braddnmr mgh harvard edu Functional neuroanatomy Attention Language

[email protected] mgh. harvard. edu Functional neuroanatomy • • • 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

What are we doing with our brains at this moment? (The student’s brain) • • • Feeling your chair Squirming (moving) Watching Listening Remembering Paying attention Sleeping Feeling anxious Feeling hungry What happens when you ask a question? Learning

5 types of cortical tissue

Localization of function in the nervous system: Functional networks n 5 major brain systems subserving cognition and behavior Left perisylvian language network q. Parieto-frontal network for spatial attention q. Occipitotemporal network for object/face recognition q. Medial temporal/limbic network for learning & memory q. Prefrontal network for attention & comportment q

Knowledge: The convergence of language, perception, and memory Language & naming Visual systems & category-specific processing Imagery/sensory memory

Knowledge: The convergence of language, perception, and memory Language & naming Visual systems & category-specific processing Imagery/sensory memory

Lesion studies of the language network: The major nodes Broca’s (production) Wernicke’s (comprehension)

Lesion studies of the language network: Disconnection syndromes Alexia without agraphia Geschwind N & Kaplan E, Neurology, 1962

Functional neuroimaging of the language network One to many, many to one CJ Price, J Anat 2002

Language function: Using neuroimaging to test hypotheses CJ Price, J Anat 2002

What’s in a name? A means to access specific types of knowledge

What’s in a name? A means to access specific types of knowledge Elephant

Linguistic access to specific types of knowledge Damasio H, Nature 1996

Knowledge: The convergence of language, perception, and memory Language & naming Visual systems & category-specific processing Imagery/sensory memory

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 (Balint’s); constructional apraxia, akinotopsia

Visual processing streams: Confirmation of hypotheses using neuroimaging Ungerleider LG, PNAS 1998

Visual processing: Attention influences which stream is used Ungerleider LG, PNAS 1998

Visual object recognition: Lesion studies Agnosias may be specific to certain categories of information

Visual object recognition: Distinct but overlapping functional areas Haxby JV, Science 2001

Visual object recognition: Faces & places Kanwisher N, Science, 2006

Visual object recognition: Faces Tsao

Knowledge: The convergence of language, perception, and memory Language & naming Visual systems & category-specific processing Imagery/sensory memory

Visual perception & imagery Ganis G, Cog Brain Res 2004

Auditory imagery Kosslyn SM, Nat Rev Nsci 2001

Motor imagery Kosslyn SM, Nat Rev Nsci 2001

Naming vs. recognition: Networks for conceptual knowledge Name this animal and tell me what you know about it

Naming vs. recognition: Networks for conceptual knowledge Name this person and tell me what you know about him

Naming vs. recognition: Networks for conceptual knowledge Object-specific naming deficits Object-specific recognition deficits Damasio H, Cognition 2004

Encoding & recall of categoryspecific information Faces: Fusiform gyrus Places: Parahippocampal gyrus Encoding of category-specific information activates relevant areas of cortex Polyn SM et al. , Science, 2005

Encoding & recall of categoryspecific information Reactivation of category-specific areas occurs prior to verbal recall Polyn SM et al. , Science, 2005

Plasticity in heteromodal cortical regions: The basis for learning

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 Fernandez B, Stroke 2004

Attention, arousal, awareness • Focused attention & visuospatial attention • Arousal • Coma • Persistent vegetative state • Sleep • Conscious awareness

Attention

Attention: Trinodal cortical network Hypothesized from patients & animals with lesions Mesulam MM, Phil Trans R Soc London, 1999

Attention: Trinodal cortical network Confirmed with functional neuroimaging (f. MRI & PET) Gitelman DR et al. , Ann Neurol 1996; 39: 174 -9 Gitelman DR et al. , Brain 1999; 122: 1093 -1106

Attention Mesulam MM, Phil Trans R Soc London, 1999

State vs channel functions States Sleep/arousal Needs (e. g. , hunger) Mood Channels

The limbic system directs heteromodal cortex toward relevant information La. Bar KS, Behavioral Neuroscience 2001

Neurotransmitter systems

Neurotransmitter systems Genetic variations in neurotransmitter substrates Enzymes, receptors, etc (e. g. , Weinberger DR) Pharmacologic f. MRI e. g. , dopaminergic modulation of attention PET imaging of receptors & enzymes

Sleep/Anatomy ARAS & thalamus

Sleep/EEG

Sleep/EEG

Conscious awareness: Default mode Raichle M, et al. ,

Conscious awareness: Persistent vegetative state Owen A, et al. , Science, 2006

What are we doing with our brains at this moment? (The student’s brain) • • • Feeling your chair Squirming (moving) Watching Listening Remembering Paying attention Sleeping Feeling anxious Feeling hungry What happens when you ask a question? Learning