5- Learning: Perceptual learning in adulthood Flashcards
What is this term describing?
an active process which describes the increase in the ability to extract information from the environment, as a result of experience and practice with stimulation coming from it.
Perceptual learning
-with practice, individuals can achieve high levels of perceptual expertise in detecting and distinguishing sensory stimulation
Perceptual learning is prevalent in everyday life
Name some examples in the natural world:
Identifying injury and disease in x-rays and brain scans
Bird watching – visual and auditory learning (multisensory)
Categorical discriminations (e.g. faces belong to different races, colour categories)
Perception of most, if not all, visual attributes improves with practice
Name Characteristics of perceptual learning:
sleep
error correcting feedback
complex
task difficulty
active process
task, stimuli
initial performance levels
permanent
adaption is an unconscious inference. It does not refer to learning, as learning is an…
active process
The amount of learning is determined by the…
initial performance levels
There is more learning on which type of tasks?
complex tasks
Perceptual learning does not require which type of feedback?
error-correcting feedback
The perceptual benefits of learning are often specific to the … and … used during training
task, stimuli
The degree to which learning transfer to other tasks and stimuli is determined by …?
task difficulty
The perceptual benefits of learning are relatively … , and can be retained over many years
permanent
What has a critical role in the consolidation of perceptual learning?
Sleep
Perception on very simple perceptual tasks improves with practice.
Name 3 types of discrimination task:
1- Vernier (position) discrimination
2- Orientation discrimination
3- Stereoscopic depth discrimination
Which type of task is this?
Present 2 slightly displaced bars. Person has to guess which bar is to the top of left or right, over trails reduce this displacement to where it is no longer possible. The minimum displacement between 2 bar which a person can correctly identify.
Vernier (position) discrimination
Which type of task is this?
2 oriented patterns presented. person needs to identify whether the stimuli is to the left or the right of the target. Through trials, amount of orientation is changed until P determine minimum threshold difference.
Orientation (tilt) discrimination
Which type of task is this?
Stereoscopic (depth) discrimination
There is more perceptual learning on complex tasks:
Compared amount of learning in 16 studies in humans using simple to more complex tasks.
Their findings showed tasks using stimuli with … showed more learning than low level tasks
Which Complex tasks showed more learning?
external noise
tasks that required discriminations along more perceptual dimensions
Amount of learning inversely related to initial performance levels:
Researchers measured the relationship between subjects initial level of performance on a Vernier discrimination task and the amount they learnt on the task.
What did they find?
Found a linear relationship
-The poorer a subject’s’ Vernier discrimination performance was before training, the more they learnt on the task
-Doesn’t matter what your threshold is, it about your starting point of how good or bad you are.
Perceptual learning is specific to the trained task and stimuli:
Rationale for Transfer Experiments
Subjects repeatedly practice and improve their visual performance on a task over several training sessions
After period of time, the task (e.g. detection, discrimination) or stimulus (e.g. position, orientation) is changed to test for …?
What are the three potential outcomes?
transfer of learning (train for the right visual field instead of left visual field)
No transfer of learning
Partial transfer of learning
Full transfer of learning
The amount of transfer (or generalisability) is determined by difficulty of the task:
Research: Ahissar and Hochstein (1997) investigated the degree to which learning on a visual search task transferred between “easy” 35* discrimination threshold and “hard” versions of the task.
When did Full transfer and no transfer of learning occur?
Full transfer of learning occurred:
-between “easy” initial training and subsequent “easy” transfer tests in which target and distractors differed by 30 degrees
No transfer of learning occurred:
-between two difficult tasks in which target and distractor orientation differed by 16 degrees
Evidence for the claim that perceptual learning is specific to the trained task and stimuli
practice improved grating phase discrimination, but learning did not transfer to gratings rotated by 90 degrees
Poggio et al (1992) - described a similar orientation specificity for Vernier discrimination
Specificity for retinal position and eye used during training was found on a figure-ground texture discrimination task (Karni and Sagi, 1991)
Learned improvements did not transfer between very similar position discrimination tasks
Perceptual learning does not require error-correcting feedback:
info slide
Improvement through learning in visual tasks is possible even in the absence of external error feedback
Partial feedback (on half of trials) produces comparable learning to that with complete feedback
These findings pose difficult problems for neural models of perceptual learning
So the feedback speeds up your learning (might be slower without error-correcting feedback)
Sleep has a critical role in the consolidation of learning:
Learning is often so fragile immediately after training, it is necessary to allow processing time - period known as what to make it permanent?
consolidation
Perceptual benefits of learning are retained over many years:
With sufficient training, there is very little forgetting of the learned improvements on a visual discrimination task
Learned improvement on a figure-ground texture discrimination task were retained for how many years?
2-3 years
Sleep has a critical role in the consolidation of learning:
Depriving subjects of which 2 sleep stages nullifies learning on perceptual tasks?
slow-wave sleep (SWS)
and
rapid eye movement (REM)
