2.3 The Search for MemoryIf I tell you something today and you can recall this some time in the future, then you must have stored it somewhere in your body. Where and how is it stored? One would assume that it must be stored in the association areas of your brain. Sensory and motor functions, to receive stimuli and initiate responses, have been localized in certain parts of the brain. The association areas are the "uncommitted cortex", the parts of the brain not directly linked to the environment, But precisely where in those association areas is memory stored?
Kurt Lashley spent a lifetime trying to find out. He trained rats to run a maze, cut out parts of their association areas, and retested them on the maze. The extent of the deficiency was related not to the location of the ablation but to the extent of the ablation. The more association area removed, the greater the deficiency, regardless of where it was removed from. He concluded that, for certain functions, the association area acts as a whole. This principle of mass action was presented as an alternative to the principle of localization [LASHLEY].
Karl Pribram concluded that Lashley could not find memory anywhere because it is everywhere [PRIBRAM]. The nervous system is like a hologram, in which all the information is contained in all the nervous system. Each part of the hologram contains the whole image. The smaller the part of the hologram, the worse the resolution of the image. That is parallel to what Lashley discovered - the more association tissue he removed, the more the deficiency in maze-running.
A psychologist called James McConnell generated some evidence that memory is stored throughout the body with a series of experiments he conducted using worms [MCCONNELL]. In one experiment, he taught worms to turn right in a T maze. When the worms regenerated after he cut them in half, he found that the new worms took significantly less time to learn to go right in the T maze than the regenerated halves of untrained worms. In an even more dramatic experiment, he ground up trained worms, fed them to untrained worms, and found that those cannibal worms took less time to learn to go right in a T maze than worms which had been fed on untrained worms. The information must thus be retained at a chemical level, since that is all that survives being minced and eaten.23
McConnell suspected that the information is retained in the chemical ribonucleic acid (RNA) which is a biological cousin to deoxyribonucleic acid (DNA), which contains the instructions for the development of the organism. If phylogenetic memory is stored in DNA, it is not surprising that ontogenetic memory is stored in RNA. Phylogenetic and ontogenetic memory can dovetail at a chemical level. Mother Nature leaves gaps in our program to be filled in by our environment so that we can adapt to our particular environment. McConnell's results were so bizarre that they were simply ignored by traditional psychology. His findings were not disproved by subsequent research. They were simply ignored [INGRAM 1998]. In the light of evolutionary psychology, those findings are no longer so bizarre. Perhaps we should look at them again.
The nervous system of the worm permits it to choose between response A and response B. However, it is only with the development of an association area in the brain, which mediates between the sensory and motor areas, that the organism begins to escape from the tyranny of the environment. It can then choose not only whether to make response A or response B but whether to respond or not to respond.
Thus it is no coincidence that, in the octopus, we find the beginning of an association area and also the beginning of the capacity not to respond. The spontaneous response of the octopus to the stimulus "crab" is the response "grab".24 A psychologist has been able to teach octopuses to inhibit this response for a few seconds [YOUNG]. This capacity for a delayed response is possible only when sensory neurons are not directly linked to motor neurons. The organism can say "no" to the environment. The capacity not to respond, or, more accurately, to delay responding, is a sophisticated accomplishment of living systems. The length of delay possible is a useful index of phylogenetic development.
The spontaneous response of the octopus on seeing a crab is to go straight to it. Young put a glass screen between the octopus and the crab and found that the octopus was capable of learning to go around the screen to get at the crab. This detour behavior is very significant. In turning away from the crab, the behavior of the octopus is directed not by the stimulus of the crab but by an image of the crab. We see here the beginning of mental life. The octopus can make a sketchy subjective map of the objective world and operate within the map as well as within the world. This emancipation from the tyranny of the environment is possible only if there is a part of the nervous system (neither sensory nor motor) in which images can be stored. The uncommitted cortex has yielded the unsolicited gift of consciousness.
Wilder Penfield found evidence that memory is localized in a particular place within the association area of the brain [PENFIELD & ROBERTS]. He was operating on patients suffering from epilepsy by removing the area of the brain which triggered the epileptic seizure. Such an operation can be conducted while the patient is fully conscious, since there are no pain receptors in the brain. He dropped an electrode into the brain of the patient to make sure that the affected area is not part of the speech center. If it was, the cure would be worse than the disease. When he dropped the electrode into the temporal lobe of one patient she reported experiencing an event in her past. It was a rerun of a past event with all the accompanying sights, sounds, smells, tastes, and touches. When Penfield lifted the electrode and dropped it again into the same place, the relived experience continued where it had left off. It was as if the patient had a complete videotape of her past which could be played by triggering it with an electrode.
The localization of memory in a particular area would seem incompatible with the mass action of the brain as a whole. However just as the deposit and withdrawal of money in a bank differs from the storage of that money in the bank, so the deposit and retrieval of information from the memory bank may differ from its storage. When you withdraw $100 from your bank account you don't expect to get back the same five crumbled $20 bills you deposited some time before. Memory may be stored chemically throughout the brain yet deposited and retrieved neurologically in a particular area of the brain. Whatever the mechanism, the important point is that the nervous system has the means of storing information (memory) and transmitting information (speech). It is interesting that the storage and transmission areas of the brain are close to one another. No doubt, as the solution to the mystery of memory and speech unfolds we will find how this first generation of media is ingeniously designed by natural selection.
Memory (however nature designs it) is the foundation of all media (however we design them). In Greek mythology, Mnemosyne (memory) was the mother of the nine muses:
23 This produced a rash of rude suggestions about what to do with retired professors who had lost their faculties.
24 Or, more accurately, "grab, grab, grab,grab, grab, grab, grab,grab".