Editing Semir Zeki (section)

==Time at University College London==
He later showed, using brain imaging techniques, that the same principles apply to the organisation of the human visual brain.<ref>Zeki, S. et al. (1991). A direct demonstration of functional specialization in human visual cortex. '''''J. Neurosci.'' 11''':641–649.</ref> In recent work he has shown that parallel processing appears to extend beyond the mere processing of visual signals to their grouping in parietal cortex.<ref>Zeki, S. and Stutters, J. (2013). Functional specialization and generalization for grouping of stimuli based on colour and motion. '''''Neuroimage'' 73''': 156–166.</ref> His work on colour vision was influenced by the work and methods of [[Edwin H. Land]], whose techniques he employed in his physiological and brain imaging experiments,<ref>Zeki, S. (1980). The representation of colours in the cerebral cortex. '''''Nature'' 284''', 412–418</ref> and which led him to the view that colour is constructed by the brain and that a specialised visual area, area [[Visual cortex#V4|V4]], is critical to this process.<ref>Zeki, S. (1984). The construction of colours by the cerebral cortex. '''''Proc. Roy. Inst. Gt. Britain'' 56''':231–257</ref>

These findings raised the question of how the signals processed in these separate visual areas are integrated to give a unified picture of the visual world. In psychophysical experiments undertaken with colleagues, he showed that we perceive, and become aware of, different visual attributes at different times, with colour preceding motion by about 80 ms and form (orientation) by about 40 ms,<ref>Moutoussis, K and Zeki, S (1997). A direct demonstration of perceptual asynchrony in vision. '''''Proc. R. Soc. Lond. B.'' 265''':393–399</ref> leading to the view that there is a temporal asynchrony in vision which is the result of different processing speeds for different attributes. This in turn led him to suggest that visual consciousness is not unified; rather there are many visual micro-consciousness which are distributed in time and space,<ref>Zeki, S. (2003). The disunity of consciousness. '''''Trends in Cogn. Neurosci.'' 7''':214–218.</ref> and that activity in each visual area can acquire a conscious correlate without the necessity of reporting to another cortical area, though acknowledging that there must be other enabling systems, possibly located in the reticular formation.<ref>Zeki, S and ffytch, DH (1998). The Riddoch syndrome: insights into the neurobiology of conscious vision.  '''''Brain'' 121''':25–45</ref> Thus, functional specialisation manifests itself in the temporal sequence with which we see different attributes such as colour

More recently he has also studied the brain reaction to affective states generated by sensory inputs, such as the experience of love<ref name="love">Bartels, A and Zeki, S (2004). The neural correlates of maternal and romantic love. '''''NeuroImage'' 21''':1155–66</ref> and hate.<ref name="hate">Zeki, S. and Romaya, J (2008). Neural correlates of hate. '''''PLOS ONE'' 3''' (10) Article e3556</ref> His studies of the experience of visual<ref name="kawabata2004">Kawabata, H and Zeki, S (2004). Neural correlates of beauty. '''''J Neurophysiol.'' 91''':1699-705 (2004)</ref> and musical beauty has led him to suggest that a specific part of the emotional brain, field A1 of the medial [[orbito-frontal cortex]], is critical for such experiences.<ref>Ishizu, T and Zeki, S. (2011). Toward a brain-based theory of beauty. '''''PLoS One'' 6''' (7) e21852</ref>