Cognitive Neuroscience PSYC 768 Introduction

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Cognitive NeurosciencePSYC 768Introduction

• Raja Parasuraman

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OverviewWhat is Cognitive Neuroscience?Levels
of AnalysisLevels of ExplanationBrief History
of Cognitive NeuroscienceOverview of Topics
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IMPORTANT DATES

• February 19 Take home short paper assigned
• February 26Take home short paper due
• March 25, April 15 Class presentations
• April 22 In-class test
• April 22 Final date for approval of term paper
  topic
• May 6 Term paper due

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What this course tries to do

• Provide a theoretically compelling account of how
  the brain produces the components of mind
• In addition, seek a theoretically-based
  explanation for the structural and functional
  characteristics of cognition, not just
  description
• why, not just how

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What this course is NOT about

• A basic course in cognitive psychology
• A course in biopsychology or physiological
  psychology
• A basic course in neuroscience
• A course in neuropsychologyfor those interested
  in helping remediate function in people with
  brain disorders
• A course with other immediate practical
  applicationsfor that, see neuroergonomics

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NeuroergonomicsUsing Brain Function to Enhance
Human Performance in Complex Systems
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Neuro-Ergonomics

• The scientific study of brain mechanisms and
  psychological and physical functions of humans in
  relation to technology, work, and environments

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Why Cognitive Neuroscience?

• Because
• Cognitive psychology has been brainless
• Neuroscience has been mindless
• We need to move beyond a brainless psychology
  and a mindless neuroscience to a true
  neuropsychology (Mario Bunge, 1980)
• Gazzanigas Manhattan taxi ride with George
  Miller is fanciful Origins of cognitive
  neuroscience precede this by several years
• e.g., First International Conference on Cognitive
  Neuroscience, 1982

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Cognitive Neuroscience
Stimulus
Response
But not phrenology!
Peering into the Black Box to Understand the
Machinery of the Mind
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Levels of Analysis (Vision Marr, 1982)
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• Computational theory
• Representation and algorithm
• Hardware implementation

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In Marrs view, these levels are hierarchical,
with the computational level being the
highest. Once the computational theory is
determined, the other levels will follow easily.
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Example for Vision (Marr, 1982)

• Computational theory What computations must be
  carried out in order to see (e.g., identify
  objects)?
• Representation and algorithm How are the results
  of these computations represented (symbolically),
  and what algorithms are used to manipulate these
  object representations?
• Hardware implementation Which neural (computer)
  structures carry out these computations and how?

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A Revised View of Levels of Analysis

• Computational level
• Psychological level
• Neural level

Levels need not be hierarchical but interactive.
Hardware (neural form) may constrain
computational theory, not follow directly from
it.
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Testing Across Levels of Analysis

• Computational level
• Psychological level

Data from the psychological level (e.g., reaction
time, errors) provide a psychological reality
test of a computational model Example ACT-R
predicts human response times in different
cognitive tasks
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Testing Across Levels of Analysis

• Psychological level
• Neural level

Data from the neural level (e.g., fMRI, ERPs)
provide a neural reality test of a psychological
model Example ERP early-latency component P1
supports early-selection theory of attention
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The Ultimate Test

• Computational level
• Psychological level
• Neural level

A computational model that passes the
psychological reality test and in turn generates
a psychological model that passes the neural
reality test
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One Model That Comes Somewhat Close ..

• Max Colthearts multi-route model of reading
  aloud
• Symbolic (rule based), not a connectionist, model
  (McClelland, Seidenberg, Plaut, Kello, etc.)
• Passes psychological reality test because it
  predicts specific error types in reading aloud
  regular words (e.g., few), exception words
  (e.g., sew), and pronounceable non-words (e.g.,
  tew)
• Passes neural reality test because it predicts
  specific effects of brain damage on reading
• Phonological dyslexia
• Surface dyslexia
• Deep dyslexia
• etc

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Levels of Explanation

• An integrated understanding across the three
  levels of analysis is good, but not sufficient
• This is because we have only answered the how
  question
• Like children, we must continually ask the why
  question

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A How and Why Conversation

• Zach How are we able to think?
• Dad Because we have a brain
• Zach How does the brain think?
• Dad A part of the brain called the prefrontal
  cortex is active when we think
• Zach Why?
• Dad Because it is large and complexly
  inter-connected
• Zach Why is it large and complexly
  inter-connected?
• Dad Because it became larger over thousands of
  years of life on earth
• Zach Why?

The Brain, by Zach, age 4 years
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A How and Why Conversation

• Dad Because a larger prefrontal cortex gave our
  ancestors a special advantage over others
• Zach Why does this have anything to do with us
  today?
• Dad Because they passed on their genes to their
  offspring and we are descended from them
• Zach How does the prefrontal cortex become
  complexly inter-connected?
• Dad Environmental influences in infancy and
  childhood help form greater connections in the
  prefrontal cortex
• Zach Like if I take music lessons?
• Dad Exactly!
• Zach How does music affect my brain structure?
• Dad We are not sure exactly, but the nerve cells
  in parts of your brain become more efficient in
  processing musical stimuli as you learn
• Zach Why?
• etc
• etc

The Brain, by Zach, age 4 years
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Levels of Explanation (Jared Diamond, Guns,
Germs, Steel, 1996)

• Proximal explanation How something works
• Description across 3 levels of analysis
  (computational, psychological, neural)
• Ultimate explanation Why something works the way
  it does
• Explanation in terms of genetics, evolution,
  development, environmental influences, etc.

