Chapter 1: History of Cognitive neuroscience · • Franz Joseph Gall: Ø Brain is the organ of the...
Transcript of Chapter 1: History of Cognitive neuroscience · • Franz Joseph Gall: Ø Brain is the organ of the...
Chapter 1: History of Cognitive neuroscience • Thomas Willis (neurologist) Ø Coined the term Neurology Ø Best-known doctor of his time Ø Resurrection of Anne Green Ø First to link: o Abnormal behaviors to changes in brain structure o Specific brain damage to specific behavioral deficits o Theorize how the brain transfers info (later called neuronal conduction) Ø Created most accurate representations of the brain with Christopher Wren
(architect who designed St. Paul’s Cathedral) Ø Coined names for brain regions Ø Thomas Willis set in motion ideas & knowledge base for the field of cognitive
neuroscience v Cognitive neuroscience: a field geared toward understanding how the brain
works, how brain structure/function affects behavior, ultimately how the brain enables the mind
• Cognition: process of knowing, arises from awareness, perception & reasoning • Neuroscience: study of how the nervous system is organized & functions
§ Historical perspective: • 1970’s: field of cognitive neuroscience received its name from George A.
Miller • Properties of brain function built through evolution (Earth 4.5 billion years
old, life first appeared 3.8 billion years ago) • Human brains in present form have only been around for 100,000 years • Oligocene epoch: primate brain appeared 34-23 million years ago • Miocene epoch: primate brains evolved progressively larger 23-7 million
years ago • Humans diverged from the last common ancestor (chimpanzee) 5-7 million
years ago • Take on evolutionary perspective (WWHGD? – what would a hunter gatherer
do?) • Evolutionary perspective helps to ask more informed questions & provides
insight into how/why brain functions as it does • Oedipus Rex: attempt to understand world & our place in it, Greek play
dealing with parent-child conflict • Mesopotamian & Egyptian theories: nature religion & the universe • Thales (pre-Socratic Greek philosopher): rejected supernatural explanations,
everything has a natural cause (presage of modern cognitive neuroscience) • Limitation of Greek philosophers: no experimentation • 19th century: observe, manipulate & measure became the norm • Scientific method: experimentation to support/refute hypotheses &
conclusions
v The Brain story: • Central issue: whether the mind is enables by the whole brain working in
concert or by specialized parts of the brain working independently (fuels modern research in cognitive neuroscience)
• Thomas Willis: brain damage (biology) could affect behavior (psychology) • Franz Joseph Gall: Ø Brain is the organ of the mind & innate faculties are localized in specific
regions of the cerebral cortex Ø Hypothesized that if a person used one faculty more than others, the part of the
brain representing that function would grow & cause a bump in the skull (Gall & Spurzheim)
Ø Anatomical personology (Gall): analysis of the skull to describe personality Ø Phrenology (Spurzheim): character could be divined through palpating the
skull • Marie-Jean-Pierre Flourens: Ø Asked by Napoleon Bonaparte to come up with findings to back up Gall’s
theory Ø First to show that certain parts of the brain were responsible for certain
functions (experimentation with rats & pigeons) Ø Removed cerebral hemispheres – no perception, motor ability or judgment Ø Removed cerebellum- uncoordinated & no equilibrium Ø Couldn’t find any areas for advanced abilities (memory, cognition) –
concluded scattered throughout the brain. Ø Aggregate field theory: whole brain participates in behavior • Marc Dax: Ø Localizationism: theory of localized brain functions Ø Observed that speech could be disrupted by a lesion on one hemisphere only • John Hughlings Jackson: Ø Noticed that it was rare for a patient to lose a function completely Ø First to observe that lesions on the right side of the brain affect visuospatial
processes more than lesions on the left side Ø First to realize essential feature of brain organization Ø Observed behavior of people with brain damage Ø ^ Start of seizures, patients moved in characteristic ways. Seizure appeared to
stimulate a set map of the body in the brain. Jerks in muscles produced by abnormal epileptic firings of neurons in the brain progressed in the same orderly pattern from one body part to another.
Ø ^ Topographic organization in the cerebral cortex: map of body represented across a particular cortical area (verified by Wilfred Penfield)
• Paul Broca: Ø Patient nicknamed “Tan” (real name Leborgne) had aphasia Ø Could understand language but “tan” was only word he could say Ø Broca’s area: left hemisphere, inferior frontal lobe • Carl Wernicke: Ø Patients talk freely but do not make sense, cannot understand spoken/written
language Ø Wernicke’s area: posterior region of the left hemisphere, an area in & around
where the temporal & parietal lobes meet