perception and cognition Flashcards
What are the 4 main ways of studying human cognition?
Cognitive psychology- behavioural evidence
Cognitive neuropsychology- studying brain damaged patients
Cognitive neuroscience- evidence from behaviour and the brain
Computational cognitive science- computational models to further understanding cognition
How does energy become a representation?
Transduction (transforming energy from the outside world into a neural signal) -> Sensation (picking up that raw signal from the outside world) -> Perception (recognising what that signal means).
What is the difference between perception and sensation?
Example: duck and rabbit image. We all sense the same thing but perception differs- it is aimed at getting the best possible sensation of the stimulus
What are examples of top down processing?
Speech segmentation- speakers of a language can hear when one word ends and another begins even though the input is a continuous sound stream- KNOWLEDGE creates the perception of individual words
What are examples of bottom up processing?
sensory input such as sight, hearing, touch, smell and taste
Visual perception is influenced by memory- once you see something in an image you cannot undo this.
What is Helmhotiz’s theory of unconscious inference?
a particular pattern of activation in the retina can be caused by a range of objects, e.g. likelihood principle: we perceive the object that is most likely to have caused that pattern. Thus, judgement is a result of unconscious assumptions (inferences) that we make about the environment and it happens automatically. We see objects in a 3-dimensional world; if there is a chance to interpret an object as 3D, we do. Illusion shows we do not see 2D rectangles as they are but instead the 3D shape of objects.
Briefly list the 6 Gestalt principles (grouping)
Law of: Similarity, Pragnanz, Proximity, Continuity, Closure, Common Fate
What is the Law of Similarity?
things that look similar are grouped together
What is the Law of Pragnanz?
simplest explanation
What is the Law of Proximity?
things that are near to each other seem to belong together
What is the Law of Continuity?
points that are connected are seen as belonging together rather than separate
What is the Law of Closure?
things are grouped together when they seem to appear like one entity; our brain draws the picture even if there are gaps
What is the Law of Common Fate?
grouped together as an object if it moves at the same speed and or direction as a single stimulus
What is categorisation?
The brain has to figure out what the object is and what characteristics make it a member of a category of objects
What are the monocular cues of depth?
Relative size- a person is perceived as smaller when further away- we take distance into account when perceiving size.
Interposition- the overlapped object seems further away
Linear perspective: parallel lines converging in the distance are seen as further away, e.g. railway lines
Arial perspective- the scattering of blue light in the atmosphere- distant items seem more blue, e.g. mountains on clear days, mountains seem closer
Light and shade- we assume light comes from above- perspective changes if an image is viewed upside down- shade is reversed
Monocular movement parallax- when the head moves close, the object moves fast, far objects move relatively slowly