Sensation & Perception Flashcards
What is sensation?
The process by which the dense organs gather information about the environment
What is perception?
The process by which sensory information is selected, organised and interpreted
What is transduction?
Turning environmental energy into neural impulses
Sense receptors can ‘transduce’ stimuli into signals
What is sensory adaption?
Activation is greatest when we first detect a stimulus, after this, the response declines in strength
What is the absolute threshold?
Is the lowest level of a stimulus (on its own) that we can detect 50% of the time
What is JND (just noticeable difference)?
Smallest change in intensity that we can detect
Our ability to distinguish a stronger stimulus from a weaker stimulus
Depends on the level of intensity of the new stimulus and the level of stimulation already
What is the Weber-frechner law?
Regardless of the magnitude of two stimuli, the second one must differ from the first by a constant proportion for it to be perceived as different
The stronger the stimulus is the bigger the change needed for a change in stimulus intensity to be noticeable
Signal detection theory?
Sensation occurs when we judge whether a stimulus is present or not
There are two processes that contribute to signal detection
Initial sensory process which is sensitivity to the stimulus
Decision process the individuals readiness to report detecting a stimulus when uncertain
What is selective attention
Allows us to select some input for further processing and ignore others
What is Broadbents bottleneck theory of attention
Allows us to pay attention to certain stimuli and ignore others it’s an early filtering mechanism
Messages or stimuli go into a selective filter before going into a limited capacity decision channel
This is where it is decided if the stimuli will go into a long-term memory store
What is the cocktail party phenomenon
Suggest that some information gets through the filter even when we are selectively attending to a conversation we are subconsciously monitoring other conversations around us can suddenly switch of attention if it is relevant
What are the errors of attention
Inattentional blindness which is the failure to see something in plain sight
Change blindness which is the inability to detect changes in scenes when looking directly at them
Can we really multitask
No we shift our attentional resources between the tasks. The more efficiently we do this the better we can multitask
What is top-down processing
Prior knowledge and experience organises our perceptions by selecting specific features that meet our expectations to form a perception
What is bottom up processing
We detect features of sensory features analyse specific features and combine component parts into a whole to form a perception
What are perceptual sets
We group things together that go together within a context
What is perceptual constancy
A tendency to perceive objects as perceptually stable despite any variation in stimulation of sensory receptors
Shape we recognise as an object as having the same shape when viewed at a different angle
Size objects do not differ in size when viewed from different distances
What are Gestalt principles
The rules describing how elements are organised into groups or unified wholes
Analysing an image in the context of its surroundings and our expectations
What are the Gestalt principles
Simplicity Proximity Similarity Continuation Closure Symmetry Figure ground
What is proximity
Objects that are close together tend to be recognised as a whole
What is similarity
We see similar objects as being a whole
What is continuation
We still perceive them as whole even when other objects block a part of them
What is symmetry
We perceive objects that are symmetrically arranged as whole
What is figure ground
Instant decision to focus attention on what we believe to be central and ignore the rest
What is motion perception
There are two types
The eye is stationary as the object moves on the Retina
That eye moves to maintain object as same place on the retina
What is depth perception
The organisation of perception into 3-D
There are two kinds of visual cues that enable us to judge depth and distance these are monocular cues and bonocular cues
What are binocular cues
It is the visual input from two eyes
What is retinal disparity?
Degree of overlap between the retinas in each eye
What is convergence?
Eyes converge at small distances but our brain is aware of how much and uses this to calculate distance
What are Monocular cues
It’s when only one eye provide visual input
What are we able to gather from monocular cues
Relative size texture gradient Height in plain motion parallax linear perspective Interposition shading
What is synaesthesia
Different perceptual experiences can be produced by cross modal processing or overlap in brain areas
these include hearing colour and tasting shapes
What is subliminal perception?
Processing of sensory information that occurs below the level of conscious awareness
Can have a brief short-term impact on behaviours and attitudes. our subconscious is aware
Subliminal persuasion effects?
Fairly unlikely to produce large scale or enduring attitudes
Happens below the level of conscious awareness
Extrasensory perception (ESP)?
The perception of events outside of the known channels of sensation
What is precognition
Predicting events from the future
What is telepathy
Aware of others thoughts
What is clairvoyance
Can predict the future
