Functional neuroanatomy

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Functional neuroanatomy
bradd_at_nmr.mgh.harvard.edu

• Attention
• Language
• Knowledge
• Imagery
• Memory
• States of mind (and body)
• Adaptation/plasticity
• Language visual processing mental imagery
• How our brains integrate types of information to
  develop concepts how previous experience affects
  processing of new information

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What are we doing with our brains at this
moment?(The students brain)

• Feeling your chair
• Squirming (moving)
• Watching
• Listening
• Remembering
• Paying attention
• Sleeping
• Feeling anxious
• Feeling hungry
• What happens when you ask a question?
• Learning

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5 types of cortical tissue
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Localization of function in the nervous system
Functional networks

• 5 major brain systems subserving
• cognition and behavior
• Left perisylvian language network
• Parieto-frontal network for spatial attention
• Occipitotemporal network for object/face
  recognition
• Medial temporal/limbic network for learning
  memory
• Prefrontal network for attention comportment

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Knowledge The convergence of language,
perception, and memory
Language naming Visual systems
category-specific processing Imagery/sensory
memory
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Knowledge The convergence of language,
perception, and memory
Language naming Visual systems
category-specific processing Imagery/sensory
memory
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Lesion studies of the language networkThe major
nodes
Brocas (production)
Wernickes (comprehension)
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Lesion studies of the language networkDisconnect
ion syndromes
Alexia without agraphia
Geschwind N Kaplan E, Neurology, 1962
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Functional neuroimaging of the language network
One to many, many to one
CJ Price, J Anat 2002
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Language function Using neuroimaging to test
hypotheses
CJ Price, J Anat 2002
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Whats in a name?A means to access specific
types of knowledge
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Whats in a name?A means to access specific
types of knowledge
Elephant
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Linguistic access to specific types of knowledge
Damasio H, Nature 1996
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Knowledge The convergence of language,
perception, and memory
Language naming Visual systems
category-specific processing Imagery/sensory
memory
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Visual processing Two pathways
Dorsal (Occipito-parietal) Object object
feature recognition Disorders visual object
agnosia prosopagnosia achromatopsia Ventral
(Occipito-temporal) Visual recognition of
spatial location Disorders optic ataxia, ocular
apraxia, simultanagnosia (Balints)
constructional apraxia, akinotopsia
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Visual processing streams Confirmation of
hypotheses using neuroimaging
Ungerleider LG, PNAS 1998
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Visual processing Attention influences which
stream is used
Ungerleider LG, PNAS 1998
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Visual object recognition Lesion studies
Agnosias may be specific to certain categories of
information
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Visual object recognition Distinct but
overlapping functional areas
Haxby JV, Science 2001
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Visual object recognition Faces places
Kanwisher N, Science, 2006
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Visual object recognition Faces
Tsao
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Knowledge The convergence of language,
perception, and memory
Language naming Visual systems
category-specific processing Imagery/sensory
memory
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Visual perception imagery
Ganis G, Cog Brain Res 2004
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Auditory imagery
Kosslyn SM, Nat Rev Nsci 2001
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Motor imagery
Kosslyn SM, Nat Rev Nsci 2001
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Naming vs. recognition Networks for conceptual
knowledge
Name this animal and tell me what you know about
it
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Naming vs. recognition Networks for conceptual
knowledge
Name this person and tell me what you know about
him
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Naming vs. recognition Networks for conceptual
knowledge
Object-specific naming deficits
Object-specific recognition deficits
Damasio H, Cognition 2004
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Encoding recall of category-specific information
Faces Fusiform gyrus
Places Parahippocampal gyrus
Encoding of category-specific information
activates relevant areas of cortex
Polyn SM et al., Science, 2005
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Encoding recall of category-specific information
Reactivation of category-specific areas occurs
prior to verbal recall
Polyn SM et al., Science, 2005
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Plasticity in heteromodal cortical regions The
basis for learning
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Recovery of language function after stroke
Mapping plasticity in the human brain
1 month after stroke
1 year after stroke
Plasticity Many levels of scale in both time
space
Fernandez B, Stroke 2004
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Attention, arousal, awareness

• Focused attention visuospatial attention
• Arousal
• Coma
• Persistent vegetative state
• Sleep
• Conscious awareness

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Attention
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Attention Trinodal cortical network
Hypothesized from patients animals with lesions
Mesulam MM, Phil Trans R Soc London, 1999
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Attention Trinodal cortical network
Confirmed with functional neuroimaging (fMRI
PET)
Gitelman DR et al., Ann Neurol 199639174-9 Gitel
man DR et al., Brain 19991221093-1106
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Attention
Mesulam MM, Phil Trans R Soc London, 1999
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State vs channel functions

• States
• Sleep/arousal
• Needs (e.g., hunger)
• Mood
• Channels

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The limbic system directs heteromodal cortex
toward relevant information

• LaBar KS, Behavioral Neuroscience 2001

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Neurotransmitter systems
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Neurotransmitter systems
Genetic variations in neurotransmitter
substrates Enzymes, receptors, etc (e.g.,
Weinberger DR) Pharmacologic fMRI e.g.,
dopaminergic modulation of attention PET
imaging of receptors enzymes
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Sleep/Anatomy
ARAS thalamus
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Sleep/EEG
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Sleep/EEG
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Conscious awarenessDefault mode
Raichle M, et al.,
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Conscious awarenessPersistent vegetative state
Owen A, et al., Science, 2006
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What are we doing with our brains at this
moment?(The students brain)

• Feeling your chair
• Squirming (moving)
• Watching
• Listening
• Remembering
• Paying attention
• Sleeping
• Feeling anxious
• Feeling hungry
• What happens when you ask a question?
• Learning