Why we walk the way we do

By using inverse dynamics and forceplate recordings, this study established the principle of oscillating systems and the influence of gravity and body parameters on the programming of the gait parameters, step frequency and length. Calculation of the ratio of the amplitude of the center of mass (CM) and the center of foot pressure (CP) oscillations yielded an equation and established a biomechanical constant, the natural body frequency (NBF). NBF appears to be an absolute invariant parameter, specific to human standing posture and gait in terrestrial gravity, which influences the relative positions of CM and CP and whose value separates the frequency bands of standing posture from those for gait. This equation was tested by using the experimental paradigm of stepping in place and then used in calculating the magnitude of CM oscillations during gait. The biomechanical analysis of the experimental observations allows one to establish the relationships between body parameters and gravity and the central programming of locomotor parameters.     

Movement patterns of persons with HIV receiving treatment in public clinics in the Southern Health Region,Puerto Rico

A survey conducted among 187 HIV-infected patients from publicly supported HIV clinics in the Puerto Rican Southern Health Region (SHR) failed to substantiate health planners' concern that this group travels frequently to the US to receive medical services. Respondents were questioned about all places of residence and all sites of HIV treatment in the past 12 months. Movement was defined as being anywhere outside of the SHR for 2 weeks or longer. 7% of the sample had moved at least once in the past year; 4% had moved outside the SHR but within Puerto Rico, while 3% had been in the continental US. Compared to the heterosexual risk group, intravenous drug users and men who have sex with men were 7-8 times more likely to have moved. The attainment of at least a high school education was also significantly and independently associated with increased probability of movement. Medical care was not identified by any of these respondents as the primary reason for travel. 58% indicated they were in their current place of residence to be near family, friends, and relatives. Both the small sample size and the low socioeconomic status of respondents may have limited the ability of this study to identify the so-called "air bridge," however.     

Assessing the effectiveness of a multimedia-based lab for upper division psychology students

The efficacy of multimedia-based training in producing increased learning was evaluated. Two multimedia software packages were compared with live or videotaped lectures on the same material. Results differed by type of student (low or high initial knowledge) and type of program. Multimedia training programs may need to provide more aid to students with less initial knowledge in the training domain. In addition, the effects of multimedia may be subtle and therefore require rigorous evaluation.     

Influence of African American elders' age stereotypes on their cardiovascular response to stress

Although it has been shown that White elders are vulnerable to the influence of age stereotypes, it was not known whether this effect applied to African American elders. In the present study, African American elders were randomly assigned to negative or positive implicit-age-stereotype groups. Compared to participants in the positive age-stereotype group, those in the negative age-stereotype group demonstrated significantly more elevated cardiovascular response to stress, as measured by blood pressure and heart rate following mental challenges. These results suggest that negative age stereotypes generate a susceptibility to stress among African American elders, whereas positive age may provide them with a defense against this stress.     

Obsessive-compulsive disorder with and without tic disorder: a comparative study from India

Introduction: Evidence from phenomenological, family, genetic, and treatment studies from Western centers have suggested that tic-related obsessive-compulsive disorder (OCD) could be different from non-tic-related OCD. This study from India investigated the differences in OCD with and without tics, with respect to sociodemographics, symptom profile, and comorbidity, including obsessive-compulsive spectrum disorders, to examine whether the clinical profile of tic-related OCD is similar to that reported previously. Methods: Fifty subjects with OCD and tics (chronic motor tics and Tourette syndrome) were compared with 141 OCD subjects without tics. Results: Subjects having OCD with tics tended to be males, and had an earlier onset of illness. They had more of symmetry/aggressive and religious obsessions, and cleaning, ordering/arranging, hoarding, and repeating compulsions and were associated with trichotillomania and hypochondraisis. Stepwise backward (Wald) regression analysis showed that an early age of onset, male gender, aggressive obsessions, cleaning compulsions, and trichotillomania were significantly associated with tic-related OCD. Conclusion: The findings of this study from India are broadly similar to those reported previously from the West indicating the universality of differences in tic- and non-tic-related OCD. Our findings also support the existing evidence that tics contribute to the heterogeneity of OCD.     

Retention of high tactile acuity throughout the life span in blindness

Previous studies of tactile acuity on the fingertip, using passive touch, have demonstrated an age-related decline in spatial resolution for both sighted and blind subjects. We have reexamined this age dependence with two newly designed tactile-acuity charts that require active exploration of the test symbols. One chart used dot patterns similar to braille, and the other used embossed Landolt rings. Groups of blind braille readers and sighted subjects ranging from 12 to 85 years old were tested in two experiments. We replicated previous findings for sighted subjects by showing an age-related decrease in tactile acuity by nearly 1% per year. Surprisingly, the blind subjects retained high acuity into old age, showing no age-related decline. For the blind subjects, tactile acuity did not correlate with braille reading speed, the amount of daily reading, or the age at which braille was learned. We conclude that when measured with active touch, blind subjects retain high tactile acuity into old age, unlike their aging sighted peers. We propose that blind people's use of active touch in daily activities, not specifically braille reading, results in preservation of tactile acuity across the life span.     

Conceptualizing and assessing self-enhancement bias: a componential approach

Four studies implemented a componential approach to assessing self-enhancement and contrasted this approach with 2 earlier ones: social comparison (comparing self-ratings with ratings of others) and self-insight (comparing self-ratings with ratings by others). In Study 1, the authors varied the traits being rated to identify conditions that lead to more or less similarity between approaches. In Study 2, the authors examined the effects of acquaintance on the conditions identified in Study 1. In Study 3, the authors showed that using rankings renders the self-insight approach equivalent to the component-based approach but also has limitations in assessing self-enhancement. In Study 4, the authors compared the social-comparison and the component-based approaches in terms of their psychological implications; the relation between self-enhancement and adjustment depended on the self-enhancement approach used, and the positive-adjustment correlates of the social-comparison approach disappeared when the confounding influence of the target effect was controlled.     

Imagerie visuelle et rappel moteur d'enchaînements : effet du bilinguisme français vs créole

The two experiments reported in the present paper concern (i) the differential imagery value of French and Creole and (ii) the influence of language on the recall of sequences of patterned movements in a bilingual population. Creole words were obtained a higher imagery value than French words, certainly because Creole is an oral and vernacular language. Motor recall scores were better when the sequence was presented in Creole compared to French. The generation of visual images by Creole would facilitate the memorization and recall of new sequences of movements. The effect of language on imagery value of words and motor recall among bilingual French-Creole subjects was discussed in terms of nature of information encoding in each language.     

Increased use of safety-seeking behaviors in chronic back pain patients with high health anxiety

Many patients with chronic pain also exhibit elevated levels of health anxiety. This study examined the effect of health anxiety on the use of safety-seeking behaviors (SSBs) in pain-provoking situations. Participants were 20 chronic back pain patients with high health anxiety (Group H), 20 with low health anxiety (Group L) and 20 pain-free controls (Group C). Two physical tasks were video recorded, and compared both for overt pain behavior (identified by blind observers following a standardized procedure) and for the occurrence of SSB (identified by showing the participants video playback and asking them to specify motivation for all actions/behaviors displayed during the tasks). While there were no differences in the display of overt pain behaviors, Group H deployed a greater number of SSBs than Groups L and C. This finding held true for both tasks and remained significant when concurrent pain and mood ratings were statistically controlled for. SSB was correlated with catastrophizing thoughts but not pain intensity; pain intensity was correlated with overt pain behavior but not catastrophizing. Taken together, these findings suggest that SSB is distinct from overt pain behavior and may be a defining characteristic of chronic pain patients reporting high levels of health anxiety.