Midterm 1 Flashcards
motor learning
- relatively permanent changes in motor behaviours resulting from practice or experience
- focuses on acquiring or modifying the capability to perform skilled movements
motor control
- the process of initiating, directing, and grading purposeful voluntary movement
- an area of study dedicated to understanding the neural, physical, and behavioural aspects of movement
- how the brain, nervous system, muscles, and sensory systems work together to initiate and regulate movements
motor performance
- the execution of a motor skill at a specific time and in a specific situation
- can be measures in terms of outcome (eg. accuracy, distance, speed) or quality of movement (eg. coordination, balance)
- may vary from one attempt to another due factors like fatigue, stress, or learning
why study motor skills?
applies to:
- coaching and teaching
- rehabilitation
- medicine
- ergonomics
- robotics
motor behaviour sub-categories
- motor learning
- motor development
- motor control
motor skills definition
the ability to bring about some end result with maximum certainty and minimum outlay of energy, or of time and energy
characteristics of a motor skill
- a well defined goal
- must produce skill reliably, on demand, without luck
- minimize physical and mental energy costs of performance (not require of all motor skills)
- speed is the main goal of many motor skills (eg. races, surgery)
factors affecting motor skills
constraints
- individual: knowledge, previous experiences
- environment: what’s going on, opponents
- task: what are we being asked to do
3 elements critical to production of most motor skills
steps of information processing
- perceiving relevant environment features
- deciding what to do, where and when to do it to achieve the goal
- producing organized muscular activity to generate movements that achieve the goal
exceptions of motor skills
- reflexive movements: involuntary, rapid, and localized
- learned automaticity: expertise, effortless execution, low cognitive load, subconscious control
classifications of motor skills (5)
discrete vs. continuous
open vs. closed
fine vs. gross
manipulation of object (Y/N)
body transport (Y/N)
discrete motor skills
defined beginning and end, typically briefer, defined outcome
serial motor skills
typically a series of discrete skills to make a more complicated action, typically slightly longer than discrete skills
continuous motor skills
more arbitrary beginning and end points, measure with tracking tasks, typically last minuted to hours
produce many error scores on a single trial
open motor skills
- affected by: reaction time, anything that affects adaptability
- unpredictable environment making it difficult to predict how it will change
closed motor skills
- more predictable and stable environment
- usually performers can predict task and plan motor skills
fine motor skills
smaller muscle groups, more precise
gross motor skills
large muscle groups, doesn’t require much accuracy, trying to produce greater force
taxonomy
a complex classification system for characterizing motor skills
scientific method steps (7)
- observation and question generation
- hypothesis development
- experimentation
- data collection and analysis (typically more quantitative in this field)
- interpretation and conclusion
- publication and peer review
- replication and further research
theories
well-developed explanations of how various phenomenon occur
very comprehensive, involve relevant scientific constructs
scientists pull out specific predictions (ie. hypotheses) from theories
hypotheses
identify relationships between scientific constructs that can be measured (ie. variables)
error
on a single trial we can calculate how far the arrow is away from the target
constant error (CE)
- measures the amount and direction of bias away from target (ie. accuracy)
- when averaged among trials can have cancellation effects which can incorrectly quantify accuracy
- tells us average error
constant error equation
CE = sum of [(Xi-T)/N]
- start by calculation the error deviation of each trial relative to target, then calculate the average of these error deviations
absolute error (AE)
- measure of the overall accuracy in performance
- not interested in direction (whether target was over- or under thrown
- was commonly used in foundational research
absolute error equation
AE = sum of absolute value of [(Xi-T)/N]
variable error (VE)
- measures how consistent someone’s performance is
- it is the variability in the movement outcome about the mean value
- variable error does to depend on whether the performer was close to the target
variable error equation
VE = square root of {sum of [(Xi-CE)^2/N]}
- square the deviations between each trial’s error score and the subject’s CE
- add together all of the values from the previous step and divide by the number of trials
- compute the square root of this value
total variability (E)
- measure of overall error
- similar to VE, but reference to target position
- preferred when representing a combined measure of accuracy and variability
total variability equation
E = square root of {sum of [(Xi-T)^2/N]}
- square the difference between each trial’s error score and the target
- sum those over all the trials and divide by the number of trials
- compute the square root of this value
E^2 = VE^2 + CE^2
root mean squared error (RMSE)
- measures the deviations between performed trajectory and target trajectory at a constant interval (distance or time)
- similar to total variability: provides measure of bias (accuracy) and consistency in the tracking behaviour
RMSE equation
RMSE = square root of {sum of[Xi-Xt)^2/N-1]}
- N-1 = degrees of freedom (DoF) provides a more accurate picture of error, because one value is tied to other values (eg. calculating a mean)
- square the deviations between each trial’s error score and the target at the constant interval
- add together all of the values from the previous step and divide by DoF
- compute the square root of this value
correlation
- simple statistical way to quantify the strength of a relationship between two variables
- measures both the direction and strength of a relationship
- correlation coefficient (r), number = strength, sign = direction
