MODULE 8: Information Processing (KPE160)

what is the sensory-motor processing model

it describes how the nervous systems..

• takes in sensory info

• processes it

• produces a movement

what are the 3 stages of sensorimotor processing

input → processing → output

what is the input stage

refers to the information received and collected by the PNS

• which allows the body to detect what is happening around it

what is the processing stage

where information is processed in a series of steps

1. stimulus identification

2. response selection

3. response programming

what do the 3 processing stages entail

1. stimulus identification - what is happening

2. response selection - what should i do

3. response programming - how should i do it

what is the output stage

when the motor response (based on processed sensory information) is executed based on the brain’s motor commands

what is sensation

low-level, neural and biochemical detection of changes

• detects a change

• involves the receptors / spinal-cord

what is perception

high-level, interpretation of what the detected stimulus means

• identifies what the change is

• involves the brain areas / memory systems

how does sensation occur

detecting the presence of a stimulus

• ex. notici

how does perception occur

by forming / activating a representation to determine what the stimulus is

which senses provide environmental input

• vision (dominant for spatial info)

• hearing

• smell (olfaction)

• taste (gustation)

which senses provide information from inside the body

1. somatosensory system

   1. touch

   2. proprioception (muscle length, joint position)

      1. where your body is in space

   3. internal cues (ex. blood pressure)

2. vestibular system (located in the inner ear)

   1. head orientation

   2. balance

why does movement rely on multiple senses

because accurate movement requires the brain to combine information from many sensory systems

what is a “representation” in the brain

a neural code for a specific concept, object or action

how does the brain “create” a representation

by activating a specific set of neurons / neural networks which correspond to that concept or object

what decides which neurons fire during a representation

existing knowledge and past experiences

• the brain activates the neurons that have coded that object before

types of memory

1. short-term (“working”) memory

2. long-term memory

what is working memory

a temporary storage and manipulation system

• which holds information just long enough to complete a task (seconds)

types of working memory

1. verbal - repeating a phone # so you don’t forget it

2. visuospatial - keeping a flashed pattern or shape in mind after it disappears

3. motor - remembering brief target locations to guide a reach or movement

limitations of working memory

it has limited capacity so information decays quickly

• if you forget then the information is lost

what is long-term memory

a system for long-lasting storage

• which can hold information for hours, years or a lifetime

what does long-term memory require

1. encoding - transforming information into a stable long-term memory trace

2. storage - keeping that encoded information in the brain over time

3. retrieval - bringing stored information back into working memory so you can use it

subsystems of long-term memory

1. semantic (facts, knowledge) - paris it the capital of france

2. episodic (events) - remembering a specific event, like a birthday

3. procedural (skills, habits) - riding a bike automatically

why do we select and prioritize information

because our information-processing capacity is limited so we can’t process everything at once

what is selection and prioritization

by choosing which information to process first and which to ignore (based on importance)

how do we select and prioritize information to process

1. limited capacity

2. attention can be shifted

3. attention can be divided

how can attention shift

1. voluntarily (you choose to refocus)

2. reflexively (when attention is pulled by something sudden / important)

how can attention divide

it can divide but performance becomes worse because resources are limited

• errors increase, response slows or information is missed

what does “limited capacity” mean

that you can only process a small amount of information at one time

what is distractor interference

when non-target information (irrelevant stimuli) is also processed which makes it harder to select and process the target

• ex. stroop effect (word meaning interferes w/ naming ink colour)

why does distractor interference hurt performance

it uses up capacity which hinders/slows down the processing of the correct target

what is inattentional blindness

when a person fails to notice even very obvious information

• because their visual attention is focused on something else

why does inattentional blindness happen

because attention is limited, when it’s fully focused on one task, there’s no remaining capacity to process unexpected events

• we do not process everything we see

• visual attention is selective

what is change blindness

a reduced ability to notice changes in the environment because one’s attention and working memory are limited

why does change blindness happen

often times changes go undetected even if they’re important because..

