The Tell-Tale Brain: A Neuroscientist's Quest for What Makes Us Human

     Can we exploit our laws to heighten this effect? Two psychologists, Bennett Bertenthal of Indiana University and James Cutting of Cornell University, mathematically analyzed the constraints underlying biological motion (which depend on permissible joint motions) and wrote a computer program that incorporates the constraints. The program generates a perfectly convincing display of a walking person. While these images are well known, their aesthetic appeal has rarely been commented on. In theory it should be possible to amplify the constraints so that the program could produce an especially elegant feminine gait caused by a large pelvis, swaying hips and high heels as well as an especially masculine gait caused by erect posture, stiff stride, and tight buttocks. You’d create a peak shift with a computer program.

     We know the superior temporal sulcus (STS) has dedicated circuitry for extracting biological motion, so a computer manipulation of human gait might hyperactivate those circuits by exploiting two aesthetic laws in parallel: isolation (isolating the biological motion cues from other static cues) and peak shift (amplifying the biological characteristics of the motion). The result might end up being an evocative work of kinetic art that surpasses any Calder mobile. I predict that STS cells for biological motion could react even more strongly to “peak-shifted” point-light walkers.

CHAPTER 8 THE ARTFUL BRAIN: UNIVERSAL LAWS

1. Indeed, peekaboo in children may be enjoyable for precisely the same reason. In early primate evolution while still primarily inhabiting the treetops, most juveniles often became temporarily occluded completely by foliage. Evolution saw fit to make peekaboo visually reinforcing for offspring and mother, as they periodically glimpsed each other, thereby ensuring that the child was kept safe and within a reasonable distance. Additionally, the smile and laugh of parent and offspring would have mutually reinforced each other. One wonders whether apes enjoy peekaboo.

     The laughter seen after peekaboo is also explained by my ideas on humor (see Chapter 1), that it results from; a buildup of expectation followed by a surprising deflation. Peakaboo could be regarded as a cognitive tickle.

2. See also Note 6 of Chapter 3, where the effect of altering type to match the meaning of the words was discussed—there from the standpoint of synesthesia rather than humor and aesthetics.

3. To these nine laws of aesthetics we may add a tenth law that overarches the others. Let’s call it “resonance” because it involves the clever use of multiple laws enhancing each other in a single image. For example, in many Indian sculptures, a sexy nymph is portrayed languorously standing beneath the arched branch of a tree which has ripe fruits dangling from it. There are the peak shifts in posture and form (for example, large breasts) that make her exquisitely feminine and voluptuous. Additionally, the fruits are a visual echo of her breasts, but they also conceptually symbolize the fecundity and fertility of nature just as the nymph’s breasts do; so the perceptual and conceptual elements resonate. The sculptor will also often add baroque ornate jewelry on her otherwise naked torso to enhance, by contrast, the smoothness and suppleness of her youthful estrogen-charged skin. (I mean contrast of texture rather than of luminance here.) A more familiar example would be a Monet in which peekaboo, peak shift, and isolation are all combined in a single painting.

CHAPTER 9 AN APE WITH A SOUL: HOW INTROSPECTION EVOLVED

1. Two questions may legitimately be raised about metarepresentations. First, isn’t this just a matter of degree? Perhaps a dog has a metarepresentation of sorts that’s richer than what a rat has but not quite as rich as a human’s (the “When to you start calling a man bald” issue). This question was raised and answered in the Introduction, where we noted that nonlinearities are common in nature—especially in evolution. A fortuitous coemergence of attributes can produce a relatively sudden, qualitative jump, resulting in a novel ability. A metarepresentation doesn’t merely imply richer associations; it also requires the ability to intentionally summon up these associations, attend to them at will, and manipulate them mentally. These abilities require frontal lobe structures, including the anterior cingulate, to direct attention to different aspects of the internal image (although concepts such as “attention” and “internal image” conceal vast depths of ignorance). An idea similar to this was originally proposed by Marvin Minsky.