Neuropsychology

1. Neuropsychology Study of the relationship between brain and behavior Often analyzing the deficits in human function following brain injury or pathology; ablation or lesion approach Single-case studies Provides powerful diagnostic tool to determine sites of brain lesions May provide insights into normal brain function Major advances are developing in areas of imaging technology

2. Unit Objectives • To review function of some major brain regions • To understand differences in findings using brain damaged and intact individuals • To gain an overview of the types of tasks that allow predictions of brain-behavior relationships • To familiarize self with diagnostic tests used to assess function

3. Tests and Assessment To assess function, tests, or batteries of tests are administered • Some examples: • Intelligence tests • Binet: IQ = MA / CA * 100 (ave = 100, sd = 15) • Wechsler IQ (WAIS): verbal and performance subtests • Personality tests • inventories: MMPI, many different dimensions • projective tests: Rorschach, Thematic apperception test (TAT) • Basic idea is to allow individual to project her/his personality through descriptions, generating stories, etc.

4. Tests and Assessment • Cognitive tests • Mini mental state exam (MMSE): One of the most widely used tests for assessing cognitive mental status. • WHY? Quick and comprehensive test of multiple functions • Memory tests: • Wechsler Memory Scale: Prose passage (declarative), paired associates (verbal assoc), priming task (“implicit”) • Working memory: backward digit, listening (verbal), arithmetic (calculation) • Famous face • Procedural tasks: Tower of Hanoi, serial response task • Executive function: Wisconsin Card Sort Test • Attention: visual-spatial (line bisecting, embedded figures drawing), cognitive (stroop)

5. Tests and Assessment • Visual – spatial • Mental rotation / rod and frame: V-S manipulation • Rey-Osterrieth Figure: drawing • Block design • Embedded figure • Language: fluency, comprehension, naming, repetition, grammar, • Calculation: arithmetic • Sensory-motor: tracking, finger tapping • Recognition tests: • Objects, faces, places • Laterality and function of corpus callosum: • L-R: Block design, R-O figure, emotion detection, • Chimeric stimuli, dichotic listening, dichaptic presentation

6. Overview of Brain Areas Different approaches to define

7. Gross Anatomy: 4 lobes Frontal Executive Motor Sequences, starting and stopping Appropriate emotional responses Parietal Multimodal assoc Spatial processing Object recognition S-M coordination Occipital Vision Temporal Object recognition Memory Audition emotions

8. Overview of Brain Areas Gyri and sulci

9. Maps of the Cerebral Cortex Cytoarchitectonic

10. Some subcortical structures

11. Some subcortical structures

12. Structure – Function relationships

13. Cortex has Topographic Organization somatosensory motor This map is very PLASTIC and DYNAMIC!

14. Hemispheric Specializations Left vs Right Structure: • Function: • Verbal L, Visuospatial R • component (L) vs global identification (R) • spatial processing (R) • face, object recognition (R) • emotion detection (R) • temporal processing (L) • language (L) While damage to each hemisphere can result in specific deficits, actions = unified processing of single brain

15. Split-Brain Procedure

16. Evidence from Split-Brain Patients Accuracy low Accuracy high LH regulates language output RH superior at face and object recognition, spatial processing

17. Evidence from Lateralized Lesioned and Intact Individuals • Tasks: • Wada technique • divided visual field (tachistoscopic), dichaptic presentation, dichotic listening • Findings: • RH processes nonverbal info, nonverbal sounds, global aspects, emotion detection • LH processes verbal info (95% right handers), local aspects, details,

18. Emotion detection: which looks happier?

19. Neuropsychological bases of specific mental functions Object recognition Spatial processing Attention Language Memory Executive function Dementia • Visual processing pathways: • dorsal stream --“where” • ventral stream -- “what”

20. Object Recognition Inability to perceive or to identify stimulus through specific sensory modality = AGNOSIA Rule out memory disorders or primary sensory problems Visual agnosias: Apperceptive visual agnosia: can’t form “percept” of parts; can’t recognize objects Associative visual agnosia: can’t draw from knowledge; don’t know what looking for Prosopagnosia: inability to recognize or differentiate faces

