[email protected] 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 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 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 (fMRI & 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 LaBar KS, Behavioral Neuroscience 2001 Neurotransmitter systems 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 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
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