930 likes | 1.17k Views
Cognitie en het Brein. Victor A.F.Lamme Cognitive Neuroscience group Dept Psychology, University of Amsterdam Eye and Brain Institute, Royal Academy of Sciences V.A.F. Lamme@UVA.nl. PFC = cortex connected with Dorsomedial nucleus of the thalamus. Damage to the Prefrontal Cortex
E N D
Cognitie en het Brein Victor A.F.Lamme Cognitive Neuroscience group Dept Psychology, University of Amsterdam Eye and Brain Institute, Royal Academy of Sciences V.A.F. Lamme@UVA.nl
PFC = cortex connected with Dorsomedial nucleus of the thalamus
Damage to the Prefrontal Cortex • Phineas Gage - Harlow (1868) ”He is fitful, irreverent, indulging at times in the grossest profanity,impatient of restraint or advice when it conflicts with his desires; at times pertinaciuously obstinate yet capricious and vascillating. His friends and acquaintances said he was no longer Gage”
Utilisation Behaviour The tendency to grasp common objects when presented, and perform the function commonly associated with the object E.g Lhermite (1983)
Imitation behaviour The tendency to imitate the gestures, actions, sentences of the person in front of you (Lhermitte, 1983)
Wisconsin card sorting test • Deck of cards containing objects varying along 3 dimensions • shape, color, & numerosity • Place top card of deck under one of four target cards • Sort cards according to experimenter defined sorting rule • 2 catches • subject is not informed of sorting rule, but must discover it through trial and error • experiment gives correct/incorrect feedback • once subject has learned to sort by one dimension, the experimenter changes the rule without informing the subject • requires flexibility to discard a previously reinforced hypothesis, • requires WM to retain knowledge about relevance of certain dimensions on previous responses • pre-frontal lobe patientsperseverate • keep applying initial rule even after the switch, despite experimenter’s negative feedback
Perseveration Utilization Imitation Lack of social inhibition Inability to make long terms plans All point to the same: Environmental Dependency
New and flexible stimulus-response associations Flexibility Established, well-learned stimulus response associations Routine How does the PFC do that?
PFC keeps information in store, so that it can be used to moderate subsequent sensori-motor processing Working memory Is the basis for many cognitive functions
Assessment of WM function in monkey’s with pre-frontal lesions
Assessment of WM function in monkey’s with pre-frontal lesions • WM delayed-response task • monkey sees one well baited with food • after delay period animal retrieves the food • location of food is randomly determined • requires WM: at the time of response there are no external cues indication the location of the food • Associative memory task • food reward always associated with one of two visual cues • location of food and cues randomly determined • requires LTM: animal must remember which visual cue is associated with the reward • Lesions of lateral pre-frontal cortex • impair performance on WM task but NOT on associative memory task (Goldman-Rakic, 1992) • also in pre-frontal patients, but only with delayed alternation task
PFC neurons maintain firing after removal of a behaviorally relevant stimulus(Fuster, Goldman-Rakic), until response
Maintained firing reflects crude stimulus properties Like What and Where (Miller)
Prefrontal Cortex functions • Working Memory • Flexibility of behaviour • Inhibition of inappropriate behaviour • Personality • Thinking • Attention • Consciousness (?)
Sensory Motor
Sensory Motor Consolidation(long-term storage) Learning and memory Memories, habits and skills (Hippocampus, basal ganglia, etc.)
Learning and memory (Hippocampus, basal ganglia, etc.) Executive Functionsgoal-related information Sensory Motor Consolidation(long-term storage)
Learning and memory (Hippocampus, basal ganglia, etc.) Executive Functionsgoal-related information Top-down Selection(flexibility) Sensory Motor Bottom-up Consolidation(long-term storage)
Learning and memory (Hippocampus, basal ganglia, etc.) Executive Functionsgoal-related information Top-down Selection(flexibility) Sensory Motor Bottom-up Consolidation(long-term storage)
Learning and memory (Hippocampus, basal ganglia, etc.) Executive Functionsgoal-related information Top-down Selection(flexibility) Sensory Motor Bottom-up Consolidation(long-term storage)
Learning and memory (Hippocampus, basal ganglia, etc.) Executive Functionsgoal-related information Top-down Selection(flexibility) Sensory Motor Bottom-up Consolidation(long-term storage)
