As I said a few weeks ago, I’ve been reading Temple Grandin’s Animals in Translation at work. And before some people start saying, “What, still?,” I would like to point out that 1) I am actually expected to do other things at work ocassionally, and 2) there’s so much information in this book I kept having to stop and think all the time, which slows down the reading process a bit. Darn that interesting nonfiction. So anyway, I finished the book today and now have several posts worth of stuff to talk about.
For today, I’ve picked out some of the information she had to present about the way human verbal vs. visual cognition works. Grandin is known for her assertion that she thinks in pictures, hence the name of her autobiography, Thinking In Pictures, so she’s done a lot of thinking about this topic, clearly. She describes the following study to demonstrate how the two types of thinking seem almost opposed.
Research shows that language suppresses visual memory. This is called verbal overshadowing and is a well-established phenomenon… For example, in one study people watched a short videotape of a bank robbery, then spent twenty minutes doing something unrelated. Then one group spent five minutes writing down everything they could remember about the bank robber’s face, while the other group did an unrelated task.
Two thirds of the people who wrote nothing down and did unrelated tasks could identify a photograph of the robber, while only one third of the people who wrote verbal descriptions could pick him out…
I think for normal people language is probably a kind of filter. One of the biggest challenges for an animal or an autistic person is dealing with the barrage of details from the environment. Normal people with language don’t have to see all those details consciously…
She cites another study in which rats out-performed humans in a lever pressing behavior experiment. (There was a screen on which dots appeared in different places, and a lever to press. 70% of the lever presses would be rewarded, regardless of where on the screen the dot appeared. The rats pressed the lever every time the screen changed and got their full 70% reward; the humans tried to figure out which dot placement resulted in reward and therefore got less than the full 70%.) She interprets the findings as showing that humans’ need to interpret their environment, getting rid of the parts that don’t fit their narrative explanation and sometimes combining unrelated bits of data, interfered with their ability to simply perform what the rats found to be a very simple task.
One thing we do know about humans is that the left brain, which is the conscious language part of the brain, always makes up a story to explain what’s going on. Normal people have an interpreter in their left brain that takes all the random, contradictory details of whatever they’re doing or remembering at the moment, and smoothes everything out into one coherent story. If there are details that don’t fit, a lot of times they get edited out or revised. Some left brain stories can be so far off from reality that they sound like confabulations.
The interpreter probably got in the way on the lever-pressing experiment [in which humans were less accurate than rats]. The human subjects kept trying to come up with a story about the dots [appearing on the screen], and when they did come up with a story they stuck to it. Then the dot story kept them from realizing that they should just forget about the dots and press the lever every time the screen changed.
In addition, she mentioned a study in which a researcher looked at fMRI scans of people who had experienced traumatic events, half of whom had developed post-traumatic stress disorder (PTSD) and half of whom had not. The study found that all of those who developed PTSD were remembering the event with the visual parts of their brain, and those who had not were recalling with the verbal, or language, areas.
So what does this mean? Beyond just being interesting bits of information, I mean. I’m not really sure, but the most basic conclusion seems to be that even though most people seem to process things via their language centers, this has both advantages and disadvantages. It distances us from our experiences, and clearly, as in the PTSD example, we sometimes need that. On the other hand, it’s actually interfering with our ability to remember things accurately.
Doesn’t it make you wonder what we used to be like before writing and literacy became so prevalent? We’ve all gotten in the habit of taking notes when we want to remember things, but what if that’s actually making it harder to remember? I remember learning in school about the amazing memories people supposedly used to have, and some of the memory exercises people used to do, such as the method of loci, better known as the “memory palace,” in which people built a visual palace in their minds and stored their memories, represented by a visual object key, in its rooms.
Many people with savant skills, such as Daniel Tammet, are known for their prodigious memories. Could this be why? Tammet certainly credits his synaesthesia, in which he sees numbers and words as having distinct characteristics and colors, as being a huge contributing factor.
I can’t even imagine the amount of effort it would take to retrain myself to think in such a way now.