THE AUDITORY SYSTEM SENSE OF HEARING

THE AUDITORY SYSTEM Mechanoreception: detection of vibration, perceived as hearing Stimulus: sound waves Sense organ: ears Function: hearing Auditory transduction: transforms sound waves into electrochemical impulses that the brain can interpret

SOUND WAVE PROPERTIES Sound has 3 characteristics: Wavelength: frequency (determines pitch) longer = lower frequency = lower pitch shorter = higher frequency = higher pitch measured in hertz = Hz Wave amplitude: intensity (determines loudness) shorter = less intensity = quieter taller= more intensity = louder measured in decibels = dB roughly every 10 dB doubles loudness Purity: quality (determines timbre/tone saturation) uniqueness of sound

PARTS OF THE EAR Outer ear – air conduction Pinna Auditory canal Middle ear – bone conduction Eardrum (tympanic membrane) Ossicles Hammer (malleus), anvil (incus), stirrup (stapes) Inner ear – fluid conduction Oval window Cochlea Basilar membrane and hair cells Semicircular canals Vestibular sacs Auditory nerve

PITCH PERCEPTION Place Theory Frequency Theory States that each frequency produces vibrations at a particular spot on the basilar membrane. Location Explains high pitched sounds States that the perception of a sound's frequency depends on how often the auditory nerve fires. Neural impulses Explains low pitched sounds

VOLLEY PRINCIPLE Modification of frequency theory stating that a cluster of nerve cells can fire neural impulses in rapid succession, producing a volley of impulses. Fixes limitations of frequency theory

AUDITORY LOCALIZATION We have two ears Sounds may reach one ear faster than the other ear Or sounds may be louder in one ear than another This let’s us locate the sound Our head acts as a “shadow” Sound shadow Can not localize if directly in front, back or above

Conductive Hearing Loss Sensorineural Hearing Loss Hearing loss occurs when sound is not conducted efficiently through the outer ear canal to the eardrum and the tiny bones (ossicles) of the middle ear. Usually involves a reduction in sound level or the ability to hear faint sounds. Can often be corrected medically or surgically Caused by damage to the parts of the ear that connect to the cochlea hearing loss occurs when there is damage to the inner ear (cochlea), or to the nerve pathways from the inner ear to the brain. Most of the time, cannot be medically or surgically corrected. most common type of permanent hearing loss.  reduces the ability to hear faint sounds. Caused by damage to the cochlea or to the auditory nerve Mixed Hearing Loss

HEARING LOSS

THE TACTILE SYSTEM SENSE OF TOUCH

THE TACTILE SYSTEM Mechanoreception: detection of pressure, perceived as touch Thermoreception: detection of temperature; perceived as warm and cold Nociceptors: detection of noxious stimuli; perceived as pain Stimulus: mechanical, thermal, and chemical energy Sense organ: skin Function: touching Tactile transduction: transforms mechanical, thermal, and chemical energy on the skin into electrochemical impulses that the brain can interpret

THE SENSORY SYSTEM Three kinds of receptors: touch temperature warm cold pain Four distinct skin senses: pressure warmth Extreme heat & extreme cold are THE SAME!

PAIN Pain tells the body that something has gone wrong. Congenital Insensitivity to Pain (CIP): A rare disease in which the afflicted person feels no pain. no sense of smell unable to sweat sodium channel mutation

PAIN PATHWAYS Two pain pathways: fast A-delta fibers less than 1 second myelinated slow C fibers a couple of seconds unmyelinated

PAIN PERCEPTION Gate Control Theory: creates neural blockage Studied by Ronald Melzack & Patricia Wall (1965)

ENDORPHINS Neurotransmitters natural opiate morphine-like painkillers

THE GUSTATORY SYSTEM SENSE OF TASTE

THE GUSTATORY SYSTEM Chemoreception: detection of chemical stimuli, perceived as taste Stimulus: soluble chemicals Sense organ: tongue Function: tasting Gustatory transduction: transforms soluble chemicals in food into electrochemical impulses that the brain can interpret

THE OLFACTORY SYSTEM SENSE OF SMELL

THE OLFACTORY SYSTEM Chemoreception: detection of chemical stimuli, perceived as smell Stimulus: volatile chemicals Sense organ: nose Function: smelling Olfactory transduction: transforms volatile chemicals in the air into electrochemical impulses that the brain can interpret

THE KINESTHETIC SYSTEM SENSE OF POSITION & MOVEMENT

THE KINESTHETIC SYSTEM Mechanoreception: detection of vibration, perceived as hearing Stimulus: sound waves Sense organ: ears Function: hearing Auditory transduction: transforms sound waves into electrochemical impulses that the brain can interpret

SENSE OF BALABNCE & MOVEMENT THE VESTIBULAR SYSTEM SENSE OF BALABNCE & MOVEMENT

THE VESTIBULAR SYSTEM Mechanoreception: detection of vibration, perceived as hearing Stimulus: sound waves Sense organ: ears Function: hearing Auditory transduction: transforms sound waves into electrochemical impulses that the brain can interpret

EXTRASENSORY PERCEPTION (ESP) THE 6th SENSE EXTRASENSORY PERCEPTION (ESP)

PARAPSYCHOLOGY The study of paranormal phenomena. Over 75 years of research No evidence of paranormal phenomena exists

EXTRASENSORY PERCEPTION Perception without sensory input. Energy source? Sensory receptors? Paranormal phenomena include: Astrological predictions, psychic healing, communication with the dead, out-of-body experiences, telepathy, clairvoyance, and precognition.

TYPES OF ESP Telepathy: Mind-to-mind communication. One person sending thoughts and the other receiving them. Clairvoyance: Perception of remote events. Precognition: Perceiving future events.