Cortex; a journal devoted to the study of the nervous system and behavior
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For individuals with vision-touch synaesthesia, the sight of touch on another person elicits synaesthetic tactile sensation on the observer's own body. Here we used the traditional rubber hand paradigm (Botvinick and Cohen, 1998) and a no-touch rubber hand paradigm to investigate and to authenticate synaesthetic tactile sensation. In the traditional rubber hand paradigm, the participant views a prosthetic hand being touched by the Examiner while the participant's hand - hidden from view - is also touched by the Examiner. ⋯ Thus, synaesthetic tactile sensation on the (untouched) hidden hand was referred to the prosthetic hand. These individuals also demonstrated proprioceptive drift (a change, from baseline, in proprioceptively perceived position) of the hidden hand towards the location of the prosthetic hand, and a pattern of increased proprioceptive drift with increased trial duration (60 sec, 180 sec, 300 sec). The no-touch rubber hand paradigm was an excellent method to authenticate vision-touch synaesthesia because participants were naïve about the rubber hand illusion, and they could not have known how they were expected to perform on either the traditional or the no-touch rubber hand paradigm.
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Patients with Huntington's disease (HD), a neurodegenerative disorder that causes major motor impairments, also show cognitive and emotional deficits. While their deficit in recognising emotions has been explored in depth, little is known about their ability to express emotions and understand their feelings. If these faculties were impaired, patients might not only mis-read emotion expressions in others but their own emotions might be mis-interpreted by others as well, or thirdly, they might have difficulties understanding and describing their feelings. ⋯ By contrast, alexithymia and empathy scores were very similar in HD and controls. This might suggest that emotion deficits in HD might be tied to the expression itself. Because similar emotion recognition-expression deficits are also found in Parkinson's Disease and vascular lesions of the striatum, our results further confirm the importance of the striatum for emotion recognition and expression, while access to the meaning of feelings relies on a different brain network, and is spared in HD.
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Hypnotic modulation of pain perception and of brain activity triggered by nociceptive laser stimuli.
Neuroimaging studies indicate that hypnotic suggestions of increased and decreased pain intensity and unpleasantness may modulate somatosensory and cingulate cortex activity, respectively. ⋯ Hypnotic suggestions exerted a top-down modulatory effect on both evoked and induced-cortical brain responses triggered by selective nociceptive laser inputs. Furthermore, correlation analyses indicated that gamma power modulation and suggestions of hyperalgesia may reflect the process of allocating control resources to salient and threatening sensory-affective dimensions of pain.
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Traumatic brain injury (TBI) sustained during childhood can cause difficulties in a wide range of physical, neurological, cognitive, social and functional domains. However, the ability of health professionals and researchers to accurately predict the outcome of pediatric TBI remains limited. The advent of advanced neuroimaging techniques shows some promise in improving outcome prediction, as they contribute to greater sensitivity in characterizing intracranial lesions underlying many cognitive and functional deficits. In this study, the relationship between lesions identified on susceptibility weighted imaging (SWI) and cognitive and functional outcomes was investigated following childhood TBI. ⋯ SWI is a sensitive technique for detecting brain lesions at all TBI severity levels and shows promise in contributing to prediction of cognitive outcomes in the initial stages post-injury.
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Brain regions simultaneously activated during any cognitive process are functionally connected, forming large-scale networks. These functional networks can be examined during active conditions [i.e., task-functional magnetic resonance imaging (fMRI)] and also in passive states (resting-fMRI), where the default mode network (DMN) is the most widely investigated system. The role of the DMN remains unclear, although it is known to be responsible for the shift between resting and focused attention processing. ⋯ Interestingly, and despite the fact that we considered eight different resting-state fMRI networks previously identified in humans, only the connectivity within the posteromedial parts of the DMN (precuneus) prior to the fMRI n-back task predicted WM execution. Our results using a data-driven probabilistic approach for fMRI analysis provide the first evidence of a direct relationship between behavioural performance and the degree of negative correlation between the DMN and WM networks. They further suggest that in the context of expectancy for an imminent cognitive challenge, higher resting-state activity in the posteromedial parietal cortex may be related to increased attentional preparatory resources.