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A How and Why Conversation

• Zach How are we able to think?
• Dad Because we have a brain
• Zach How does the brain think?
• Dad A part of the brain called the prefrontal
  cortex is active when we think
• Zach Why?
• Dad Because it is large and complexly
  inter-connected
• Zach Why is it large and complexly
  inter-connected?
• Dad Because it became larger over thousands of
  years of life on earth
• Zach Why?
• Dad Because a larger prefrontal cortex gave our
  ancestors a special advantage over others
• Zach Why does this have anything to do with us
  today?
• Dad Because they passed on their genes to their
  offspring and we are descended from them
• Zach How does the prefrontal cortex become
  complexly inter-connected?
• Dad Environmental influences in infancy and
  childhood help form greater connections in the
  prefrontal cortex
• Zach Like if I take music lessons?
• Dad Exactly!
• Zach How does music affect my brain structure?
• Dad We are not sure exactly, but the nerve cells
  in parts of your brain become more efficient in
  processing musical stimuli as you learn
• Zach Why?

Neuroimaging
Neuroanatomy
Evolution
Genetics
Development
Plasticity
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Integrated Description and Explanation in
Cognitive Neuroscience
EXPLANATION
DESCRIPTION
Computational level
Development
Evolution
Psychological level
Neural level
Genetics
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Origins of Mind A Brief History

• Ancient Egyptians and Greeks Spirits in bodily
  organs (heart, liver, etc.), some imbued with
  soul
• Aristotle Blood essential to life, hence seat of
  the soul brain is but a cooling mechanism for
  the blood
• Plato Highest structure of the body (brain) must
  also be the most important for soul

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Origins of Mind A Brief History

• Middle ages Heart produces a vital spirit sent
  to the brain where it mixes with air from
  nostrils to produce animal spirit stored in the
  brains ventricles the source of mnd
• 17th Century (Renaissance) Da Vincis dissection
  of animal brains disproved ventricle theory, but
  theory of brain as the source of mind established

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Origins of Mind A Brief History

• 19th Century Idea of localization of function
• Franz Gall (Phrenology)
• John Hughlings Jackson (Neurological studies of
  epilepsy)
• Paul Broca (Case studies of speech and language
  Brocas area)
• Carl Wernicke (Case studies of speech and
  language Wernickes area
• Korbinian Brodmann (Anatomical studies
  Brodmanns area)

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Origins of Mind A Brief History

• 19th-early 20th Centuries Idea of holistic
  processing by the brain
• Pierre Flourens (Lesion studies in birds)
• Camilio Golgi (The Golgi stain)
• Karl Lashley (Law of Equipotentiality)

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Origins of Mind A Brief History

• Early 20th Century Behaviorism and
  Psychoanalysis
• Mid 1950s The Cognitive Revolution
• Donald Broadbent
• George Miller
• Noam Chomsky
• 1950s-1980s Cognitive PsychologyUnderstanding
  Rules of the Mind
• Influence of artificial intelligence
• No consideration of the brain
• Functionalism

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Origins of Mind A Brief History

• 1900-present NeuroscienceUnderstanding the
  macroscopic and microscopic structure of the
  brain
• Enabling technologies
• Microscope
• Staining techniques
• Microelectrode
• Electron microscope
• Neurochemical analytical techniques
• Neuroimaging
• Molecular genetics

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Origins of Mind A Brief History

• 1980s-present Cognitive Neuroscience
• Brain produces mind
• Hence brain structure must be studied together
  with functional studies of cognition
• Computational theories of cognition
• The rise of brain imaging
• Bandwagon effect of leaders and followers

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Key Historical Figures
Michael Posner, USA 1970s - present
George A. Miller, USA 1950s - 1990s
Donald Broadbent UK, 1950s - 1980s
Michael Gazzinga, USA 1980s - present
Marcus Raichle, USA 1970s - present
Steven Kosslyn, USA 1980s - present
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Professional Societies and Journals

• Society for Neuroscience
• Journal Journal of Neuroscience
• Cognitive Neuroscience Society
• Journal Journal of Cognitive Neuroscience
• Other Journals
• Science
• Nature
• Nature Neuroscience
• Proceedings of the National Academy of Sciences
• Cerebral Cortex
• Neuron
• Human Brain Mapping
• Neuroimage
• Cognitive, Affective, and Behavioral,
  Neuroscience
• Neuropsychology
• Neuropsychologia

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Internet Resources

• www.cogneurosociety.org (Cognitive Neuroscience
  Society)
• www.sfn.org (Society for Neuroscience)
• http//www.humanbrainmapping.org/ (Organization
  for Human Brain Mapping)
• http//www9.biostr.washington.edu/da.html
  (University of Washington Digital Anatomist
  Project)
• http//www.med.harvard.edu/AANLIB/home.html
  (Harvard Brain Anatomy and Pathology Project)
• http//www.univie.ac.at/anatomie2/plastinatedbrain
  /main.html (The Plastinated Brain)
• http//www-medlib.med.utah.edu/kw/sol/sss/subj2.ht
  ml University of Utah Medical School)