Exploring the contributions of the supplementary eye field to subliminal inhibition using double‐pulse transcranial magnetic stimulation

Abstract

It is widely accepted that the supplementary eye fields (SEF) are involved in the control of voluntary eye movements. However, recent evidence suggests that SEF may also be important for unconscious and involuntary motor processes. Indeed, Sumner et al. ([2007]: Neuron 54:697-711) showed that patients with micro-lesions of the SEF demonstrated an absence of subliminal inhibition as evoked by masked-prime stimuli. Here, we used double-pulse transcranial magnetic stimulation (TMS) in healthy volunteers to investigate the role of SEF in subliminal priming. We applied double-pulse TMS at two time windows in a masked-prime task: the first during an early phase, 20-70 ms after the onset of the mask but before target presentation, during which subliminal inhibition is present; and the second during a late phase, 20-70 ms after target onset, during which the saccade is being prepared. We found no effect of TMS with the early time window of stimulation, whereas a reduction in the benefit of an incompatible subliminal prime stimulus was found when SEF TMS was applied at the late time window. These findings suggest that there is a role for SEF related to the effects of subliminal primes on eye movements, but the results do not support a role in inhibiting the primed tendency. Hum Brain Mapp 38:339-351, 2017. © 2016 Wiley Periodicals, Inc.

On the Mechanisms of Transcranial Magnetic Stimulation (TMS): How Brain State and Baseline Performance Level Determine Behavioral Effects of TMS

“…For cognitive neuroscientists using brain stimulation to study brain-behavior relations, the implication is that observing a TMS effect (or lack of an effect) at any given intensity or perceptual/cognitive state may not be the whole story; in standard experiments, we generally observe only a specific combination of excitability and stimulation intensity – and the observed effect may very well be different at other combinations. In addition, it is also important to acknowledge that the timing of TMS in priming paradigms modulates the induced effect ( Chiau et al, 2017 ). Thus to fully exploit the potential of TMS to characterize how a given brain area processes perceptual information, one should assess performance at different levels of baseline performance, timing and TMS intensity.…”

On the mechanisms of Transcranial Magnetic Stimulation (TMS): How brain state and baseline performance level determine behavioral effects of TMS

“…For cognitive neuroscientists using brain stimulation to study brain-behaviour relations, the implication is that observing a TMS effect (or lack of an effect) at any given intensity or perceptual/cognitive state may not be the whole story; in standard experiments, we generally observe only a specific combination of excitability and stimulation intensity -and the observed effect may very well be different at other combinations. In addition, it is also important to acknowledge that the timing of TMS in priming paradigms modulates the induced effect (Chiau, 2017). Thus to fully exploit the potential of TMS to characterise how a given brain area processes perceptual information, one should assess performance at different levels of baseline performance, timing and TMS intensity.…”

How to Test the Association Between Baseline Performance Level and the Modulatory Effects of Non-Invasive Brain Stimulation Techniques

“…Converging evidence demonstrates that the behavioral effects of transcranial magnetic stimulation (TMS) could dramatically change as a function of different factors, such as stimulation intensity (Moliadze et al, 2003;Abrahamyan et al, 2011Abrahamyan et al, , 2015, timing of stimulation (Kammer, 2007;de Graaf et al, 2014;Chiau et al, 2017; and the initial brain "state" when stimulation is applied (Siebner, 2004;Silvanto and Pascual-Leone, 2008;Ruzzoli et al, 2010;Schwarzkopf et al, 2011;Perini et al, 2012;Romei et al, 2016;. In this framework, there is lately a growing interest toward the importance of considering the interindividual differences in baseline performance when describing the impact of TMS.…”