84 research outputs found
Special issue "Culture and Cognition". Cognitive Neuroscience
No full textThere is increasing interest in the nature and both environmental and cognitive origins of culturally associated differences in a range of behaviors. This special issue of Cognitive Neuroscience presents six empirical papers investigating diverse categories of potential culturally related effects as well as a review article, all of which provide timely updates of the current state of knowledge in this area
An unavoidable modulation? Sensory attention and human primary motor cortex excitability
No full textThe link between basic physiology and its modulation by cognitive states, such as attention, is poorly understood. A significant association becomes apparent when patients with movement disorders describe experiences with changing their attention focus and the fundamental effect that this has on their motor symptoms. Moreover, frequently used mental strategies for treating such patients, e.g. with task-specific dystonia, widely lack laboratory-based knowledge about physiological mechanisms. In this largely unexplored field, we looked at how the locus of attention, when it changed between internal (locus hand) and external (visual target), influenced excitability in the primary motor cortex (M1) in healthy humans. Intriguingly, both internal and external attention had the capacity to change M1 excitability. Both led to a reduced stimulation-induced GABA-related inhibition and a change in motor evoked potential size, i.e. an overall increased M1 excitability. These previously unreported findings indicated: (i) that cognitive state differentially interacted with M1 physiology, (ii) that our view of distraction (attention locus shifted towards external or distant location), which is used as a prevention or management strategy for use-dependent motor disorders, is too simple and currently unsupported for clinical application, and (iii) the physiological state reached through attention modulation represents an alternative explanation for frequently reported electrophysiology findings in neuropsychiatric disorders, such as an aberrant inhibition
Effects of Cerebellar Stimulation on Processing Semantic Associations
No full textCurrent research in cerebellar cognitive and linguistic functions makes plausible the idea that the cerebellum is involved in processing temporally contiguous linguistic input. In order to assess this hypothesis, a lexical decision task was constructed to study the effects of cerebellar transcranial magnetic stimulation on semantic noun-to-verb priming based on association (e.g. ‘soap–cleaning’) or similarity (e.g. ‘robbery–stealing’). The results demonstrated a selective increase in associative priming size after stimulation of a lateral cerebellar site. The findings are discussed in the contexts of a cerebellar role in linguistic expectancy generation and the corticocerebellar ‘prefrontal’ reciprocal loop
Transcranial direct current stimulation in sports training: potential approaches
No full textIn recent years several studies have focused on the application of non-invasive brain stimulation in motor training and rehabilitation. Of particular promise is transcranial direct stimulation (tDCS), which has been shown to produce improvements in motor behavior in normal adults and appears to offer utility for enhancing training-induced improvements in motor function in those suffering cortical damage (e.g. stroke patients). This raises the possibility of the use of tDCS more broadly, including in motor training in sport. In this opinion piece we discuss the potential utility of tDCS in sports training and the extent to which individual differences in motor expertise may influence the efficacy of tDCS on motor learning. In addition we discuss different aspects of motor learning that may be enhanced by tDCS and target brain regions that may be good candidates for this process.</p
Human frontal eye fields and spatial priming of pop-out
No full text"Priming of pop-out" is a form of implicit memory that facilitates detection of a recently inspected search target. Repeated presentation of a target's features or its spatial position improves detection speed (feature/spatial priming). This study investigated a role for the human frontal eye fields (FEFs) in the priming of color pop-out. To test the hypothesis that the FEFs play a role in short-term memory storage, transcranial magnetic stimulation (TMS) was applied during the intertrial interval. There was no effect of TMS on either spatial or feature priming. To test whether the FEFs are important when a saccade is being programmed to a repeated target color or location, TMS was applied during the search array. TMS over the left but not the right FEFs abolished spatial priming, but had no effect on feature priming. These findings demonstrate functional specialization of the left FEFs for spatial priming, and distinguish this role from target discrimination and saccade-related processes. The results suggest that the left FEFs integrate a spatial memory signal with an evolving saccade program, which facilitates saccades to a recently inspected location
Beyond inhibition:Exploiting the potential of state-dependency in cognitive and therapeutic TMS studies
No full textTranscranial magnetic stimulation is one of a relatively small number of techniques that allow for direct intervention in neural processes in healthy human subjects and it is frequently used as a 'virtual lesion' technique to establish whether a cortical region is essential to specific cognitive processes. While these studies are typically thought of as being equivalent to disruption of or 'turning off' a stimulation site, there is potential for a greater degree of sophistication in not only elucidating temporal characteristics of cortical involvement in behavioural processes (which has been employed in numerous studies), but also interactions with factors such as cortical excitability (which is much less investigated). In relation to the later, recent studies have shown that manipulating the activational state of a brain area prior to stimulation can also result in behavioral enhancement. Here we discuss this work and describe the potential of approaches involving manipulation of excitability for extending the scope of TMS investigations of cognitive processes.</p
Original Articles Brain stimulation and inhibitory control
No full texta b s t r a c t Inhibitory control mechanisms are important in a range of behaviours to prevent execution of motor acts which, having been planned, are no longer necessary or appropriate. Examples of this can be seen in a range of sports, such as cricket and baseball, where the choice between execution and inhibition of a bat swing must be made in a very brief time window. Deficits in inhibitory control have been associated with problems in behavioural regulation in impulsive violence as well as a range of clinical disorders. The roles of various areas, including the frontal eye fields (FEF), the pre-supplementary motor area (pre-SMA) and the inferior frontal gyrus, in inhibitory control have been investigated using an inhibitory control task and both transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS). Typically effects on response inhibition but no effects on response generation have been seen. The contributions of these areas to performance seem to differ with, for example, pre-SMA being involved when the task is relatively novel whereas this is not the case for FEF. The findings from brain stimulation studies offer both insight into which areas are necessary for effective inhibitory control and recent extension of findings for the role of the inferior frontal gyrus illustrate how the specific functions by which these areas contribute may be further clarified. Future work, including making use of the temporal specificity of TMS and combination of TMS/tDCS with other neuroimaging techniques, may further clarify the nature and functions played by the network of areas involved in inhibitory control
Electrophysiological investigation of the effects of Tai Chi on inhibitory control in older individuals
No full textOriginal Articles Brain stimulation and inhibitory control
No full texta b s t r a c t Inhibitory control mechanisms are important in a range of behaviours to prevent execution of motor acts which, having been planned, are no longer necessary or appropriate. Examples of this can be seen in a range of sports, such as cricket and baseball, where the choice between execution and inhibition of a bat swing must be made in a very brief time window. Deficits in inhibitory control have been associated with problems in behavioural regulation in impulsive violence as well as a range of clinical disorders. The roles of various areas, including the frontal eye fields (FEF), the pre-supplementary motor area (pre-SMA) and the inferior frontal gyrus, in inhibitory control have been investigated using an inhibitory control task and both transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS). Typically effects on response inhibition but no effects on response generation have been seen. The contributions of these areas to performance seem to differ with, for example, pre-SMA being involved when the task is relatively novel whereas this is not the case for FEF. The findings from brain stimulation studies offer both insight into which areas are necessary for effective inhibitory control and recent extension of findings for the role of the inferior frontal gyrus illustrate how the specific functions by which these areas contribute may be further clarified. Future work, including making use of the temporal specificity of TMS and combination of TMS/tDCS with other neuroimaging techniques, may further clarify the nature and functions played by the network of areas involved in inhibitory control
Beyond Inhibition: Exploiting the Potential of State-Dependency in Cognitive and Therapeutic TMS Studies
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