Neurobiologist explores in depth how brain works in consciousness

William Mosshammer

During a public lecture, California Institute of Technology professor Christof Koch explained the question of consciousness, framing it within a neurobiological view.

Koch gave a one-hour lecture explaining why the brain must play a key role in consciousness, how parts of the brain contribute to consciousness and what the ultimate goal of understanding is, on Friday afternoon, Oct. 24 at the Oviatt Library.

According to Koch the key for understanding consciousness rests entirely within the workings of the brain, as opposed to a dualist philosophy of mind that ascribes consciousness to the workings of some non-material entity distinct from the physical.

‘Destruction of a small part of the brain can give rise to very circumscribed loss of conscious perceptions,’ Koch said, such as losing the ability to see motion, recognize faces or loss of the feeling of familiarity.

For Koch, this is evidence that the brain must be necessary to consciousness since alterations to or loss of parts of the brain can result in alterations in or loss of some aspects of perceptual consciousness.

‘The brain is a virtual reality machine,’ said Jerry Stinner, the dean of the CSUN College of Science and Math during his introduction of Koch. ‘It’s simply creating its best guess of what’s out there using action potentials.’

An action potential is an electric charge generated by the movement of ions across the neuron’s membrane. Neurons use action potentials to transmit sensory information like pain, vision, hearing and the like.

According to Koch, there are aspects of pain, such as the action potentials, which have been explained in terms of their physical structures of the body, and there are other parts of pain, the actual experience of it, its ‘painfulness,’ that have yet to be explained.
‘It’s utterly unclear where this painfulness comes from,’ Koch said.

The problem, as Koch sees it, is how the physical world relates to the subjective experience of each person and how that subjective experience arises from his or her physiological make up.

To demonstrate the problem Koch displayed an image with a sphere composed of swirling blue dots; inside the sphere were two small yellow squares placed beside each other.

Koch then directed the audience to focus their attention on a letter in the footnotes at the bottom of the image. After a brief period of focused attention the yellow squares disappear from perception.

‘Physically, in both cases’hellip; the photons from (the yellow squares), from that surface is emitted and strikes your eyes,’ Koch said.

‘What is the difference in the brain when you don’t see the yellow and when you see the yellow?’ he said.

‘Once we have a really solid scientific understanding’hellip;of how you perceive things like yellow then probably we’re a huge step toward understanding all of consciousness like smell and’hellip; more elaborate aspects of consciousness,’ Koch said.

‘There is something special about the brain,’ said Koch. ‘What it is? We don’t know.’
Koch spoke in front of a packed audience in the Oviatt Presentation Room, with faculty and students lining the walls, sitting on tables and laying on the floor.

‘It was very interesting, I liked it,’ said Opal Brown, a second-year senior whose experimental psychology professor recommended the lecture to him.

More of Koch’s thoughts and research can be found in his book, ‘The Quest for Consciousness: A Neurobiological Approach.’