The Senses

receptors in the eyes which see differences in light and dark as well as angles

they are more numerous

receptors in the yeses which perceive color

red, blue, and green sensitive receptors in the retina

combination of red/green, blue/yellow and luminance channels allows for color perception

the amplitude of sound waves

the frequency of sound waves

the auditory complex is organized tonotopically

this depends on the timing of sound at each ear

haptic

depends on the density of mechanoreceptors (touch receptors)

the somatosensory cortex organizes somatotopically- body mapping- most sensitive

indpendent warm and cool thermoreceptors

more warm than hot

the type of pain that is sharp, immediate pain- causes a reflexive withdrawal

type of pain based on chemical signs of dmage, stopping the body part

competing sensory input can reduce pain

ex: rubbings something that hurts

sweet, salty, bitter, sour and umami

sense that bypasses the thallamus

it evokes emotion and memory
pheremones not consciously smelled by humans

can communicate threat, emotion, sexual signals

loss of smell which reduces interest in sex and food

sleep walking

sleep allows the brain and body to rest and repair

falling asleep in the day for a few minutes or seconds

regulation of biological patters in regular cycles

biological clock work controlled by light and dark--> developed to keep us safe during most dangerous times of day (quiet)

sleep is time when circuits wired in the day are strengthened

gland that secretes melatonin--> darkness triggers its release

plot of dream

what a dream symbolizes

neural stimulation from the pons activates mechanisms that normally interpret visual input

our psychological experiences of phsycial stimuli

how much energy is needed to sense?

absolute minimum amount of intensity of stimuli that must occur before you experience the sensation

ex: hearing- the softest sound you can hear 50% of the time

the minimum amount of change require for you to notice the difference in sense stimulus

the threshold increases as the stimulus grows in intensity

threshold based on proportion of original rather than size of difference

perception of the faintest stimuli requires a judgement about its presence or absence

a decrease in sensitivity to a constant level of stimulation

the region of visual space to which neurons in the primary visual cortex are sensitive

"shape, form, organized whole"

our brains use innate principles to organize sensory information