Section 10.2.1 A single site for visual awareness

The continuing debate about the location of the mechanisms which cause binocular rivalry (see section 10.2.1.4) has been reviewed by Tong et al. (2006). They support a multi-locus model where many stages of the visual system, from the LGN to the inferotemporal cortex, can be involved. An excellent account is given of the dynamic integration of these visual areas by both recurrent, top-down connections and lateral interactions within each site. New tie-ins between the recurrent connectivity and selective attention are also indicated.

Side-box 10.1 Can area V1 generate consciousness?

Further evidence for a direct role for recurrent input to V1 in visual awareness comes from the TMS studies of Silvanto et al. (2005a, b) and the fMRI connectivity studies of Sterzer et al. (2006).

Side-box 10.2 The neural bases of imagery

The imagery debate continues with Kosslyn et al. (2006) summarising the arguments and evidence in favour.

Section 10.3.2.2. What is the latency of awareness?

Continuing discussion for and against Libet’s theory may be found in four consecutive papers in Consciousness and Cognition 15, 540-565 (2006) and in the edited volume by Pockett et al. (2006).

For further support for the idea that sensory awareness develops progressively over a short period of time — ‘microgenesis’ rather than instantaneous creation — see Breitmeyer and Ögmen (2006) and Ögmen and Breitmeyer (2006).

References

Breitmeyer, B.G. and Ögmen, H. (2006) Visual Masking: time slices through conscious and unconscious vision. Oxford University Press, New York.

Kosslyn, S.M., Thompson, W.L. and Ganis, G. (2006) The Case for Mental Imagery. Oxford University Press, New York.

Ögmen, H. and Breitmeyer, B.G. (2006) eds. The FIrst Half Second: the microgenesis and temporal dynamics of unconscious and conscious visual processing. MIT Press, Cambridge MA.

Pockett, S., Banks, W.P. and Gallagher, S. (2006) eds. Does Consciousness Cause Behavior? MIT Press, Cambridge MA.

Silvanto, J., Cowey, A., Lavie, N. and Walsh, V. (2005a) Striate cortex (V1) activity gates awareness of motion. Nature Neuroscience 8, 143-144.

Silvanto, J., Lavie, N. and Walsh, V. (2005b) Double dissociation of V1 and V5/MT activity in visual awareness. Cerebral Cortex 15, 1736-1741.

Sterzer, P., Haynes, J.D. and Rees, G. (2006) Primary visual cortex activation on the path of apparent motion is mediated by feedback from hMT+/V5. Neuroimage 32, 1308-1316.

Tong, F., Meng, M. and Blake, R. (2006) Neural bases of binocular rivalry. Trends in Cognitive Sciences 10, 502-511.