Challenging the brain’s canon
Alfred North Whitehead famously quipped that all Western philosophy consists of a series of footnotes to Plato. Although Aristotelians would beg to differ, a similar observation may be made that modern theories of the mind are footnotes to Charles Darwin.
Unfortunately, for more than a century, many psychologists were sidetracked by the blank slate theory of the mind that eschewed the facts that humans are animals subject to the same forces of natural selection as other animals and that 99% of the history of our species involved hierarchical social primates living in small hunter-gatherer bands of 150 to 200 individuals, struggling to survive in a harsh and pitiless physical environment and a complex and confusing social environment.
In 1975, psychology was brought back into the Darwinian fold when evolutionary biologist Edward O. Wilson penned a work, “Sociobiology,” that launched a new science. By the 1990s, sociobiology had mutated into evolutionary psychology, now a vibrant field replete with its own journals, textbooks, conferences, departments, professorships, graduate students and all the trappings of a science in full bloom.
According to the EP-ers, the mind is like a Swiss Army knife, sated with specialized tools that evolved in our Paleolithic past to solve specific problems of survival, such as face recognition, language acquisition, mate selection and deception detection. In this reductionist model, the brain is represented as a host of modules, or bundles of neurons, some in a single spot (as in French brain surgeon Paul Broca’s area for language), others sprawled out over the cortex. Large modules coordinate impute from smaller modules, which collate neural events from still smaller bundles. This reduction continues all the way to the single-neuron level.
For many years Peggy La Cerra, a graduate in evolutionary psychology from UC Santa Barbara, and Roger Bingham, at the Center for Brain and Cognition at UC San Diego, were outspoken advocates of the evolutionary psychology paradigm. Bingham even produced an award-winning 1996 PBS documentary series, “The Human Quest,” which was nothing short of adulatory in canonizing the doctrines of this new science. In “The Origin of Minds,” however, La Cerra and Bingham challenge the canon and reveal that they have become evolutionary psychology revisionists. Our ancestral inheritance is not a set of fixed cognitive tools, they argue, but a living “brain/mind-construction system” that exploits pliable brain tissue, changing it with new or changing experiences. The Swiss Army knife, it seems, can design new blades.
There are two causal levels under consideration here: the proximate level that asks how the mind works and the ultimate level that asks why the mind works. At the how level, the mind is an emergent property of billions of individual neurons, each of which is connected to thousands of other neurons that together produce trillions of potential neuronal states. La Cerra and Bingham argue that as the individual grows and develops into adulthood, the interconnections grow and develop according to individual life experiences. Although we share a common evolutionary ancestry that generated a universal neural architecture, no two life paths are the same, so with trillions of possible permutations of neural connections in each brain, every human mind is unique. There are, the authors say, literally 6 billion different minds.
Shifting from the how to the why, La Cerra and Bingham show that the basic underlying structure that makes up these 6 billion minds can be found in all living beings, from bacteria and bees to birds and baboons. Sensation and perception, learning and memory, cognition and decision-making are mental processes shared by all living organisms. There is not only a human nature, there is a life nature, at the core of which is energy management. “To do anything -- locate food, find a mate, reproduce, compose a sonata, solve an equation -- you have to stay alive with enough surplus energy to perform the task at hand,” the authors explain.
To solve energy management problems, organisms evolved intelligence, which functions “in an ever-fluctuating environment by changing itself with every experience.” The foundation of this intelligence is what La Cerra and Bingham call the adaptive representational network, “a network of neurons that memorializes a brief scene in the ongoing movie of your life, linking together your physical and emotional state, the environment you are in, the behavior or thought you generate, and the problem-solving outcome.”
What La Cerra and Bingham are describing is an auto-catalytic (self-generating) feedback loop. New experiences stimulate neurons to grow new synaptic connections. Those new connections are distinctive to every individual mind, which then responds to the environment in an idiosyncratic way, producing a behavioral repertoire of responses. This network evolved as an adaptation to help organisms survive in an ever-changing environment. No brain module can do what the adaptive representational network does, because modules evolved to solve specific problems whereas the adaptive representational network evolved to solve a range of problems, even those never encountered.
This revisionist model of the mind spins a new interpretation on some old problems. “Intelligence,” for example, is not a fixed set of specific abilities (memory or math), nor is it simply a generalized processor (as in British psychologist Charles Spearman’s “g” or general intelligence). Rather, the adaptive representational network is the fundamental unit of intelligence whose flexibility leads “to a surprising range of human abilities -- the creation of selves and personalities, the generation of unprecedented thoughts and metaphors, and the ability to make inferences about our world and the people with whom we share it.”
Critics of sociobiology will be attracted to this new evolutionary model of flexible intelligence: “An inner-city child who is dealing with life-threatening problems at home is intelligent if he’s thinking about those problems -- even when there’s an intelligence test sitting on his desk and his teacher is expecting him to be performing word analogies. This model makes it blatantly obvious that socioeconomic factors are inextricably imbedded in any measure of ‘intelligence.’ ”
La Cerra and Bingham also reinterpret clinical depression in terms of its adaptive response consequences. The symptoms of depression -- restlessness, agitation, disturbed sleeping and eating, impaired concentration and loss of motivation -- are not signs of an illness; rather, they represent an adaptive response to do something different in one’s life. “Because behavior is so enormously expensive energetically, the best thing a person in this situation can do is to stop what he has been doing, reconfigure his life, and try to formulate a more viable trajectory into the future.”
Why would this intelligence system have evolved? “If you were an ancestral human who was being exploited by another individual or group of individuals, a complete behavior shutdown could abruptly force a renegotiation of the inequitable social relationship.” Even in the modern world, depression “serves as a wake-up call, prodding people to abandon dead-end jobs and relationships.”
The authors creatively reexamine numerous such issues in the psychological literature through the lens of adaptive representational networks. Although the volume is slim and would serve scientists and scholars better if it included references to the many and important studies discussed within, I was struck by how much La Cerra and Bingham packed onto every page. The narrative is comfortably divided between anecdotal stories and hard data. The theory’s strength emerges in the integration of the life history of the species with the life history of the individual and in the way both histories shape brains into unique minds and selves.
The theory’s weakness is the same one that plagues all such theories, and that is the fact that there is still so much we do not understand about how the mind works. Thus, theorists are forced to turn to mind metaphors, such as Swiss Army knives, modules, memes, holograms and the like. La Cerra and Bingham claim that the adaptive representational network is not a metaphor but a descriptive model for what actually happens at the neuronal level. They may be right. We shall see how the community of practicing neuroscientists responds in attempting to test this theory against other theories.
Still, La Cerra and Bingham’s model explains more than the evolutionary psychology model, itself an improvement on earlier theories, so in the tradition of cumulative science and progressive paradigms, “The Origin of Minds” takes us closer to understanding the workings of the most complex machine in the cosmos. *
