After going on for so long about subjective truth and retrospective reconstruction of experience in my review of The Red Tree, I was highly amused when what I picked up to read after finishing the review turned out to have some highly relevant passages. From Michael S. Gazzaniga’s “The Split Brain Revisited” (Scientific American, 1998), a section reviewing research on false memories (emphases mine):
There are several views about when in the cycle of information processing such memories are laid down. Some researchers suggest they develop early in the cycle, that erroneous accounts are actually encoded at the time of the event. Others believe false memories reflect an error in reconstructing past experience: in other words, that people develop a schema about what happened and retrospectively fit untrue events–that are nonetheless consistent with the schema–into their recollection of the original experience.
The left hemisphere has exhibited certain characteristics that support the latter view. First, developing such schemata is exactly what the left hemisphere interpreter excels at. Second, Funnell has discovered that the left hemisphere has an ability to determine the source of a memory, based on the context or the surrounding events. Her work indicates that the left hemisphere actively places its experiences in a larger context, whereas the right simply attends to the perceptual aspects of the stimulus. Finally, Michael B. Miller, a graduate student at Dartmouth, has demonstrated that the left prefrontal regions of normal subjects are activated when they recall false memories.
These findings all suggest that the interpretive mechanism of the left hemisphere is always hard at work, seeking the meaning of events. It is constantly looking for order and reason, even when there is none–which leads it continually to make mistakes. It tends to overgeneralize, frequently constructing a potential past as opposed to a true one.
George L. Wolford of Dartmouth has lent even more support to this view of the left hemisphere. In a simple test that requires a person to guess whether a light is going to appear on the top or bottom of a computer screen, humans perform inventively. The experimenter manipulates the stimulus so that the light appears on the top 80 percent of the time but in a random sequence. While it quickly becomes evident that the top button is being illuminated more often, people invariably try to figure out the entire pattern or sequence–and they deeply believe they can. Yet by adopting this strategy, they are correct only 68 percent of the time. If they always pressed the top button, they would be correct 80 percent of the time.
Rats and other animals, on the other hand, are more likely to “learn to maximize” and to press only the top button. It turns out the right hemisphere behaves in the same way: it does not try to interpret its experience and find deeper meaning. It continues to live only in the thin moment of the present–and to be correct 80 percent of the time. But the left, when asked to explain why it is attempting to figure the whole sequence, always comes up with a theory, no matter how outlandish.
So, some neurological perspective. (Also, “the thin moment of the present” is a really nice phrase.) If there’s anything you learn in neuroscience and behavioral science, it’s that all organisms are pattern-interpretation machines; what patterns we find most relevant, and how we interpret them, is all contingent on our biology. So humans can make up stories – and then write stories about how we make up stories – but if we were rats, we would just be expending a lot of unnecessary effort and energy on processing of irrelevant stimuli. But we’re not rats, so that’s okay, and awesome stuff is written.
The Red Tree (2009) [E]