Sound & the Sound & the EarEar

AmplitudeAmplitudeIntensity of the sound waveIntensity of the sound wave

Loudness: the perception of intensityLoudness: the perception of intensity

FrequencyFrequencyNumber of compressions per second Number of compressions per second measured in Hzmeasured in Hz

PitchPitchPerception closely related to frequencyPerception closely related to frequency

The higher the frequency, the higher The higher the frequency, the higher the pitchthe pitch

Structure of the Structure of the EarEar

Outer EarOuter EarIncludes the Pinna & External Auditory Includes the Pinna & External Auditory CanalCanal

Middle EarMiddle EarIncludes the Eardrum, & Auditory Includes the Eardrum, & Auditory OssiclesOssicles

Inner EarInner EarIncludes the Oval Window & the Includes the Oval Window & the CochleaCochlea

The Cochlea contains the auditory The Cochlea contains the auditory receptorsreceptors

When the fluid in the Cochlea vibrates it When the fluid in the Cochlea vibrates it stimulates the hair cells which stimulate stimulates the hair cells which stimulate the Auditory Nerve Cellsthe Auditory Nerve Cells

Theories of Theories of HearingHearing

Frequency TheoryFrequency TheoryEntire Basilar Membrane acts like a Entire Basilar Membrane acts like a microphone, vibrating as a whole in microphone, vibrating as a whole in response to sound. The nerve response to sound. The nerve receptors send out impulses that are receptors send out impulses that are tied directly to the frequency of the tied directly to the frequency of the sounds: Frequency = Impulsessounds: Frequency = Impulses

Place TheoryPlace TheoryDifferent areas of the Basilar Different areas of the Basilar Membrane respond to different Membrane respond to different frequencies. High tones register frequencies. High tones register most strongly at the base of the most strongly at the base of the cochlea (near the oval window), cochlea (near the oval window), lower tones mostly move the hair lower tones mostly move the hair cells near the tip of the Cochleacells near the tip of the Cochlea

Theories of Theories of HearingHearing

Volley Volley PrinciplePrincipleFor Pitch Discrimination: For Pitch Discrimination: Sound waves produce a Sound waves produce a volley of impulses by volley of impulses by auditory nerve fivers, which auditory nerve fivers, which in turn signal high in turn signal high frequencies to the brainfrequencies to the brain

Current TheoryCurrent TheoryCombines Both Frequency & Combines Both Frequency & Place TheoriesPlace Theories

The Volley Principle is important The Volley Principle is important for pitch perception in middle for pitch perception in middle frequency sounds (100 – 5000 frequency sounds (100 – 5000 Hz)Hz)

High frequency sounds (+5000 High frequency sounds (+5000 Hz) the Place Theory worksHz) the Place Theory works

Low frequency sounds (-100 Hz) Low frequency sounds (-100 Hz) the Frequency Theory worksthe Frequency Theory works

Pitch Perception in the Pitch Perception in the Cerebral CortexCerebral Cortex

Subcortical StructuresSubcortical StructuresAuditory information passes through Auditory information passes through several subcortical structures with an several subcortical structures with an important crossover at Midbrainimportant crossover at Midbrain

Crossovers enable each hemisphere of the Crossovers enable each hemisphere of the forebrain to get its major auditory input forebrain to get its major auditory input from the opposite earfrom the opposite ear

Primary Auditory Primary Auditory CortexCortexAuditory information destined for the Auditory information destined for the temporal lobe with cells responding to temporal lobe with cells responding to location; another part responds to toneslocation; another part responds to tones

The cortical area with the greatest response The cortical area with the greatest response indicates what sound or sounds are heardindicates what sound or sounds are heard

Hearing LossHearing LossConduction DeafnessConduction Deafness(Middle-ear deafness) Failure of (Middle-ear deafness) Failure of the ossicles to transmit sound the ossicles to transmit sound waaves properly to the cochleawaaves properly to the cochlea

Nerve DeafnessNerve Deafness(Inner-ear deafness) Damage to (Inner-ear deafness) Damage to the cochlea, hair cells, or auditory the cochlea, hair cells, or auditory nerve causing permanent nerve causing permanent impairment in hearing in one or all impairment in hearing in one or all ranges of frequenciesranges of frequencies

Stimulation DeafnessStimulation DeafnessCaused by excessive stimulation Caused by excessive stimulation of the hair cellsof the hair cells

TinnitusTinnitusFrequent or constant ringing in Frequent or constant ringing in the ear(s)the ear(s)

The Vestibular The Vestibular SensesSenses

The Vestibular The Vestibular OrganOrganComprised of 2 Otolith Organs Comprised of 2 Otolith Organs (the Saccule & Uricle) & 3 (the Saccule & Uricle) & 3 Semicircular CanalsSemicircular CanalsMonitors head movements & Monitors head movements & directs compensatory movements directs compensatory movements of the eyesof the eyesOtoliths lie next to hair cells & Otoliths lie next to hair cells & excite them when the head tiltsexcite them when the head tiltsAcceleration of the head causes Acceleration of the head causes the jelly-like substance in the the jelly-like substance in the Semicircular canals to push Semicircular canals to push against the hair cells causing against the hair cells causing action potentialsaction potentials

