Intracranial Recordings of Occipital Cortex Responses to Illusory Visual Events.
Ambiguous visual stimuli elicit different perceptual interpretations over time, creating the illusion that a constant stimulus is changing. We investigate whether such spontaneous changes in visual perception involve occipital brain regions specialized for processing visual information, despite the absence of concomitant changes in stimulation. Spontaneous perceptual changes observed while viewing a binocular rivalry stimulus or an ambiguous structure-from-motion stimulus were compared with stimulus-induced perceptual changes that occurred in response to an actual stimulus change. Intracranial recordings from human occipital cortex revealed that spontaneous and stimulus-induced perceptual changes were both associated with an early transient increase in high-frequency power that was more spatially confined than a later transient decrease in low-frequency power. We suggest that the observed high-frequency and low-frequency modulations relate to initiation and maintenance of a percept, respectively. Our results are compatible with the idea that spontaneous changes in perception originate from competitive interactions within visual neural networks.



Ambiguous visual stimuli elicit different perceptual interpretations over time, creating the illusion that a constant stimulus is changing. The literature on the neural correlates of conscious visual perception remains inconclusive regarding the extent to which such spontaneous changes in perception involve sensory brain regions. In an attempt to bridge the gap between existing animal and human studies, we recorded from intracranial electrodes placed on the human occipital lobe. We compared two different kinds of ambiguous stimuli, binocular rivalry and the phenomenon of ambiguous structure-from-motion, enabling generalization of our findings across different stimuli. Our results indicate that spontaneous and stimulus-induced changes in perception (i.e., "illusory" and "real" changes in the stimulus, respectively) may involve sensory regions to a similar extent.
Department of Experimental Psychology, Helmholtz Institute, Utrecht University, 3508 TC Utrecht, The Netherlands, dejongmc@gmail.com.
Maartje C
MC
de Jong
Department of Experimental Psychology, Helmholtz Institute, Utrecht University, 3508 TC Utrecht, The Netherlands.
Ralph J M
RJ
Hendriks
Department of Neurology and Neurosurgery, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands.
Mariska J
MJ
Vansteensel
Department of Neurology and Neurosurgery, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands.
Mathijs
M
Raemaekers
The University of Sydney, School of Psychology, New South Wales 2006 Sydney, Australia Department of Experimental Psychology, Helmholtz Institute, Utrecht University, 3508 TC Utrecht, The Netherlands.
Frans A J
0000-0002-5487-1755
FA
Verstraten
Department of Neurology and Neurosurgery, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands.
Nick F
NF
Ramsey
Department of Experimental Psychology, Helmholtz Institute, Utrecht University, 3508 TC Utrecht, The Netherlands.
Casper J
0000-0002-7234-1029
CJ
Erkelens
Department of Neurology and Neurosurgery, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands.
Frans S S
FS
Leijten
Philips Research Laboratories, Department of Brain, Body & Behavior, 5656 AE Eindhoven, The Netherlands, Laboratory of Experimental Psychology, University of Leuven, 3000 Leuven, Belgium, Donders Institute, Radboud University, Department of Biophysics, 6500 GL Nijmegen, The Netherlands, and.
Raymond
R
van Ee
D000328:Adult; D001931:Brain Mapping; D000069279:Drug Resistant Epilepsy / Q000601:surgery; D004569:Electroencephalography; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007088:Illusions / Q000502:physiology*; D008297:Male; D009038:Motion; D010775:Photic Stimulation; D013057:Spectrum Analysis; D015357:Vision Disparity / Q000502:physiology*; D014793:Visual Cortex / Q000503:physiopathology*; D014796:Visual Perception / Q000502:physiology*
ambiguous; binocular rivalry; illusion; intracranial; occipital; visual