Textbook Notes (362,730)
Canada (158,028)
Psychology (3,256)
PSYC 2410 (149)

Audio-Somato-Chemo Notes.pdf

27 Pages
Unlock Document

University of Guelph
PSYC 2410
Elena Choleris

AUDITION Perception of sound – the perception of objects through the sounds that they make Sound: vibration of air molecules – a material wave Joseph FOURIER 1768 - 1830 A complex wave can be expressed as the sum of simple sine waves Fourier Analysis 1 Fourier analysis Human perception: 20 – 20,000 Hz (cycles per sec) Cats: 100 - 32,000 Bats: 1,000 - 150,000 Dogs: 40 - 46,000 Grasshoppers/ locusts: 100 - 50,000 Horses: 31 - 40,000 Rodents: 1,000 - 100,000 Elephants: 16 - 12,000 Whales and dolphins 70 - 150,000 Cattle: 16 - 40,000 Seals/sea lions: 200 - 55,000 Below human perception (<20 Hz): infrasounds Above human perception (>20,000 Hz): ultrasounds 2 Pinna Semicircular canals (vestibular system) Auditory Canal (eardrum) Inner Ear Middle Ear External Ear Ossicles (small bones) Malleus (=hammer) Incus (=anvil) Stapes (=stirrup) Eustachian tube (connected with the throat) 3 Image from: BrainConnection.com ORGAN OF CORTI Fluid rich in K+ and Ca++ ions 4 5 The Scientist, May 10, 2004, page 25 after Kolb & Wishaw 2001 6 (Stiff) Image from: BrainConnection.com The tonotopic organization of the basilar membrane Image from: BrainConnection.com Pathways of the Auditory System: a network Tonotopic Organization Both ipsilateral and contralateral VIII cranial nerve 7 AUDITORY CORTEX 2 Areas of Primary Auditory Cortex 7 Areas of Secondary Auditory Cortex Columnar and Tonotopic Organization: each cortical column is optimally responsive to one dominant frequency range. Organized hierarchically: primary auditory cortex  simple sounds, pure tones secondary auditory cortex  complex sounds, specific voices, music, etc. Posterior- parietal association cortex Prefrontal association cortex Figure 7.8 8 AUDITORY SYSTEM DAMAGE 1) Auditory cortex damage Conductive deafness 2) Deafness Nerve deafness e.g. age-related 3) Tinnitus Image courtesy of Advanced Bionics SOUND LOCALIZATION We can localize sounds because we have two ears… … and because they are far apart Phase difference  medial superior olives  superior colliculus Superior colliculus: two spatial maps 1. auditory map (deep layer) 2. retinotopic map (superficial layer) Amplitude difference  lateral superior olives  inferior colliculus 9 ECHOLOCATION Great horned owl Bechstein's bats Bubo virginianus Myotis bechsteinii ECHOLOCATION VESTIBULAR SYSTEM - 1 Semicircular canals Bone structures around a membranous canal On the three planes of the head (sagittal, transverse, horizontal). Ampulla: enlargement at the base of each canal. Contains the receptors Vestibular Sacs (utricle and saccule): roundish. Also contain receptors, on the “wall” of the saccule and on the “floor” of the utricle Endolymph: fluid contained in the vestibular system 10 VESTIBULAR SYSTEM - 2 Receptors: Hair cells, with cilia Embedded in a gelatinous mass (cupola) Otoconia: small crystals of Calcium Carbonate. VESTIBULAR SYSTEM - 3 Receptors in the ampullas: angular acceleration Receptors in the vestibular sacs: linear acceleration VESTIBULAR PATHWAY Vestibular nerve Medullar Many projections: (part of the VIII Vestibular nuclei Cerebllum cranial nerve) Pons, Spinal Cord Projections to eye muscles Temporal cortex help keep the eyes still in (maybe) space as the head moves 11 SOMATOSENSATION (Ch. 7) Sensations from the surface and the inside of the body Exteroceptive System: external stimuli applied to the skin (mechanical, nociceptive (pain), and thermal). Proprioceptive System: stimuli on body position. From muscles, joints and organs of balance (e.g., vestibular system in inner ear). Interoceptive System: stimuli within the body (e.g. blood pressure, internal temperature; autonomic sensory information). Soma = body CUTANEOUS RECEPTORS (Skin) Free nerve endings Pacinian Corpuscles Merkel’s Disks Ruffini Ending Faster adaptation: Free nerve endings: simplest - no particular structure - respond best to temp changes and pain Pacinian corpuscles: largest and deepest - sudden skin displacement Slower adaptation: Merkel’s disks: gradual skin indentation (superficial) Ruffini ending: gradual skin stretch (deeper) 12 CUTANEOUS RECEPTORS - 2 Touch Temperature Pain CUTANEOUS RECEPTORS - 2 Touch: Sensitivity to pressure and vibration. Pacinian Corpuscles. Merkel’s Disks and Ruffini Ending. Temperature: Two types of receptor: warmth and coolness. Free nerve endings. CUTANEOUS RECEPTORS - 3 Pain: 3 types of pain receptors (nociceptors). 1- High-threshold mechanoceptors. Intense pressure. Striking, stretching or pinching. Free nerve endings. 2- Extreme heat, acids and capsaicin. Burning and inflammatory pain. Free nerve endings. 3- Pain of migraine, angina, muscle damage and cancer. ATP-dependent ionotropic receptor (Na and Ca ). ATP release following spasms of blood vessels. 13 CUTANEOUS RECEPTORS - 4 Adaptation: receptors respond optimally to pressure changes, not to constant pressure. A moderate constant stimulus will stop producing sensation after a short time (e.g., clothes, hat). Different receptors have different adaptation rates.  info about static and dynamic tactual stimuli Stereognosis: identification of objects by touch Because of adaptation, we need to move object around in hands. DERMATOMES Areas of innervation of each pair of sensory nerves that enters the spinal cord through the dorsal root Somatosensory Ascending Pathways The Dorsal-Column Medial-Lemniscus System The Anterolateral System 14 The Dorsal-Column Medial-Lemniscus System Touchand Proprioception - contralateral Decussation - ipsilateral The Anterolateral System Pain and Temperature 1- Spinothalamic Tract 2- Spinoreticular Tract 3- Spinotectal Tract Decussation SOMATOSENSORY CORTEX Penfield studies in 1937 Primary somatosensory cortex (SI): post-central gyrus contralateral sensations Secondary somatosensory cortex (SII): ipsilateral and contralateral (mostly) sensations. Other secondary somatosensory cortices: two sma
More Less

Related notes for PSYC 2410

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.