Study Quiz 4 Flashcards
Memory and Learning
What is learning
A relatively long change in ability
Memory and Learning
What is long term memory
the ability to store info over an extended period of time for later recall.
Requires Neural Plasticity
Memory and Learning
What is plasticity
the neural process by which neurons (or other connections) are altered to suppot long term memoy and learning
Memory and Learning
What is sensorimotor learing
relaitvely permanent change in the capacity fo skilled movement.
* relies on long-term memory
Memory and Learning
What can long-term memory be divided into
-
Explicit/Declaritive memory
- consciously accessible
- can be verbally declared
-
Implicit/procedural memory
- not consciously accessible
- not verbally declared
Memory and Learning
What can declarative memory be broken down into
- Semantic memory (facts)
- Episodic memory (Scenarios)
- Autobiographical memory (self or things that occured to us)
- Visual memory (memoy of visual env.)
Memory and Learning
What areas of the brain does declarative memory draw upon
Medial temporal lobe (MTL), hippocampus and prefrontal cortex.
Memory and Learning
What is the role of the MTL and hippocampus in memories
important in the formation of new memories and storage of these memories
Declarative memory
Memory and Learning
What is the role of the prefrontal cortex in memories
critical to aquiring new memories (figuring out what strategies work, context) and retrieving/using long-term memoies stored in MTL
Declarative memory
Memory and Learning
What areas of the brain does procedual memories draw upon
Cortical motor areas, basal ganglia and cerebellum
Memory and Learning
What is the role of the cortical moto areas in memories
Convert ideas to act into concrete motor plan
Procedual memory
Memory and Learning
What role does the basal ganglia have in memories
work with cortical motor areas to control sequenced muscle contractions
procedural memory
Memory and Learning
what role does the cerebellum have in memories
helps identify errors in motor plan to effect corrections for next time (feedback)
Proceedural memories
Memory and Learning
Who is patient H.M and what is his importance
Surgery removed large section of MTL and hippocampus (bilaterally). Had no recollection of ever coming to lab or peforming motor tasks (episodic), however motor ability improved (implicit remained while explicit was damaged)
Memory and Learning
What is sensorimotor learning characterized by
A process characterized by early fast gains and slow iterative gains associated with practice. It cannot be measured directly, and is instead infered through sustained changes in sensorimotor performance
Memory and Learning
What is early, fast learning/gains
the result of formation of declaritive memories tied to rules, strategies and context around a movement
Memory and Learning
What is slow, iterative learning/gain
the result of proceedural memories that can only be formed through experience/practive.
- require brain to make short-term adaptions acuired during practive more permanent
Memory and Learning
Explain ability vs effort and Dual-Task cost
Increased sensorymotor ability is reflected in less effo to perfom the skill, the amount of effort can be quantified through dual task cost.
Dual task cost is the decline in skilled motor performance of a task while doing a second task.
Memory and Learning
What are the main theroies of learning explored
- Fitts & Posner
- Gentile
- Bernstein’s model
Memory and Learning
Explain the Fitts & Posner theory
- Cognitive stage: learning what to do (verbalize goal/expected result)
- Associative stage: refined practice (determine best motor plan)
- Autonomous stage: skill relatively automatic (minimal cognitive resources)
Shift from high to low physiological effort
Memory and Learning
Explain the Gentile theory
- Early stage: understanding the movement (cognitive stage from F&P)
- Late stage: fixation &diversification (associate/automatic stages from F&P)
Shift from low to high effort
Memory and Learning
Explain the Bernstein’s Model theory
- Stage 1: Reduce degrees of Freedom (reduce movement of non-essential body parts)
- Stage 2: Release degrees of freedom (relax restictions to find optimal pattern)
- Stage 3: Exploit passive dynamics (max certainty, min effot)
High to low biomechanical effort
Memory and Learning
How can you measure sensorimotor performance
- Measured of ability (reaction time, accuracy, req. effort)
- Measures of process (movement kinematics, EMG)
- Measures of neural function (non-invasive brain imaging/stimulation)
Memory and Learning
What is sensoimoto performance
The observable attempt to perform a motor skill. Reflects short-term adaptions and non-learning related flucuations in performance
Determiniants of Learning
What are the determinants of leaning
- Practice dose
- Practice schedule
- Feedback
these are all primary determinants if sustained change in performance
Determiniants of Learning
Explain Practice Dose
- Not just quantity, but quality of practice
- Must have a goal to improve, repitition along is not a strong driver of sustained change
Determiniants of Learning
Explain Practice schedule
- Generally, shorter periods of distributed practice result in more learning than longer, massed practice sessions
- Practicing different variations of same skill is more effective
- blocked practice leads to better performance during practice, but gains not as permanent
- Rndom practice are not as immediately evident, but evident next time you practice
Determiniants of Learning
What is Distributed practice
Same does but with breaks between bouts of practice
Determiniants of Learning
What is massed practice
continuous practice with little rest
Determiniants of Learning
What is blocked practice
completing all trials of one distance before practicing next
Determiniants of Learning
What is random practice
intermixes practice trials of different distances in an unpredictable order
Determiniants of Learning
Explain Feedback
Can be intrinsic or extrinsic. If you don’t know that you did not achieve you goal, or why/how you didnt, how will you learn?