input
- the information to be processed by the human
- comes in all sensory forms: vision, tactile, proprioception, auditory, smell, and taste
- most complex input comes from vision: object, movement, perception
- the greater the amount of information to process, the greater the time require to process
steps of information-processing
input > stimulus identification > response selection > movement programming > output
stimulus identification stage
- first individual must perceive the stimulus
- involves stimulus detection and then identification, detection is influenced by stimulus clarity and intensity
- stimulus must be sensed and processed, processed until it contacts memory
response selection stage
- once we identify stimulus, we need t decide how to respond with consideration of the situation, environment, and goals
- process of determining what to do and how it should be done
- involves memory and stimulus comes from environment
movement programming stage
- final stage begins after receiving decision about what movement to make
- preparation of the motor system to make the desired movement
- readies mechanisms of brainstem (eg. substantia nigra: fine movements) and spinal cord (eg. motor neurons, ascending sensory pathways)
- retrieve and organize learned motor programs
what is output?
- stages involved in producing motor output (ie. voluntary and involuntary movements)
- often the focus of motor control research
reaction time (RT)
- performance measure of speed and effectiveness or accuracy of decision making
- RT interval is period of time that elapses from when a stimulus is presented to the beginning of the response
factors that influence information processing
- any factor increasing duration of greater or equal to 1 of the stages will increase the RT interval
- two main factors affect RT (ie. motor performance) at response selection stage:
- number of stimulus response (S-R) alternative (ie. number of choices)
- stimulus-response compatibility, more compatible = more natural response and will likely occur faster
number of S-R alternatives
- amount of information in a situation = amount of uncertainty in the situation
Hick’s Law
- in log base 2 scale, the relationship between S-R alternatives and RT
becomes linear - choice RT linearly relates to the logarithm to the base 2 of the # of S-R alternatives, choice Rt increase ~ constant amount (150 ms) when # of S-R alternatives doubled
- as number of S-R alternatives increases the reaction time increases curvalinearly
- as one variable increases, the other also increases by not at a constant rate
- largest gap is observed between 1 and 2 S-R alternatives
choice RT equation
= a + b[Log base 2 (N)]
a is the y-intercept
b is the slope
S-R compatibility
extent to which the stimulus and response are connected in a natural way, as S-R compatibility increases RT decreases
Fits and Seeger S-R compatibility study
- had participants respond to combinations of stimulus and response patterns
- population stereotypes: arbitrary S-R relationships become natural through practice and experience
- spatial and anatomical relationships: alignment of mental representation of stimuli and the possible responses
types of S-R compatibilty
- stimulus and response intensity
- Simon effects
- compatibility and complex actions
stimulus and response intensity
- faster RT when intensity of stimulus matches the required force of response
- high intensity stimulus is easier to match with high intensity response rather than high intensity stimulus with weak response required
- weak or strong isometric thumb press: 50-75ms advantage when compatible
Simon effects
- auditory stimuli presented via headphones
- participants to respond to content of the message (left or right) by pressing appropriate button on the indicated side
- spatial location (which ear) of message irrelevant to task but affects RT
- suggests interference in selecting response when irrelevant stimulus incompatible
- spatial dimensionality of stimulus counteracts the response causing slower RT
compatibility and complex actions
- complex actions (ie. responses) seem related to intentions (ie. final position) of the action
- trade off an awkward early posture for efficiency at the end of movement “end-comfort effect”
anticipation
highly skilled performers are able to predict what is going to happen in the environment and when
- have encoded motor programs in memory that help them respond quickly
- divided in spatial and temporal anticipation
spatial anticipation
predicting what will occur and where you need to be to be successful, eg. penalty kick situation in soccer
temporal anticipation
predicting when some event will occur but not knowing what will occur, eg hiking the ball in football
benefits and costs of anticipation
benefits:
- reduction in effective RT, can get near 0ms
- can disadvantage opponent
costs:
- can cause more processing activities, ie. if we anticipate one thing but another occurs, we have to deprogram initial program
- can move you further from the best location
- can put you at biomechanics disadvantage
memory basics
- believed to be a consequence of information processing
- can be used in a direct way to facilitate solving a current problem (search and retrieval)
- can also be used in an indirect way unconscious to us
types of memory
- short-term sensory store (STSS)
- short-term memory (STM) divided into working memory and motor short-term memory
- long-term memory (LTM)
short-term sensory store (STSS)
STSS thought to have limitless capacity but information held for very brief period, approx 1 sec
short-term memory
- STM has a limited capacity (7+/- 2 items) that lasts a short duration
- 60 sec is thought to be upper limit
- rehearsal promotes retention
- abstract coding: items given names (chunking)
working memory
part of STM where:
- information from the STSS is stored for processing
- information from LTM can be retrieved and integrated
- effortful and limited capacity conscious processing
long-term memory
- practice leads to enhanced LTM for movement
- limitless storage duration and capacity
- for continuous skills, retention is almost perfect after years, while discrete skills are much more easily forgotten
patient H.M.
