Self-motion perception during locomotor recalibration: more than meets the eye

Do locomotor aftereffects depend specifically on visual feedback? In 7 experiments, 116 college students were tested, with closed eyes, at stationary running or at walking to a previewed target after adaptation, with closed eyes, to treadmill locomotion. Subjects showed faster inadvertent drift during stationary running and increased distance (overshoot) when walking to a target. Overshoot seemed to saturate (i.e., reach a ceiling) at 17% after as little as 1 min of adaptation. Sidestepping at test reduced overshoot, suggesting motor specificity. But inadvertent drift effects were decreased if the eyes were open and the treadmill was drawn through the environment during adaptation, indicating that these effects involve self-motion perception. Differences in expression of inadvertent drift and of overshoot after adaptation to treadmill locomotion may have been due to different sets of ancillary cues available for the 2 tasks. Self-motion perception is multimodal.     

Semantic feature knowledge and picture naming in dementia of Alzheimer's type: a new approach

This study addresses continuing controversies concerning the nature of semantic impairment in early dementia of the Alzheimer type (DAT), and the relationship between conceptual knowledge and picture naming. A series of analyses of fine-grained feature knowledge data show that: (1) distinctive features of concepts were more vulnerable than shared; (2) the amount of attribute knowledge about a concept was associated reliably, and in a graded fashion, with the ability to name a picture of that item; (3) sensory features were differentially important in naming; and (4) the degree of disruption to different types of attribute knowledge did not vary between items from living and nonliving domains. These findings are discussed in the context of contemporary cognitive and computational models of semantic memory organisation.     

Motivation influences the underestimation of cumulative risk

Past research has shown that people typically underestimate the cumulative risk of events. This effect has mainly been interpreted as resulting from the use of cognitive heuristics and judgment strategies, such as availability or anchoring and adjustment. The authors suggest that motivational processes can be an additional force in the generation of cumulative risk estimates. Using an experimental design, Study 1 shows that people underestimate the cumulative risk of infection with sexually transmitted diseases of appealing prospective sexual partners by using risk-irrelevant information for their judgment. Using a correlational design, Study 2 demonstrates that people underestimate the cumulative risk of being infected with a sexually transmitted disease and that commitment to the present partner is directly related to a low cumulative risk estimate as well as indirectly through its effect on the perceived risk of the present partner. Together, the two studies demonstrate that motivation influences the underestimation of cumulative risk.     

The prediction of above-average participation in volunteerism: a test of the theory of planned behavior and the volunteers functions inventory in older Australian adults

In the present prospective study of 81 older volunteers from a nonprofit organization in Australia, the authors compared the predictive utility of I. Ajzen's (1988) theory of planned behavior with that of E. G. Clary and M. Snyder's (1991) functional approach to volunteering. The authors mailed questionnaires to 385 volunteers in two waves of data collection. The first wave measured theory-of-planned-behavior variables and functional-approach variables. The second wave measured self-reported volunteering behavior for the previous month. Regression analyses supported both the theory of planned behavior and the functional approach; the theory of planned behavior accounted for a significantly larger proportion of variance in above-average participation in self-reported volunteerism. The findings of the present study provided some support for both the theory of planned behavior and the functional approach as models of self-reported volunteerism.     

Task goals and change in dynamical degrees of freedom with motor learning

In this article, the authors examined the hypothesis that the direction of the change (increase or decrease) in the dynamical degrees of freedom (dimension) regulated as a function of motor learning is task-dependent. Adult participants learned 1 of 2 isometric force-production tasks (Experiment 1: constant force output; Experiment 2: sinusoidal force output) over 5 days of practice and a 6th day with augmented information withdrawal. The results showed that over practice, the task goal induced either an increase (Experiment 1) or a decrease (Experiment 2) in the dimension of force output as performance error was reduced. These findings support the proposition that the observed increase or decrease in dimension with learning is dependent on both the intrinsic dynamics of the system and the short-term change required to realize the task goal.     

Overactive action monitoring in obsessive-compulsive disorder: evidence from functional magnetic resonance imaging

The anterior cingulate cortex (ACC) in patients with obsessive-compulsive disorder (OCD) has been found to be hyperactive at rest, during symptom provocation, and after commission of errors in cognitive tasks. This hyperactivity might reflect an abnormality in conflict detection, a hypothesized basic mechanism for the action-monitoring function of the ACC. This hypothesis was tested using functional magnetic resonance imaging, by scanning 11 OCD patients and 13 matched control subjects while they performed a version of the continuous-performance task with four trial types that induced graded levels of response conflict. Although a behavioral index of conflict (i.e., accuracy) was similar for patients and control subjects, the ACC activation was increased in patients during high-conflict trials. The error-related activity in the same brain region was also higher in patients, consistent with previous electrophysiological findings. Both conflict- and error-related activity showed trends for positive correlations with severity of OCD symptoms, but not with anxiety. These findings suggest that as part of an overactive action-monitoring system, the ACC is more directly involved in the pathophysiology of OCD than previously thought.     

Prison wardens' perception of psychosocial and service needs of incarcerated women

Wardens and administrators of 77 women's correctional facilities were mailed a questionnaire designed to assess the psychosocial and service needs of incarcerated female inmates nationally. 35 completed surveys were returned. Representativeness of the sample is discussed. Analysis identified attitudes about recent correctional trends perceived by wardens, including concerns about child care while incarcerated.     

Do you see what I see? Testing horses’ ability to recognise real-life objects from 2D computer projections

Animal Cognition - The use of 2-dimensional representations (e.g. photographs or digital images) of real-life physical objects has been an important tool in studies of animal cognition. Horses are...