Procedural Memory
Double dissociation of Radial arm maze
- MTL damage impairs declarative version of the task, but not procedural - Basal ganglia damage impairs the procedural version of the task, but not the declarative version
What are the brain substrates of procedural memory?
- basal ganglia - cortex - cerebellum
How is procedural memory different than declarative memory
- can be acquired without conscious awareness - implicit learning - typically hard to verbalize - requires practice
Power law of learning
- gains in learning are very rapid at first, but rate of learning declines with practice (law of diminishing returns) - pattern hold true across a wide range of tasks and species
Implicit Learning & The Serial Reaction Time Task
- press button that corresponds to a visual cue - cues mostly appear in random order, but sometimes sequences repeat - with training RT to repeated sequences is faster that random sequences (participants are usually unaware of repeating sequences)
How is procedural memory different from priming?
- priming is facilitated performance regarding a particular stimulus - skill learning is facilitates performance of a particular task involving a range of stimuli
Basal ganglia's involvement in procedural learning
- receives information from a wide range of cortical areas - sends output to: - the thalamus, which in turn influences motor cortex - brain stem, which sends signals to the spinal cord - plays a key role in regulating the direction, speed, and strength of movements
Neural basis of Huntingtons Disease
- results from gradual death of the neurons in the basal ganglia itself - genetic cause - autosomal dominant mutation - if your parent hs HD, you have a 50% chance of developing HD
Thorndike's identical elements theory (1901)
- transfer depends on the similarity of the training context to the new context - the more shared (identical) elements, the better the transfer of skill learning
Cerebellum
-evolutionary ancient region of the brain - receives inputs from sensory systems, the spinal cord and the cortex - sends outputs to the spinal cord and cortical motor areas
Parkinson's disease
-neurodegenerative disease affecting about 1 million people in the US, typically later in life -primarily movement disorder: - muscle tremors - rigidity - slowness of movement - difficulty initiation spontaneous movements in the absence of stimuli Also affects cognition: impairments in procedural learning (both perceptual motor and cognitive)
what can reset the power law?
Additional sources of feedback can reset the power law - eg. first learn through visual feedback, then watch an instructional video
Basal ganglia activity during learning
Basal ganglia activity changes during skill learning - Early in training - 50% of BG neurons show task-related firing - most fire when rat turns in maze - Late in training - 90% of BG neurons show task-related firing - most fire at beginning or end of maze
What are the types of perceptual-motor skills
Closed skills: - performing pre-defined sequences of actions (ex. gymnastics, ice-skating, or diving routines) Open skills: -require adjustments based on changes in the environment (playing basketball) most skills fall somewhere on the spectrum of closed to open
What are the stages of skill learning (in Fitts' three stage model 1964)
Cognitive stage: - initial period, typically verbal, in which effort is required to perform a skill Associative stage: - less reliance on verbal rules - more stereotyped behavior Autonomous stage: - skill is automatic and requires little attention (habitual)
What are some factors that affect how effective practice is?
Feedback - knowledge of performance during practice Spacing - massed: concentrated practice - spaced: practice spread out over multiple sessions Variability - constant: practice focused on a single skill - variable: practice that alternates between a set of skills
What plays an important role in early learning?
Goals. Habitual behavior arises after extensive training
How do we know when a skill has become a habit?
Human research: - for a perceptual-motor skill, remove/change the relevant stimulus in the middle of the motor sequence. - is the motor sequence still completed?
What is procedural learning? What are the types of procedural learning?
Improved performance on motor, perceptual or cognitive tasks with practice -perceptual-motor skills: motor patterns guided by sensory inputs -cognitive skills: ability to problem solve and apply strategies - many skills involve a combination of motor, perceptual and cognitive abilities
What is transfer specificity?
Jazz pianist isn't necessarily a good jazz dancer relative to a novice however a pianist is more likely to rapidly learn trumpet
Radial arm maze. What are the two versions? What do they test?
The two versions are designed to assess either declarative or procedural learning. Declarative: - each arm is baited with food - performance requires remembering which arms have been visited Procedural: - half of the arms are baited and signaled with a light - performance requires entering illuminated arms only (S->R)
Transferring skills
Transfer: generalization of skill learning from one context to another (gymnastics to diving) generally, most skills do not transfer
how does damage to the cerebellum affect skill learning?
cerebellar damage causes impairments in learning skills taht require: - precise timing - aiming at or tracking a target fMRI studies reveal changes in cerebellar activity during cognitive skill learning (eg. mirror reading)
Huntington's disease
neurodegenerative disease affecting about 250,000 people in the US -motor symptoms - involuntary jerking and writhing movements (chorea) - difficulty walking - impaired speech -cognitive symptoms - lack of impulse control - impaired procedural learning (both perceptual-motor and cognitive), particularly with tasks involving planning and sequencing of actions
Procedural memory will focus in on...
non-declarative memory -> skills/habits -acquisition of new skills and habits with practice over time
how are skills trained in animals? how can you tell whether a skill has become a habit?
often trained using operant conditioning can test whether a skill has become a habit via reinforcer devaluation
Neural basis of parkinsons disease
results from gradual death of the neurons in the substantia nigra, which provides input to the BG - decreased input causes dysfunction of the BG and thus dysfunctional interaction with the thalamus and brainstem
Cortical changes during skill learning
skills involve many components. playing guitar for ex. - feel of strings on your fingers - motor movements required to play notes - sound provides feedback about performance - cognition required to, eg., read music or coordinate timing with other musicians - cortical regions associated with theses sensory, motor and cognitive components change with practice
Weather prediction task
test of cognitive skill learning that involves probabilistic classification
Rotary persuit task
track a spot target on a revolving wheel
Cortical expansion
training expands cortical areas associated with specific elements of a skill - fMRI research in humans: - greater somatosensory activity when moving fingers on string hand in expert violinist relative to novices (but not true for bow hand) - during learning of a novel motor task, increased performance was paralleled by increased activity in motor cortex