Psychological and sex features of delayed gut transit in functional gastrointestinal disorders.
(65/6813)
BACKGROUND: The relation of demographic and psychological factors to the presence and extent of gut transit impairment in the functional gastrointestinal disorders has received little attention. AIMS: To compare the psychosocial and demographic features of patients with functional gastrointestinal disorders and delayed transit in one region of the gastrointestinal tract with those displaying more widespread delayed transit (that is, delay in two or three regions), and those with normal transit in all three regions. PATIENTS: Of 110 outpatient participants who satisfied standardised criteria for functional gastrointestinal disorders, 46 had delayed transit in one region, 32 had delay in two or three regions, and 17 exhibited normal transit in all regions. METHODS: Transit in the stomach, the small intestine, and the large intestine was assessed concurrently using a wholly scintigraphic technique; psychological status was assessed using established psychometric measures. RESULTS: Patients with delayed transit displayed demographic and psychological features that contrasted with patients with normal transit in all regions. In particular, widespread delayed transit featured female sex, a highly depressed mood state, increased age, frequent control of anger, and more severe gastric stasis, while the features distinguishing normal transit were male sex and high levels of hypochondriasis. CONCLUSION: These data suggest the existence of a distinct psychophysiological subgroup, defined by the presence of delayed transit, in patients with functional gastrointestinal disorders. (+info)
Limitations of the SF-36 in a sample of nursing home residents.
(66/6813)
OBJECTIVE: to assess test characteristics of the Medical Outcomes Study SF-36 (Short-Form 36) with residents of nursing homes. RESEARCH DESIGN: nursing home residents with 17 or more points on the Mini-Mental State Examination (MMSE) and > or = 3 months residence (128 of 552 screened) were selected randomly. Interviewers administered the SF-36 (repeated after 1 week), Geriatric Depression Scale and MMSE. We recorded activities of daily living and medication data from medical records. Data analysis included test-retest intraclass correlations, item completion, score distributions and SF-36 correlations with measures of physical and mental functioning. RESULTS: 97 nursing home residents (75.8%) consented. Test-retest intraclass correlation coefficients were good to excellent (range = 0.55 to 0.82). Convergent validity between SF-36 physical health scales and the activities of daily living index was modest (r range = -0.37 to -0.43). About 25% of residents scored zero (lowest score) on at least one SF-36 physical function measure. SF-36 mental health scales correlated strongly with the Geriatric Depression Scale (r range = -0.63 to -0.71) and modestly with bodily pain (r = -0.35). No SF-36 scales correlated strongly with the MMSE. CONCLUSION: only one in five nursing home residents met minimal participation criteria, suggesting limited utility of the SF-36 in nursing homes. Reliability and validity characteristics were fairly good. Skewed scores were noted for some SF-36 scales. The utility of the SF-36 may be limited to assessments of subjects with higher cognitive and physical functioning than typical nursing home residents. The SF-36 might benefit from modification for this setting, or by tests of proxy ratings. (+info)
Velocity tuned mechanisms in human motion processing.
(67/6813)
We determined two-dimensional motion discrimination contours in the spatio-temporal frequency plane to characterize the mechanisms underlying velocity perception. In particular, we wanted to determine whether there exist mechanisms tuned specifically to velocity, rather than separable mechanisms tuned to spatial and temporal frequency. A 4-AFC paradigm was used to determine spatio-temporal frequency discrimination thresholds for moving sinewave gratings defined by luminance contrast. Three of the grating patches used were defined by the same spatial and temporal frequency (standard), the other (test) differed by a fixed proportional change in spatial and temporal frequency. Subjects had to indicate which grating differed most from the others and the thresholds determined for varying proportions of change in spatial and temporal frequency were used to trace out complete threshold contours in the plane spanned by these attributes. Some of the contours, primarily at speeds above 1 deg/s, were noticeably oriented along lines of constant velocity. To further isolate these mechanisms, spatio-temporal noise was added to the standard stimuli either along a line of constant velocity or in the direction orthogonal to it. When spatio-temporal noise of constant velocity was added to the standard stimuli, threshold contours became elongated only along the direction of the noise. The same amount of noise in the orthogonal direction produced an overall increase in thresholds without changing the shape of the contour, presenting clear evidence for velocity tuned mechanisms. In further experiments we discovered that velocity tuned mechanisms interact with separable mechanisms to produce optimal discriminability. Analogous experiments with isoluminant stimuli failed to exhibit evidence for velocity tuning, supporting the notion that the human color vision system is impaired in its coding of stimulus speed, despite excellent sensitivity to direction of motion. (+info)
Discriminating local continuity in curved figures.
