Week 7 Lecture Flashcards
In the human information processing as a computer metaphor:
- Sensory systems take in information from an _________________ source
- Perceptual processes lead to creation of some form of symbolic representation of ________________ and __________________
- Information is compared with _____________________________and processed for learning
- Speed of processing determines when _____________ occurs
- Information output can result in various kinds and qualities of ________________.
- Sensory systems take in information from an EXTERNAL source
- Perceptual processes lead to creation of some form of symbolic representation of ENVIRONMENTAL and TASK
- Information is compared with EXISTING MEMORY STORES and processed for learning
- Speed of processing determines when OUPTUT occurs
- Information output can result in various kinds and qualities of MOVEMENT.
see slide 5
see slide 5
stimulus identification (perception) –>
response selection (decision making)
response selection (decision making) –>
response execution
what is an example of stimulus identification:
icy sidewalk
What is an example of response selection:
take smaller steps
What is an example of response execution:
decrease push-off in gait
stimulus identification =
receptors transform stimuli into coding impulses
What are 3 coding impulses of stimulus identification:
- frequency (or rate) coding
- temporal coding
- population coding
perception –>
meaning is assigned to stimuli
What 3 components of of perception:
- pattern recognition
- stimulus features
- predictive capablities
Response selection compares choices from existing:
motor memory stores
In response execution, the CNS may organized the following details:
- muscles to perform the task
- temporal onset of muscle action (relative timing - e.g. from GMP)
- muscle organization force / duration (parameters)
Output =
organized movement response
Movement preparation takes __________ time.
finite
Reaction time (RT) =
between “go” signal and response initiation
movement time (MT) =
between response initiation and response termination
response time =
from “go” signal to response termination
foreperiod =
between warning signal and “go” signal
what is the most common measure of cognitive performance/ information processing with movement?
reaction time
Does reaction time include the movement itself?
no
signal may be a sound, light, snap of a football…
Why use reaction time?
can be used to infer multiple characteristics of movement
What characteristics of movement can reaction time be used to infer?
- mental processing
2. situation recognition - recognition of environmental hazards, interaction with the EN
simple RT =
one signal, one movement
choice RT =
> 1 signal, different response for each signal
discrimination RT =
> 1 signal, one response
What type of RT situation has the fasted RT time?
simple RT
Which is the most difficult RT situation?
discrimination Rt
Where can the system break down in pts in perceiving sensation?
- lack of peripheral sensation - e.g. diabetic neuropathy
* perception of sensation - parietal lobe lesions
Where can the system break down in pts in response selection?
• brain injury, vestibular lesions
Where can the system break down in pts in response execution?
- slowed movement - Parkinson’s Disease
* musculoskeletal pain
List some Task/Environmental factors that influence movement preparation during stimulus identification:
- stimulus intensity
- stimulus type
- stimulus predictability
List some Task/Environmental factors that influence movement preparation during response selection:
- stimulus-response compatibility
2. number of choices
List some Task/Environmental factors that influence movement preparation during response execution:
- movement complexity
2. accuracy demands
visual stimulus (light) RT =
~ 200ms
auditory stimulus (buzzer) RT =
~180ms
Force-period (FP) =
time between warning signal and Go signal
RT improves with (during FP) =
- time predictability and
* stimulus predictability
Time predictability =
optimal force-period length (1-4 seconds)
Stimulus predictability =
- football snap signals
* orchestra downbeat
FP is dependent on attention:
if you divert attention b/n the pre-cue and the signal to move, the benefit of the pre-cue is lost
RT increases as foreperiod interval increases e.g. longer the Foreperiod length, __________________________ .
the longer the RT to stimulus (‘go’ signal)
stimulus-response compatibility =
extent to which stimulus and response naturally related
If stimulus-response compatibility is low –>
increased preparation time
If stimulus-response compatibility is high –>
decreased preparation time
A decision making study of simple vs choice RT found (right finger on button; finger on button):
- press right when right light comes on
* press left when left comes one
Hick’s law =
as number of choice increases: reaction time increases
Specifically hick’s law found:
as the number of decision increases, RT increases by about 150 ms.