- suffered severe epilepsy
- had a bilateral medial temporal lobectomy resulted in anterograde amnesia
- could not commit STM to LTM
was given a task to draw a star with arm without seeing arm, he improved over 3 days even though he had no previous recollection of the task - didn’t improve on a cognitive learning task on navigating a maze drawing, couldn’t remember correct choices for where to go
attention
- our capability to allocate our limited capacity to specific stimuli
- when overwhelmed or mis-allocated: information is missed, interference within or between stages, and performance suffers
- if a task is less demanding we have more capacity for a second task, more complex leaves less attention for second task
attention and high performance
high performers have learned:
- what information to attend to and when
- how to shift between external/internal information
- planing future actions
- other processes, eg. instructions from a coach
serial processing
- processing stimuli in sequential steps
parallel processing
- during stimulus identification, some sensory information can be processed in parallel and without interference such as aspects of visual display (Stroop effect) or different auditory information (cocktail party effect)
Stroop effect
- psychological phenomenon demonstrating interference in reaction time of a task
- occurs when the name of a colour is printed in a colour not denoted by the name, making it difficult for participants to identify the colour of the word quickly and accurately
inattention blindness
- goal-directed allocation of attention to visual or auditory stimuli can make us ‘blind’ to other stimuli
- people engaged in attention-demanding tasks can miss obvious and important stimuli
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sustained attention and causes of decrement
- stimuli may be brief, performance in many contexts requires vigilance with attention
- vigilance decrements caused by many factors:
- motivation, fatigue, arousal
- secondary tasks
- environment, eg. distraction, temperature
limitations in response selection
interference occurs at this stage when two actions, both requiring mental operation, must be performer simultaneously
- choice from multiple responses, eg. which hand to use, body position, monitoring task
controlled processing
- a mental process that requires attention, cognitive capacity and has to be initiated by the subject
- characteristics: slow, attention demanding, serially organized, and volitional
- performing two information-processing tasks under controlled processing at the same time can disrupt both tasks
automatic processing
- related to processing information in parallel, quickly, and without interference from other processing tasks
- characteristics: fast, not attention demanding, organized in parallel, involuntary
- result of large amounts of practice
- evidence “consistent-mapping” ideal condition, consistent type of environment can help form deliberate practice
limitations in motor programming
many movements are programmed in changing environments
- preprogramming movement involves various levels of the nervous system
- critical adjustments require time
psychological refractory period (PRP)
- when presented two stimuli arriving closely together, generating the second response can be delayed, this is term the psychological refractory period (PRP)
- first stimulus is processed in parallel to second until motor programming stage where first stimulus must be processed and initiated before a response to the second stimulus can begin
- how soon can a person switch from making a goal-directed response to one stimulus to making a different goal-directed response to a different stimulus
- when the SOA is very short, the motor system responds to the first and second stimulus as if they were one, which produces both responses simultaneously, termed grouping
stimulation paradigm
- represents when the first and second stimulus are presented in relation to each other
- points represents time interval between when 1st and 2nd stimuli are presented
- after 200ms, first stimulus is not going to interfere with second
main 5 senses
vision, touch (haptic), smell (olfactory). taste, and hearing (audition)
equilibrioception
sense of balance, some argue its part of proprioception
proprioception
sense of body position, often paired with tactile sense
thermoception
sense of temperature
nociception
sense of pain
closed-loop control system
- sensory information is used to modify motor control in a closed-loop control system
- components:
1. an executive for decision making about errors
2. an effector system for carrying out the decisions
3. a reference of correctness against which the feedback is compared to define an error
4. an error signal, which is the information acted on by the executive
exteroceptive senses
vision, audition, haptic
proprioceptive senses
equilibrioception, nociception, haptic, thermoception, proprioception
closed-loop control system component functions
- input: system received instructions
- reference mechanism: the goal is defined and set to be achieved
- executive system relays instructions to achieve the goal
- effector system enacts the instructions that are relayed
- sensors in the environment produce feedback
executive system
responsible for stimulus identification, response selection, and movement programming
effector system
responsible for conveying motor program to spinal cord, and muscles
sensation
activation of sensory receptions, specialized sensory organs are activated by a stimulus
