Perception & Attention Flashcards
Define sensation
The stimulus detection system by which our sense organs respond to and translate environmental stimuli into nerve impulses that are sent to the brain
Define perception
The active process of organising the stimulus output and giving it meaning
Describe top-down perception
Processing in light of existing knowledge
Motives, expectations, experiences, culture
E.g. ‘backmasking’
concepts, grammar -> expectations
Describe bottom-up perception
Individual elements are combined to make a unified perception
vibration of the tympanic membrane + activation in the auditory cortex
Which factors affect perception
Attention Poor experiences Current drive state e.g. arousal Emotions Individual values and expectations Environment Cultural backgrounds
Give examples of Gestalt laws
Figure-ground relations
Continuity
Proximity
Closure
What are figure-ground relations
our tendency to organise stimuli into central or foreground and a background. Focus of attention becomes the figure, all else is background
What is continuity
When the eye is compelled to move through one object and continue to another object
What is the gestalt law of proximity
Object near each other are grouped together
What is the gestalt law of closure
Things are grouped together if they seem to complete some entity.
Describe visual agnosia
Primary visual cortex can be mostly intact
Patient not blind
Knowledgeable about information from other senses (e.g. if they touch an object then naming is typically simple)
Associated with bilateral lesions to the occipital, occiptotemporal, or occipitoparietal lobes.
What is apperceptive agnosia
A failure to integrate the perceptual elements of the stimulus.
Describe apperceptive agnosia
Individual elements perceived normally
May be able to indicate discrete awareness of parts of a printed word but cannot organised into a whole
Damage to lower level occipital regions
What is associative agnosia
A failure of retrieval of semantic information
Describe associative agnosia
Shape, colour, texture can all be perceived normally
Typically sensory specific e.g. if object touched, then recognised
Damage to higher order occipital regions
What are the steps of object recognition (Humphreys & Riddoch (2001))
- Visual perceptual analysis
- Viewer centred representation
- Visual object recognition system
- Semantic system
- Name retrieval
What is attention
The process of focusing conscious awareness, providing heightened sensitivity to a limited range of experience requiring more intensive processing
What are the 2 processes involved in attention
Focus on a certain aspect
Filter out other information
What are the components of attention
Focused attention Divided attention (paying attention to more than one thing at once)
Which stimulus factors affect attention
Intensity Novelty Movement Contrast Repetition
Which personal factors affect attention
Motives Interests Threats Mood Arousal
Describe the cocktail party effect
We can focus our attention on one person’s voice in spite of all the other conversations
But, what happens when someone says your name in another conversation nearby?
Describe the attention in clinical skills development
Development of mental resources Learning requires explicit instruction through teaching from an ‘expert’, demonstration, and self-observation.
An effective motor programme has been developed to carry out the broad skill but lacks ability to perform finer subtasks with fluency
The skill is largely automatic Rely on implicit knowledge and motor co-ordination, rather than instruction
Whats the consequence of a task being increasingly automatic
Less conscious control available
High levels of stress and anxiety can impact performance
Over half of patient deaths were due to unconscious errors that could be the direct consequence of automatic behaviour
Checks needed to reduce errors
