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localization of cortical function•  Franz Joseph Gall and phrenology (1798)

–  Johann Spurzheim (1813) –  Jerry Fodor (1983)

•  Jean Pierre Flourens (1825)•  Phineas Gage (1848)•  Paul Broca (1865)

–  Carl Wernicke (1874)•  Karl Lashley (1929, 1950)•  Wilder Penfield (1941)

–  Bell (1811) and Magendie (1822)–  Fritsch and Hitzig (1870)–  David Ferrier (1876)

localization of cortical function•  Franz Joseph Gall and phrenology (1798)

–  Johann Spurzheim (1813) –  Jerry Fodor (1983)

•  described Gall’s type of faculties as “vertical”, now to be called “modules” – these are self-contained and deal with a single kind of information unaffected by context, e.g., vision, speech

•  as opposed to “horizontal faculties” – these make use of different types of information, e.g., memory, reasoning, judgment, problem-solving

•  Jean Pierre Flourens (1825) – only general regions found in animals, no localization

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Legitimate discoveries of Franz Joseph Gall

1) cortex as functioning tissue, not just protective covering ("cortex" is literally "bark" or "skin")

2) commissures (or connecting pathways) between brain hemispheres, other than the already known corpus callosum

3) crossing of ascending nerve pathways from spinal cord to contralateral hemispheres of the brain

4) distribution of and distinction between grey matter and white matter tracts (where grey matter was recognized in the 20th century as mostly neuron cell bodies doing information processing, and white matter as mostly myelinated axons sending signals over longer distances)

Gall’s science of “Organology”, more widely called Phrenology

As originally put forward, there were four cardinal premises [of phrenology], namely that:

(1) the brain is the material instrument through which the mind holds intercourse with the outer world;

(2) the mind entails a congeries [or jumbled collection] of discrete mental faculties each with its own specific center or organ;

(3) the size of each organ corresponds with the functional efficiency of each faculty [WRONG!]; and

(4) the development of the organ is reflected in the shape, size and irregularities of the encompassing cranium [WRONG!]

from MacDonald Critchley (1979) The Divine Banquet of the Brain, New York, Raven Press. cited in: Jerry Fodor (1983) Modularity of Mind: An Essay on Faculty Psychology. Cambridge, Mass.: MIT Press. pp. 131-132 (from Fodor (1983) footnote [10] quoting Critchley)

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Fodor (1983) The Modularity of MindMODULES: usually perceptual processes - parsing, speech recognition, auditory perception, vision form or color•  input driven; very fast; mandatory; superficial•  encapsulated from much of the organism's background knowledge•  largely organized around bottom-to-top information flow•  largely innately specified (hence ontogenetically eccentric)•  characteristically associated with specific neuroanatomical

mechanisms (sometimes even with specific neuroanatomical loci)•  tend also to be domain specific

Fodor (1983) The Modularity of MindNON-modular: most higher cognitive faculties - "thought", "problem solving", other traditional ones like reason, judgement, imagination•  slow; deep; global rather than local•  largely under voluntary (or, as one says, "executive") control•  typically associated with diffuse neurological structures•  neither bottom-to-top nor top-to-bottom in their modes of

processing, but characterized by computations in which information flows every which way

•  unencapsulated - the higher the cognitive process, the more it turns on the integration of information across superficially dissimilar domains

•  higher cognitive processes are notably similar to processes of scientific discovery

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localization of cortical function•  Phineas Gage (1848) – personality in brain

–  explosion sent iron rod through skull removing part of frontal lobe (probably pre-frontal area)

–  resulting personality change from responsible and gentle to argumentative, impulsive and vile

–  but this description is probably exaggerated •  Paul Broca (1865) – identified region in

patient’s brain responsible for speech– Carl Wernicke (1874) – identified separate

region responsible for comprehension

localization of cortical function•  Phineas Gage (1848)

•  Paul Broca (1865)

– Carl Wernicke (1874)

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localization of cortical function•  Karl Lashley (1929, 1950) – laws of mass action

and equipotentiality – no localization of learning•  Wilder Penfield (1941) – specific regions in

human brain trigger specific responses; motor and sensory homunculi maps–  Bell (1811) and Magendie (1822) – separate pathways

in spinal cord: dorsal incoming sensory signals, ventral outgoing motor signals

–  Fritsch and Hitzig (1870) – electrical stimulation of dog’s motor areas caused movement

–  David Ferrier (1876) – extended Fritsch and Hitzig to make detailed motor area maps in animals

Penfield: Motor & Somatosensory Cortex