movements takes more time than bimanual symmetric movements in choice reaction-time conditions. This bimanual asymmetric cost may be caused by increased processing demands on any stage of movement preparation. The authors tested the contributions of each stage of movement preparation to the asymmetric cost by using the additive factors method. This involved altering the stimulus contrast, response compatibility, and response complexity. These manipulations changed the processing demands on stimulus identification, response selection, and response programming, respectively. Any manipulation with a larger reaction time cost than control suggests that stage contributes to the bimanual asymmetric cost. The bimanual asymmetric cost was larger for incompatible stimuli, which supports that response selection contributes to the bimanual asymmetric cost.     

External focus of attention improves performance in a speeded aiming task

Athletic skills are often executed better when learners focus attention externally (e.g., on the trajectory of the ball after a tennis serve), rather than internally (e.g., on the position of their arm) (e.g., Wulf, 2007a). The current study explored the effects of attention focus on learning of speeded responses, and examined whether these benefits hold for retention and transfer. Participants performed a computerized speeded aiming task while focusing on the direction of the cursor (external focus) versus the direction in which their hand moved the mouse (internal focus). One week later, half of the participants performed the same task again (retention), and half performed the task under conditions in which the mouse movements were changed (transfer). Relative to internal focus, external focus led to faster acquisition and better maintenance of speeded responses over the retention interval.     

Pointing out new news, old news, and absent referents at 12 months of age

There is currently controversy over the nature of 1-year-olds' social-cognitive understanding and motives. In this study we investigated whether 12-month-old infants point for others with an understanding of their knowledge states and with a prosocial motive for sharing experiences with them. Declarative pointing was elicited in four conditions created by crossing two factors: an adult partner (1) was already attending to the target event or not, and (2) emoted positively or neutrally. Pointing was also coded after the event had ceased. The findings suggest that 12-month-olds point to inform others of events they do not know about, that they point to share an attitude about mutually attended events others already know about, and that they can point (already prelinguistically) to absent referents. These findings provide strong support for a mentalistic and prosocial interpretation of infants' prelinguistic communication.     

A Priori Causal Models of Natural Selection

Plato articulates a deep perplexity about inquiry in ‘Meno's Paradox’—the claim that one can inquire neither into what one knows, nor into what one does not know. Although some commentators have wrestled with the paradox itself, many suppose that the paradox of inquiry is special to Plato, arising from peculiarities of the Socratic elenchus or of Platonic epistemology. But there is nothing peculiarly Platonic in this puzzle. For it arises, too, in classical Indian philosophical discussions, where it is formulated with great clarity, and analysed in a way that casts it in a new light. We present three treatments of the puzzle in Indian philosophy, as a way of refining and sharpening our understanding of the paradox, before turning to the most radical of the Indian philosophers to tackle it. The Indian philosophers who are optimistic that the paradox can be resolved appeal to the existence of prior beliefs, and to the resources embedded in language to explain how we can investigate, and so move from ignorance to knowledge. Highlighting this structural feature of inquiry, however, allows the pessimist philosopher to demonstrate that the paradox stands. The incoherence of inquiry is rooted in the very idea of aiming our desires at the unknown. Asking questions and giving answers rests on referential intentions targeting objects in a region of epistemic darkness, and so our ‘inquiry sceptic’ also finds structurally similar forms of incoherence in the pragmatics of interrogative discourse.     

Learning and forgetting in schizophrenia

Recent studies of patients with schizophrenia have consistently demonstrated marked deficits on measures of initial learning. However, contradictory results have been reported concerning retention and forgetting. The present study examined the level of initial and delayed recall of stories and visual figures in a group of 76 patients with schizophrenia and 51 normal controls. Schizophrenia patients demonstrated marked impairments in initial and delayed recall as well as significantly worse percentage retention scores. However, schizophrenia patients and healthy controls individually matched on level of initial recall had nearly identical delayed recall performance. The results suggest a primary deficit in the initial acquisition of information rather than an accelerated rate of forgetting in schizophrenia.     

An anatomically constrained, stochastic model of eye movement control in reading

This article presents SERIF, a new model of eye movement control in reading that integrates an established stochastic model of saccade latencies (LATER; R. H. S. Carpenter, 1981) with a fundamental anatomical constraint on reading: the vertically split fovea and the initial projection of information in either visual field to the contralateral hemisphere. The novel features of the model are its simulation of saccade latencies as a race between two stochastic rise-to-threshold LATER units and its probabilistic selection of the target for the next saccade. The model generates simulated eye movement behavior that exhibits important characteristics of actual eye movements made during reading; specifically, simulations produce realistic saccade target distributions and replicate a number of critical reading phenomena, including the effects of word frequency on fixation durations, the inverted optimal viewing position effect, the trade-off between first and second fixation durations of refixated words, and the dependence of parafoveal preview benefit on eccentricity.     

The impact of neuroticism upon married bipolar patients

The NEO Personality Inventory was given to 33 married patients with bipolar disorder. Consistent with previous findings, patients with bipolar disorder did not show an abnormal personality profile as a group. Extremely wide variation on all scales indicated that the group profile tells little about individual patients. Trait neuroticism robustly predicted psychiatric symptoms at entry to the study when assessed retrospectively for the two years prior to entry and when averaged over a year of treatment. Neuroticism also negatively predicted the self-confidence of the patients in this sample. The patients identified as outliers on neuroticism form a clinically difficult group for whom the distinction between Axes I and II appears to be less meaningful.     

Intergroup contact between professional groups: Two evaluation studies

We report two studies which evaluate practically-oriented programmes of interprofessional contact involving doctors and social workers. The evaluation is based on the ‘contact hypothesis’ in intergroup relations, and highlights four sets of dependent measures: background perceptions, ingroup and outgroup ratings, knowledge, and judgements about work with outgroup partners and experienced contact. Consistent with the contact hypothesis, both studies revealed an improvement in outgroup attitudes, evidence of mutual intergroup differentiation (acknowledged superiority of ingroup and outgroup on independent dimensions), and increased outgroup knowledge. Greater change in Study 2 is interpreted in terms of its longer duration, and the opportunity it provided for contact with multiple outgroup members, compared with a single outgroup partner in Study 1. These findings from field studies are consistent with results from published laboratory experiments.