1. Neuropsychology Cognitive Psychology Psychophysics Cognitive Neuroscience Electrophysiology (animal studies)

2. Brain Lesions (Chapter 5)(Cognitive Neuropsychology) • The “traditional” approach to establishing a connection between the mind & brain. • Limitation of imaging (or any correlational) methods • Does the activation have anything to do w/ function? • Car analogy • One way to prove something is necessary… • Take it out

3. History LANGUAGE VISION

4. Cortical Lobes Vision, Audition, Language “What vs. Where” Recognizing words Pathways/Networks (10’s cm) Cortical Areas (1 cm) Motion direction Directions of motion, orientation Cortical Column(.1 cm, 1 mm) Computations Lateral inhibition Neural Circuit (.01 cm, .1 mm) Neuron (pfs) Code Levels of Analysis Anatomical Functional

5. Advancements • (1) MRI: localize brain injury in vivo • Very precisely locate injury and adapt tests accordingly • “patient populations”: identify groups of individuals with common brain injuries

6. Advancement • The use of control subjects

7. Advancements • (2) Cognitive psychology paradigms • Area “A” is important for reading • What are the components of reading? • Perceiving letters • Letter strings activate corresponding meanings • Link words coherently • What specific component is affected by area A damage?

8. Disengage – Shift – Engage XXXX Disengage – Shift – Engage

9. Cognitive Psychology Perspective • Mental processes are composed of elementary “mental operations” • These operations are localizable in time • The operations are localizable in discrete, contiguous regions of the brain

10. Single and Double Dissociations • Start with a model/hypothesis • Facial recognition and emotion recognition (based on facial features) are different processes Emotion task Recognition task Performance (% Correct) Region 1 (FFA) Region Damaged

11. Single and Double Dissociations • Start with a model/hypothesis • Facial recognition and emotion recognition (based on facial features) are different processes Emotion task Recognition task Performance (% Correct) Performance (% Correct) Region 1 (FFA) Controls Region Damaged

12. Problems with Single Dissociation • Possible alternative interpretations: • Recognition task might be more difficult • See “task-resource artefact” in text (p 82)

13. Single and Double Dissociations • Start with a model/hypothesis • Facial recognition and emotion recognition (based on facial features) are different processes Emotion task Recognition task Performance (% Correct) Performance (% Correct) Region 1 (FFA) Controls Region 2 (STS) Region Damaged

14. Double Dissociations (and fMRI) • Start with a model/hypothesis • Facial recognition and emotion recognition (based on facial features) are different processes Emotion task Recognition task fMRI Activation Region 1 (FFA) Region 2 (STS)

15. Problems w/ lesions • A process must be localizable to specific regions • Compounded by lack of specificity of lesions • Lesion may disrupt connectivity– other “non-damaged” areas might be non-functioning. • Assumption that intact regions continue to function in the same way • No timing information

16. Transient “Lesions” • Transcranial Magnetic Stimulation • Magnetic field induced disruption of neural activity • A brief pulse is applied that causes neural “activity” for 10’s ms • If the area is involved in the task, the “dual firing” (task and to the TMS pulse) results in behavioral disruption

18. Advantageous • Quickly reversible (no reorganization as w/ true lesions) • Within-subject designs • Moveable lesions • Very focused (~ 1 cm resolution) • Precise timing