Apr 05 2007
To put it bluntly, human memory stinks. Well, everything is relative, so let me clarify – it works fine, even quite well, for the purposes for which it evolved. However, now we humans are trying to survive for 80+ years in a complicated technological civilization with brains that evolved on the savanna and are designed to work for maybe 40 years.
Our memories work well for some things. Memory is largely based on pattern recognition, and this remains our cognitive strong point. We remember patterns well, we can see correlations between different patterns, we can see underlying meaning in patterns. However, this also biases our memory. We tend to anchor our memories to meaningful patterns – and this helps us remember and also we tend to remember the important stuff and forget the not-so-important stuff.
But the flip side of this is that we are not very good at remembering details. The details of our memories tend to fade, even when the big picture remains. Worse, the details change to suit the patterns we think we remember. In other words, we remember well the emotions of an event, the significance it has in our lives, and the meaning we attach to it. The little details then morph over time to enhance the emotion, significance, and meaning of our memory of the event. We even make up new details as necessary.
This probably worked really well on the savannah – for example remembering that near that big rock is where my friends were killed by the lion is important. That area, perhaps even the smells of the area, strongly associate with that memory, especially the emotions of the memory, the fear and the blood. What is important is to remember the fear and the danger, and perhaps survival is enhanced if the details of the memory morph to enhance the fear and danger. So perhaps over time we remember more lions and more blood than there actually were. We might even fuse in details from other bad events to enhance the memory further.
Now fast forward a few million years to today. The details of our memories are much more important. With regard to science and the paranormal – the devil is in the details. Someone may have an experience where they encounter a strange beast in the woods. The experience was tinged with fear and confusion, and so perception was less than cool and controlled. The encounter may have some meaning for the experiencer – perhaps they have heard of Bigfoot, perhaps they are even a believer. Over time the details of their memory will migrate over to Bigfoot to enhance the meaning and significance of the encounter.
This is why subjective memory (read anecdotal evidence) is not very useful to science. Science works in a way very opposite to that of human memory. Memory focuses on the meaning and then alters the details to fit. Science endeavors to start with the details (often obsessing over the details with fanatical fidelity) and then derive the meaning from them.
Fortunately we developed writing and now the electronic information age, to keep memories outside our brains in a medium that is not malleable, that does not morph over time, and can preserve exquisite detail.
In keeping with the theme this week we can also ask: do some people have better or worse memories than others, specifically a greater tendency to change memories to suit the needs of belief? The answer appears to be yes (no surprise).
A recent study by Maarten Peters of Maastricht University in the Netherlands looked at subjects who believe they have recovered under hypnosis memories of past lives and compared them to controls who did not have memories of past lives. He did an interesting experiment where he asked them to recite a list of unfamiliar names. The next day they were shown a list including some famous names, some not famous names, and some of the unfamiliar names from the day before. Those who had memories of past lives were more likely than controls to believe that the unfamiliar names from the day before were actually of famous people they had heard of before.
What this means is that they attached a significance to the fact that they recognized these names and created a false memory of having previously heard of them as famous people. Peters likens this to attaching significance to the images of past lives (either suggested to them under hypnosis or just the product of their own imagination) to actual past life experiences.
Once again we see a tendency toward a suite of traits that predisposes to belief in the paranormal and involves how the brain perceives and processes information.
I also think there is another end to this spectrum – those who have a good mind for details, in fact they may get lost in the details and fail to see the forest for the trees. Like many such things, the optimal situation for any such individual may be to have a good balance of both – appreciating details while trying to place them in the context of the bigger picture. I also think that society is likely to benefit from having people who span the entire spectrum, for even though it may not be optimal overall, each end of the spectrum likely has advantages for particular tasks. Perhaps we have great engineers at one end of the spectrum and great artists at the other, and society can use both.
It is already the case also, as I mentioned above, that technology will continue to provide options for mitigating the negative consequences of our weaknesses, both individual and as a species. We already keep most of our knowledge in books, computers, and other media to compensate for the deficiencies of our brains (doctors like to jokingly refer to their portable books or PDA’s filled with essential medical information as their “ectopic brains”). As I blogged about last week, we will likely also directly enhance our brain functions with computer prostheses in the future. Imagine if the pattern seeking and creative biological memory of our brains were enhanced with the high fidelity and detailed memory of a computer – the best of both worlds.
In the meantime it is the job of skeptics and scientists to use the methodologies of science to examine and explain the torrent of paranormal, pseudoscientific, and spiritual mumbo-jumbo that flows forth from those among us who are reality-challenged by virtue of their particular hard-wiring.
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