Perception

Question 1

How does how we perceive the world differ between species?

Answer 1

• how a person sees the world depends on how the world is represented in their brain
• what we know about the world comes from senses, under the impression that the information gathered is all there is in the world however other species have different ranges for their senses
• humans see infrared and UV, while some see UV only
• some species hear higher or lower frequencies

Question 2

How does energy become a neural signal/representation?

Answer 2

• transduction to sensation to perception
• transduction: transforming energy from the outside world into a neural signal
• sensation: picking up that raw signal from the outside world, only those that are paid attention to become part of our conscious perception
• perception: recognising what that signal means
• perception and sensation have a feedback loop, more we perceive stimulus the quicker we sense it again

Question 3

What are the 2 types of processing?

Answer 3

• perception is to achieve the best possible interpretation of stimuli and is done by combining the 2 sensations
• top-down sensation: knowledge,culture, experience, memories (e.g. knowing when 1 word ends and the other begins, knowledge creates that perception)
• bottom-up sensations: sensory input

Question 4

What can perception be influenced by?

Answer 4

• visual perception can be influenced by memory (e.g. in abstracts you’ll see the same that you did the first time due to memory distinguishing it)
• can be influenced by context, whatever makes the more sense

Question 5

What is Helmholtz’s theory of unconscious inference?

Answer 5

-particular pattern of activation in the retina can be caused by a range of objects

Question 6

What is the likelihood principle?

Answer 6

• perceive the object that’s most likely to have caused the pattern
• judgement is a result of unconscious assumptions that are made automatically about the environment

Question 7

What is the Gestalt principle?

Answer 7

• visual system has to figure out what can be grouped with what, to do this there are laws that determine how things are grouped
• after grouping the entities the brain then has to figure out what’s an object and what characteristics make it a member of that category
• once the stimuli is perceived we have to perceive where the stimuli is/where it’s going

Question 8

What are the laws that determine grouping in the Gestalt principle?

Answer 8

• law of similarity: groups that are similar
• law of Pragnanz: objects are seen in way that makes them appear as simple as possible
• law of proximity: close to each other
• law of continuity: points connected by straight/curving lines are seen in way that follows smoothest path
• law of closure: grouped if they seem complete
• law of common fate: humans perceive visual elements that move in the same speed

Question 9

What are the monocular cues of depth?

Answer 9

• relative size: distance is taken into account when perceiving size
• interposition: overlapped object seems further away
• linear perspective: parallel lines converging in the distance are seen as further away
• arial perspective: distant items seem more blue, the scattering of light that does this creates a blur making them seem further away while closer items are sharper
• light and shade: have light from above assumption, perspective changes when image is upside-down
• monocular movement parallel: when the head moves close objects move fast, far objects are relatively slow

Question 10

What is the need for 2 eyes?

Answer 10

• use the slightly different information from each eye to perceive depth (convergence)
• binocular disparity: things closer to the face become blurrier, visual cortex uses process of stereopsis to correct binocular disparity
• overlapping visual fields enable stereoscopic visions by blending slightly dissimilar views of object
• allows us to see farther into the distance with higher resolution

Question 11

What did Held and Hein (1963) find on the interaction between perception and action in kittens?

Answer 11

• investigated if movement is necessary in order to develop normal vision
• some walked in circles (active) while others were kept in box (passive)
• saw the same visuals but one moved other didn’t
• all active developed visually guided paw placement while no passive kittens did
• active kittens avoided deep end of glass cliff
• self-produced movement and concurrent visual feedback are essential for development of visually-guided behaviour

Question 12

What is the interaction of perception and action?

Answer 12

• data coming from our eyes only mean something when we can cross-reference it, need feedback on what the information means so what we touch influences how we see
• cross-cultural studies of perception provide evidence that how we perceive the world depends on what surrounds us
• colour vision is affected by native language (specifics like light/dark rather than just blue), gender and age can also affect colour vision