Determiniants of Learning
Explain intrinsic vs extrinsic feedback
Intrinsic feedback: feedback relating to physical feel of movement
Extrinsic feedback: feedback provided originating from external sources (what we see or hear for ex)
Determiniants of Learning
What is concurrent feedback
real-time feedback about knowledge of performance as the movement is performed
Determiniants of Learning
What is the guidence hypothesis
suggests concurrent feedback created a reliance on feedback and its removal would be a detriment to the movement performance
Determiniants of Learning
What is feedback after movement
either knowledge of performance or results given after the movement is complete
Determiniants of Learning
What is the feedback delay interval
THe delay between intrisic and extrinsic feedback. It must be long enough to allow the individual ti process intrinsic feedback before recieving extrinsic feedback
Learing and memory
What are the 2 types of sensorimotor learning
- Skill learning: NS changes that facillitate the acquisition of novel movement patterns to enhance motor ability
- Adaption: NS changes that adapt existing motor patterns to restore motor ability in response to chance in context or environment
Learing and memory
What is an example of sensorimotor adaption
VOR reflex
Learing and memory
What are after-effects
Persistant decrease in performance seen after environmental perturbation is removed
Learing and memory
What is savings
the ability to use your past experience with a pertubation the next time you experience it
Neural Plasticity
What is neural plasticity
A continuous, life-long process that mediates the structural and functional reaction of dendrites, axons and synapses to development, experience and injury. It is the foundation for short and long-term changes of the NS that underpin memory and learning
Neural Plasticity
What is functional Neuroplasticity
changes in the strength of connections between neurons o synapses
Neural Plasticity
What is structural neuroplasticity
permanent changes in synapses/neurons (not just strength) due to learning and development
Neural Plasticity
What is neurogenisis
A process which involves the growth of new neurons
Neural Plasticity
What is synaptogenesis
growth of new synapses and is fundamental to structural neuoplasticity
Neural Plasticity
Describe key points of neuroplasticity examples
Somatosensory system, Motor cortex, Posterior parietal cortex, After injury
- Somatosensory system: training in primaetes led to changes in the representation of the sensory inputs at the primary somatosensory cotex activiated by their digits
- Motor cortex: motor training and leanign is associated with changes in cortical representation in M1, trained ice showed neuons with many more synapses compared to control
- Posterior parietal cortex: brain imaging used to see changes in human structure after training/learning to juggle. Changes persisted even after 4 weeks with no practice
- After injusry: experience is critical to diving neural plasticity and rehabilitaion. Motor ehab shows much less loss post stroke. additionally, depriving an area of the brain experience is also a driver of neural plasticity = “learned non-use” and can lead to loss of digit representation in an amputation for ex.
Neural Plasticity
What is memory storage the result of
NOT the result of a linear sequence of events cumulating in long-term memory.