perception
interpretation of sensory signals, involves the combination and integration of sensory (or afferent) information from multiple sources
visual system - receptors
- light from a object in the visual field is refracted and focused onto the retina
- retina contains photoreceptors, divided into rods and cones
- rods are responsible for motion/detection and have a more rod-like shape
cones are responsible for fine detail and have a more cone-like shape
photoreceptors
light sensitive cells that line the back of the retina, divided into rods and cones
visual system - central processes
- visual information travels through the optic nerve and various subcortical structures to the lateral geniculate nucleus (LGN)
- from LGN in the thalamus, visual information is relayed to the primary visual cortex (V1)
- primary visual cortex is where visual features such as stimulus direction, stimulus speed, and object orientation are processed
visual streams
- from the primary visual cortex (V1), visual information can travel to either the dorsal or ventral stream
dorsal stream
- focused on “where is it?” of stimulus
- inputs from full visual field
- visual information travels to parietal areas of the brain
- uses optical array to determine location of stimulus
ventral stream
- focused on “what is it?” of stimulus
- inputs from the LGN, mainly from central visual field
- visual information travels to the temporal lobe
- contributes to how we plan movement
optical array
- reflection of light entering the eyes at specific angles from objects in the environment
- gives us sense of where objects are in our environment due to the angle of the light
effects of vision on motor control
optical array and flow descriptions
- optical array: rays of light that, collectively, reflect from objects in our environment onto the surface of our retina
- optic flow: when we move our head the angle the light rays hit the retina changes, gives us critical information about our position and the position of object when in motion
time-to-contact information
- also know as Tau
- is directly proportional to the size of the retinal image (A) divided by the rate of change in size of the image (Å) multiplied by a constant (b)
- area of retina covered by light rapidly increases as object gets closer
how we detect direction of movement of objects
- light reflected from edges of objects change at different speeds when not on a direct path towards us
- ability to detect angle of movement is carried out by detecting angle of optical array
- if an object is approaching us at an angle, one side of optical array will travel toward us at a faster rate than the other side
balance - moving room experiments
- children lose balance easier than adults
- conflict between visual information and information sensed by vestibular system
- children have less visual-vestibular integration skills
- when wall was pulled away from them, they’d lean towards it, if the wall was pushed toward them, they leaned away from it based on input from peripheral vision
effects of vision on motor control
- used to provide feedback so relatively quick adjustments can be made to movement program without processing
- some reaction for muscle activity in moving wall study was within 100ms, and could not have been consciously processed
effects of audition on motor control
- less understood than vision, mainly explored as vision-audition conflict
- audition contributes to predictive judgements, eg. tennis, baseball
- delayed, masked, or distorted auditory information can disrupt motor control
- high level participants often use audition to predict what will occur, but what they hear and see can cause conflicting predictions and inhibit their processing
- grunting in tennis players, did studies using white noise ad cause interaction with time of contact prediction
proprioceptive informaion
- sensory information about the position of body in space
- proprioceptive sensing includes: vestibular system, sensory organs in the muscles and joints, and cutaneous receptors (haptic feedback)
vestibular system
- important for balance and orientation
- located in the inner ear: semicircular canals and otolith organs
semicircular canals
- three fluid-filled half-circles, each aligned with one of the horizontal (transverse), sagittal and frontal places
- can sense direction and rotation
- uses hair cells as mechanoreceptors
otolith organs
- provide information about orientation of the head with respect to gravity
- utricle and saccule sense linear accelerations
muscle receptors
- muscle spindles are located within muscle fibres, also known as intramural fibres, function to detect muscle stretching
- afferent sensory nerves go from muscle to spinal cord, efferent motor nerves go from spinal cord to muscles
- Golgi tendon organs are located in tendon, senses muscle tension by detecting tendon stretch, tries to protect muscle by inhibiting too much muscle contraction
joint receptors
- embedded in joint capsule, primarily located in areas of the capsule that are stretched the most
- neural signals are strongest at the end ranges of joint movement
- less involved in position sense than muscle spindles
proprioceptive closed-loop control feedback loops
- M1 feedback loop is from muscle spindles detecting fibre stretching via afferent neurons to spinal cord, takes 30-50ms
- M2 feedback loop is from golgi tendon organs responding to tendon stretch indicating muscle contraction, takes more time and has more steps, goes from muscle to motor program
proprioception is processed in..
