CH4 Flashcards
bottom-up processing
process of “sensation”, input of sensory information from the external world is received and sensed as it is
top-down processing
interpretation of incoming information based on our prior knowledge, experiences, and expectations, perception heavily relies on top-down processing
sensation
simple stimulation of sense organ
perception
forming a mental representation
transduction
sense receptors convert physical signals from the environment into neural signals that are sent to the central nervous system
what is the psychological dimension for light waves of LENGTH
hue/colour
sensation → perception from eyes
light waves → retina →rods & cones (photo receptors) →ganglion cells → optic nerve → thalamus → visual cortex
retina
contains sensory receptors that transduce light into neural signals
photoreceptors
rods and cones transduce light waves into signals
bipolar cells
sensory neurons; transfer visual input to ganglion cells
ganglion cells
generates an action potential, sent to the brain by the optic nerve
thalamus
relaying signal to visual cortex
binocular depth cues (binocular disparity)
difference in the retinal images of the 2 eyes that provide information about depth (greater disparity = closer object)
monocular depth cues
information about depth when viewed with only one eye; linear perspective, texture gradient, interposition, relative height, relative size, familiar size
colour blindness
genetic disorder where one (or more) of the cone types is missing causing a colour vision deficiency
synethesia
see words as colours
trichromatic theory
colour vision based on 3 primary colours (red/green/blue → 3 different cone receptors)
what colour & wavelength is the L- cone
red, long
what colour & wavelength is the M- cone
green, medium
what colour & wavelength is the S- cone
blue, short
Opponent process theory
perceive colours in terms of 3 pairs of opposing colours: red vs green, blue vs yellow, white vs black
How do we perceive motion
to sense motion, the visual system must encode information about both space and time (PERCEIVING CHANGE OVER TIME)
dorsal visual stream
travels up from the occipital lobe to the parietal lobes; enables us to identify where an object is and how it is moving; crucial for guiding actions
ventral visual stream
travels from the occipital visual regions into the lower temporal lobe; enables us to identify what we see
what are the 3 physical properties of sound waves?
frequency, amplitude, complexity
frequency
repetition rate, corresponds to our perception of pitch (low frequency = low pitched)
amplitude
corresponds to our perception of loudness (high amplitude = loud sound)
complexity
corresponds to our perception of timbre (simple = pure tone)
sound waves from sensation to perception
sound waves enter the outer ear, making the eardrum vibrate. they pass to the middle ear making ossicles and oval windows vibrate. finally, they pass to the cochlea in your inner ear
sensation of sound waves
pressure waves in the cochlea move the basilar membrane, stimulating the sensory receptors, called hair cells, in your inner ear.
transduction of sound waves
when the hair cells bend they convert the pressure waves into signals that are sent to the brain by the auditory nerve
perception of sound waves
the auditory nerve carries the neural signal first to the thalamus and then to the primary auditory cortex which processes your perception of the sound
how does the pitch, timbre, and loudness of a sound relate to its physical properties
low pitch → low frequency
pure tone/timbre → simple
loud sound → high amplitude
how do touch receptors transmit messages to the brain?
stimuli from the external world from skin → receptors in skin transmit signal → pathway along cranial nerve/spinal nerve through the thalamus to area of somatosensory cortex that processes the body parts that were touched
how do odourant molecules convert into neural impulses?
smell stimuli → oderants pass into your nose and nasal cavity → olfactory receptors in the olfactory epithelium transmit signal to olfactory bulb →olfactory bulb transmit signal along olfactory nerve to areas of cortex and amygdala
what is the importance of smell in personal and social experiences?
smells have close relationship w/ areas involved with emotional & social behaviour and memory, perception of smell can be influenced by previous experience
how are taste sensations converted into neural impulses by tongue?
bit into something → molecules dissolve in fluid on your tongue → received by taste receptors in taste buds on your tongue and in your mouth and throat → taste buds transmit signal along cranial nerve through thalamus to other areas of brain
what sense contributes to perception of flavour?
smell
heritability
measure of the variability of behavioural traits among individuals that can be accounted for by genetic factors
4 important points about heritability
- heritability is an abstract concept
- heritability is a population concept
- heritability is dependent on the environment
- heritability is not fate