RT increases nearly linearly as # of stimulus-response choices:
DOUBLES
What is the biggest influence on movement time?
interval between start and completion of movement
(Movement time) When used in conjunction with RT measures can determine whether movement is being planned in:
advance of movement or during execution
Rapid movements (
advance planning
Greater accuracy demands required:
increased amount of preparation time
What is the logarithmic speed/ accuracy tradeoff (3 factors interact):
- how far you have to move
- how fast you move
- how accurate you need to be
Fitt’s law =
MT = a + b log2(2D/W)
MT =
movement time
D =
distance moved
W =
target size
Average _____________________ increases as _________________ increases and ____________________ decreases.
Average MOVEMENT TIME (MT) increases as MOVEMENT AMPLITUDE (D) increases and TARGET WIDTH (W) decreases.
log2 (2D/W) =
index of difficulty
index of difficulty =
as targets get smaller or farther apart, the movement time gets longer)
the index of difficulty can be applied to:
- aiming tasks
- reaching / grasping
- piano playing
- pegs into holes … etc
(Fitt’s law) How does this apply to movement (action) preparation?
- need to prepare movement goal (do i go fast or do I try to be accurate)
- need to select program for ballistic movement
- need to prepare how to stop (example of putting a key into a keyhole)
(influence of instruction type) If emphasize speed, movement latency will:
decrease at the cost of accuracy
(influence of instruction type) If emphasize accuracy, latency will:
increase but accuracy improves
If the level of arousal is too high, at a certain level, the quality of performance:
decreases
True or false: Level of arousal can be too high or too low?
True
The optimal level of arousal depends on difficulty of task. Higher arousal for _____________ tasks to reach maximum performance ; lower level of arousal for _____________ task to reach maximum performance.
Higher arousal for EASY tasks
(slightly) Lower arousal for HARDER tasks
Performer characteristic influencing movement preparation is TASK EXPERIENCE. For this there are 2 types of attention focuses:
- signal (sensory set)
2. movement (motor set)
Signal (sensory set) =
focus on sound of gun (signal)
movement (motor set) =
focus on moving as quickly as possible (movement required)
Sensory set RT __________________ motor set RT by ~20ms
faster than
Age is a performer characteristic influencing movement preparation. RT more variable with age (not just speed of mental processing). Older adults:
- are more thorough with response monitoring
* tend to attend to one stimulus, ignore another
Sleep is a performer characteristic influencing movement preparation. Deprivation causes:
longer RT and missing stimuli (24 hours sleep deprivation lengthened RT of 20-25 year old subjects; no effect on 52-63 year old subjects)
RT gets longer with mental ___________.
fatigue
but not muscular fatigue
Physical fitness is important more fit =
faster RT (attributed to increased arousal)
Distraction is a performer characteristic influencing movement preparation.
Background noise decreases RT by:
inhibiting parts of cerebral cortex
…. cell phones
Evidence shows that the perception of increased productivity when multitasking is a _____________.
fallacy
Up to 50% of all motor vehicle accidents (MVA) can be related to:
driver inattention
85% of cell phone owners use while driving. True or false?
True
_______% of people in MVA’s used cell phone within 10 min prior to accident
24
Driving simulator studies showed drivers missed ______________ more traffic signals while on phone and RT significantly _____________.
2x
longer
Is there is a significant difference between hand-held and hands-free cell phone use?
NO
Thus, it’s not that your hand is off the wheel, but that your MIND is distracted
Drivers also show movement coordination problems with:
hands-free unit
Accident risk when using cell phone while driving is 5.36X ______________ than undistracted driver
greater
the same as drivers with BAC = 0.8, the legal limit for DUI
Texting is even worse:
accounting for 25% of all driving accidents
Surveys show that a high percentage of drivers have the belief that the law of attention does not apply to them. True or false?
True
i.e. they have seen others impaired by multitasking but they, themselves, are the exception
Increase size, contrast, and or intensity of stimuli for:
identification
Practice under a variety of:
stimulus conditions
If possible:
simplify the movement
Pre-cue pts on:
what to expect
Teach patient to anticipate=
problem solve potential obstacles or hazards
