Related Experiment Video
Updated: Apr 17, 2026
11:33
Transcranial Magnetic Stimulation for Investigating Causal Brain-behavioral Relationships and their Time Course
Published on: July 18, 2014
44.4K
Spatially specific vs. unspecific disruption of visual orientation perception using chronometric pre-stimulus TMS
Tom A de Graaf1, Felix Duecker1, Martin H P Fernholz1
1Faculty of Psychology and Neuroscience, Department of Cognitive Neuroscience, Maastricht University Maastricht, Netherlands ; Maastricht Brain Imaging Centre Maastricht, Netherlands.
Frontiers in Behavioral Neuroscience
|February 18, 2015
Summary
Pre-stimulus transcranial magnetic stimulation (TMS) disrupts visual processing via two distinct mechanisms in the occipital cortex. These findings reveal the spatiotemporal dynamics of state-dependent visual processing.
Area of Science:
- Neuroscience
- Cognitive Science
- Visual Perception
Background:
- Transcranial magnetic stimulation (TMS) over the occipital cortex can disrupt visual processing.
- Previous research focused on TMS applied after visual stimulus onset (positive SOAs).
- Recent work explored TMS at negative SOAs, revealing pre-stimulus disruption and hinting at two mechanisms.
Purpose of the Study:
- To map the temporal dynamics of state-dependent visual processing mechanisms.
- To differentiate between spatially specific and unspecific pre-stimulus TMS effects.
- To control for potential confounds like TMS-induced pupil covering.
Main Methods:
- Utilized a chronometric design with transcranial magnetic stimulation (TMS).
- Applied TMS pulses at negative stimulus onset asynchronies (SOAs) prior to visual stimuli.
- Measured effects on orientation perception while controlling for pupil covering.
Main Results:
- TMS at 60–40 ms pre-stimulus impaired orientation processing irrespective of stimulus location (spatially unspecific).
- TMS at 30–10 ms pre-stimulus caused a local suppressive effect (spatially specific).
- These results demonstrate distinct temporal dynamics for different pre-stimulus disruption mechanisms.
Conclusions:
- Pre-stimulus TMS reveals distinct spatiotemporal mechanisms underlying visual processing state-dependency.
- Identified both spatially specific and unspecific disruption effects occurring at different times before visual stimulus onset.
- Provides a foundation for linking pre-stimulus TMS effects to other visual biasing mechanisms.