21. Apperceptive agnosia Associative agnosia Examples of visual agnosias Apperceptive agnosias: inability to form perceptual categorization Associative agnosia: able to group, but unable to do so from memory

22. A Special Agnosia: Problems with Face Recognition Configural information important for recognizing faces Evidence: Intact participants exhibit more difficulty remembering inverted stimuli than up-right stimuli This inversion effect is greater for faces than for other objects, such as houses Damage to ventro-medial areas of RH impair face recognition

23. What’s wrong with this picture?

24. Spatial Processing Dorsal visual stream Perception involves a multitude of basic skills localization of points in space depth perception orientation of lines geometric relations motion rotation Construction Route Finding Processing can involve extrapersonal or intrapersonal space. Damage to parietal, occipital, and temporal cortex disrupts spatial processing; worse with RH damage

25. Construction deficits Rey-Osterrieth figure: Shows evidence of damage to posterior regions of RH (temporo-parietal) Block design test shows evidence of B. RH damage C. LH damage

26. Hemineglect Inattention to space contralateral to lesion

27. Language disorders: Aphasias

28. Memory and Amnesia Differences between Anterograde and Retrograde • Anterograde (e.g. Leonard Shelby in Memento): • impairment in LTM, not WM • global in modality • impairment in memory for new info, but not skills • inflexibility of learned material • Retrograde: • varies in length of time • has a temporal gradient • never ALL memory • skilled performance tends to be spared

29. Multiple memory systems Case study: H.M. Many taxonomies have been derived: explicit v implicit, declarative (relational) v procedural, episodic v semantic, working v reference Not all forms of learning and memory are affected in amnesics

30. Brain Correlates Medial temporal lobes / Hippocampus Midline Diencephalon Neocortex Frontal lobes Basal Ganglia / Caudate nucleus Memory for information and events is processed in a distributed fashion, with different attributes handled by different cortical and subcortical systems

31. Memory Disorders Retrograde vs anterograde amnesia

32. Frontal Lobe and Executive Function

33. Mini Mental State Exam QUICK AND EASY: Simple 30 point scale Orientation (10 pts): what (yr, season, date, day month?) and where (state, county, town/city, bldg, floor?) Registration / Memory (3 pts): 3 objects, “pen, ball, ring” Attention / calculation (5 pts): serial 7’s backward from 100 Recall (3 pts): Ask for all 3 objects Language (8 pts): Naming (2 pts): point to pencil, watch Reading (1 pt): “No ifs, ands, or buts.” Listen and do (3 pts) : “Take paper in your right hand. Fold paper in half. Put paper on floor.” Read and do (1 pt): “CLOSE YOUR EYES.” Writing (1 pt): Ask to write a sentence of choice. Visual-spatial construction (1 pt): copy design:

34. MMSE Ratings 27-30 = Normal 23-26 = Borderline < 22 = Abnormal Alzheimer’s ratings 20-26 Mild AD 10-19 Moderate AD < 10 Severe AD Performance on MMSE varies with age and education Remember the MMSE is not a true dementia diagnostic It is a useful tool for a quick memory screening and to chart change with time

35. Dementia

36. Neuropathology of Alzheimer’s Disease

37. Progression of AD

38. Deficits Associated with Chronic Alcohol Use Visuospatial problems Learning and memory deficits Mid-line diencephalic pathology Thiamin (B1) deficiency Deficits in oxidative metabolism?

39. Assessment Issues Validity: does a test measure what it sets out to measure? predictive: test can predict future performance (e.g. MCATs predict performance in med school) construct: performance fits well with scheme about what test attempts to measure (e.g. MCATs measure ability to retain loads of material and to endure long, exams) Reliability: consistency of a test Test-retest: repeated tests yield same results Split-half: performance on similar portions yield same results

40. Summary Brain damage can produce specific and reliable deficits in behaviors, providing a powerful diagnostic tool. Findings suggest that the brain is lateralized and specialized in function across different neural systems. Functional consequences of brain damage may lend insights into normal brain function in intact individuals. Improvements in functional imaging technology will allow researchers and clinicians to explore the workings of the intact brain and to provide treatment with minimal invasion.