cognition Flashcards
(28 cards)
what is sensation
Sensation refers to the initial detection and processing of stimuli.
stages of sensation
reception, transduction, transmission
stages of perception
selection, organisation, integration
what is perception and what is an example
Perception involves the selection, organisation and interpretation of transmitted sensory stimuli. Example (responses may vary): While one is talking to a friend at a bus stop, different sound waves are picked up by the ears. The brain selects only the voice of the friend talking, organises the sounds into meaningful words and gives the words meaning (interpretation).
what is the Cornea
what is its function
Transparent covering that protects the eye
Helps focus the light rays onto the retina
what is the pupil
what is its function
Small adjustable opening that looks like a black circle in the middle of the eye
It expands or contracts to control the amount of light allowed into the eye-shutter
what is the iris
what is its function
Coloured muscle part of the eye surrounding the pupil
Regulates the expansion and contraction of the pupil
what is the lens
what is its function
clear structure attached to the eye with ciliary muscles
focuses light onto the retina
what are Ciliary muscles
what are their function
Ring-shaped tissue that surrounds the lens
Holds and controls the movement and shape of the eye lens
what is Vitreous humour
what is its function
jelly like substance between the lens and the retina
Helps maintain the shape of the eyeball and helps in focusing
what is the Retina
what is its function
Sensitive surface at the back of the eye
Coverts light energy into signals that are carried by nerves to the visual cortex
what are photoreceptors
what are their function
Cells in the retina that contain photopigments and are sensitive to light; e.g. rods and cones
Pick up any type of light energy and convert it to neural signals
what is the fovea
what is is function
small part of the retina with a high concentration of cones
Point of highest visual acuity; cones are concentrated here
what is the Optic nerve
function
nerve at the back fo the eyeTransmit visual information from the retina to the occipital lobe (visual cortex) where perception occurs
what is perception
Perception takes place when certain stimuli are selected, organised and given meaning by the brain.
whites a perceptual illusion
Perceptual illusion occurs when there is a mismatch between physical reality and what we perceive.
what is Perceptual compromise –
an illusion occurs due to visual cues that contradict each other. When the brain interprets conflicting information, a compromise between the two is reached. In the Müller-Lyer Illusion, the length of the middle line gives a different length information from the distance between the tips of the arrows at the end. The brain compromises by perceiving the middle line to be longer when the arrows are pointing outwards.
what is Perceptual expectancy
our expectations are based on the interplay between perceived size and perceived distance. Our experience with rooms and buildings lead us to interpret a line with inward pointing ends as nearer than the ones pointing outwards (hence, longer).
steps of perception
Selection – the brain filters the stimuli choosing only those that are important and ignoring those that are not. This involves specialised neurons called feature detectors.
Step 2 Organisation – involves grouping selected features of the stimuli to form a whole, sometimes referred to as a ‘gestalt’, where missing information can be filled in or assumed to be present make a complete figure.
Step 3 Interpretation – the brain gives meaning to this whole. The meaning is highly subjective and depends on the individual’s past experiences and motivations.
what is reception
the first step of sensation, the presence physical stimuli is detected by sensory neurons in our sense organs.
what is transduction
the stimuli detected in sensation is converted into electrochemical energy, the form of energy our brains can process
what is transmission
the electrochemical energy converted in transduction is transferred to our brains for processing
what is perception
perception takes place when the information detected in sensation is organised and given meaning by the brain. it comprises of three steps selection, organisation and integration.
what is selection
the brain filters stimuli to select important information for further processing and ignores irrelevant information. the task of selection involves specialised neurons called feature detectors.
