Module 20: Hearing, Skin, Chemical, and Body Senses

Audition

Hearing

Pitch

A tone’s experiences highness or lowness, depends on frequency

Frequency

The number of complete wavelengths that pass a point in a given time (measured in hertz)

Decibels

Measure of sound intensity

Middle Ear

The chamber between the eardrum and cochlea containing three tiny bones that concentrate the vibrations of the eardrum on the cochlea’s oval window

What are the 3 tiny bones in the middle ear?

Hammer (malleus), anvil (incus), and stirrup (staples)

What is the purpose of the three tiny bones in the middle ear?

They pick up the vibrations of sound and transmit them to the cochlea

Cochlea

Coiled, boney fluid-filled tube in the inner ear

Sound waves traveling through the cochlear fluid trigger…

nerve impulses

Inner Ear

The innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs

Oval Window

Cochlea’s membrane-covered opening

Purpose of the Oval Window

Vibrates, moving the fluid inside the cochlea

The motion of the fluid in the cochlea causes…

Ripples in the basilar membrane

The ripples in the basilar membrane leads to…

bending of the hair cells lining its surface, which triggers impulses in adjacent nerve cells

When impulses in adjacent nerve cells are triggered in the ear…

axons connect those nerve cells to form the auditory nerve

Auditory Nerve

Carries neural messages to the thalamus and then to the auditory cortex in the temporal lobe

Sensorineural Hearing Loss

Most common form of hearing loss, caused by damage in the cochlea’s receptor cells or to the auditory nerve (also called nerve deafness)

Conduction Hearing Loss

Less common form of hearing loss, caused by damage to the mechanical system that conducts sound waves to the cochlea

Cochlear Implant

Device for converting sounds into electrical signals and stimulating the auditory nerve through electrodes threaded into the cochlea

Place Theory

The theory that different sound frequencies activate different locations along the cochlea’s basilar membrane, allowing the brain to determine pitch depending on where the membrane vibrates (also called place coding)

Frequency Theory

The theory that the rate of nerve impulses traveling up the auditory nerve matches the frequency of the tone, thus enabling us to sense its pitch (also called temporal coding)

Nociceptors

Sensory receptors that detect hurtful temperatures, pressure, or chemicals - brain processes these sensations and then produce perceptions of pain (mostly located in skin, but also on other organs)

Gate-Control Theory

Theory that the spinal cord contains a neurological ‘gate’ that blocks pain signals or allows them to pass on to the brain

How does the gate-control theory work?

The ‘gate’ is opened by the activity of pain signals traveling up small nerve fibers and is enclosed by activity in larger fibers or by information coming from the brain

Endorphins

Natural painkillers that are released in response to strong pain or vigorous exercise

Phantom Limb Sensations

Brain may misinterpret and amplify spontaneous but irrelevant central nervous system activity without normal sensory imput from a missing limb

Tinnitus

The phantom sound of ringing in the ears

Who experiences phantom sights/hallucinations?

It occurs in those who lose vision

The 2 factors of memory snapshots that are recorded

1. Pain’s peak (worst moment)

2. Amount of pain at the end

Longer duration of pain=…

less painful over time

What can help reduce pain (other than having it for a longer duration of time)?

Placebos, distractions, and hypnosis

Hypnosis

Social interaction where one person (hypnotist) suggests to another (the subject) that certain perceptions, feelings, thoughts, or behaviors will spontaneously occur

Social Influence Theory

States that hypnosis is a by-product (results from) normal social and mental processes

Dissosiation Therapy

States that hypnosis is a special dual-processing state of dissociation, this theory seeks to explain why, when no one is watching, previously hypnotized people may carry out post-hypnotic suggestions

Dissociation

A split in different levels of consciousness, allows some thoughts and behaviors to occur simultaneously with others

Posthypnotic Suggestions

A suggestion, made during a hypnosis session, to be carried out after the subject is no longer hypnotized

Why are posthypnotic suggestions used by some clinicians?

To help control undesired symptoms and behaviors

Selective Attention

Attention is redirected to a particular stimuli, plays a role in hypnotic pain relief

Gustation

Our sense of taste

How does gustation work?

Each taste bud contains a pore that catches food chemicals and releases neurotransmitters

Olfaction

Our sense of smell

How does olfaction work?

Molecules of a substance carried in the air reach a tiny cluster of receptor cells at the top of each nasal cavity. Olfactory receptors then respond selectively

Pheromones

Chemical substance that can be smelled that affect the behavior or physiology of the person

How do pheromones work?

Hotline runs between brain area receiving info from nose and brain’s limbic centers associated with memory and emotion

Propioceptors

Position and motion sensors all over the body that provide constant feedback to the brain

Kinesthesia

Our movement sense, our system for sensing the position and movement of individual body parts

Vestibular Sense

Our balance sense, our sense of body movement and position that enables our sense of balance

We can be fooled by mechanisms that…

normally give us an accurate experience of the world

Sensory Interaction

The principle that one sense can influence another

The smell of food influences taste. This is an example of…

Sensory interaction

Embodied Cognition

The influence of bodily sensations, gestures, and other states on cognitive preferences and judgements

Synesthesia

The simulation of one sense triggers the experience of another

Some people who hear certain numbers think of it as a specific color in their head. This is an example of…

synesthesia

Extrasensory Perception (ESP)

The controversial claim that perception can occur apart from sensory input. Includes telepathy, clairvoyance, and precognition

Telepathy

Mind-to-mind communication

Clairvoyance

Perceiving remote events (ex. knowing there is a house on fire across the country)

Precognition

Perceiving future events (ex. predicting unexpected events in the next month)

Parapsychology

The study of paranormal phenomena, includes ESP and telekinesis/psychokinesis (mind reading)

Auditory Canal

Tube in the outer ear that collects sound waves and sends them to the eardrum