A Language Circuit  Wernicke’s areas and Broca’s areas are part of a connected circuit for receiving and producing language.  Wernicke predicted conduction aphasia – a disorder produced by breaking the connection between the two regions. Results in paraphasia – omitting and substituting parts of speech. Also, inability to repeat phrases.

Brodmann Areas  Different areas of the brain with different functions have different kinds of neurons.  Brodmann mapped the areas based on the kinds of cells found: Cytoarchitectonic method 52 functionally distinct areas identified by number.

Support for the Field View  Lashley found that the greater the lesions, the greater the impairment in functioning. No matter where lesions were made, learning was impaired. Mass action -- brain mass, not specific regions was most important to functioning.  Maze learning involves multiple functions, so it is unsuitable for studying localization.

The Current View  Functions consist of multiple processes that occur in specific areas of the brain. Imaging studies reveal the different processes, called elementary operations. Processing is both serial and parallel.  Even the simplest mental activity requires coordination of processes in multiple areas of the brain. Such processing appears introspectively seamless.

The Mind-Body Duality Source: Robert H. Wozniak

Rene Descartes ( )

Mind-Body Dualism  Descartes -- The rational mind connects with the animal body at the pineal gland. Thus, mind affects body and body affects mind. Animals have no minds.  We now know the pineal gland does something else, but…  Is there a “mind” or “soul” independent of the brain?

18 th Century Philosophy (1700’s)  All is mind vs. all is body.  Berkeley’s “Immaterialism” – There is no body because all matter is perceived by the mind and can’t be known apart from it.  Materialism – there is no mind, only matter. Mental events don’t exist. La Mettrie, “L’homme machine.” States of the soul depend upon states of the body.

19 th Century Philosophy (1800’s)  Localization of cerebral function showed that the brain is the organ of the mind.  Mental states were shown to affect the body. Trauma, mesmeric trance, mental suggestion.  Huxley’s “Epiphenomenalism” – mental states have no causal efficacy, like paint on a stone (neurophysiology is the stone).

Dual-Aspect Monism  Lewes – mental and physical processes are two aspects of the same psychophysical event. Mind is subjective while body is objective. Terms used to describe the two are not inter-translatable.  Lewes still provides the best argument for why psychology cannot be replaced by neuroscience.

Mind-Stuff Theory  Higher properties of mind are compounded from mental elements (pieces of mind-stuff).  When molecules come together at a level of complexity sufficient to form a brain and nervous system, correlative mind-stuff forms consciousness.

William James  James adopted a pragmatic empirical parallelism of the sort many psychologists still support.  The "simplest psycho-physic formula…” is a "blank unmediated correspondence, term for term, of the succession of states of consciousness with the succession of total brain processes..."  Principles of Psychology, p. 182

Ongoing Controversy  We still do not know how “mind” emerges from “body.” The nature of the relationship between specific mental states and the neural substrate is still not understood.  Those debating mind-body today largely express ideas that are versions of the philosophical arguments proposed over the past 250 years.

Interview with Rodney Brooks Human as machine, machine as human: