Cortex; a journal devoted to the study of the nervous system and behavior
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In the present study, we used learning-testing paradigm to examine brain activation of "Aha" effects with event-related functional magnetic resonance imaging (fMRI) during solving Chinese logogriphs. Blood oxygenation level-dependent fMRI contrasts between Aha and No-aha conditions were measured. Increased activities in the precuneus (BA 19/7), the left inferior/middle frontal gyrus (BA 9/6), the inferior occipital gyrus (BA 18), and the cerebellum were specifically associated with the "Aha" effects. The results indicate that (1) the precuneus might be involved in successful prototype events retrieval, (2) the left inferior frontal/middle frontal gyrus might be involved in forming novel association and breaking mental sets, (3) the inferior occipital gyrus and the cerebellum might be involved in re-arrangement of visual stimulus and deployment of attentional resources.
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The interaction of information derived from the voice and facial expression of a speaker contributes to the interpretation of the emotional state of the speaker and to the formation of inferences about information that may have been merely implied in the verbal communication. Therefore, we investigated the brain processes responsible for the integration of emotional information originating from different sources. Although several studies have reported possible sites for integration, further investigation using a neutral emotional condition is required to locate emotion-specific networks. ⋯ We confirmed the results of previous studies by finding that the bimodal emotional condition elicited strong activation in the left middle temporal gyrus (MTG), and we extended this finding to locate the effects of emotional factors by using a neutral condition in the experimental design. We found anger-specific activation in the posterior cingulate, fusiform gyrus, and cerebellum, whereas we found happiness-specific activation in the MTG, parahippocampal gyrus, hippocampus, claustrum, inferior parietal lobule, cuneus, middle frontal gyrus (MFG), IFG, and anterior cingulate. These emotion-specific activations suggest that each emotion uses a separate network to integrate bimodal information and shares a common network for cross-modal integration.
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We describe the case of a patient with right hemisphere damage and left unilateral neglect. The patient was asked to draw from memory common objects, either with or without visual feedback. ⋯ This patient's pattern of performance may result from the contribution of a deficit of spatial working memory. Alternatively or in addition, the patient, who was undergoing cognitive rehabilitation for neglect, may have found easier to compensate for his neglect with visual feedback, which allowed him to visually explore the left part of his drawings.
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Clinical Trial
Decomposing interference during Stroop performance into different conflict factors: an event-related fMRI study.
In the current event-related functional magnetic resonance imaging (fMRI) study, we sought to trace back Stroop-interference to circumscribed properties of task-irrelevant word information - response-incompatibility, semantic incongruency and task-reference - that we conceive as conflict factors. Thereby, we particularly wanted to disentangle intermingled contributions of semantic conflict and response conflict to the overall Stroop-interference effect. To delineate neural substrates of single factors, we referred to the logics of cognitive subtraction and cognitive conjunction. ⋯ As supported by the consistent negative correlation with behavioral conflict costs, these activations most probably reflect strengthened control efforts to overcome interference and to ensure adequate task performance. Finally, task-reference elicited activation in the left temporo-polar cortex (TPC) and the right medial superior as well as in left rostroventral prefrontal cortex (rvPFC, sub-threshold activation). As strongly supported by prior studies' findings, this neural activation pattern may underlie residual semantic processing of the task-irrelevant word information.
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Comparative Study
Sex and performance level effects on brain activation during a verbal fluency task: a functional magnetic resonance imaging study.
Neuroimaging studies investigating the neural correlates of verbal fluency (VF) focused on sex differences without taking into account behavioural variation. Nevertheless, group differences in this verbal ability might account for neurocognitive differences elicited between men and women. The aim of this study was to test sex and performance level effects and the combination of these on cerebral activation. ⋯ LF subjects had stronger activations than HF ones in the ACC whereas HF subjects showed stronger activations in the cerebellum. Activity in three discrete subregions of the ACC is related to sex, performance and their interaction, respectively. Our findings emphasize the need to consider sex and performance level in functional imaging studies of VF.