Some neurobiological aspects of psychotherapy. A review.
(1/995)Ever since the idea was accepted that memory is associated with alterations in synaptic strength, studies on the cellular and molecular mechanisms responsible for the plastic changes in neurons have attracted wide interest in the scientific community. This article explores the process of memory consolidation leading to persistent modifications in synaptic plasticity as a mechanism by which psychotherapy facilitates changes in the permanent storage of information acquired throughout the individual's life. The psychobiological interrelationships of affect, attachment, and memory offer a perspective regarding the etiology and treatment of clinical disturbances of affect. Analogies between brain physiology and modes of psychotherapy provide the foundation for a review of psychiatric disorders involving the inability to control fear, obsessions, compulsions, and delusions, all of which respond to psychotherapeutic interventions. (+info)
Integration of proprioceptive and visual position-information: An experimentally supported model.
(2/995)To localize one's hand, i.e., to find out its position with respect to the body, humans may use proprioceptive information or visual information or both. It is still not known how the CNS combines simultaneous proprioceptive and visual information. In this study, we investigate in what position in a horizontal plane a hand is localized on the basis of simultaneous proprioceptive and visual information and compare this to the positions in which it is localized on the basis of proprioception only and vision only. Seated at a table, subjects matched target positions on the table top with their unseen left hand under the table. The experiment consisted of three series. In each of these series, the target positions were presented in three conditions: by vision only, by proprioception only, or by both vision and proprioception. In one of the three series, the visual information was veridical. In the other two, it was modified by prisms that displaced the visual field to the left and to the right, respectively. The results show that the mean of the positions indicated in the condition with both vision and proprioception generally lies off the straight line through the means of the other two conditions. In most cases the mean lies on the side predicted by a model describing the integration of multisensory information. According to this model, the visual information and the proprioceptive information are weighted with direction-dependent weights, the weights being related to the direction-dependent precision of the information in such a way that the available information is used very efficiently. Because the proposed model also can explain the unexpectedly small sizes of the variable errors in the localization of a seen hand that were reported earlier, there is strong evidence to support this model. The results imply that the CNS has knowledge about the direction-dependent precision of the proprioceptive and visual information. (+info)
Attentional ability among survivors of leukaemia.
(3/995)Attentional ability in 19 survivors of acute lymphoblastic leukaemia and 19 sibling controls was assessed using a neuropsychological model of attention. Analysis revealed that children who had received treatment for leukaemia exhibited significantly poorer performance on measures of the "focus encode" and "focus execute" elements of attention and on measures of the ability to respond to external cues and feedback. No significant differences in performance were found for measures of sustained attention and the ability to shift attention. These results indicate that children who have received treatment for leukaemia may experience highly specific attentional deficits that could have an impact on academic performance, particularly mathematical and reading skills. It is suggested that this underlying attentional deficit might be the source of the neuropsychological sequelae associated with the disease. Future attempts at remediation should incorporate activities specifically designed to ameliorate focusing difficulties. (+info)
Parallel information processing in the dorsal striatum: relation to hippocampal function.
(4/995)We investigated the effects of localized medial and lateral CPu lesions and fornix/fimbria lesions on responses to a local cue and to behavior based on cognitive-spatial information in the water maze. Rats were trained concurrently on the cue (visible platform) and spatial (submerged platform) components of the task, followed by a test in which responses to the two types of information were dissociated by a measure of competing response tendencies. Bilateral lesions of lateral CPu did not affect acquisition of either cue or spatial responding but produced a preference for the spatial response on the competition test. Bilateral lesions of the medial CPu retarded but did not prevent learning both components and produced a preference for the cue response on the competition test. The latter effect was accompanied by increased thigmotaxis (swimming in the periphery of the pool), primarily during the early acquisition trials, which was attributed to an impaired ability to respond to learned spatial information. Fornix/fimbria lesions prevented spatial but not cue learning and produced a preference for the cue response on the competition test. Asymmetric lesions (unilateral hippocampus and contralateral medial CPu) produced mild retardation of acquisition of both the cue and spatial tasks and a preference for the cue response on the competition test. These findings dissociate the functions of the lateral and medial CPu and suggest that the hippocampus and medial CPu may be parts of a system that promotes responding based on learned cognitive-spatial information, particularly in competitive cue-place response situations. (+info)
Neurocognitive and social functioning in schizophrenia.