IS result of a dynamic outcome involving several interactive processes (encoding, short-term, long-term and intermediate memoy, updating and integrating, etc)
Neural Plasticity
What are the 2 mechanisms of neural plasticity that have been focused on
- Long term potentiation (LTP)
- Long-term Depression (LTD)
Neural Plasticity
What is long-term potentiation (LTP)
Relatively persistant strengthening of synaptic efficacy driven by recent patterns of activity (same AP ariving at synapse at a later time generates a larger post-syn. potential)
An intermediary step towards ‘permanece’, synaptogenesis makes memoy resilient to forgetting
Neural Plasticity
What happens in the early and late phases of LTP
Early phase: strengthens the existing synapse
Late phase: leads to formation of new synapses
Neural Plasticity
What are the key ionotropic glutamate receptors involved in post-synaptic LTP
and explain them
- AMPA receptor is an ionotropic receptor for glutamate that leads to fast synaptic transmission (Na+ influx)
- NMDA receptor is a voltage gated ionotropic receptor that requires glutamate and a depolarized membrane which will then open for Ca2+ and Na+
Both AMPA and NMDA bind to glutamate, however, NMDA also has MG2+ ‘blocker’ that must be moved before channel becomes pemeable to ions
Neural Plasticity
Explain Calcium’s (Ca2+) role in post-synaptic LTP
Ca2+ seves as a 2nd messenger & mobilizes other molecular activities to increase sensitivity of post-syn. cell response to pre-syn. cell
For post-syn. LTP, the rapid influx of Ca2+ via open NMDA:
1. triggers an increase in AMPA receptors
2. Releases nitic oxide to increase release of NT from pre-syn. cell
3. Sends signal to cell nucleus to initiate other structural changes
Neural Plasticity
What does synaptogenesis lead to
Spatial summation (synchronous activity at multiple synapsis leads to larger post-syn. potential)
Locomotion
What is locomotion
Movement or ability to move from one place to another
Locomotion
What is the difference between walking vs gait
Walking: to move (or locomote) by alternating placement of feet
Gait: the manner or style of walking; can be changed voluntaily (walking on ice) or by injury/disease
Locomotion
What is human gait
the bipedal limb movement to propel COG of the human body, control requires rythmical (alternating) limb control & dynamic balance control
Locomotion
What is locomotor rhythm
the rhythmical and sequential activation of muscles to achieve inter/intra-limb coordination
Locomotion
How is CNS control of locomotor rhythm achieved
through a network of interneurons that represent a ‘generalized motor program’
- common across species and provides invarient model of gait
- elements like speed, stride length, etc are surface features
Locomotion
What is inter-limb vs intra-limb coordination
Inter-limb coordination: coordinated concurrent control of whole limb extension (stance) and contralateal limb flexion (swing) [coordination of both limbs with each other]
Intra-limb coordination: alternating multijoint control of limb extension and then flextion [coordinations of joints within one limb]
Locomotion
What is locomotor invariance
the rhythmical pattern of muscle activity supporting locomotion/gait is consistent across species, magnitudes and speeds
Locomotion
What is the ‘flight period’
time where both legs are off of the ground when walking/running
The central pattern generator (CPG)
What is a central pattern generator (CPG)
a neural network that is capable of producing rhythmic muscle activation patterns without any contribution from centripetal or centrifugal influences
The central pattern generator (CPG)
Explain how centripetal/centrifugal influences are impotant and examples of CPGs
Centripetal and centrifugal influences are extremely important to initiation and modulation (and regulation) of CPG, however CPG can generate base rhythm without them. Locomotor rhythm is maintained even with deaffrentation (no periphery inputs) or spinalization (no high NS inputs)
Examples: breathing (medulla)
chewing (medulla)
Gait (intermediate zone of SC)
The central pattern generator (CPG)
Explain propriospinal tracts
Propriospinal tracts are collections of nerves that interconnect various levels of the SC. The can ascend or descend the SC and cross (o not cross) the midline to interconnect levels. critical for limb coordination
The central pattern generator (CPG)
What are the 3 main sources of CPG modulation
- Afferent modulation (sensoy inputs)
- Interlimb modulation (spinal centres)
- Descending modulation (supraspinal)
The central pattern generator (CPG)
Even though CPGs don’t need input, why is input/modulation useful
- On their own, CPGs will continue their natural rhythm even if not appopriate due to unexpeced change or voluntary behaviour (ex breathing underwater, or wanting to stop walking) descending inputs must supress/inhibit.
- Descending inputs also provide about curent goals and response appropriate behavious
- sensory inputs convey info about muscle state to modulate typical pattern
- inputs are then interpreted by CPG and CPG details the muscle activity
The central pattern generator (CPG): descending input
What is the Mesencephalic Locomotor egion (MLR) and what info does it provide to CPG?
MLR provides important excitatory input to spinal CPG via reticula formation of medulla
* one role is to convey changes in rate of locomotor rhythm being maintained by CPG (think of MLR like ‘gas pedal’ for locomotion)
* Changes in tonic (continuous) input from MLR leads to ‘phasic’ activity at CPG and MNs leading to changes in rate of rhythm
The central pattern generator (CPG): sensory input
What do sensory input to CPGs do?
- signal phase transition (stance/swing) [hip position triggers stance to swing]
- Reinforce extensor activity
- Contro movement adaptions to ‘errors’ or environmental challenges
The central pattern generator (CPG)
How does relience of CPGs change across species
Contribution of CPG to elicit behaviour decrease as NS complexity increases (the is instead an increasing contribution of modulatory sources like sensory feedback and descending modulation)
