Motor and attention
- Created by: becky_99
- Created on: 27-12-19 00:00
Sebanz & Shiffrar (2009)
Two experiments were conducted to determine how well experienced and novice basketball players can distinguish a fake pass from a true pass based on various types of information.
Experiment 1 - compared deception detection from static and dynamic cues.
- Static = still
- Dynamic = moving
Experiment 2 - investigated whether dynamic cues alone are sufficient for the detection of deceptive intention.
Sebanz & Shiffrar (2009)
Participants:
- 30 participants were recruited for this experiment
- 12 were experts who had been playing basketball for an average of 12.4 years (9 male, 3 female - mean age of 21.3 years)
- 10 were novices (10 males - mean age of 26.0 years)
- Experts reported playing for 3.4 hours per week and watched 3 games per week
- Novices reported watching 0.7 games per week
Movie stimuli condition:
- Basketball player filmed interacting with two other people - "teammate" and "defender", which was then edited
- 30 convincing fakes, 30 passes
- Movies ended one frame before a pass or fake was completed
- 1/3 displayed overhead passes, 1/3 displayed chest passes, 1/3 displayed bounce passes
- Average movie length was 1.9 seconds
Sebanz & Shiffrar (2009)
Design:
IV: expert/novices; dynamic movie/static picture
DV: % correct responses
Procedure:
- Task: participants reported whether the player intended to pass or fake
- Black cross for 100 m/s followed by movie or picture
- Static pictures displayed for 4 seconds and participants had an unlimited response time window after the pictures disappeared
- Pressed "P" for a pass, "F" for fake
- At the end, participants responded to two open questions describing what kind of strategies they had relied on
Sebanz & Shiffrar (2009)
Results:
- Experts and novices were all significantly above chance (50%) in both conditions
- Experts were better than novices in the movie condition
- Experts were no different to the novices in the picture condition
Motor systems
Cortical motor areas:
- Primary motor area
- Supplementary motor area
- Premotor cortex
- Prefrontal cortex
Subcortical motor areas:
- Basal ganglia
- Cerebellum
Central & peripheral nervous system:
- Reflexes
Main functions of the motor system?
- Action planning
- Action execution
During the preparation of the action: planning the action (e.g. direction) may include imaging actions.
During the execution of actions: force, direction, timing.
Both preparation and execution of actions are handled differently depending on whether the task is a well-learned vs. novel task.
The Homunculus man
Our primary motor and sensory cortex explained.
The Homunculus man is a representation of the relative proportion of our body segments as they appear in our motor and sensory cortex.
fMRI images show that neurons aren't exclusively organised. There is some overlap of neurons in relation to the somatotopic ordering.
Neural efficiency of the primary motor cortex in e
Naito & Hiros (2014) - efficient foot motor control by Neymar's brain.
Much like the earlier discussion on intelligence, these results suggest that neural efficiency occurs as a result of exposure to motor planning and execution.
This could mean less energy spent on movement, more energy spent elsewhere.
Supplementary motor area (SMA)
The role of the SMA is in programming or mental rehearsal rather than simply executing movements.
When performing a complex movement sequence with the fingers, neural activity, as measured by cerebral blood flow, increased in:
- Primary motor cortex
- Supplementary motor area (SMA)
However, when subjects were told to rehearse the finger sequence mentally without executing it, neural activity increased only in the SMA.
Role of SMA and the premotor cortex
Executing a well-learned action vs. executing an action that is unfamiliar.
The premotor cortex: selectively activated when subjects prepare movements under the guidance of external cues, such as visual, auditory, or somatosensory cues.
The supplementary motor area: involved in preparing complex movement sequences that are already learned, or that require complex coordination.
Cerebellum
Functions:
- Fine-tunes actions
- Uses sensory feedback to adjust the motor programme if needed
- Cerebellum patients appear to be drunk (because the cerebellum is affected by alcohol)
- They are unable to fine-tune their actions (e.g. slurred speech, staggering gait)
Subcortical motor areas of the brain
Basal ganglia:
- Regulates the excitability of the motor and premotor cortex
- Biases the likelihood and nature of movement
Cerebellum:
- Coordinates timing and trajectory of movement using sensory and motor information
- Uses sensory feedback to adjust the motor programme if needed
Basal ganglia
Functions:
- Initiate appropriate actions
- Inhibit inappropriate actions
Parkinson's disease:
- The pathology: loss of dopamine-producing cells in the substantia nigra, which is part of the basal ganglia
- Symptoms: tremours; slow movements; rigidity; poor balance; changed walking pattern
Ultimately, action means contracting muscles, or preventing muscle contraction:
- Muscle reflexes
- Primary motor cortex - execute actions
- Other frontal lobe areas - plan and execute
- Basal ganglia and cerebellum = modulate and fine-tune actions
Proprioception
Muscles contain proprioceptors that sense different aspects of the muscle state.
Muscle spindles: stretch receptors; very sensitive to changes in length of the muscle.
Golgi tendon organs: sensitive to changes in tension (force) exerted by the muscle.
Primary motor cortex
Provides the most important signals for the production of skilled voluntary movements.
What aspects of movement are controlled by the activity of neurons in primary motor cortex?
- Force
- Direction
- Speed/timing
Attention to doing things:
- Attention to action: automatic vs. controlled processing; dual task situations (Strayer & Johnston, 2001)
Primary motor cortex
Attention to the environment - perceptual attention/spatial attention:
- What automatically captures attention? (Attentional capture, spatial cueing)
- What doesn't (Inattentional blindness)
- Directing spatial attention
Attention means many things
- Focusing on a lecture - concentration
- Driving a car - attention to guide actions
- Doing two things at once - divided attention
- Doing things without needing attention anymore - automaticity
- Listening to a conversation in a noisy room - selective attention
- Searching for the mustard in the refrigerator - visual search
Attention to action
Automatic vs. controlled processing:
Automatic processing:
- Attention is not required to execute an action
- Automaticity achieved through practice
Controlled processing:
- Attention is required to execute an action
- What types of situations require controlled processing?
Attention to action - Norman & Shallice (1980s)
Controlled processing needed for:
- Situations requiring planning or decision making
- Novel or unfamiliar situations
- Dangerous or highly important situations
- Situations where a habitual, or well-learned response must be overcome
Stroop task - Stroop (1935)
In the incongruent condition, did naming the ink colours use controlled processing or automatic processing?
- Controlled processing
Why?
- The automatic response is to read the words
- This habitual response must be overcome
Why is reading automatic?
- Most people have had a huge amount of practice
Automatic responses, such as reading, can therefore with less learned tasks, such as ink colour naming.
Controlled processing is required to overcome the automatic response.
What is the orienting response?
This is when attention is pulled automatically to a new location.
What automatically captures attention?
- Abrupt onset of noise or new object
- Motion
- Eye gaze
So:
- We notice some changes in our environment but not all
Spatial cueing task - Posner (1980)
"Valid cue" trials are when the asterisk occurred on the same side as the target.
"Invalid cue" trials are when the asterisk occurred on the opposite side as the target.
Spatial cueing task:
- Valid cues produce faster RTs than invalid cues
- This is true even when the participant knows that the cue has only a 50% chance of correctly predicting the target (non-predictive)
Task with eye gaze cues:
- Valid cues (eyes look toward target) produce faster RTs than invalid cues (eyes look away from target)
- This is true even when the participant knows that the cue has only a 50% chance of correctly predicting the target (non-predictive)
Spatial attention
"Spotlight" metaphor.
Attention can be "overt" or "covert".
Overt attention - attention focused where the eyes are focused.
Covert attention - attention focused on a different location from where the eyes are focused.
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