Sensation & Perception:Our Other

Senses

• Goals Describe how our senses of touch, taste, and smell interact to form our perceptions.

Touch• Basic skin senses = pain,

cold, warmth pressure(other sensations are combo

of these four)• Receptors located in our

skin = detect touch sensations– More sensitive = more

receptor cells = larger areas on somatosensory cortex in the brain

Touch

• Our brain significantly affects whether, and how, we perceive pain.

• Gate-control theory = pain sent through small nerve fibers in spinal cord, while non-pain is sent through large nerve fibers– Non-pain fibers can close

the “pain gates” to the brain

Gate Control Theory

Kinesthetic Sense• Tells us where our body parts are in

relation to one another and to our environment

• Coordination • Receptors located in

our muscles and joints• = Proprioception

Vestibular Sense

• Tells us where our body is oriented in space.

• Our sense of balance.

• Located in our semicircular canals in our ears.

• Am I vertical? Horizontal?

Taste is a Chemical Sense • Receptor cells on the tongue’s

surface respond to chemical structure • Five tastes

– Sweet Energy source– Salty Sodium essential to

physiological processes– Sour potentially toxic acid– Bitter potential poisons– Umami proteins to grow &

repair tissue

Taste Receptors• Inside each little bump on the sides

and top of your tongue are 200 or more taste buds, each containing a pore that catches food chemicals

• In each pore, 50 to 100 taste receptors project antenna-like hairs that sense food molecules

Taste Receptors• Taste receptors reproduce every week or

so• # of taste buds decreases with age

– Smoking & drugs also affect taste buds• Expectations influence

brain’s response• Linda Bartoshuk et al. (1994)

– 25% of pop. = “supertasters”– 25% of pop. = “non-tasters”

Olfaction – Our Sense of SmellSmell• Smell is also a chemical sense

• Olfactory receptors in upper nasal passages detect molecules in the air

• Odor molecules come in many shapes and sizes, so we have many different receptors to detect them

• Some odors trigger a combination of receptors in patterns that are interpreted by the olfactory cortex

• Odor molecules combine to produce the 10,000 odors we can detect

Sensory Interaction

• Taste and smell interact to create flavor– If your sense of smell is blocked, foods

will not taste the same

• Synaesthesia one sensation produces another – Hearing a sound

and seeing a color– Number and a

taste sensation

Smells are primitive

• Pheromones!• Why can we recognize

long-forgotten odors and their associated memories?– Connection between

brain area receiving info from nose and limbic system

Extrasensory Perception (ESP)• Claim that

perception can occur without sensory input

• Clairvoyance = perception of events happening somewhere remote from perceiver

• Precognition = perceiving future events (i.e. psychic)

Extrasensory Perception (ESP)• Telepathy =

perceiving another’s thoughts

• Telekinesis = moving objects with one’s mind

• Is ESP real? – Difficult to test– Research has not

replicated results, therefore no evidence exists