SomatosensationSomatosensationKinesthetic SenseKinesthetic SenseInvolves sensation of the body Involves sensation of the body & its movements& its movements

Touch, Pressure, Touch, Pressure, etc.etc.Includes discriminative touch, Includes discriminative touch, deep pressure, cold, warmth, deep pressure, cold, warmth, pain, itch, tickle, & the pain, itch, tickle, & the position & movements of the position & movements of the jointsjoints

Pancinian Pancinian CorpusclesCorpusclesDetects sudden displacements Detects sudden displacements or high-frequency vibrations or high-frequency vibrations on the skinon the skin

PainPainNeurotransmittersNeurotransmittersMild pain release is Mild pain release is GlutamateGlutamate

Stronger pain release is Stronger pain release is Substance PSubstance P

Opioid MechanismsOpioid Mechanisms

Systems that respond to Systems that respond to opiate drugs & similar opiate drugs & similar chemicals block Substance Pchemicals block Substance P

Opiate receptors in the brain Opiate receptors in the brain bind to Endorphinsbind to Endorphins

Met-enkephalin, leu-Met-enkephalin, leu-enkaphalin, & beta-enkaphalin, & beta-endorphinendorphin

Endorphins inhibit Endorphins inhibit painpain

The Gate Theory of The Gate Theory of PainPain

Information Not Related to Information Not Related to Pain Travels to the Spinal Pain Travels to the Spinal Cord & Closes “Gates” for Cord & Closes “Gates” for each Pain Messageeach Pain MessagePain Gates Closed by Pain Gates Closed by Stimuli through the Stimuli through the Activation of Neurons that Activation of Neurons that release Endorphins in the release Endorphins in the Periaqueductal Gray Area Periaqueductal Gray Area in the Midbrainin the MidbrainEndorphins Block the Endorphins Block the release of Substance P in release of Substance P in the Spinal Cord & the Spinal Cord & Brainstem Brainstem

Painful HeatPainful HeatBurns Detected Burns Detected by Special Heat by Special Heat Receptors Receptors Stimulated by Stimulated by AcidsAcids

CapsaicinCapsaicinChemical that stimulates heat receptors & Chemical that stimulates heat receptors & found in hot peppers & jalapenosfound in hot peppers & jalapenos

Causes neurons to release Substance PCauses neurons to release Substance P

Eventually leads to pain insensitivityEventually leads to pain insensitivity

High doses can cause damage to pain High doses can cause damage to pain receptorsreceptors

Other Aspects Other Aspects of Painof Pain

Pain & EmotionPain & EmotionPain is a sensation but Pain is a sensation but how much it hurts is an how much it hurts is an emotional reactionemotional reaction

Pain activates both the Pain activates both the sensory pathway to the sensory pathway to the somatosensory cortex & a somatosensory cortex & a pathway to the pathway to the hypothalamus, amygdale, hypothalamus, amygdale, & cingulate cortex& cingulate cortex

These areas are These areas are important for important for

emotional emotional responsesresponses

Sensitization of PainSensitization of PainBody mechanisms exist Body mechanisms exist that increase pain after that increase pain after tissue damagetissue damage

Pain sensitization is the Pain sensitization is the result of the body result of the body releasing histamine, NGF, releasing histamine, NGF, & other chemicals & other chemicals necessary to repair the necessary to repair the bodybody

Nonsteroidal anti-Nonsteroidal anti-inflamatory drugs inflamatory drugs decrease pain by reducing decrease pain by reducing the release of chemicals the release of chemicals from damaged tissuesfrom damaged tissues

Other Aspects Other Aspects of Painof Pain

Pain ControlPain ControlMorphine & other opiates Morphine & other opiates are primary for serious are primary for serious painpain

Problem with opiate Problem with opiate addictionaddiction

Placebos can sometimes Placebos can sometimes relieve pain or at least relieve pain or at least subjective distresssubjective distress

ItchingItchingThe receptors have yet to The receptors have yet to be identifiedbe identified

The release of The release of histamines histamines produces produces itchingitching

Itching directs you to Itching directs you to scratch an area removing scratch an area removing whatever is irritating the whatever is irritating the skinskin

Itch is not a type of painItch is not a type of pain

TasteTasteStimulating the Stimulating the Taste BudsTaste BudsTaste differs from flavorTaste differs from flavor

Taste ReceptorsTaste ReceptorsModified skin cellsModified skin cells

Taste receptors located in taste buds in the Taste receptors located in taste buds in the papillae on the surface of the tonguepapillae on the surface of the tongue

Kinds of TastesKinds of Tastes5 types of tastes5 types of tastes

Taste Coding in Taste Coding in the Brainthe BrainTaste depends on a pattern of responses Taste depends on a pattern of responses across taste fibersacross taste fibers

OlfactionOlfactionOlfactory ReceptorsOlfactory ReceptorsOlfactory Cells line the Olfactory Epithelium Olfactory Cells line the Olfactory Epithelium which is responsible for olfactionwhich is responsible for olfaction

