Brain and cognition
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Brain and cognition · Oct 2009
Chronic glucocorticoid hypersecretion in Cushing's syndrome exacerbates cognitive aging.
Cumulative exposure to glucocorticoid hormones (GC) over the lifespan has been associated with cognitive impairment and may contribute to physical and cognitive degeneration in aging. The objective of the present study was to examine whether the pattern of cognitive deficits in patients with Cushing's syndrome (CS), a disorder characterized by chronic exposure to elevated levels of glucocorticoids (GC), is similar to that observed in older individuals. Ten subjects with CS were compared to sex-, age-, and education-matched healthy controls and older subjects (age of CS subjects+15 yr). ⋯ Further, a principal component analysis revealed two significant factors, representing general cognitive function and verbal memory explaining 39.9% and 10.0% of the variance, respectively. Additional MANCOVAs with depression as a covariate revealed that CS and older control subjects showed impaired performance on general cognitive function compared to age-matched controls. These results suggest that hypersecretion of GCs has "aging-like" effects on cognitive performance in individuals with CS.
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Watching a rubber hand being stroked by a paintbrush while feeling identical stroking of one's own occluded hand can create a compelling illusion that the seen hand becomes part of one's own body. It has been suggested that this so-called rubber hand illusion (RHI) does not simply reflect a bottom-up multisensory integration process but that the illusion is also modulated by top-down, cognitive factors. ⋯ These findings first suggest that the RHI seems to be resistant to top-down knowledge in terms of a conceptual interpretation of tactile sensations. Second, they argue against the hypothesis that participants own hand tends to disappear during the illusion and that the rubber hand actively replaces it.
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Brain and cognition · Mar 2009
Superior temporal activation in response to dynamic audio-visual emotional cues.
Perception of emotion is critical for successful social interaction, yet the neural mechanisms underlying the perception of dynamic, audio-visual emotional cues are poorly understood. Evidence from language and sensory paradigms suggests that the superior temporal sulcus and gyrus (STS/STG) play a key role in the integration of auditory and visual cues. ⋯ Results suggest that the bilateral superior temporal region plays distinct roles in the perception of emotion and in the integration of auditory and visual cues. Given the greater ecological validity of the stimuli developed for this study, this paradigm may be helpful in elucidating the deficits in emotion perception experienced by clinical populations.
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Brain and cognition · Mar 2009
Long-term ability to interpret facial expression after traumatic brain injury and its relation to social integration.
There is considerable evidence that individuals with traumatic brain injury (TBI) experience problems interpreting the emotional state of others. However, the functional implications of these changes have not been fully investigated. ⋯ A significant relationship was also established between social integration and ability to interpret facial expression for TBI participants. These results support the inclusion of therapy targeting this area within rehabilitation programs for individuals with TBI.
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Brain and cognition · Nov 2008
Case ReportsThe persistence of erroneous familiarity in an epileptic male: challenging perceptual theories of déjà vu activation.
We report the case of a 39-year-old, temporal lobe epileptic male, MH. Prior to complex partial seizure, experienced up to three times a day, MH often experiences an aura experienced as a persistent sensation of déjà vu. Data-driven theories of déjà vu formation suggest that partial familiarity for the perceived stimulus is responsible for the sensation. ⋯ Clearly, in epilepsy, erratic neuronal firing is the likely contributor, and in this paper we postulate that such brain firing causes higher-order erroneous 'cognitive feelings'. We tentatively extend this account to the general population. Rather than being a reaction to familiar elements in perceptual stimuli, déjà vu is likely to be the result of a cognitive feeling borne of the erroneous activation of neural familiarity circuits such as the parahippocampal gyrus, persisting as long as this activation persists.