(68/6813)
We assessed whether the visual system's ability to discriminate subtle perturbations from smoothness in curved shapes was based on 1st-order properties or 2nd-order properties. We investigated which of the two would determine performance in a task where the observer had to detect spatial jitter on aligned, unaligned or unoriented Gabor patches forming either an open or enclosed path. Surprisingly, performance was no better in the conditions employing aligned micropatterns, implicating the use of 2nd-order properties. Varying the peak spatial frequency or the size, (standard deviation of the Gaussian envelope), produced little change in the jitter threshold. By contrast, increasing the spacing between the Gabor patches had a large detrimental effect. Randomizing the orientation of the Gabors also hampered performance. These results indicate that orientation linking may only aid psychophysical performance in detection tasks. If variance was imposed on the size of the blobs (a 2nd-order property), performance was degraded. Variance on the carrier spatial frequency (a 1st-order property) resulted in a smaller worsening of performance. Overall, our results imply that shape discrimination is performed by mechanisms sensitive to 2nd-order micropattern properties, although some dependence on 1st-order properties exists. (+info)
Everyday cognition: age and intellectual ability correlates.
(69/6813)
The primary aim of this study was to examine the relationship between a new battery of everyday cognition measures, which assessed 4 cognitive abilities within 3 familiar real-world domains, and traditional psychometric tests of the same basic cognitive abilities. Several theoreticians have argued that everyday cognition measures are somewhat distinct from traditional cognitive assessment approaches, and the authors investigated this assertion correlationally in the present study. The sample consisted of 174 community-dwelling older adults from the Detroit metropolitan area, who had an average age of 73 years. Major results of the study showed that (a) each everyday cognitive test was strongly correlated with the basic cognitive abilities; (b) several basic abilities, as well as measures of domain-specific knowledge, predicted everyday cognitive performance; and (c) everyday and basic measures were similarly related to age. The results suggest that everyday cognition is not unrelated to traditional measures, nor is it less sensitive to age-related differences. (+info)
Reduction of frontal neocortical grey matter associated with affective aggression in patients with temporal lobe epilepsy: an objective voxel by voxel analysis of automatically segmented MRI.
(70/6813)
BACKGROUND: Interictal episodes of aggression are often reported in patients with epilepsy. Some have characteristics of what has been referred to as episodic dyscontrol or intermittent explosive disorder (IED). Although structural brain abnormalities are thought to play a part in the pathophysiology of aggression, there are few in vivo studies of structural cerebral changes in patients with epilepsy and aggression. Using quantitative MRI, subtle structural brain abnormalities can be investigated in subgroups of patients with both epilepsy and episodes of affective aggression. METHODS: After automated segmentation of cerebral grey matter from T1 weighted MRI, the objective technique of statistical parametric mapping (SPM) was applied to the analysis of 35 control subjects, 24 patients with temporal lobe epilepsy (TLE) with a history of repeated, interictal episodes of aggression, and 24 patients with TLE without episodes of aggression. Both TLE patient groups were compared with each other and with the control subjects on a voxel by voxel basis for increases and decreases of grey matter. RESULTS: The patients with TLE with aggressive episodes had a decrease of grey matter, most markedly in the left frontal lobe, compared with the control group and with patients with TLE without aggressive episodes. CONCLUSION: These findings suggest that a reduction of frontal neocortical grey matter might underly the pathophysiology of aggression in TLE. These voxel by voxel comparisons can guide further in vivo studies into aggression. (+info)
Alcohol-Use Disorders Identification Test: a comparison between paper and pencil and computerized versions.
(71/6813)
The use of screening questionnaires to detect early problem drinking has been stimulated by the development of the AUDIT (Alcohol-Use Disorders Identification Test). A comparison of a computerized version of the test and its paper and pencil original was conducted on 110 consecutive attenders at an alcoholism day-treatment facility. The findings suggest that the computer version is as acceptable as the paper and pencil one and that scores on the two formats are comparable. (+info)
The "benefits" of distractibility: mechanisms underlying increased Stroop effects in schizophrenia.
(72/6813)
Recent studies of selective attention in schizophrenia patients suggest a particular pattern of single-trial Stroop performance: increased facilitation but not interference in reaction times (RTs), combined with increased error interference. Our Stroop task analysis suggests that this pattern can be explained by a selective attention deficit if one accounts for (1) performance in the congruent condition; (2) the nature of the neutral stimulus; (3) the relationship between accuracy and RT; and (4) response set effects. To test these hypotheses, we examined Stroop performance in 40 DSM-IV schizophrenia patients and 20 healthy control subjects, using a range of neutral stimuli (color patches, noncolor words, color words not in the response set). The findings confirmed several of our predictions and the results were consistent with the hypothesis that abnormal Stroop performance in schizophrenia reflects a failure to adequately attend to the task-appropriate stimulus dimension (color). This inattention affects both the congruent and incongruent conditions and multiple points in the information processing pathway. (+info)