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