Other Minds

Peter Godfrey-Smith’s “Other Minds”

There are two sides to the world that have to fit together somehow, but do not seem to fit together in a way that we presently understand. One is the existence of sensations and other mental processes that are felt by an agent; the other is the world of biology, chemistry, and physics. Subjective and Objective?? I would rather say two worlds instead of two sides of one world. But so what?

L 440: The story so far is a telling of the familiar pre Cambrian time (Ediacaran) with some details and animals that are new to me. The focus is on the rôle the nervous system. As the Cambrian explosion exploded the arms race began with the considerable help of the nervous system.

L 462: Cubozoa: Jelly(fish) with eyes and no brains. Bizarre! N.B. there is no implication that our common ancestor had eyes.

L 460: “From this point [Cambrian] on, the mind evolved in response to other minds.” The books emphasis on information begins to pay off.

L 477: This sections describes well the purpose of a model. What is truth? Has that changed since we modeled in order to predate, or escape predators?

L 877: This section is sort of “What it like to be an octopus”.

L 945:

Learning by attending to reward and punishment, by tracking what works and what does not work, seems to have been invented independently several times in evolution. I had not known this. It would be interesting to track down the evidence and ramifications of this.

L 967:

Defenders of embodied cognition often say that the body’s shape and organization encodes information. I hope they don’t mean anything more than “The body evolved, with the brain, to survive and prosper.”. I deny the meaningfulness of anything like “The body is doing some of the thinking.” except that there is some combinatorial nervous logic outside the brain.

L 991: William James said that consciousness did not irrupt in evolution. Good point. I suggest that the semi conscious state that human’s go thru as they waken is a decent approximation of partly conscious, except for the dying dreams sometimes experienced.

L 1081:

To deal with this problem, whenever a fish emits a pulse it also sends a copy of the command around to the sensing system, enabling that system to counteract the effect of the pulse it has produced. Engineers often have this problem. A radar emits a signal it would not only overwhelm the receiver, but ruin it, except for the fact that hardware is activated to blind and protect the receiver.

L 1143: Milner & Goodale’s dorsal stream of visual information is the same as blind sight as described by Ramachandran.

L 1172:

Then, at some stage in evolution, extra capacities appear that do give rise to subjective experience: the sensory streams are brought together, an “internal model” of the world arises, and there’s a recognition of time and self. A bit like this.

L 1588: Regarding photoreceptors in the skin of cuttlefish and octopuses: The chromatophores in the skin may act as filters for the monochrome photoreceptors there. This provides sensing different colors and would indeed motivate changing colors in various patterns. This in turn suggests how these animals know how to camouflage themselves.

The author goes immediately on to this explanation. Where most people are trichromats, the octopus is a unichromat. Its eyes see black and white.

L 1671: “Any color changes that do not contribute to signaling and camouflage are side effects, from an evolutionary point of view.” I claim they are just looking at ambient colors which means that those monochrome photoreceptors do inform the brain.

I had always wondered how the fish that camouflaged themselves figured out what they were supposed to look like.

L 1839: The author may be leading up to the idea that speech evolved originally as a means of organizing complex thought. That form would have no phonetics associated with it. Julian Jaynes thought that humans have a ‘tape recorder’ with which we remember plans for the hunt. That recorder was definitely phonetic in nature and malfunctions of that recorder result in hearing voices today.

L 1868: I think there are at least two sorts of thinking. The old stuff was primarily retrieving situations from memory in response to recognized patterns; then filling in the parameters. The second is linear combinatorial thinking. I.e. Kahneman. In between is nested goals which allowed the monkeys the figure out how to stack boxes.

L 2142: Why do we age? Telomeres are the mechanism but then how does the next generation get long telomeres that the single organism cannot use. There seems to be a planned obsolescence.

L 2274:

And once you have a larger nervous system, this makes it worthwhile to further expand the body’s possibilities—collecting all those sensors on the arms, creating the machinery of color change and a skin that can see. A nice example of the adjacent possible.

Collected Impressions

I think the book considers the evolution of brain functions more closely than any other that I have read. I think it does a good job but still I am a bit disappointed at ⅓ thru. I approve of the perspective. I am learning interesting biology. I think that the last third of the book is the best.

There is considerable discussion on the role of the nervous system and its evolution.

The speculations on the relationship between language and thinking are very interesting.

The author quotes many ideas about consciousness that I had not heard. They are interesting but do not dislodge my ideas. They are fairly compatible.

I think I know just one thing about octopuses that is not in the book. The retina of their eye is between the lens and the blood vesicles that tend to the retina. In vertebrates the vesicles are between. We got it wrong.