(5/995)This cross-sectional study examined the relationships between neurocognitive and social functioning in a sample of 80 outpatients with DSM-III-R schizophrenia. The neurocognitive battery included measures of verbal ability, verbal memory, visual memory, executive functioning, visual-spatial organization, vigilance, and early information processing. Positive and negative symptoms were assessed with the Positive and Negative Syndrome Scale. A range of social behaviors were assessed using the Social Functioning Scale (SFS), the Quality of Life Scale (QLS), and a video-based test, the Assessment of Interpersonal Problem-Solving Skills (AIPSS). Social functioning as assessed by the SFS was unrelated to neurocognitive functioning. Poor cognitive flexibility was associated with low scores on the QLS and the AIPSS. Verbal ability and verbal memory were also significantly associated with the AIPSS. Visual-spatial ability and vigilance were associated with the sending skills subscale of the AIPSS. In this study, which used a wide range of neurocognitive tests and measures of community functioning and social problem solving, results support earlier research that suggests an association between certain aspects of neurocognitive functioning and social functioning. (+info)
Physical exercise habit: on the conceptualization and formation of habitual health behaviours.
(6/995)An observation one can make when reviewing the literature on physical activity is that health-enhancing exercise habits tend to wear off as soon as individuals enter adolescence. Therefore, exercise habits should be promoted and preserved early in life. This article focuses on the formation of physical exercise habits. First, the literature on motivational determinants of habitual exercise and related behaviours is discussed, and the concept of habit is further explored. Based on this literature, a theoretical model of exercise habit formation is proposed. More specifically, expanding on the idea that habits are the result of automated cognitive processes, it is argued that physical exercise habits are capable of being automatically activated by the situational features that normally precede these behaviours. These habits may enhance health as a result of consistent performance over a long period of time. Subsequently, obstacles to the formation of exercise habits are discussed and interventions that may anticipate these obstacles are presented. Finally, implications for theory and practice are briefly discussed. (+info)
Guanfacine, but not clonidine, improves planning and working memory performance in humans.
(7/995)The present study compares, using a double-blind, placebo controlled design the effects of two alpha 2-agonists, clonidine (0.5, 2, and 5 micrograms/kg) and guanfacine (7 and 29 micrograms/kg) on spatial working memory, planning and attentional set-shifting, functions thought to be dependent on the "central executive" of the prefrontal cortex. Blood pressure and the subjective feeling of sedation were affected equally by clonidine and guanfacine. The 0.5 microgram/kg and 5 micrograms/kg doses of clonidine disrupted spatial working memory, but the medium dose had no effect. The 0.5 and 2 micrograms/kg doses of clonidine increased impulsive responding in the planning test. The 5 micrograms/kg dose of clonidine slowed responding at effortful levels of planning and attentional set-shifting tests. The 29 micrograms/kg dose of guanfacine improved spatial working memory and planning. Guanfacine had no effect on attentional set-shifting. These data indicate that guanfacine improved planning and spatial working memory, but clonidine dose-dependently disrupted performance. It is possible that the greater selectivity of guanfacine for alpha 2A-adrenoceptor subtype may underlie its differences from clonidine. (+info)
Correlating fibreoptic nasotracheal endoscopy performance and psychomotor aptitude.
(8/995)We have investigated the correlation between the scores attained on computerized psychometric tests, measuring psychomotor and information processing aptitudes, and learning fibreoptic endoscopy with the videoendoscope. Sixteen anaesthetic trainees performed two adaptive tracking tasks (ADTRACK 2 and ADTRACK 3) and one information management task (MAZE) from the MICROPAT testing system. They then embarked on a standardized fibreoptic training programme during which they performed 15 supervised fibreoptic nasotracheal intubations on anaesthetized oral surgery patients. There was a significant correlation between the means of the 15 endoscopy times and both ADTRACK 2 (r = -0.599, P = 0.014) and ADTRACK 3 (r = -0.589, P = 0.016) scores. The correlation between the means of the 15 endoscopy times and MAZE scores was not significant. The ratios of the mean endoscopy time for the last seven endoscopies to the mean endoscopy time for the first seven endoscopies were not significantly correlated with ADTRACK 2, ADTRACK 3 or MAZE scores. Psychomotor abilities appeared to be determinants of trainees' initial proficiency in endoscopy, but did not appear to be determinants of trainees' rates of progress during early fibreoptic training. (+info)