Cortex; a journal devoted to the study of the nervous system and behavior
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Recent research has demonstrated that a negative deflection in the event-related potential (ERP) that is usually elicited by errors, negative performance feedback, and monetary losses, and which has been associated with response monitoring and reinforcement learning, is also present when we observe others. In the present study we aimed to extend these findings to the domain of coaching behavior. ⋯ However, their advice is sometimes rejected. Here we show that a rejection of one's advice elicits the same negative potential as when one receives negative feedback about one's own behavior.
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Clinical Trial
An fMRI study of the numerical Stroop task in individuals with and without minimal cognitive impairment.
Aim of this functional magnetic resonance imaging (fMRI) study was to dissociate normal aging and minimal cognitive impairment (MCI) concerning magnitude processing and interference control. We examined the neural correlates of a numerical Stroop task in elderly individuals with and without MCI. Fifteen elderly participants (six patients with MCI and nine controls) were subjected to a numerical Stroop task requiring numerical/physical magnitude classifications while inhibiting task-irrelevant stimulus dimensions. ⋯ MCI patients exhibited stronger pre-/postcentral and thalamic activations, possibly reflecting more effortful response-selection processes or alternatively, deficient inhibitory control. Moreover, MCI patients exhibited additional activations in fronto-parietal (magnitude) and occipital/cerebellar (congruity) regions. To summarize, though MCI patients needed to recruit more distributed activation patterns conjunction analysis revealed common activation sites in response to magnitude processing and interference control.
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Case Reports
Selective deficit of mental visual imagery with intact primary visual cortex and visual perception.
There is a vigorous debate as to whether visual perception and imagery share the same neuronal networks, whether the primary visual cortex is necessarily involved in visual imagery, and whether visual imagery functions are lateralized in the brain. Two patients with brain damage from closed head injury were submitted to tests of mental imagery in the visual, tactile, auditory, gustatory, olfactory and motor domains, as well as to an extensive testing of cognitive functions. A computerized mapping procedure was used to localize the site and to assess the extent of the lesions. ⋯ Computerized analysis of the lesions showed a massive involvement of the left temporal lobe in both patients and a bilateral parietal lesion in one patient. In both patients the calcarine cortex with the primary visual area was bilaterally intact. Our study indicates that: (i) visual imagery deficits can occur independently from deficits of visual perception; (ii) visual imagery deficits can occur when the primary visual cortex is intact and (iii) the left temporal lobe plays an important role in visual mental imagery.
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Comparative Study
Sustained and transient neural modulations in prefrontal cortex related to declarative long-term memory, working memory, and attention.
Common activations in prefrontal cortex (PFC) during episodic and semantic long-term memory (LTM) tasks have been hypothesized to reflect functional overlap in terms of working memory (WM) and cognitive control. To evaluate a WM account of LTM-general activations, the present study took into consideration that cognitive task performance depends on the dynamic operation of multiple component processes, some of which are stimulus-synchronous and transient in nature; and some that are engaged throughout a task in a sustained fashion. PFC and WM may be implicated in both of these temporally independent components. ⋯ In addition, a common item response for all memory tasks involved left dorsolateral PFC (DLPFC). The latter response might be seen as reflecting WM processes during LTM retrieval. Thus, our findings suggest that a WM account of shared PFC recruitment in LTM tasks holds for common transient item-related responses rather than sustained state-related responses that are better seen as reflecting more general attentional/control processes.