Functional neuroanatomy

1. bradd@nmr.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

2. 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

3. 5 types of cortical tissue

4. 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

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

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

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

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

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

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

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

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

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

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

15. 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

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

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

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

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

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

21. Visual object recognition: Faces Tsao

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

23. Visual perception & imagery Ganis G, Cog Brain Res 2004

24. Auditory imagery Kosslyn SM, Nat Rev Nsci 2001

25. Motor imagery Kosslyn SM, Nat Rev Nsci 2001

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

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

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

29. 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

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

31. Plasticity in heteromodal cortical regions: The basis for learning

32. 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

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

34. Attention

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

36. 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

37. Attention Mesulam MM, Phil Trans R Soc London, 1999

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

39. The limbic system directs heteromodal cortex toward relevant information LaBar KS, Behavioral Neuroscience 2001

40. Neurotransmitter systems

41. 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

42. Sleep/Anatomy ARAS & thalamus

43. Sleep/EEG

44. Sleep/EEG

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

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

47. 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