Each cell has cilia where receptor sites are Each cell has cilia where receptor sites are locatedlocated

Replaced every monthReplaced every month

Axons of the olfactory receptors carry Axons of the olfactory receptors carry information to the olfactory bulbinformation to the olfactory bulb

Olfactory bulb sends axons to several specific Olfactory bulb sends axons to several specific parts of the cortex with precise connections parts of the cortex with precise connections

From the cortex, information is sent to other From the cortex, information is sent to other areas that control feeding & reproductionareas that control feeding & reproduction

Olfactory DisorderOlfactory DisorderAnosmia: the general lack of olfactionAnosmia: the general lack of olfaction

Specific Anosmia: the inability to smell a Specific Anosmia: the inability to smell a specific chemicalspecific chemical

Vomeronasal Vomeronasal SensationSensation

Vomeronasal OrganVomeronasal OrganLocated near the olfactory Located near the olfactory receptorsreceptorsHave a different structure than Have a different structure than the olfactory receptorsthe olfactory receptors

PheromonesPheromonesChemicals released by an animal Chemicals released by an animal that affects the behavior of other that affects the behavior of other members of the speciesmembers of the speciesVMO receptor is specialized to VMO receptor is specialized to respond to only one pheromonerespond to only one pheromoneVMO has no receptors in humansVMO has no receptors in humansHumans respond to pheromones Y Humans respond to pheromones Y have at least one type of receptor have at least one type of receptor in the olfactory mucosain the olfactory mucosaPheromones play a role in human Pheromones play a role in human & animal sexual behavior& animal sexual behavior

Subliminal Subliminal PerceptionPerception

Below Conscious Below Conscious AwarenessAwarenessHave No Influence on Have No Influence on BehaviorBehaviorExert subtle & demonstrable Exert subtle & demonstrable effectseffectsCan slightly influence behaviorCan slightly influence behaviorConscious & unconscious Conscious & unconscious material activate the same material activate the same areas of the occipital & areas of the occipital & temporal cortextemporal cortexConscious material activates Conscious material activates the prefrontal & parietal the prefrontal & parietal corticescorticesThe consciousness of a The consciousness of a stimulus depends on how stimulus depends on how strongly it arouses the brainstrongly it arouses the brain

NeglectNeglectOpposite of AttentionOpposite of AttentionCaused by certain types of brain damageCaused by certain types of brain damage

Spatial (Visual Neglect)Spatial (Visual Neglect)Tendency to ignore the left side of the body & itsTendency to ignore the left side of the body & itssurroundings, including visual, auditory, & touchsurroundings, including visual, auditory, & touchDamage to superior temporal gyrus in the rightDamage to superior temporal gyrus in the righthemispherehemisphere

ADHDADHDCharacteristics:Characteristics:Distractibility, fidgetiness, impulsivity, Distractibility, fidgetiness, impulsivity, mood swings, short temper, high sensitivity mood swings, short temper, high sensitivity to stress, & impaired ability to make & to stress, & impaired ability to make & follow plansfollow plans

Diagnosis TasksDiagnosis TasksChoice-delay task: choice between choice between immediate reward or a larger reward laterimmediate reward or a larger reward laterStop signal task: wait for a signal & make a wait for a signal & make a response as soon as the signal occurs response as soon as the signal occurs unless another signal follows the 1unless another signal follows the 1stst signal signal which means to disregard the 1which means to disregard the 1stst signal signalAttention blink task: watch a series of black watch a series of black letters with one blue letter flashed on the letters with one blue letter flashed on the screen – another letter is designated as the screen – another letter is designated as the probe letter & may or may not follow the probe letter & may or may not follow the blue letter – the task is to name the blue blue letter – the task is to name the blue letter & state whether the probe letter came letter & state whether the probe letter came after the blue letterafter the blue letter

ADHDADHDPossible CausesPossible CausesADHD runs in familiesADHD runs in families

One form of dopamine receptor gene (DOne form of dopamine receptor gene (D44) ) slightly more common in ADHDslightly more common in ADHD

Brain volume 95% of normals with a Brain volume 95% of normals with a smaller than average right prefrontal cortex smaller than average right prefrontal cortex & cerebellum& cerebellum

Brain differences inconsistentBrain differences inconsistent

TreatmentsTreatmentsStimulant drugs (Ritalin or amphetamines)Stimulant drugs (Ritalin or amphetamines)

These increase the availability of dopamine These increase the availability of dopamine at the postsynaptic receptorsat the postsynaptic receptors

Attentiveness is increased, school Attentiveness is increased, school performance & social relationships performance & social relationships improved, & impulsiveness is decreasedimproved, & impulsiveness is decreased

Behavioral techniques are used to Behavioral techniques are used to supplement or substitute for drugs: lists, supplement or substitute for drugs: lists, calendars, schedules, etc. to organize time, calendars, schedules, etc. to organize time, pacing strategies, & learning to relaxpacing strategies, & learning to relax

They reduce distractionThey reduce distraction