Chapter 9 Flashcards
Sensation
acquisition of information
Perception
interpretation of information
Receptor Cell
-specialized neuron that responds to a particular form of energy
-converts energy into a neural response
Adequate Stimulus
energy form for which the receptor is specialized
Law of Specific Nerve Energy
-the nature of perception is defined by the pathway over which the sensory info is carried
-Johannes Peter Müller
Adequate Stimulus for hearing is…
vibration in a conducting medium
Frequency (Hz)
-number or cycles or waves of alternating compression and decompression of the vibrating medium that occur in a second
- Hertz (Hz) = sounds wave per second
Frequency =
-pitch
-high pitch = more sound waves per second
Amplitude (V)
-height of the sounds waves, which dictates intensity
-Voltz (V) = wave amplitude
Amplitude =
-loudness
-def: our experience of sound energy
Pure Sound
sounds comprised of one frequently
Complex Sound
sound comprised of a mixture of frequencies
Pinna
flap of the skin and cartilage protruding from either side of the head
What does the pinna do?
it captures and amplifies sounds o auditory canal
What makes up the outer ear?
-pinna
What makes up the middle ear?
-tympanic membrane (eardrum)
-ossicles
Tympanic membrane (eardrum)
very thin membrane stretched across the end of the auditory canal
Ossicles
tiny bones that operate in a lever-like fashion to transfer vibration from the tympanic membrane to the cochlea
Ossicles are comprised of…
-maleus (hammer)
-incus (anvil)
-stales (stirrup)
Inner ear is made up of …
cochlea
Cochlea
-contains sound analyzing structures
-subdivided into 3 fluid filled chambers
Vestibular Canal
point of entry of sound
Tympanic Canal
-allows pressure waves to travel in cochlear fluid
Basilar Membrane
-contains hair cells
-vibration passed from cochlear canal
Hair cells
-receptors for auditory stimulation
- vibration bends the hair cells, opening Ca+ and K+ channels (depolarization)
- when the hair cells move back in the opposite direction, K+ channels close
2 Sets of Hair Cells
- single row of about 3,500 inner hair cells, which provides about 90-95% of auditory neurons (provide majority of auditory info)
- three rows of 12,000 outer hair cells, which increase the cochlea’s sensitivity
Auditory Pathway
auditory (8th cranial nerve) -> inferior colliculi (sound from both ears converge) -> medial geniculate nucleus (mostly opposite ear info) -> primary auditory cortex (temporal lobe)
Topographical Organization
neurons of adjacent receptor locations in the ear (hair cells) project to adjacent cells in the cortex
Dorsal Stream
- auditory cortex -> parietal loves -> frontal lobes
- “where” the sound is
Ventral Stream
-travels from the temporal lobe to the frontal lobes
- secondary auditory areas are involved in analyzing sounds and understanding their meaning
-“what” the sound is
Cocktail Party Effect
ability to sort out meaningful sounds embedded in confusing background of sounds
Selective Attention
our brain enhances some sounds around us and suppresses others
Auditory objects
a sound we identify as distinct from others
Identify Sounds
-voices are identified in the superior temporal lobe
-environment sounds are identified in the posterior temporal areasa
