David Bourget (Western Ontario)
David Chalmers (ANU, NYU)
Rafael De Clercq
Jack Alan Reynolds
Learn more about PhilPapers
Consciousness and Cognition 9 (1):86-116 (2000)
It has been shown that visual awareness in the blind hemifield of hemianopic cats that have undergone unilateral ablations of visual cortex can be restored by sectioning the commissure of the superior colliculus or by destroying a portion of the substantia nigra contralateral to the cortical lesion (the Sprague effect). We propose that the visual awareness that is recovered is due to synchronized oscillatory activities in the superior colliculus ipsilateral to the cortical lesion. These oscillatory activities are normally partially suppressed by the inhibitory, GABAergic contralateral nigrotectal projection, and the destruction of the substantia nigra, or the sectioning of the collicular commissure, disinhibits the collicular neurons, causing an increase in the extent of oscillatory activity and/or synchronization between activities at different sites. This increase in the oscillatory and synchronized character is sufficient for the activities to give rise to visual awareness. We argue that in rodents and lower vertebrates, normal visual awareness is partly due to synchronized oscillatory activities in the optic tectum and partly due to similar activities in visual cortex. It is only in carnivores and primates that visual awareness is wholly due to cortical activities. Based on von Baerian recapitulation theory, we propose that, even in humans, there is a period in early infancy when visual awareness is partially due to activities in the superior colliculus, but that this awareness gradually disappears as the nigrotectal projection matures
|Keywords||*Awareness *Brain *Electrical Activity *Neurons *Visual Perception Animals|
|Categories||categorize this paper)|
Setup an account with your affiliations in order to access resources via your University's proxy server
Configure custom proxy (use this if your affiliation does not provide a proxy)
|Through your library|
References found in this work BETA
No references found.
Citations of this work BETA
No citations found.
Similar books and articles
Matthew Kennedy (2007). Visual Awareness of Properties. Philosophy and Phenomenological Research 75 (2):298–325.
Alvaro Pascual-Leone & Vincent Walsh (2001). Fast Backprojections From the Motion to the Primary Visual Area Necessary for Visual Awareness. Science 292 (5516):510-512.
Randolph Blake, Duje Tadin, Kenith V. Sobel, Tony A. Raissian & Sang Chul Chong (2006). Strength of Early Visual Adaptation Depends on Visual Awareness. Pnas Proceedings of the National Academy of Sciences of the United States of America 103 (12):4783-4788.
Rainer Goebel, Lars Muckli, Friedhelm E. Zanella, Wolf Singer & Petra Stoerig (2001). Sustained Extrastriate Cortical Activation Without Visual Awareness Revealed by fMRI Studies in Hemianopic Patients. Vision Research 41 (10):1459-1474.
Juha Silvanto (2008). A Re-Evaluation of Blindsight and the Role of Striate Cortex (V1) in Visual Awareness. Neuropsychologia.
T. W. Kjaer, M. Nowak, K. W. Kjaer, A. R. Lou & H. C. Lou (2001). Precuneus-Prefrontal Activity During Awareness of Visual Verbal Stimuli. Consciousness and Cognition 10 (3):356-365.
Peter V. Nguyen (2001). Tracking the Cortical Signals That Mediate Visual Awareness. Trends in Neurosciences 24 (7):371-372.
Antti Revonsuo (1998). Visual Perception and Subjective Visual Awareness. Behavioral and Brain Sciences 21 (6):769-770.
Terence V. Sewards & Mark A. Sewards (2002). On the Neural Correlates of Object Recognition Awareness: Relationship to Computational Activities and Activities Mediating Perceptual Awareness. Consciousness and Cognition 11 (1):51-77.
Terence V. Sewards & Mark A. Sewards (2001). On the Correlation Between Synchronized Oscillatory Activities and Consciousness. Consciousness and Cognition 10 (4):485-495.
Added to index2009-01-28
Total downloads12 ( #130,771 of 1,103,219 )
Recent downloads (6 months)4 ( #85,078 of 1,103,219 )
How can I increase my downloads?