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Cognitive Neuroscience - An Introduction. cognitive neuropsychology cognitive neuroscience. Ways of acquiring brain damage 1. neurosurgery – split brain, H.M. 2. stroke – W.B. 3. head injuries 4. tumors in situ – difficult to determine area affected
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cognitive neuropsychology cognitive neuroscience
Ways of acquiring brain damage 1. neurosurgery – split brain, H.M. 2. stroke – W.B. 3. head injuries 4. tumors in situ – difficult to determine area affected 5. viral infections (Herpes Encephalitis, Warrington & Shallice, 1984) 6. neurodegenerative disorders – DAT, SD, PD brain area can be IDed via MRI testing should occur around same time as MRI
Henry Molaison (H.M.) intractable epilepsy (perhaps due to bike accident at age 9) underwent surgery to remove hippocampus at age 27 left him profoundly amnesic
Aperceptive Agnosia
Associative Agnosia
Associative Agnosia
Dissociations and Associations Association Brain Region Process A X Y
Dissociations and Associations Dissociation Brain Region Process A X Y
Dissociations and Associations Double Dissociation – need 2 different patients Brain Region Process A X B Y A X B Y
Interpretations of a single dissociation – Patient shows deficit for Task A, but not Task B functional independence - Tasks A and B tap into independent processes task resource artifact – Tasks A and B rely on same process but that process requires different amount of resources task demand resources – Patient approaches tasks differently
Dissociations and Associations Association Brain Region Process A - occipital lobe X - object vision Y - animal vision
Dissociations and Associations Dissociation Brain Region Process A X object ID Y animal ID
Dissociations and Associations Double Dissociation Brain Region Process A X object ID B Y A X B Y animal ID
Dissociations and Associations Double Dissociation Brain Region Process A X speech B Y comprehension A X speech B Y comprehension
Dissociations and Associations Single Dissociation Brain Region Process A X explicit memory B Y implicit memory
Interpretations of a single dissociation – Patient shows deficit for Task A, but not Task B functional independence - Tasks A and B tap into independent processes task resource artifact – Tasks A and B rely on same process but that process requires different amount of resources task demand resources – Patient approaches tasks differently
Dissociations and Associations Double Dissociation Brain Region Process A X explicit memory B Y implicit memory A X explicit memory B Y implicit memory
Double Dissociation traditionally viewed as evidence for independence of processes does a DD suggest a modular system? what is a module? - encapsulated process - specialized for 1 type of info (e.g., animal ID vs. object ID) if modules exist a DD can be found DD can arise from an interactive distributed model
Cognitive Psychology – processes, e.g., memory, attention, perception, language, decision making, etc. Cognitive Neuropsychology – cognition via brain damage Cognitive Neuroscience – the relationship b/w cognition and brain
Cognitive Psychology – word recognition Cognitive Neuropsychology – dyslexia Cognitive Neuroscience – fMRI
/beri/ bury The Dual Route Model Letter Detectors Lexicon (Mental Dictionary) Sublexical System (Rules) Pronunciation Code
Acquired Dyslexia Surface Dyslexia– impaired irregular-word reading bury, chaos Phonological Dyslexia– impaired nonword reading blarky, flirple
/buri/ The Dual Route Model Surface Dyslexia bury Letter Detectors DAMAGE Sublexical System (Rules) Pronunciation Code
????? The Dual Route Model Phonological Dyslexia blask Letter Detectors DAMAGE Lexicon (Mental Dictionary) Pronunciation Code
Word Processing and the Brain Semantic Areas
Word Processing and the Brain Orth-phono-artic. areas
Cognitive Neuroscience Philosophical Issues monoism – mind and brain are one dual aspect theory – mind and brain represent two different levels of the same thing reductionism – concepts of the mind will be replaced by concepts of the brain
Cognitive Neuroscience Philosophical Issues reductionism – concepts of the mind will be replaced by concepts of the brain Example: Semantic priming (doctor-nurse vs. chain-nurse) cognitive explanation – the prime activates its corresponding mental representation, and that activation spreads in a semantic network and activates the representations of related items.
hypothesized semantic network for nurse care health clinic nurse doctor hospital uniform orderly patient
hypothesized semantic network for nurse care health clinic nurse doctor hospital uniform orderly patient
hypothesized semantic network for nurse care health clinic nurse doctor hospital uniform orderly patient
Cognitive Neuroscience Philosophical Issues reductionism – concepts of the mind will be replaced by concepts of the brain Example: Semantic priming (doctor-nurse vs. chain-nurse) cognitive explanation – the prime activates its corresponding mental representation, and that activation spreads in a semantic network and activates the representations of related items. biological explanation – neurons that represent the prime fire when it is presented, and this causes neurons associated with the target to fire.
Mind-Body Problem – Summary and Conclusion To study the mind scientifically, we must assume that the mind and brain are one - mind and brain represent two diff. levels of same thing - brain concepts will replace mind concepts
Paradigm Shift? – Cognitive Psychology to Cognitive Neuroscience APA Monitor (July, 2011) Cognitive Neuroscience Positions = 5 Cognitive Psychology Positions = 1 Either = 2 APA Monitor (August, 2011) Cognitive Neuroscience Positions = 4 Cognitive Psychology Positions = 5 Basic = 2, Applied = 3 Either = 3 APA Monitor (September, 2011) Cognitive Neuroscience Positions = 17 Cognitive Psychology Positions = 18 Either = 13 APA Monitor (October, 2011) Cognitive Neuroscience Positions = 19 Cognitive Psychology Positions = 19 (5 applied, 1 ETS) Either = 16
Scientific Issues Brain Hypothesis – brain controls thoughts and behavior trepanning – prehistoric times (as early as 6500 BC), for seizures, migraines, mental disorders
Scientific Issues Brain Hypothesis – brain controls thoughts and behavior trepanning – prehistoric times (as early as 6500 BC), for seizures, migraines, mental disorders Aristotle (384-322 BC) – heart Hippocrates (460-377 BC)
Scientific Issues Brain Hypothesis – brain controls thoughts and behavior trepanning – prehistoric times (as early as 6500 BC), for seizures, migraines, mental disorders Aristotle (384-322 BC) – heart Hippocrates (460-377 BC) Galen (129-199 AD) – brain ventricles - idea persisted until 1800s
Scientific Issues Phrenology (early 1800s) functional specialization bumps on skull represent individual differences
Scientific Issues Experimental lesions in animals – no specialization? Flourens (mid 1800s) Lashley (early-to-mid 1900s) - lesion size, not location related to performance - small animals, general function measured
Scientific Issues Breakthroughs Broca (1861) – speech Wernicke (1874) - comprehension Broca (1824-1880) Wernicke (1848-1905)