Christof Koch, Consciousness Researcher - Abstracts and Book Chapter

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Alfredo Pereira Jr (group admin)

Date:

26 August 2007

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1: Trends Cogn Sci. 2007 Jan;11(1):16-22. Epub 2006 Nov 28.

Attention and consciousness: two distinct brain processes.

Koch C, Tsuchiya N.

Division of Biology 216-76, California Institute of Technology, Pasadena, CA
91125, USA. koch@klab.caltech.edu

The close relationship between attention and consciousness has led many scholars
to conflate these processes. This article summarizes psychophysical evidence,
arguing that top-down attention and consciousness are distinct phenomena that
need not occur together and that can be manipulated using distinct paradigms.
Subjects can become conscious of an isolated object or the gist of a scene
despite the near absence of top-down attention; conversely, subjects can attend
to perceptually invisible objects. Furthermore, top-down attention and
consciousness can have opposing effects. Such dissociations are easier to
understand when the different functions of these two processes are considered.
Untangling their tight relationship is necessary for the scientific elucidation
of consciousness and its material substrate.

Publication Types: Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov’t Research Support, U.S. Gov’t, Non-P.H.S. Review

PMID: 17129748 [PubMed – indexed for MEDLINE]

2: Conscious Cogn. 2004 Dec;13(4):691-708.

Motion-induced blindness does not affect the formation of negative afterimages.

Hofstoetter C, Koch C, Kiper DC.

Institute of Neuroinformatics, Swiss Federal Institute of Technology and
University of Zurich, Zurich, Switzerland. connie@ini.phys.ethz.ch

Aftereffects induced by invisible stimuli constitute a powerful tool to
investigate what type of neural information processing can occur in the absence
of visual awareness. This approach has been successfully used to demonstrate that
awareness of oriented gratings or translating stimuli is not necessary to obtain
a robust orientation-specific or motion-specific aftereffect. We exploit
motion-induced blindness (MIB, Bonneh, Cooperman, & Sagi, 2001) to investigate
the related question of the influence of visual awareness on the formation of
negative afterimages. Our results show that MIB does not affect the persistence
and intensity of afterimages. Thus, there is no significant contribution to the
formation of afterimages beyond the sites mediating MIB.

Publication Types: Research Support, Non-U.S. Gov’t Research Support, U.S. Gov’t, Non-P.H.S. Research Support, U.S. Gov’t, P.H.S.

PMID: 15522627 [PubMed – indexed for MEDLINE]

3: Neurosurgery. 2004 Aug;55(2):273-281; discussion 281-2.

Consciousness and neurosurgery.

Crick F, Koch C, Kreiman G, Fried I.

Salk Institute for Biological Studies, La Jolla, California, USA.

The neuronal basis of consciousness is the greatest challenge to the scientific
worldview. Much relevant empirical work is carried out on the minimal neuronal
mechanisms underlying any one specific conscious percept. Two broad approaches
are popular among brain scientists: electrophysiological recordings from
individual neurons in the cortex of behaving monkeys or behavior combined with
functional brain imaging in humans. However, many aspects of consciousness are
problematic or remain off-limits to the former approach, while the latter one
lacks sufficient spatial and temporal resolution to monitor individual neurons
that are key to perception, thought, memory, and action. It is here that
neurosurgeons, probing the living human brain on a daily basis, can play a
decisive role. This article explores the contributions of neurosurgeons to this
quest and outlines some of the results that have already been achieved.

PMID: 15271233 [PubMed – indexed for MEDLINE]

4: Sample Chapters of his Book The Quest for Consciousness

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