Transcranial alternating current stimulation (tACS) at 40â¯Hz enhances face and object perception.
Neuropsychologia
; 135: 107237, 2019 12.
Article
em En
| MEDLINE
| ID: mdl-31655161
ABSTRACT
Neurophysiological evidence suggests that face and object recognition relies on the coordinated activity of neural populations (i.e., neural oscillations) in the gamma-band (>30â¯Hz) range over the occipito-temporal cortex. To test the causal effect of gamma-band oscillations on face and object perception we applied transcranial Alternating Current Stimulation (tACS) in healthy volunteers (Nâ¯=â¯60). In this single-blind, sham-controlled study, we examined whether the administration of offline tACS at gamma-frequency (40â¯Hz) over the right occipital cortex enhances performance of perception and memory of face and object stimuli. We hypothesized that gamma tACS would enhance the perception of both categories of visual stimuli. Results, in line with our hypothesis, show that 40â¯Hz tACS enhanced both face and object perception. This effect is process-specific (i.e., it does not affect memory), frequency-specific (i.e., stimulation at 5â¯Hz did not cause any behavioural change), and site-specific (i.e., stimulation of the sensory-motor cortex did not affect performance). Our findings show that high-frequency tACS modulates human visual perception, and it is in line with neurophysiological studies showing that the perception of visual stimuli (i.e., faces and objects) is mediated by oscillations in the gamma-band range. Furthermore, this study adds insight about the design of effective neuromodulation protocols that might have implications for interventions in clinical settings.
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MEDLINE
Assunto principal:
Reconhecimento Visual de Modelos
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Ritmo Gama
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Reconhecimento Facial
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Lobo Occipital
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article