• attention cannot capture every detail

• working memory cannot store all visual information

• ex. someone shirt colour changes but you didn’t notice bc your attention is on the dialogue

what is the response selection stage

where the brain decides which action to perform

• when there are multiple possible responses

what happens during response selection

there are several possible actions which compete

• the brain chooses the action w/ the highest chance of achieving the goal

• brain must inhibit inappropriate or unwanted responses

• requires cognitive resources (working memory)

why is working memory needed in response selection

to hold and compare possible action plans before choosing one

product of response selection

a general motor plan

• the chosen action

• but not yet parameterized (detailed)

what is the end-state comfort effect

planning movements so that the final position is comfortable and efficient for completing the goal

what is the response programming stage

when the brain turns the chosen action into a specific motor program

what happens during response programming

the general motor plan becomes a specific motor plan which considers..

• direction, amplitude (size of movement), end point, force, velocity, timing

what is a motor program

a detailed representation of timing and forces of muscles contractions that are needed to achieve the movement

how is a motor program executed

it is converted into a sequence of action potentials

• which is then sent to muscles to produce the movement

why are motor programs like computer code

because they contain pre-planned instructions that run in a specific order to produce the desired output (movement)

where are motor programs represented in the body

represented by distributed neural networks which are found through the CNS

what must the brain specify

1. which muscles are involved (to coordinate correctly)

2. the order in which they activate (smooth movement)

3. the relative force each muscle should produce

4. the timing + sequencing of contractions (accuracy of movement)

5. how long each contraction should last

what is an open-loop system

a system where the movement is based only on the motor program with no adjustments during the action

why are there no adjustments in an open-loop system

because once the motor program is running, the movement cannot be corrected (so no feedback is used)

when is an open-loop system used

for fast, automatic or ballistic movements (ex. throwing, kicking)

• basically instances where there’s no time for feedback

what is a closed-loop system

a system where movement uses feedback to check performance and make corrections during the action

• which improves accuracy + helps the brain learn from every action

why does a closed-loop system use feedback

because if the movement isn’t achieving the goal, error detection triggers adjustments

when is an close-loop system used

for slow, continuous or precision movements (ex. balancing, tracking, writing)

how does # of alternatives responses affect RT

idea that RT increases as the # of alternatives increase

• think hick’s law (which proves this scenario)

what is stimulus-response compatibility

how naturally a stimulus matches its response

how does stimulus-response compatibility affect RT

1. high compatibility = easier pairing = faster RT

2. lower compatibility = increase RT

   1. its harder to select the correct response

   2. more decision-making required

what is response complexity

how complicated the required movement is

• consider # of muscles, movement parts and sequencing

how does response complexity affect RT

where RT time increases as response complexity increased because..

• there are more muscles involved

• more movement components

• a larger + more detailed motor program

which takes longer to prepare = increased RT

why does practice reduce RT

because practice makes each stage of information processing faster, more automatic and more efficient

how does practice improve stimulus identifcation

practices increases your knowledge and experiences with stimuli so you can..

• recognize important cues faster

• be able to ignore irrelevant information

which allows for faster identification = reduced RT

how does practice improve response selection

practice builds stronger links between a specific stimuli and response

• which gives a better understanding of the range of possible actions

this makes choosing the correct response faster + more automatic = reduced RT

how does practice improve response programming

practice increases efficiency in specifying movement parameters like..

• timing, amplitude, force, velocity

better programming = faster movement preparation = reduced RT

why do we care about factors that affect RT

because understanding them helps us..

• design safer technology

• improves sport performance

• reduces error

• makes environments more user-friendly

how do reaction-time principles apply in real life

1. # of alternatives → where more choices = slower RT

   1. design environments to limit options

   2. sport strategies aim to reduce opponents’ choices

2. S-R compatibility → makes controls/settings logical and intuitive

3. response complexity → more complex actions = slower RT

4. practice → use context-specific training to make responses automatic