psych unit 2 aos 2 - what influences a persons perception of the world

sensation

is the physical process by which our sensory receptors and sense organs detect and respond to sensory information

Perception

a psychological response to sensation, that gives meaning to the stimulus that our sense organs detect

attention

a voluntary or involuntary tendency to focus awareness on a specific stimulus and ignore another stimulus

different types of attention

sustained attention

divided attention

selective attention

divided attention

selective attention

sustained attention

focusing on attention on an activity or stimulus over a prolonged period without being distracted by other stimuli

divided attention

refers to rapidly switching your awareness between two or more sources of information so you can preform two or more tasks at the same time

selective attention

choosing to focus your awareness on a specific or limited range of stimuli while ignoring other stimuli

bottom-up processing

(from specific to general)

when our sensory receptors, such as out eyes, receive sensory information and we do not rely on prior experience in order to interpret it

when our sensory receptors, such as out eyes, receive sensory information and we do not rely on prior experience in order to interpret it

top-down processing

(from general to specific)

used when the brain starts with an overall perceptual hypothesis about a stimulus and uses context and general knowledge to fill in any blanks

• the stroop effect

Biological factors

includes psychological, neurological or genetic conditions that affect an individual.

Biological factor are entirely internal and can influence the way we perceive the world

• the brain interprets the 2D retinal image as a 3D representation of the world

Depth cues

a variety of internal and external stimuli or processes that inform the visual system about the depth of an object or its distance from the observer (2 types)

what are the two types of depth cues

monocular and binocular

Depth perception

the ability to see 3D space and to accurately judge distances using environmental cues

What are the types of binocular cues

retinal disparity and convergence

What are the types of monocular cues?

accommodation and pictorial cues

binocular depth cues

the use of both eyes to provide information to the brain about depth and distance

monocular depth cues

the use of only one eye to provide information to the brain about depth and distance

Convergence

involves the brain detecting and interpreting depth or distance from changes in tension in the eye muscles that occur when the two eyes turn inwards to focus on objects that are close.

retinal disparity

the very slight difference in the location of the visual images on the retina, which enables us to make judgements about the depth or distance of an object

accommodation

the automatic adjustment of the shape of the lens to focus on an object at different distances

pictorial cues

5 types

how the brain perceives flat 2D images

- linear perspective

- interposition

- texture gradient

- relative size

- height in the visual field

how the brain perceives flat 2D images

• linear perspective

• interposition

• texture gradient

• relative size

• height in the visual field

Linear perspective

The apparent convergence of parallel lines as they recede into the distance

interposition

occurs when an object partially blocks or covers another and the partially blocked object is perceived as further away than the object that observes it

texture gradient

refers to tendency to perceive the object that we know is the same size in reality, produces the largest image on the retina as being closer and the object that produces the smaller image on the retina as being further away

Height in the visual field

the location of objects in our field of vision, whereby objects that are located closer to the horizon are perceived as being more distant than objects located further from the

horizon

psychological factors

refers to processes that operate at the individual level that impact the mental state and cognition of the individual, thereby influencing behaviour

2 groups: gestalt principles and perceptual set

visual perception principles

are 'rules' we apply to visual information to assist out organisation and interpretation of the information in a consistent and meaningful way

what are the gestalt principle

figure ground

similarity

closure

proximity

• similarity

• closure

• proximity

Gestalt principles

refers to the ways in which we organise the features of a visual scene by grouping them to perceive a whole, complete form

Figure ground

perceiving an image or scene by focusing on an image (or figure) that stands out from the background

closure

is the perceptual tendency to mentality 'close up' fill in or ignore gaps in a visual image and to perceive incomplete objects as complete 'whole'

similarity

the tendency to perceive parts of a visual image that have similar feature - such as size, shape, texture or colour - as belonging together in a unit, group or whole

proximity

the perception of parts of a visual image that are positioned close together as belonging together in a group

perceptual set

is a temporary readiness to perceive something in accordance with what we expect them to see

5 factors

• past experience

• motivation/ emotional state

• context

• memory

past experience

refers to our personal experiences throughout our lives

both learned intentionally and unintentionally

context

refers to the information that surrounds a stimulus that influences the perception of the stimulus

motivation/emotional state

is an internal psychological state that activates, directs and sustains behaviour in relation to achieving a specific goal

motivation can influence how we interpret the world around us and can be influenced by

- psychological factors (pain, hunger, body temp)

- psychological factors (interests, priorities, mood)

motivation can influence how we interpret the world around us and can be influenced by

• psychological factors (pain, hunger, body temp)

• psychological factors (interests, priorities, mood)

Memory

which features of visual stimuli you attend to can be influenced by your memory

social factors

the aspects of our interactions with other people, groups, society, and culture that influence how we think and behave

culture

involves all the distinctive beliefs, values, customs, knowledge, art and language traditions that provide the basis of everyday social behaviours

• culture and upbringing can influence how we perceive the environment surrounding us

Gustatory perception - biological factors

genes and age

Gustatory perception - psychological factors

memory, food packaging and appearance

Gustatory perception - social factors

culture

Stimulus

chemical molecules combine with saliva on tongue

Reception

detect and respond to chemical molecules

Transduction

The process by which an energy source is converted into a nerve signal

Transmission

sent to brain via cranial nerves

interpretation

brain understands and is received in primary gustatory cortex

Taste: (gustatory)

the sensory experience of food or drink that is put into the mouth and perceived as flavour

• sweet

• salty

• sour

• bitter

• umami

Taste buds

are tiny structures contained in papillae, the small bumps of the tongue. The chemicals in food and drink mixed with saliva enter the taste pore and bind to the surface of the taste receptors

Genes

genetic makeup influences the amount of and composition of gustatory receptors on taste buds

Age

children are born with a natural preference for sweet and fatty foods and an aversion to bitter tastes

Memory

past food experiences helps create an expectation of a foods taste

gustatory cortex

the brain area where taste information is processed

an unpleasant experience with a food can lead to negative memory of the experience - this may lead to long lasting taste aversion to the food

Food packaging

how it feels, sounds, looks (colour) can influence the perception of the foods taste

appearance

visual appeal is a key element in food composition. we first look at our food/drink before consuming it, so our brain receives visual information before taste information

culture

culture brought up with determines whats normal

The purposes of saliva

1. to create a liquid tastant that can bond with the chemo-receptors in your tastebuds

2. saliva is an enzyme which speeds up digestion

2. saliva is an enzyme which speeds up digestion

vision illusion

is a consistent perceptual error in interpreting the features of an external stimulus

illusions occur when the perceptual rules we consistently apply to real stimuli contradict with each other

What is the Muller lyer illusion?

which line is longer

arrows pointing inwards look longer than arrows pointing outwards, even though they are the same length

The carpenter hypothesis

when the ends of the arrows are pointing away, we perceive it as sloping away like the corner of a building

when the ends of the arrows are pointing in, we perceive it as more like the far corner of the room, and therefore further away