Chapter 7 - Non-Vision Senses Flashcards
What are sound waves?
Undulating displacement of molecules by CHANGING PRESSURE
Compression/rarefaction of molecules in a fluid (squishing together & spreading apart)
What are 3 properties of waves and their related quality?
- Amplitude: loudness
- Frequency: pitch
- Purity: timbre
What are pure tones?
What are complex tones?
Sounds w/ a SINGLE frequency
Sounds w/ a MIXTURE of frequencies
What is fundamental frequency?
RATE of which the COMPLEX waveform pattern repeats
What are overtones?
Set of HIGHER-FREQUENCY sound waves that vibrate at whole-number multiples of the fundamental frequency
What do complex tones contain?
Waveforms of the notes C, E and G
First wave in EACH = is the fundamental frequency
Secondary waves are = overtones
What is the auditory system function?
Explain the path
COLLECTS sound waves from the surrounding air
CONVERTS (transduces) mechanical energy —> electrochemical neural energy (frequency, amplitude & complexity) —> routed through BRAINSTEM —-> AUDITORY CORTEX
What is the first step in hearing?
PINNA catches sound waves and DEFLECTS them into external ear canal
What are the 3 major parts of the ear?
External ear: pinna & ear canal
Middle ear: ossicles
Inner ear: the cochlea
***SOUND CONDUCTED DIFF IN EACH
What is included in the external/outer ear?
Pinna:
- funnel-like structure designed to CATCH sound waves and deflect them into ear canal
External ear canal:
- AMPLIFIES sound waves somewhat & directs them to the EARDRUM (vibrates the frequency of sound wave)
What is the second step in hearing?
Waves are amplified and directed to eardrum (causing to vibrate)
What is the third step in hearing?
The ossicles vibrate
What is the fourth step in hearing?
Ossicles amplify and convey vibrations to the oval window
What is included in the middle ear?
Ossicles:
- hammer (malleus)
- anvil (incus)
- stirrup (stapes)
Connects the eardrum (tympanic membrane) to the oval window of the cochlea- located in inner ear
What is included in the inner ear?
Cochlea:
- FLUID-FILLED ear canal that contains AUDITORY RECEPTOR CELLS
Organ of corti:
- receptors cells and the cells that support them
Basilar membrane:
- RECEPTOR SURFACE in the cochlea that transduces sound waves —> neural activity
Hair cells:
- SENSORY NEURONS in the cochlea tipped by CILIA
Tectorial membrane:
- membrane OVERLYING HAIR CELLS
What are 2 theories of hearing?
- Place theory:
- pitch perception corresponds to the VIBRATION OF DIFF PORTIONS, or places along the basilar membrane - Frequency theory:
- pitch perception corresponds to the RATE/FREQUENCY at which the BASILAR MEMBRANE VIBRATES
Low-frequency tones appear to be translated into pitch through “____________ ________”
High-frequency pure tones appear to rely on “_______ ________”
Complex tones depending on “_________ ___________” of place and frequency coding
Frequency coding
Place coding
Complex combinations
What are 2 types of hair cells? (Used in transduction)
**FOCUS - Inner hair cells:
- auditory receptors
- 3 500 total
Outer hair cells:
- alter stiffness of tectoral membrane
- 12 000 total
***MOVEMENT OF BASILAR MEMBRANE CREATES = BENDING/SHEARING IN HAIR CELLS
Movement if cilia on hair cells changes “_________ ________” and alters “______________” release
What are the 2 directions?
Membrane potential; neurotransmitter
- Depolarization:
- Ca2+ channels open, more neurotransmitters = more action potentials - Hyperpolarization:
- neurotransmitter release decreases = decreasing neuron activity
What is the pathway to the auditory cortex?
5 STEPS
- Inner hair cells SYNAPSE on bipolar cells whose axons form the AUDITORY/COCHLEAR NERVE
- Enters the BRAINSTEM (HINDBRAIN) at the level of the medulla, SYNAPSES in the COCHLEAR NUCLEUS (goes to both hemispheres & some stays on some side/some crosses)
- Cochlear nucleus projects to SUPERIOR OLIVE & TRAPEZOID BODY
- From the hindbrain, info projects into the INFERIOR COLLICULUS in the dorsal midbrain
- TWO distinct pathways from inferior colliculus:
*ventral medial geniculate nucleus —> primary auditory cortex (A1)
*dorsal medial geniculate nucleus —> other auditory regions around A1
Where does the primary auditory cortex (A1) lie?
Where does the secondary cortex (A2) lie?
A1= W/IN HESCHL’S GYRUS in LEFT HEMISPHERE
(Has specialized response to music in right hemisphere)
——————————————————————————-
A2 = BEHIND HESCHL’s GYRUS
What is Wenicke’s area?
POSTERIOR SPEECH ZONE at the rear of the LEFT TEMPORAL LOBE
Regulates LANGUAGE COMPREHENSION
What is lateralization?
Whereby FXN’s become localized primarily on ONE SIDE of the BRAIN
Speech = largely in LEFT hemisphere
Musical sounds = largely in RIGHT hemisphere
About “___%” of left-handers are similar to right-handers, having language in the left hemisphere
In the remaining “___%” speech is represented either in the right or bilaterally
70%; 30%
What is the insular cortex? (Insula)
MULTIFXN CORTICAL TISSUE containing regions related to…
- language
- perception of taste
- neural structures underlying social cognition
Located W/IN LATERAL FISSURE
INJURY = can produce disturbances to both LANGUAGE & TASTE
What is the auditory tonotopic map?
Representation of the basilar membrane is PRODUCED in the cochlear nucleus
Systematic representation is maintained thought AUDITORY PATHWAYS & into the PRIMARY AUDITORY CORTEX
What are 2 ways we can detect location?
- Neurons in BRAINSTEM compute difference in a sound waves arrival time at EACH EAR
= interaural TIME difference - RELATIVE LOUDNESS on the left & right
= interaural INTENSITY difference
Compare the auditory ventral and dorsal pathways…
- Ventral pathway:
- decodes spectrally COMPLEX SOUNDS
- auditory object recognition
- meaning of speech sounds - Dorsal pathway:
- integrates AUDITORY & SOMATOSENSORY info to control SPEECH PRODUCTION
- audition for action
What is the difference between innate and learned?
- Innate:
- Noam Chomsky & Steven pinker
- GENETIC CONSTRAINTS reposndibke for common structural characteristics across languages - Learned:
- experience REQUIRED for language learning
- sensitive period 1-3 yrs of age