Is motor response inhibition supported by a specialised neuronal inhibitory control mechanism, or by a more general system of action updating? This pre-registered study employed a context-cueing paradigm requiring both inhibitory and non-inhibitory action updating in combination with functional magnetic resonance imaging to test the specificity of responses under different updating conditions, including the cancellation of actions. Cortical regions of activity were found to be common to multiple forms of action updating. However, functional specificity during response inhibition was observed in the anterior right inferior frontal gyrus.
View Article and Find Full Text PDFBackground: Alcohol impairs response inhibition; however, it remains contested whether such impairments affect a general inhibition system, or whether affected inhibition systems are embedded in, and specific to, each response modality. Further, alcohol-induced impairments have not been disambiguated between proactive and reactive inhibition mechanisms, and nor have the contributions of action-updating impairments to behavioural 'inhibition' deficits been investigated.
Methods: Forty Participants (25 female) completed both a manual and a saccadic stop-signal reaction time (SSRT) task before and after a 0.
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 detection is impaired while the ability to discriminate 'unseen' stimuli is preserved above chance. Here we sought to reproduce this phenomenon using offline occipital cTBS, which has been shown to induce an inhibitory cortical aftereffect lasting 45-60 minutes.
View Article and Find Full Text PDFFollowing damage to the primary visual cortex, some patients exhibit "blindsight," where they report a loss of awareness while retaining the ability to discriminate visual stimuli above chance. Transient disruption of occipital regions with TMS can produce a similar dissociation, known as TMS-induced blindsight. The neural basis of this residual vision is controversial, with some studies attributing it to the retinotectal pathway via the superior colliculus whereas others implicate spared projections that originate predominantly from the LGN.
View Article and Find Full Text PDFObjectives: Past research has largely neglected to investigate mild adverse effects (MAEs) to transcranial magnetic stimulation (TMS), including headache and nausea. Here we explored the relationship between MAEs, participant characteristics (age and gender) and protocol parameters, including mode of application, coil geometry, stimulated brain region, TMS frequency, TMS intensity, and active vs. sham stimulation.
View Article and Find Full Text PDFRecent neuroimaging evidence suggests that visual inputs arising beyond the fovea can be 'fed back' to foveal visual cortex to construct a new retinotopic representation. However, whether these representations are critical for extra-foveal perception remains unclear. Using transcranial magnetic stimulation we found that relatively late (350-400 msec) disruption of foveal retinotopic cortex impaired perceptual discrimination of objects in the periphery.
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