1. |
- Kompus, Kristiina, et al.
(author)
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Deficits in inhibitory executive functions in Klinefelter (47, XXY) syndrome
- 2011
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In: Psychiatry Research. - : Elsevier BV. - 0165-1781 .- 1872-7123. ; 189:1, s. 135-140
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Journal article (peer-reviewed)abstract
- Klinefelter syndrome (47, XXY) is a sex chromosome aneuploidy associated with mild deficits in cognitive and language functions. Dysfunctions have also been reported in performance of tasks which examine executive functions. However, it is unclear whether the impaired performance is caused or accentuated by problems with semantic processing and information processing speed. In the present study we used an experimental task which is relatively insensitive to these confounding factors. We examined inhibitory executive functions in a group of XXY males compared with male (XY) and female (XX) controls, using a dichotic listening speech sound task with instructions to focus attention on either the right or the left ear stimulus. With this task, inhibitory executive functions can be assessed separately from language, processing speed, and attention orientation abilities. We found that XXY males showed a selective deficit in inhibitory executive functions compared to both control groups, whereas attentional orientation was not impaired. The present findings suggest that executive dysfunctions associated to Klinefelter syndrome can be selectively identified, and are particularly accentuated in the inhibitory sub-component. Such improved understanding of the nature of executive dysfunctions in XXY males may aid the development of specific neuropsychological rehabilitation strategies.
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2. |
- Kompus, Kristiina, et al.
(author)
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The size of the anterior corpus callosum correlates with the strength of hemispheric encoding-retrieval asymmetry in the ventrolateral prefrontal cortex
- 2011
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In: Brain Research. - Amsterdam : Elsevier BV. - 0006-8993 .- 1872-6240. ; 1419, s. 61-67
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Journal article (peer-reviewed)abstract
- Functional lateralization of episodic memory processes in the frontal lobe is an area of intense study in the field of cognitive neuroimaging. Yet, to date there is insufficient knowledge of what role the interhemispheric structural connectivity plays in this lateralized organization. We analyzed functional and structural magnetic resonance imaging data from healthy adult volunteers who performed an associative encoding and retrieval task. We examined the relationship between functional voxel-based relative asymmetry of encoding and retrieval in the frontal lobes and the size of the anterior corpus callosum (antCC; corrected for brain size). The size of the antCC was strongly associated to the relative encoding-retrieval asymmetry in the ventrolateral prefrontal cortex (BA 47). These findings show that the functional asymmetry of episodic memory processes in the frontal lobes is associated with the structural connectivity between the hemispheres.
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3. |
- Soveri, Anna, et al.
(author)
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Modulation of Auditory Attention by Training Evidence From Dichotic Listening
- 2013
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In: Experimental psychology (Göttingen). - : Hogrefe Publishing Group. - 1618-3169 .- 2190-5142. ; 60:1, s. 44-52
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Journal article (peer-reviewed)abstract
- We studied the effects of training on auditory attention in healthy adults with a speech perception task involving dichotically presented syllables. Training involved bottom-up manipulation (facilitating responses from the harder-to-report left ear through a decrease of right-ear stimulus intensity), top-down manipulation (focusing attention on the left-ear stimuli through instruction), or their combination. The results showed significant training-related effects for top-down training. These effects were evident as higher overall accuracy rates in the forced-left dichotic listening (DL) condition that sets demands on attentional control, as well as a response shift toward left-sided reports in the standard DL task. Moreover, a transfer effect was observed in an untrained auditory-spatial attention task involving bilateral stimulation where top-down training led to a relatively stronger focus on left-sided stimuli. Our results indicate that training of attentional control can modulate the allocation of attention in the auditory space in adults. Malleability of auditory attention in healthy adults raises the issue of potential training gains in individuals with attentional deficits.
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