1. Brain and Behavior 02.11.2016

2. O RGANIZATION OF THE C EREBRAL C ORTEX Gray matter –Cell bodies and dendrites Most common type: Pyramidal cells –Organized into columns and layers 2

3. O RGANIZATION OF THE C EREBRAL C ORTEX White matter –Axons travelling down into the brain Myelination appears white (fatty tissue) –Includes communication between hemispheres Corpus callosum Anterior commissure 3

4. T ERMINOLOGY : A NATOMICAL T ERMS Gyrus –“Bump” on the brain’s surface Sulcus –Fold / groove between gyri Fissure –A long, deep sulcus 4

5. M AJOR G YRI AND S ULCI Sylvian fissure aka Lateral sulcus Separates temporal lobe from frontal and parietal lobes 5

6. M AJOR G YRI AND S ULCI Parieto occipital sulcus aka Calcarine fissure Separates parietal and occipital lobes 6

7. M AJOR G YRI AND S ULCI Longitudinal fissure Divides the two hemispheres 7

8. M AJOR G YRI AND S ULCI Central sulcus One of deepest sulci in cortex Divides frontal and parietal lobes 8

9. M AJOR G YRI AND S ULCI Precentral gyrus aka Primary Motor Cortex Posterior part of frontal lobe Anterior to central sulcus Control of fine movements 9

10. M AJOR G YRI AND S ULCI Postcentral Gyrus aka Primary Somatosensory Cortex Anterior part of parietal lobe Posterior to central sulcus Touch sensation 10

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12. Homunculus = “little man” Primary somatosensory cortex 12

13. Prefrontal Cortex Everything in front of the motor areas All sensory info goes to the frontal cortex CEO of the brain

14. PFC 3 divisions: – Dorsolateral PFC Cognitive, conscious, deliberate thinking – Orbital (ventral medial) PFC Automatic, quick, emotional behavior Most frequently damaged – Medial PFC

15. PFC Challenges of PFC damage – Planning in advance – Selecting from multiple stimuli – Ignoring extraneous stimuli – Memory

16. Temporal Lobe Limbic system – Amygdala – Hippocampus Organizing sensory input Auditory perception Language and speech production Memory association and formation

17. Temporal Lobe Damage can result in Wernicke’s aphasia – Rapid and fluent speech – Use content and function words – Good prosody – MEANINGLESS SPEECH – Don’t seem to be aware of deficit https://www.youtube.com/watch?v=3oef68YabD0

18. Obtaining pictures of the brain May examine: –Structure –Functioning N EUROIMAGING 18

19. Computerized axial tomography (CAT/CT Scan) –X-rays from different angles –Useful for: brain tumors, brain injuries, structural abnormalities –Disadvantage: radiation exposure N EUROIMAGING : S TRUCTURAL T ECHNIQUES 19

20. Normal CT N EUROIMAGING : S TRUCTURAL T ECHNIQUES 20

21. Epidural bleed (A) Brain tumors (B) N EUROIMAGING : S TRUCTURAL T ECHNIQUES 21

22. Magnetic resonance imaging (MRI) –High-strength magnetic field –Signals excite and relax hydrogen atoms –Lighter/Darker sections indicate lesions or damage N EUROIMAGING : S TRUCTURAL T ECHNIQUES 22

23. Normal brain MRI N EUROIMAGING : S TRUCTURAL T ECHNIQUES 23

24. Kwon et al., 1998 24

25. Positron Emission Tomography (PET) Scan –Tracer substance is injected Substance interacts with blood, oxygen, or glucose –Shows active parts of brain Use more blood, oxygen, and glucose N EUROIMAGING : F UNCTIONAL T ECHNIQUES 25

26. Normal PET vs. Alzheimer’s PET N EUROIMAGING : F UNCTIONAL T ECHNIQUES 26

27. Single photon emission computed tomography (SPECT) –Similar to PET (different tracer) –Less accurate than PET, but less expensive N EUROIMAGING : F UNCTIONAL T ECHNIQUES 27

28. functional MRI (fMRI) –More popular than PET/SPECT in research –Measures immediate reactions to brief events Moment-to-moment oxygen use and blood flow N EUROIMAGING : F UNCTIONAL T ECHNIQUES 28

29. fMRI normal vs. ADHD N EUROIMAGING : F UNCTIONAL T ECHNIQUES 29

30. N EUROIMAGING : PET VS. F MRI PET is faster than fMRI fMRI has better resolution than PET 30