Learning

References: 1. Packard M, Knowlton B, Learning and memory functions of the basal ganglia, Annual Reviews neuroscience, Vol 25, , Clark, RE, Squire, LR, Classical Conditioning and Brain Systems: The role of awareness, Science, Vol 280, pp , Knowlton B, Mangels JA, Squire LR, A Neostriatal habit learning system in humans, Science, Vol 273, , Willingham DB, Salidis J, Gabrieli J, Direct comparison of neural systems mediating conscious and unconscious skill learning, Journal of Physiology, pp , 2001

intact in amnesia ex: motor/habitual skills ex: word priming studies ex: simple CS Squire, 2004 Working Memory DLPFC Parietal (striatum=caudate+putamen diencephalon=thalamus and vicinity)

Explicit Memory –memory of facts and experiences that one can consciously know and declare –hippocampus- neural center in limbic system that helps process explicit memories for storage Implicit Memory –retention without conscious recollection –motor and cognitive skills –dispositions- conditioning

Non-declarative memory: Occurs through modifications within specialized performance systems. May be revealed through deactivation of systems through which learning originally occurred. It is dispositional, being expressed through performance rather than recollection. So it can not be true or false.

Priming

Defn: A change in the processing of stimulus due to prior exposure to related stimulus. Types: Perceptual priming: Study versus test phases use stimuli from same or different modalities. (visual, auditory, words). Example tasks: word-fragment completion, picture naming. Effect is more observed when both stimuli are from the same modality Conceptual priming: Study versus test phases use associative pairs. Example tasks: word-association generation, category-examplar generation. Effect is more observed when study phase enhances stimulus meaning. Lesions: Amnesic patients exhibit normal performance in all these example priming tasks. as long as the task requires implicit recall. When the task requires explicit recall (for ex: cued recall) amnesic patients failed Basal ganglia damage patients also show intact priming Repetition priming (Gabrieli, 1998)

Systems: Looks like separate areas in neocortex mediate perceptual and conceptual priming. For perceptual priming, modality specific areas, for conceptual priming, amodal association cortices are in action. For example, in visual word-stem completion,, bilateral occipital cortex activation occurs. In abstract/concrete decisions about words, L frontal cortex activity is reported. For example in AD (Alzheimer's), association cortices are affected, resulting with intact perceptual but impaired conceptual priming. Also patients with right occipital lesions show intact conceptual priming but impaired visual word-identification. Repetition priming in a given domain reflects experience-induced changes in the same neural networks that subserved initial processing in that domain For ex: in fMRI, activity decreases when priming occurs

Skill Learning and basal ganglia

Procedural/Skill memory (Gabrieli, 1998) Defn: acquisition, retention, retrieval of knowledge expressed through experience induced changes in performance Tests: implicit tests where no direct reference is made to the experience (ex: skill learning, repetition priming, conditioning) Sensorimotor skills: rotary pursuit, mirror tracing... Lesions: Sensorimotor and perceptual skills such as reading are intact in amnesic patients who have poor declarative memory Basal ganglia damage impairs: sensorymotor skill learning (ex: Parkinson's) cognitive skills such as probabilistic classification Cerebellar damage impairs mirror tracing One hypothesis indicates basal-ganglia is effective in open-loop skill learning (skills related to planning of movements) cerebellum is effective in closed-loop skill learning (continuous external feedback about errors in movement)

* While a skill is being learned, the area of brain responsible for skill-related function is predominantly active. Once the skill is learned, separate areas of brain are engaged, but the activity in the early skill-learning areas diminish. Ex: in piano players, contra-lateral motor area activates while complex finger movements are practiced. In non-musicians, premotor (BA 6) activate while movements are practiced, but when movements are learned the activity in BA6 diminishes. Ex: Similarly, in finger tapping experiments, a decrease occurs in cerebellar activation with the learning of finger-tap sequences

Probabilistic Learning

Knowlton, 1996

Probabilistic Learning Knowlton, 1996 Weather prediction Survey questions about experiment

Probabilistic Learning Erdeniz, 2007

Parkinson Patients vs Controls Non-Monetary Feedback Erdeniz, 2007

Parkinson Patients vs Controls Non-Monetary Feedback Erdeniz, 2007

Parkinson Patients vs Controls Non-Monetary Feedback Erdeniz, 2007 WM and Basal Ganglia are at competition

Stimulus-Response Learning Willingham, 2002

Stimulus-Response Learning Willingham, 2002

Stimulus-Response Learning Willingham, 2002

Stimulus-Response Learning Willingham, 2002

Classical Conditioning

Involves making connections between two forms of stimuli: –Unconditional (US): reliably provokes a response Response is termed unconditional (UCR) –Conditional (CS): neutral: does not provoke the response –Pair the CS and UCS over many trials –Does the CS alone produce a response?

Reflex (delay) conditioning: (Gabrieli, 1998) Experiment: CS ms tone, US airpuff, both terminate together. US initiates eyeblink. After CS is learned, eyeblink occurs without airpuff. Electrophysiology: Hippocampus and cerebellum activity correlates with this behavior Lesion: Hippocampal lesions do not impair delay conditioning but cerebellar lesions abolish this response (humans and rabbits) Delay eyeblink conditioning is impact in amnesic patients with bilateral medio-temporal (MTL) or bilateral thalamic lesions or in patients with basal-ganglia damage

Trace conditioning (complex): Experiment: CS ms tone, US airpuff, delay between the end of CS and onset of US. Delay is msec System: Same system active in declarative memory: MTL Lesion: Delay eyeblink conditioning is impaired in amnesic patients with medio-temporal (MTL) damage (also in animals)

Cerebellum is good enough for delay conditioning

Clark, 1998 Classical Conditioning

Clark, 1998 Classical Conditioning

Worthy of note

Katrin Amunts n= 30 control, 21 pianists MRI:T mm Piano training changes the depth of your central sulcus ILPG measure