Learning and memory (Hippocampus, basal ganglia, etc.) Executive Functionsgoal-related information Top-down Selection(flexibility) Sensory Motor Bottom-up Consolidation(long-term storage)
Learning and memory (Hippocampus, basal ganglia, etc.) Executive Functionsgoal-related information Top-down Selection(flexibility) Sensory Motor Bottom-up Consolidation(long-term storage)
Learning and memory (Hippocampus, basal ganglia, etc.) Executive Functionsgoal-related information Top-down Selection(flexibility) Sensory Motor Bottom-up Consolidation(long-term storage)
Learning and memory (Hippocampus, basal ganglia, etc.) Executive Functionsgoal-related information Top-down Selection(flexibility) Sensory Motor Bottom-up Consolidation(long-term storage)
The PF cortex and cognitive control Phone rings Answer Don’t answer Inactive Active
The PF cortex and cognitive control Phone rings Answer Don’t answer Inactive Active
The PF cortex and cognitive control At home Guest Phone rings Answer Don’t answer Inactive Active
The PF cortex and cognitive control PF cortex At home Guest Phone rings Answer Don’t answer Inactive Active
Reward signals The PF cortex and cognitive control PF cortex At home Guest Phone rings Answer Don’t answer Inactive Active
The PF cortex and cognitive control PF cortex At home Guest Phone rings Answer Don’t answer Inactive Active
Reward signals The PF cortex and cognitive control PF cortex At home Guest Phone rings Answer Don’t answer Inactive Active
The PF cortex and cognitive control PF cortex At home Guest Phone rings Answer Don’t answer Inactive Active
PF cortex What is needed for that function? Reciprocal connections with high level sensory and motor areas and inputs from ‘reward systems’ Neurons encoding the ‘rules’ that link inputs and outputs (e.g. if (A AND B), then X) Neurons encoding abstract meaning (e.g. ‘being at home’) Rapid learning of rules Keeping all information ‘on-line’, because complex contingencies span time
PF cortex What is needed for that function? Reciprocal connections with high level sensory and motor areas and inputs from ‘reward systems’ Neurons encoding the ‘rules’ that link inputs and outputs (e.g. if (A AND B), then X) Neurons encoding abstract meaning (e.g. ‘being at home’) Rapid learning of rules Keeping all information ‘on-line’, because complex contingencies span time
Extrastriate areas Motor+premotor areas Dorsomedial Nucleus Thalamus Basal Ganglia, Cerebellum Brain-stem nuclei (VTA) Dopamine input
PF cortex What is needed for that function? Reciprocal connections with high level sensory and motor areas and inputs from ‘reward systems’ Neurons encoding the ‘rules’ that link inputs and outputs (e.g. if (A AND B), then X) Neurons encoding abstract meaning (e.g. ‘being at home’) Rapid learning of rules Keeping all information ‘on-line’, because complex contingencies span time
Perceptual Categories David Freedman Maximillian RiesenhuberTomaso Poggio Earl Miller www.millerlab.org
Perceptual Categorization: “Cats” Versus “Dogs” 60% Dog Morphs 60% Cat Morphs 80% Cat Morphs 80% Dog Morphs Prototypes 100% Dog Prototypes 100% Cat Category boundary Freedman, D.J., Riesenhuber, M., Poggio, T. and Miller, E.K. (2001) Science, 291:312-316 Freedman, D.J., Riesenhuber, M., Poggio, T. and Miller, E.K. (2002) J. Neurophysiology, 88:914-928.
“Cats” Category boundary “Dogs”
Delayed match to category task RELEASE(Category Match) . . . . (Match) Fixation Sample 500 ms. . HOLD (Category Non-match) Delay 600 ms. 1000 ms. Test Test object is a “match” if it the same category (cat or dog) as the sample (Nonmatch)
Fixation Sample Delay Test 13 100% Dog P > 0.1 80:20 Dog:Cat 60:40 Dog:Cat 10 Firing Rate (Hz) Cats vs. DogsP < 0.01 7 4 100% Cat 80:20 Cat:Dog P > 0.1 60:40 Cat:Dog 1 -500 0 500 1000 1500 2000 Time from sample stimulus onset (ms) A “Dog Neuron” in the Prefrontal Cortex
Freedman, D.J., Riesenhuber, M., Poggio, T. and Miller, E.K. (2001) Science, 291:312-316 Freedman, D.J., Riesenhuber, M., Poggio, T. and Miller, E.K. (2002) J. Neurophysiology, 88:914-928 ??? Freedman, D.J., Riesenhuber, M., Poggio, T. and Miller, E.K, in prep.
An ITC neuron that responded more strongly to DOGS than CATS.
D1 C1 C1 D1 C1 C1 D2 D2 D3 C1 D3 C1 C2 D1 D1 D1 C2 C1 D2 C2 D2 D2 C2 C1 D3 D3 D3 C2 C2 C1 D1 D1 C3 C3 D1 C2 D2 C3 D2 C3 D2 C2 D3 D3 C3 D3 C3 C2 D1 C3 D2 C3 C2 D3 C3 ITC C3 C1 D1 C1 D2 C1 “cats” D3 C1 D1 C2 D2 C2 D3 C2 category boundary D1 C3 D2 C3 D3 C3 “dogs” D1 D3 D2 1.0 0.5 0 Normalized firing rate Category Effects were Stronger in the PFC than ITC: Single neurons Activity to individual stimuli along the 9 morph lines that crossed the category boundary PFC Cats Dogs Cats Dogs
Quantity (numerosity) Andreas NiederDavid FreedmanEarl Miller www.millerlab.org