Christopher D. Chambers

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In the course of daily living, humans frequently encounter situations in which a motor activity, once initiated, becomes unnecessary or inappropriate. Under such circumstances, the ability to inhibit motor responses can be of vital importance. Although the nature of response inhibition has been studied in psychology for several decades, its neural basis(More)
Neural mechanisms of cognitive control enable us to initiate, coordinate and update behaviour. Central to successful control is the ability to suppress actions that are no longer relevant or required. In this article, we review the contribution of cognitive neuroscience, molecular genetics and clinical investigations to understanding how response inhibition(More)
Everyday circumstances require efficient updating of behavior. Brain systems in the right inferior frontal cortex have been identified as critical for some aspects of behavioral updating, such as stopping actions. However, the precise role of these neural systems is controversial. Here we examined how the inferior frontal cortex updates behavior by(More)
Intelligent behavior depends on the ability to suppress inappropriate actions and resolve interference between competing responses. Recent clinical and neuroimaging evidence has demonstrated the involvement of prefrontal, parietal, and premotor areas during behaviors that emphasize conflict and inhibition. It remains unclear, however, whether discrete(More)
Mechanisms of selective attention are vital for guiding human behavior. The parietal cortex has long been recognized as a neural substrate of spatial attention, but the unique role of distinct parietal subregions has remained unclear. Using single-pulse transcranial magnetic stimulation, we found that the angular gyrus of the right parietal cortex mediates(More)
Transcranial magnetic stimulation (TMS) is a unique method in neuroscience used to stimulate focal regions of the human brain. As TMS gains popularity in experimental and clinical domains, techniques for controlling the extent of brain stimulation are becoming increasingly important. At present, TMS intensity is typically calibrated to the excitability of(More)
The neural basis of selective spatial attention presents a significant challenge to cognitive neuroscience. Recent neuroimaging studies have suggested that regions of the parietal and temporal cortex constitute a "supramodal" network that mediates goal-directed attention in multiple sensory modalities. Here we used transcranial magnetic stimulation (TMS) to(More)
We used concurrent transcranial magnetic stimulation and functional MRI (TMS-fMRI) during a visuospatial cueing paradigm in humans, to study the causal role of the right angular gyrus (AG) as a source of attentional control. Our findings show that TMS over the right AG (high vs. low intensity) modulates neural responses interhemispherically, in a manner(More)
This series of experiments investigated the neural basis of conscious vision in humans using a form of transcranial magnetic stimulation (TMS) known as continuous theta burst stimulation (cTBS). Previous studies have shown that occipital TMS, when time-locked to the onset of visual stimuli, can induce a phenomenon analogous to blindsight in which conscious(More)
The stop-signal paradigm is a popular method for examining response inhibition and impulse control in psychology, cognitive neuroscience, and clinical domains because it allows the estimation of the covert latency of the stop process: the stop-signal reaction time (SSRT). In three sets of simulations, we examined to what extent SSRTs that were estimated(More)