Cortical Resonance to Visible and Invisible Visual Rhythms

Autor: Claudio de’Sperati
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Brain Sciences, Vol 10, Iss 1, p 37 (2020)
Druh dokumentu: article
ISSN: 2076-3425
DOI: 10.3390/brainsci10010037
Popis: Humans are rather poor in judging the right speed of video scenes. For example, a soccer match may be sped up so as to last only 80 min without observers noticing it. However, both adults and children seem to have a systematic, though often biased, notion of what should be the right speed of a given video scene. We therefore explored cortical responsiveness to video speed manipulations in search of possible differences between explicit and implicit speed processing. We applied sinusoidal speed modulations to a video clip depicting a naturalistic scene as well as a traditional laboratory visual stimulus (random dot kinematogram, RDK), and measured both perceptual sensitivity and cortical responses (steady-state visual evoked potentials, SSVEPs) to speed modulations. In five observers, we found a clear perceptual sensitivity increase and a moderate SSVEP amplitude increase with increasing speed modulation strength. Cortical responses were also found with weak, undetected speed modulations. These preliminary findings suggest that the cortex responds globally to periodic video speed modulations, even when observers do not notice them. This entrainment mechanism may be the basis of automatic resonance to the rhythms of the external world.
Databáze: Directory of Open Access Journals
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