Audition, Olfaction, Gustation, Somatosensory

Sound

• longitudinal waves

  • amplitude changes loudness (greater amplitude = louder)

  • wavelength changes pitch (longer wavelength = lower pitch)

Tone Deaf

• difficulty discerning different pitches

Purity / Timbre

• when most sounds are made, they produce a variety of frequencies called harmonies

  • harmonies combine in different ways to cerate distinctive sounds

• different instruments playing the same pitch

The Ear

• outer ear

• middle ear

• inner ear

Outer Ear Anatomy

• eardrum

• ear canal

• pinna

Eardrum

sound energy

Ear Canal

where sound travels as it enters

Pinna

exterior structure

Middle Ear

• mimics the vibrations hitting the outer ear and translates it to the inner ear

• made of 3 bones called ossicles

Middle Ear Anatomy

• Hammer

• Anvil

• Stirrup

Hammer

vibrates

Anvil

hammer hits the anvil

Stirrup

translates vibrations from ossicles to inner ear

Inner Ear

• contains neurons needed for perception

• cochlea

Hair Cells

• convert the movement of the basilar membrane into neutral impulses

• hair cells die through direct damage or aging

  • do not regenerate

  • hearing degenerates

• partially determine the frequencies we can hear

Echolocation

• high frequency pitches allow animals to take in the world visually through hearing

Smell and Taste

• chemical senses that work hand in hand to provide us with physical information about out physical world

• smell and taste senses converge in the orbitofrontal cortex

Olfactory Cortex

• piriform cortex

Somatosensory Cortex

• processing of texture/”mouth feel”

Gustatory Cortex

• anterior insula and frontal operculum

Smell and Mate Choice

• male college students wore t-shirts for 2 nights without any deodorant, scented soaps, etc.

• females significantly rated the smells of shirts from males with MHC gene variants dissimilar to their own to be more pleasurable compared to males with similar variants

Carbohydrates

• primary source of energy

• easily metabolized into ATP

• quick and efficient source of energy

  • fruits, starchy vegetables, grains

Fats

• secondary source of energy

• used for storing energy over long periods of time

  • dairy products and animal fats (saturated)

  • vegetable oils, fish, nuts (unsaturated)

Proteins (and amino acids)

• used to synthesize proteins for our own bodily function

• important for muscle growth

• last resort source of long-term energy

  • meat, dairy products, eggs, nuts

Basic Tastes

• Sweet

• Salty

• Bitter

• Sour

• Unami (Savory)

Sweet Tastes

• signify energy rich food

Salty Tastes

• signify the presence of electrolytes

Sour Tastes

• warn of harmful foods

Unami (savory)

• signify the presence of glutamate or aspartate

Why do we taste

• helped our ancestors identify important nutrients (and avoid bad things)

• ancestors had to expend a great deal of energy to acquire food

Somatosensory System

• respond to stimuli applied to skin, temperature, and injury

• involves specialized nerve endings in the skin (mechanoreceptors) and free nerve endings

Why is touch important

• important for social bonding, and our mental health

• comfort, safety and security

  • especially important for developing children

Pain Sensations

• some are more sensitive to pain, maybe due to the emotional component

• the gate control model argues that neutral mechanisms in the spinal cord regulate conscious awareness of pain

• following the loss of a limb people might experience persistent phantom pain