primary somatosensory cortex
- integrates info from all sensory organs to provide context to brain
haptic receptors in skin
- free nerve endings (pain, temperature)
- meissner’s corpuscle (touch)
- pacinian corpuscle (pressure)
open loop system
carries out motor program as planned with no opportunity to make adjustment once movement has occurred, seen in discrete and serial skills
cocktail-party effect
- a phenomenon of attention in which humans can attend to a single conversation in a noisy environment, neglecting most (but not all) other inputs
- developed from an experiment by Cherry, using dichotomous listening
- participants were able to identify some surface features of the message from the unattended ear such as the speaker’s
gender and loudness - illustrates that even some unattended features of sensory processing are processed in parallel with other attended information in the very early stages of sensory processing
conscious processing
- slow
- attention demanding with interference caused by competing processing
- serially organized, with a given processing task coming before or after other processing tasks
- volitional, easily halted or avoided altogether
- relatively effortful, controlled processing is a very large part of conscious information-processing activities involving mental operations among relatively poorly learned, or even completely novel activities
automatic processing
- fast
- not attention demanding, in that such processes do not generate very much interference with other tasks
- organized in parallel, occurring together with other processing tasks
- involuntary and often unavoidable
- most effective for closed skills, where the environment is relatively predictable
developing automaticity
- Schneider and Shiffrin found that practice and lots of it was an important ingredient in developing automaticity
- automaticity gradually develops and most effectively under a “consistent-mapping” condition, where the response generated was related consistently to a particular stimulus pattern
- in contrast to a “varied-mapping” condition, where a given stimulus sometimes leads to one response and sometimes to a different response
probe-task technique
- researcher would have participant perform one tasks, could be discrete or continuous, at some unexpected point in the performance of the primary task, the researcher would probe the attention it demanded by presenting a second task, usually a discrete stimulus such as tone or light, now the participants additional task would be to respond to the probe stimulus as rapidly as possible with either a manual response or vocal response and RT would measure the delay in responding to the probe
- researcher would use the RT to the probe as a measure of the attention demanded by the primary task; a more attention-demanding task would result in slower RTs to the probe stimulus
constrained action hypothesis
conscious vs automated performance
- underlying idea was that a conscious, moment-to-moment type of movement control is typical of less skilled performance and that a more free-flowing, automated type of movement control is typically of skilled performance. They theorized that consciously controlled movements were typical of an internal focus of attention and that automated movement control was used in externally focused performances
choking
- typically occurs when as the pressure builds to perform well in a critical moments, athletes who choke often shift from performing in an overlearned, automatic type of external attentional focus to thinking about how to perform the movement, or how the movement will feel when performed, this shift to an internal focus changes how movements are controlled, reducing performance quality
ironic effects
- the tendency to do something you are trying not to do
- the influence of negative thoughts on motor control are largely considered to be the end-result of a specific internal focus of attention
perceptual narrowing
- the tendency for perceptual field to shrink under stress
- attention ends up devoted to the expected or important aspects of the task and increased focus on those sources of information most pertinent to or expected in the task
- this is an important mechanism because it allows the person o devote more attention to those stimulus sources that are immediately most likely and relevant
- not limited to vision, apparently occurs with each of the senses in an analogous way
- optimal level of arousal is presumably one in which the narrowed attentional focus excludes many irrelevant cues yet allows most of the relevant cues to be detected
feedforward information
- represents anticipated sensory consequences of the movement that should be received if the movement is correct
