Sensation
Process of detecting external events by sense organs and turning those stimuli into neural signals
Perception
Involves attending to, organizing and interpreting stimuli that we sense
Transduction
Process of converting basic sensory info into neutral activity that the brain can interpret
Doctrine of specific nerve energies
Separate brain areas are specialized for different sensory input
Orienting response
Describes how we quickly shift our attention to stimuli that signal a change in the sensory world
Sensory adaptation
Reduction of activity in sensory receptors with repeated exposure to a stimulus
Pyschophysics
Measures relationship between mental world and physical world
Absolute threshold
Minimum amount of energy or quality of a stimulus requires for it to be reliably detected at least 50% of time its present
Difference threshold
Small difference between stimuli we can detect atleast 50% of the time
Signal detection theory
Recognizes that a stimulus is either present of absent and that the individual either reports detecting the stimulus or does not
Hit
You heard something and were right
Miss
Failed to detect that the stimulus was actually there
False alarm
Think you heard something but it wasn’t actually there
Correct rejection
Didn’t hear anything and were correct
4 possible outcomes of signal detection
Hit, miss, false alarm, correct rejection
Figure ground principle
We use the visual features of objects to determine which are objects in out environment and what is background
Gestalt psychology
Approach to perception that emphasizes “whole is greater than sum of parts”
Law of proximity
Grouping objects together according to their closeness in space
Law of similarity
Grouping objects together according tides tyres they have in common
Law of continuity
Tendency to view items as whole figure even if image is broken into segments
Law of closure
Tendency to fill gaps so as to see a whole object
Divided attention
Paying attention to more than one thing at a time
Selective attention
Involves only focusing on one thing at a time; can be beneficial to learn
Inattentional blindness
Failure to notice clearly visible events of objects because attention is directed somewhere else
Primary function of the eye is too…
Father light and change it into action potential
Wavelength
Difference between peaks of wave, correspond to colours
Long wavelengths
Detects more reddish colour
Medium wavelengths
Detects more yellow and green
Short wavelengths
Detects more blue and purple
Amplitude
Refers to height of wave
Low amplitude
Dims colour
High amplitude
Bright colours
Saturation
Colourfulness or density
High saturation
Mixture of different wavelengths (washed out)
High saturation
Light waves that consist of mostly one wavelength (vivid colour)
Sclera
Whiter outer shell
Cornea
Clear layer cover front portion of eye, contributed with ability to focus
Pupil
Dilated to allow more light to pass through and constricts to allow less light
Iris
Adjusts size of pupil, gives eye colour
Lens
Behind pupil, focusing light onto the back of eye, bends light either more or less according to distance of objects that need to be in focus
Bringing objects close into focus ..
Needs the objects to be more sperical and light must bend more
Bringing far objects into focus
Requires lens to be more flat, light doesn’t bend as much
Retina
Lines inner surface of eye and consists of specialized receptors that absorb light and send signals related to properties of light to brain
Photoreceptors
Light is transformed into neural signal so the brain can understand
Ganglion cells
Take signals from photoreceptors and send to brain by firing out of optic nerve
Optic nerve
Firing from ganglion cells go through a dense bundle of fibres that connect to brain
Optic disc
Creates an area of the retina where there is no photoreceptors (creates blind spot)
When the brain creates a blind spot ..
It is missing out on info and automatically fills in the blanks for you
Direction of light through eye
Cornea-pupil-lens-retina-photoreceptors-ganglion cells-brain
2 general types of photoreceptors
Ross and cones
Rods
Sensitive to under low light and provide grainy images
In dark we use rods or cones more
Rods
Cones
Sensitive to different wave lengths of light sober rely on them for colour vision
Fovea
Central of the visual field
Cones are clustered around …
Fovea
Dark adaptation
Rods and cones are adjusting their sensitivity to darker lighting conditions
Trichromatic theory
Colour vision is determined by 3 main colour red blue and green
Negative afterimage
Stare at one colour for long time and look away will cause negative after image of different colour
Staring at something red turns ..
Green
Staring at something black turns…
White
Staring at something green turns..
Red
Oppenent-process theory
We perceive colours in terms of opposing pair
Red to..
Green
Black to..
White
Yellow to..
