“THE OTHER SENSES”

AP PSYCHOLOGY

FALL 2014

CHAPTER 5: SENSATION

MS. ELKIN

SENSORY TRANSDUCTION

Energy Source Receptor Sites

Light Waves Cones/Rods

Sound Waves Hair Cells of Cochlea

Food Molecules Taste Buds

Molecules Receptor Cells in

Olfactory Membrane

Cold, heat & Receptor Cells in skin’s

Pressure dermis & epidermis

Smell

On average we “inhale and exhale nearly 20,000 breaths of life-sustaining air” subsequently “bathing our nostrils in a stream of scent-laden molecules”…

Physiology of Smell

Like the sense of taste, the sense of

smell is a chemical sense: facilitated

and perpetuated through a series of

chemical reactions

The experience of smell is captured

through olfaction

Olfaction encompasses the reception of

airborne chemical by receptor cells in the

nasal passage

The Process of Olfaction

1. 20,000 breaths per day

2. Breathed in through the nose, the molecules move toward receptor cells located in the lining of the nasal passage

1. the chemical bonds to the receptors which then travel to the brain. There are thousands of different receptors in the cells of the nasal passage

2. Finally, these olfactory signals are diffused throughout the Amygdala, Hippocampus, and Hypothalamus

Effects of Odors - Memory

Olfaction is directly linked to memory

Hippocampus

Amygdala

Hypothalamus

Our sense of smell is a powerful

associative tool

Evoke memories and feeling

Associated personal episodes

Effects of Olfaction – Ability to Distinguish Different Odors

Nursing infants and mothers Animals and Human Beings

Literal Chemistry – Ability to recognize

Sense of smell is nowhere as keen as most animals Seeing and Hearing are much more acute

Cannot separate into elemental odors

Combination of many different receptors allows us to distinguish scents

Humans have 10 to 20 million receptors (Dogs have 200 million)

Taste

What is it? On the tongue there are hundreds of

bumps called taste buds

Taste buds are clumps of around 100 taste cells on the tongue

Taste cells respond to the chemicals in your mouth and identify with one of the 5 basic tastes

Umami: meaty, savory taste, depending on the flavor, location on the tongue varies

How do we taste? Inside each bump on your tongue there are

200 or more taste buds

Each individual taste bud contains a pore

that catches food chemicals

These molecules are sensed by taste

receptor cells that project antenna like

hairs into the pore

Each of the taste receptor cells respond

differently

Fun Facts As you get older, taste buds become

less sensitive

Hot foods taste better because the heat allows aromas for nose to smell

Smoking and alcohol use accelerate the decline in taste buds

People without tongues can still taste through receptors in the back and on the roof of there mouth

Touch The detection of physical contact with

the body

The sense of touch is made up of four

different skin senses

Pressure

Warmth

Cold

Pain

Touch is sensed from various types of nerve

endings in the skin or more specifically the

bottom layer of your skin, the dermis

Touch An object can feel soft, hard, rough smooth, wet, dry,

warm, cold, etc.

Information is taken in from the skin receptor, or touch receptors, and sent to the sensory cortex in our brain

This is how we experience the sense of touch

The hands and fingers, feet and toes, lips, and genitals are especially sensitive to touch and have a major portion of the sensory cortex devoted to them

This is why people enjoy kissing and feel with their fingers and wear shoes to avoid rough terrain

The “Sixth” Sense: Kinesthesis

Not a sense, but a process in which nerve signals use sensory inputs to coordinate how muscles move to keep us upright and keep equilibrium

Kinesthesis: the system for sensing the position and movement of individual body parts

Kinesthesis

USES THREE INPUTS:

Proprioceptive System

-body awareness in space

-pressure sensors in muscles, tendons, joints

-senses gravity & joint position

Vestibular system

-inner ears

-3 semicircular canals

-vestibular nerve

-cochlea

Visual Input

-verticals & horizontals

The Vestibular Sense

How It Works

1) You move (your head)

2)Fluid in your vestibular sacs move, senses

position

3)This activates hair like receptors in the

Vestibular System

4)Messages are sent to the cerebellum via the

vestibular nerve (from canals)

5)Cerebellum, pons, and medulla work together

to keep balance

The Vestibular Sense

Where it’s located

Pain

Pain is a property of:

The senses

Our brain

Our expectations

Pain - Influences Biological:

-activity in spinal cord’s fibers

-genetic differences in endorphin production

Psychological:

-attention to pain

-learning based on experience expectations

Socio-Cultural:

-presence of others

-empathy for other’s pain

-cultural expectations

Pain

The brain creates pain: When you feel empathy for others, your

brain mirrors that feeling and creates pain for you (mirror neurons)

We can experience pain through memories

In the same way, many amputees feel pain going though “phantom limbs” (amputated limbs)

Gate-Control Theory Spinal cord contains a neurological “gate”

that either blocks pain signals or allows

them to pass on to the brain

Small nerve fibers: carry pain messages to

brain

Large nerve fibers: carry all other sensory

information to the brain

Stimulating large nerve fibers sends

competing signals through the spinal cord

“blocking” some of the pain messages

Pain Management

Pain control is indeed a physical and

a psychological phenomenon.

Pain then should be treated both

physically and psychologically.

Depending on the symptoms,

hospitals use many different ways to

treat pain.

Medication (ex: Morphine, an opiate)

Lamaze during labor

Hypnosis