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The Religious Impulse (Final A.M. Tidbit!)

25 Oct

I found my favorite chapter in The Accidental Mind.

Chapter 8, “The Religious Impulse”, is Dr. Linden’s theory/explanation of one of my favorite topics: Religion. Religion is omnipresent on this planet, in one form or another: one God, multiple Gods, spirits, versions of world creation, visions of afterlife… every culture has religion. But why?

Through a series of experiments, Dr. Linden describes the mind’s uncanny ability to create a “gap-free narrative” of our experiences — a seamless amass of consecutive perception. He draws from Roger Sperry’s fascinating studies of split-brain patients as well as from studies of patients with anterograde amnesia. I’ll let his descriptions of these experiments do the talking for me, but I’ll introduce the concept with an easier example first.

When we look around with our eyes, the images our brain creates seem continuous; however, our eyes are not actually perceiving things continuously at all. Our eyes move in jerky motions — called saccades — and do not gather light reflection in the ‘in-between’ steps (the motions themselves). Yet the brain forms an image of the world without any gaps. It seems it does the same thing when confronted with more complex, higher-order cognitive problems. Dr. Linden uses split-brain patients to demonstrate this, focusing on the lack of communication between the right and left hemispheres and the resulting story-making:

“Split-brain patients provide a unique opportunity to see how the left and right cortices process information independently. In one famous experiment, a split-brain patient was placed before a specially constructed screen, designed so that the left cortex received only an image of a chicken’s claw (projected in the right visual field: the representation of the visual field is reversed right to left in the brain) while the right cortex saw a winter landscape with snow. When asked to pick a card with an image to match, the right cortex, which controls the left hand, picked a shovel to go with the theme of snow, while the left cortex, which controls the right hand, picked an image of a chicken to go with the claw. This shows that each side of thecortex could recognize its image and make an appropriate association. When the patient was asked why he chose those two images, the response came from the left side (that is the only one that can speak–theright is mute); the response was, “Oh, that’s simple. The chicken claw goes with the chicken and you need a shovel to clean out the chicken shed.”

Let’s think carefully about what’s happening here. The left brain saw the chicken claw but not the snow scene. When faced with the shovel and the chicken it retroactively constructed a story to make these disparate choices appear to make sense. Michael Gazzaniga, in his book entitled The Mind’s Past, from which this example is taken, notes, “What is amazing here is that the left hemisphere is perfectly capable of saying something like, “look, I have no idea why I picked the shovel… Quit asking me this stupid question.” Yet it doesn’t.”

This call to narration, he suggests, may serve as a neural basis for forms of religious belief. Here it is in his own words:

“I suggest that the left cortex’s always-on narrative-constructing function promotes the acquisition of religious thought through both subconscious and conscious means. Religious ideas largely involve nonnaturalistic explanations. Whether religious ideas are regarded by their practitioners as “faith” or merely “given knowledge”, they share the property that they violate everyday perceptual and cognitive structures and categories. The left cortex predisposes us to create narratives from fragments of perception and memory. Religious ideas are similarly formed by transforming everyday perceptions, by building coherent narratives that bridge otherwise disparate concepts and entities. Pascal Boyer proposes that the most effective religious concepts preserve all the relevant inference os a particular cognitive category except those that are specifically prohibited by a special nonnaturalistic aspect.”

He ends the chapter with this statement: “Our brains have evolved to make us believers.”

While I think this curious tendency towards making ‘stories’ out of our perceived reality has some other interesting implications, applying it to religion seems to fit rather well. Unfortunately, like Dr. Linden, I have been feeling a bit hesitant to try and explain this idea to people with strong religious beliefs. I myself believe that the idea can fit well with strong believers — nothing says that ‘God’ didn’t intend for our brains to be constructed such that believing would be so natural — but others may spin the theory with science as the victor, removing the mystery and awe that should be attributed to a “leap of faith”. Hm.

This has prompted me to go out searching for more. I’ve picked up Why Would Anyone Believe in God? by Dr. Justin Barrett at Oxford — more explanation from the cognitive science perspective. I’ll keep you updated. :)

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Cortical Expansion

26 Aug

So I stumbled across this abstract and picture a little while ago. Both come from similar patterns of cortical expansion during human development and evolution, a paper published at Yale earlier this year. The title basically sums up the idea, though I think some of the finer suggestions of why this happens are pretty neat.

Hill et al. notice that the newer portions of our brains (mainly, the giant cortex, which is responsible for our ‘higher’/more ‘human’ brain function, and is the most recent to be ‘tacked on’ as in Dr. Linden’s model) tend to develop considerably after birth, whereas the basic units responsible for survival–not so unique to humans–are already developed by the time we exit the womb. It’s interesting to think about how much is left to be shaped by our experience–and it seems that the equipment and allowance of extensive experience-based molding is a large chunk of what sets us apart.

Why we keep men around… A.M Tidbit 3

24 Aug

Another bit from Linden’s The Accidental Mind

In the “Love and Sex” chapter, Dr. Linden points out that most female mammals “advertise” their ovulation – with different scents, changes in appearance, etc. Males and females won’t approach each other when the female has not begun ovulating. In human females, however, time of ovulation is completely concealed: our men have no way of knowing when we’re most fertile, and sex becomes more recreational. Why?

Here’s a direct quote from pg. 149:

“With concealed ovulation… the couple has to mate all through the woman’s cycle to have a reasonable chance of conceiving. Not only that, but if the male decides to stay and try his luck with another female, he cannot be sure that another male will not sneak in the back door and mate with the first female on her fertile days… Hence, with concealed ovulation, the best male strategy is to stick with one female and mate with her all the time.”

But what about the females? Does this type of mating system benefit us? He continues:

“Most other mammals are able to find their own food immediately after weaning, but human children do not achieve this level of independence for many more years. As a consequence, the reproductive success of a female human is much greater if she can establish a long-term pair bond with a male and he contributes in some form to child-rearing.”

So, we need concealed ovulation – so our big-brained offspring are properly taken care of by two adult parents. The bonding that comes as a result of more frequent, recreational sex stabilizes the whole situation… and even keeps us ‘doing it’ when conception isn’t in the picture (like after menopause or during pregnancy).

(These ideas are all from Linden, pgs. 147-150)

Pretty neat, eh?