Sperry’s Mentalist Paradigm

Neuropsychologist/neurobiologist Roger Sperry, who was awarded the Nobel Prize for hemispheric lateralization in split-brain patients, proposes a “mentalist paradigm” in which consciousness is a causal emergent in brain function. “Emergent determinism,” he says, “is the basic key concept behind this paradigm shift.”

Sperry applauds “the abrupt mentalist overthrow of the half-century-old, seemingly impregnable behaviorist paradigm…with its secure basis in foundational tenets consistent with the other sciences.” He points out, “The term mentalism is used throughout as in behavioral science to imply that behavior is mentally driven (in contradiction to behaviorist doctrine) and not, as in occasional philosophic usage, to imply that the physical world has reality only insofar as it is perceived mentally” (Sperry, 1990).

The Mentalist Paradigm Defined

Sperry laments that his new mentalist tenets have been misconceived in multifarious ways: as a form of dualism, mind-brain identity theory, strict functionalism, nonreductive physical monism, dualist interactionism, emergent interactionism, and various other ways. He attributes this “diversity and contradiction” to “the fact that the new mentalist paradigm is a distinctly new position that fails to fit traditional philosophic dichotomies.”

Sperry’s mentalist paradigm calls on a more generalized functionalism, where “subjective meaning depends on the overall functional effects of the physiological processes.” He insists that his theory is “not dualistic in the classic sense, but rather a new form of monism that conceives mental entities in an emergent and causal role. In this view, conscious experience, taken to be a nonreductive dynamic emergent of brain activity, cannot exist apart from the brain. There is no provision for unembodied consciousness, mind, or spirit.” Rather, he calls his theory “Mentalist Monism” (Sperry, 1978).

Emergent Monism and Mind-Brain Distinction

Sperry distinguishes his mentalist paradigm sharply from mind-brain identity theory in that “the conventional differences between mind and brain are accepted and emphasized. The brain processes, consisting of a multilevel hierarchic compound of entities and events from subatomic up through cerebral circuit and cognitive levels, are composed mostly of nonconscious elements that are common to both conscious and unconscious brain processes. Only upper levels within certain particular brain processes are presumed to sustain conscious qualities. The brain process and the conscious properties are inseparable but different. The difference between mind and brain is the kind that exists between an emergent property and its infrastructure.”

Downward Causation and Top-Down Control

Sperry says framing the problem “comes down to the issue of who pushes whom around in the population of causal forces that occupy the cranium…of straightening out the pecking-order hierarchy among intracranial control agents. Even the brain cells…do not have very much to say about when they are going to fire their messages, for example, or in what time pattern… The firing orders for the day come from a higher command. In other words, the flow and the timing of impulse traffic through any brain cell, or even a nucleus of cells in the brain, are governed largely by the overall encompassing properties of the whole cerebral circuit system…” (Sperry, 1965).

According to Sperry, “the concept of causal control is a critical key feature of the new mentalist paradigm, and often the feature that causes most misunderstanding.” Referenced erroneously “as emergent determinism, molar, holistic, or macro determinism, downward causation, emergent causation and, beginning in the 1970s, as systems thinking,” this is the feature that stands most directly in contradiction with the orthodox bottom-up form of causality previously relied on in traditional materialism. In debates about the consciousness revolution, we thus tend to focus eventually on the nature and role of downward causal determinism.

Sperry stresses “top-down control of the parts by the emergent whole legitimizing consciousness and the subjective.” He says that this modified basis for causal explanation “stands in direct conflict with the conventional exclusive micro-deterministic premises that exclude consciousness and mentalist explanation—not only in behavioral science but also in neuroscience and in all basic science.”

Taking a broader view in “understanding the mind-brain relation and associated problems,” Sperry says, “we had a choice in the past between mutually opposed explanatory frameworks: monism vs dualism, materialism vs mentalism, positivism vs epiphenomenalism or existentialism, and, in the "two cultures" of C. P. Snow: the value-free deterministic materialist descriptions of science versus the traditional humanistic (value laden, purposeful) views of the rest of society.”