Integrity of both cerebral hemispheres is required to control in-phase or anti-phase coupling of ipsilateral hand and foot oscillations, as shown by the impairment of these tasks when performed on the healthy side of hemiplegic patients. On this basis, coupling of hand–foot movements was analysed in a right-handed subject (ME) who underwent a total resection of the corpus callosum. Oscillations of the prone hand and foot, paced by a metronome at different frequencies, as well as EMG activity in extensor carpi radialis (ECR) and tibialis anterior (TA) muscles were analysed by measuring the average phase difference between the hand and foot movements and EMG cycles.
ME performed in-phase movements (right-hand extension coupled to right-foot dorsal flexion) at frequencies up to 3 Hz, though the hand cycle progressively lagged the foot cycle as the frequency increased. At 3 Hz the hand lag reached −142° (as compared to about 25° in healthy subjects). The lag increased even further after application of an inertial load to the hand, reaching 180° at 1.8 Hz (about 50° in healthy subjects). ME's hand lag is caused by the lack of any anticipatory reaction in hand movers. In contrast to healthy subjects, which activate the ECR earlier than the TA when the frequency increases, ME activated the ECR later than TA at all frequencies higher than 0.9 Hz.
Anti-phase movements (hand extension coupled to foot plantar flexion) were performed only upto 1 Hz in unloaded conditions. At 0.6 Hz, movements were in tight phase-opposition (3°), but at 1 Hz, the hand lag reached −34° because of a delayed ECR activation. After hand loading ME was unable to couple movements in anti-phase. In contrast, normal subjects maintain a tight anti-phase coupling up to 2.0 Hz, both with an unloaded or loaded hand. Similar deficits were observed by ME when performing in-phase and anti-phase coupling on the left side, as well as when he was blindfolded.
In normal subjects, an anticipated muscular activation of hand movers compensates for hand loading. Since this compensation must depend on monitoring the hand delay induced by loading, the absence in ME of such compensatory reaction suggests that callosal division had apparently compromised the mechanisms sustaining feedback compensation for differences in the biomechanical limb properties. They also confirm and reinforce the idea that elaboration of the afferent message, aiming at controlling the phase of the movement association, needs the co-operation of both cerebral hemispheres. 相似文献
This work aims is to evaluate the therapeutic efficacy of cognitive behavior therapy (CBT) in pediatric patients with obsessive-compulsive disorder (OCD) who had not previously been treated with either pharmacotherapy or psychotherapy and who remained medication-free during CBT. Sixteen OCD outpatients, 8-17 years of age, were treated in a 12-week open trial with manualized CBT. Target symptoms were rated at two-week intervals with the Children's Yale-Brown Obsessive Compulsive Scale (CY-BOCS), the National Institute of Mental Health Global Obsessive-Compulsive Scale (NIMH Global), the Clinical Global Impression Scale (CGI), and the Hamilton Anxiety Rating Scale (Ham-A). Statistical analyses showed a significant benefit for treatment. Ten patients experienced at least a 50% reduction in symptoms on the CY-BOCS; seven were asymptomatic on the NIMH Global. These results build on previous reports that CBT may be effective in the acute treatment of pediatric OCD. Further, the results of this study suggest that CBT can be efficacious in alleviating OCD symptoms in the absence of pharmacotherapy. These results must be considered preliminary, given the small sample size and open administration of treatment. 相似文献
Cognitive biases and cognitive distortions have been implicated as important factors in the development and maintenance of many disorders. The concept of thought-shape fusion (TSF) in eating disorders was developed by Shafran, Teachman, Kerry, and Rachman (British Journal of Clinical Psychology 38 (1999) 167) as a variant of thought-action fusion, described by Shafran, Thordarson and Rachman (Journal of Anxiety Disorders 10 (1996) 379). TSF occurs when thinking about eating certain types of food increases a person's estimate of their shape and/or weight, elicits a perception of moral wrongdoing, and/or makes the person feel fat. Shafran et al. (1999) examined both the psychometric and experimental properties of TSF in an undergraduate sample. This paper reports an extension of this work to a clinical group (N=20) of patients with anorexia nervosa. After completing a set of relevant questionnaires, participants were asked to think about a food which they considered extremely fattening. They were then asked to write out the sentence, "I am eating--.", inserting the name of the fattening food in the blank. After being asked to rate their anxiety, guilt, feelings about their weight, morality, etc., participants were given the opportunity to neutralize their statement in any way they chose. The majority of the participants neutralized in ways consistent with the findings of Shafran et al. (1999). The results are discussed in terms of cognitive-behavioural formulations of eating disorders, and of the influence of cognitive biases and cognitive distortions on the processing of information relevant to food, weight and shape in anorexia nervosa. 相似文献
The hypothesis that borderline personality disorder (BPD) is related to overgeneral memories was tested in a mixed sample of 39 patients. A memory test with emotional cue words and the instruction to produce specific autobiographical memories was used. Specificity was judged by an independent rater. Regression analyses indicated that age and major depressive disorder were related to the production of less specific memories, whereas educational level and presence of personality disorder were positivily related to number of specific memories. Borderline personality disorder, anxiety disorders and childhood traumas were not related to number of specific memories. 相似文献
To ascertain how useful the Beck Scale for Suicide Ideation (BSI; Beck & Steer, Manual for Beck Scale for Suicide Ideation (1991)) would be for assessing the severity of suicidal ideation in patients who were diagnosed with schizophrenia, schizoaffective, or bipolar disorders, 142 inpatients were asked to complete the BSI. Eight (6%) patients refused, and four patients (3%) were unable to complete the BSI because they were unable to concentrate. Of the 130 patients who completed the BSI, 53 (41%) had schizoaffective, 37 (28%) had paranoid schizophrenia, 30 (23%) had manic bipolar, and 10 (8%) had depressed bipolar disorders. The coefficient alpha for the BSI was .96, and its one-week test-retest reliability for a subsample of 15 inpatients was 0.88, p < 0.001. The BSI total scores were positively correlated with having ever attempted suicide, r = 0.46, p < 0.001. According to the BSI, 36 (28%) patients were classified as current suicide ideators. The results were discussed as supporting the use of the BSI with inpatients who are diagnosed with schizophrenia, schizoaffective, or bipolar disorders. 相似文献
Three chimpanzees performed a computerized matching-to-sample task in which samples were photographs of items and comparison stimuli were geometric symbols called lexigrams. In Experiment 1, samples were either defined (i.e., they represented items that were associated already with a specific lexigram label by the chimpanzees) or undefined (i.e., they did not have an already learned association with a specific lexigram). On each trial, the foil (incorrect) comparison could be either a defined or an undefined lexigram. All 3 chimpanzees selected the correct comparison for undefined samples at a level significantly better than chance only when the foil comparison was defined. In Experiment 2, three comparisons were presented on each trial, and in Experiment 3, four comparisons were presented on each trial. For Experiments 2 and 3, the foil comparisons consisted of either defined or undefined comparisons or a mixture of both. For these two experiments, when the chimpanzees were presented with an undefined sample, they typically made selections of only undefined comparisons. These data indicate that the chimpanzees responded through use of exclusion. A final experiment, however, indicated that, despite the use of exclusion to complete trials with undefined samples correctly, the chimpanzees did not learn new associations between undefined samples and comparisons. 相似文献