Exploring Consciousness with Christof Koch
On Wednesday November 14, Christof Koch, President of the Allen Institute for Brain Science, came to Reed to speak as the main psychology department speaker for the year. Dr. Koch’s talk aimed to answer the question of how is it possible that our brain, a mass of matter, can give rise to subjective ephemeral feelings, or, in other words, to consciousness.
Koch began by providing a quick overview of how people have thought about consciousness, from Plato and Aristotle to Descartes. With this basis, he began to explain that consciousness is associated with a biological system, the brain. But what is it about this system in particular that gives rise to consciousness?
To answer this question, Koch began by considering what consciousness is not. Examining previous experiments, Dr. Koch explained that consciousness does not require behavior, as people can be completely paralyzed and still be conscious, nor does it require language, long-term memory, emotions, or even self-consciousness.
Koch explained the last using several sports examples. For example, by the time a swimmer is conscious that they have heard the starting buzzer, they will have already left the starting block. And a football player doesn’t necessarily have to think about catching a ball.
Koch then moved to where consciousness resides. Patients suffering from diseases such as encephalitis, lethargica, and spinal cord injuries are nonetheless conscious, which reveals that the brain stem is not necessary for consciousness. Nor is the cerebellum necessary for consciousness, although loss of parts of the cerebellum seem to be linked to slowed processing.
So where does consciousness reside? The cortex appears to hold the key. Destruction of regions of the cortex inhibits specific parts of consciousness, so loss of some parts may cause a patient to be unable to recognize faces or colors.
What seemed to be Koch’s main take-away from this was that consciousness requires the cortex, and that consciousness is something physical.
This seems fairly straightforward, but how can we tell if other beings are conscious? According to Dr. Koch we don’t have a reliable way of measuring consciousness in others. One rudimentary technique is “zap-and-zip,” in which brief magnetic pulses are applied to the brain and scientists examine how the waves “echo” throughout the brain. The “zip” part looks at how compressible the waves are, like in a zip file. Waves echoing through our brains are not very compressible.
This technique, however, only works in humans and similar mammals such as mice or monkeys. So how do we know if other animals are conscious? Cephalopods appear to be very intelligent and to be conscious, but we have no way to measure it because of their strikingly different brain structure; the same goes animals such as bees and corvids.
At this point, we can only really guess. We know we ourselves are conscious, but we can only “abduct” consciousness in others. This relies on looking at similarity of behavior, brain structure, and closeness of evolutionary kinship. However, this technique becomes pretty much impossible when considering organisms that are radically different from human beings. Koch suggests that even single cells have some experience and feel “like” something, even if they may not have cognition.
One prediction derived from such a theory of consciousness is that consciousness is a state of being and not doing. This means that computers cannot be conscious. They can simulate functionality, but it does not have the “causal power” to allow it to be conscious. Koch explained “casual power” by comparing it to a weather simulator; it simulates the weather and the rain, but it is not actually wet inside the computer. If one were to build a brain out of the components in a human brain, however, it could be conscious; there is nothing “extra-natural” about the brain.
Another prediction is that consciousness can change. Since it is based off of experience, as we have new experiences then new connections develop in our cortex and our consciousness expands.
Unfortunately for our inner romantic and transcendentalist, however, there cannot be an ubermind. We can bridge minds using physical instruments, but it comes at the cost of individuality. When the cortexes are connected, you can see what the other person sees superimposed over your own view. There is a point, however, once both individuals cease to exist and it becomes one mind; this is the point where the integrated information across the two brains is greater than in the two individuals.
At the end, one attendee asked the inevitable question: what happens to our consciousness after death? Koch paused and answered, “Well… it’s bad news.” He continued saying that once the brain breaks into constituent parts, consciousness ceases to exist because consciousness cannot exist without a physical mechanism.