Blue
Nearsighted
Eye is elongated
Farsighted
Eye is too short, the light isn’t bent when reached retina does hit proper spot
Glasses ….
Bend light as proper spot
Optic chiasm
Point where the optic nerve cross at midline of brain. Splits and travels to both sides left and right
Left half of visual field is initially processed by ..
Right hemisphere
Right half of visual feild is initially processed by ..
Left hemisphere
Lateral geniculate nucleus (LCN)
Processing visual info fibres from nuclear, sends messages to visual cortex
Visual cortex has two streams of vision:
Ventral stream and dorsal stream
Ventral stream
Deals with processing visual info about objects identity
Perceptual consistencies
Ability to perceive objects as having constant shape size and colour despite changes in perspective
Shape constancy
Judge object relative to our position
Colour constancy
Being able to recognize an objects colour under varying levels of illumination
Size constancy
Judgments of how close an object is relative to ones position as weak as the positions of objects
Dorsal system
Deals with processing visual info for the purpose of guiding motor actions
Depth perception
Ability to use vision to guide our actions is dependent on our depth perception
Binocular depth cues
Differing perspective of both eyes
Convergence
Occurs when the eye muscles contract so that both eyes focus on a single object
Retinal disparity
Difference in relative position of an object as seen by both eyes which provides info to the brain about depth
2 steps to sensing the world around us
- sensation
- perception
Monocular depth cues
Cues that we can perceive with only one eye
Accommodation
Lens of eyes curves to allow focus on nearby objects, helps make judgment about depth
Motion parallax
Used when your surroundings are in motion t
Interpolation
Where an object is closer then another one beam cause it covers part of the other object
Object brightness
Objects that are futher away will be at lower intensity vs high intensity for our retinas
Linear perspective
Occurs when parallel lines go into the distance
Texture gradient
Far objects tend to be less defined and blurry the farther the distance
Height in plane
Objects that are higher in our visual field tend to be further away
Relative size
Object will project a smaller image if it’s further away from us
Ears are designed to…
Collect soundwaves and to transform into neural signals for the brain
Sound frequency
Pitch of the sound that is based on speed of the molecules in the air are traveling
Pitch
Perceptual experience of sound wave frequencies
Sound amplitude
Height of wave, higher is louder lower is quiet
Human audible range
Can hear from 50hz to 20000 hz
Ear consists of 3 parts
- pinna
- auditory canal
- eardrum
Pinna
Outer region that helps channel in the sounds waves and know where it’s coming from
Auditory canal
Tube from pinna to ear drum
Ear drum
Vibrates the ear drum at same frequency of sound waves
Main function of auditory ossicles
Strengthen the signal provided by the eardrum before transferring that info along inner ear
Cochlea
Fluid inside that converts sound vibrations into neural impulses
Sound localization
Identifying where the sound is coming from
Two ways that help is find origin of sound:
- arrives at ears at different times
- sound will arrive at higher intensity to whatever ear is oriented to the origin of sound (sound shadow)
Place theory of hearing
Idea that hair cells can tell if the sound is a high frequency of low frequency
Primary auditory cortex
Major centre of brain involved in perceiving what we hear, respond to specific frequencies
Secondary auditory cortex
Helps us understand complex sounds
Two point threshold device for measuring touch acuity
The more sensitive regions on the body con detect two points even when they are spaced very close together, less sensitive parts of the body have much larger two point thresholds
Haptics
Active exploration of objects to learn the properties
Kinesthesis
Sensors in our muscles joints and tendons that give us a sense of the bodily motion and position
Nocoception
The activity of the nerve pathways that respond to uncomfortable situations, send pain messages to central nervous system
Fast fibres
Sharp intense pain caused by physical injury
Slow fibres
Throbbing pain when occurs after injury occurs
Gate control theory
Explanation of the feeling of pain and why the among of actual damage doesn’t always relate to the intensity of pain that one receives (small pinch, huge pain)
Gustatory system
Functions in The sensation and perception of taste
Primary tastes
Salty, sour, bitter, sweet, umami
Papillae
Receptors for taste, lines with tastebuds
Olfactory system
Detection of airborne molecules floating around that make their way into our noses
Olfactory epithelium
Thin layer of cell that are lined by sensory reception called cilia