Week 9 Lecture Flashcards
Define sensation
the manner in which our sense organs receive information from the environment (detection)
Define perception
the manner by which people select, organise and interpret sensations (understanding)
What is transduction?
The manner by which physical energy is converted into a sensory neural impulses
What is the organisation of the sensory system in bottom up processing? (5 steps)
- receptors
- thalamus
- primary sensory cortex
- secondary sensory cortex
- association cortex
What are expectations in what you about to see a part of? (which type of processing?)
top down
What is the neocortex?
The sheet of cells covering the rest of the brain
How many square feet would the neocortex be if it was stretched out?
about two and a half square feet
What is the characteristic organisation of the neocortex? (2)
- 6 stereotypical layers
- types of cells, spatial arrangements and connections are pretty much in the same in every part of the neocortex
How is the neocortex organised in mammals in comparison to humans?
the same characteristic organisation
What is the primary visual pathway?
retina-optic nerve-optic chiasm - thalamus - occipital lobe
What is the primary auditory pathway?
auditory nerve-cochlear nuclei- superior olivary nuclei -inferior colliculus-medial geniculate-auditory corte
All senses except olfaction goes through the what?
thalamus
Describe what multi-sensory integration means”
information is assimilated from various sensory systems and coordinated
What are sound waves caused by?
rapid changes in air pressure caused by vibrating objects
What is pitch?
frequency of vibration measured in hertz
What is loudness?
function of sound waves intensity
What is timbre?
provides information about the nature or complexity of the sound
What are 3 components of auditory stimuli?
- pitch
- loudness
- timbre
Amplitude is what pereptually?
loudness
What is frequency perceptually?
pitch
What is complexity conceptually?
timbre
Where is the primary auditory receptors located?
in the inner ear (cochlea)
What are the hair cells in the cochlea?
convert sound energy to neural impulses and send them along to the primary auditory cortex
What is the pinna?
external ear
What is the tympanic membrane?
eardrum
What is the middle ear?
hollow region containing the ossicles
Where is the middle ear located?
between the tympanic membrane and the cochlea
What are ossicles?
middle ear bone
What is the cochlea?
snail shaped structure of the inner ear containing the organ of corti
What is the organ of corti?
sensory organ for the auditory system
What are 3 important components for hearing?
- basilar membrane
- hair cells
- tectorial membrane
What is the oval window?
opening “door” in the cochlea where the stapes is located.
What is the round window?
opening in the cochlea
Where is the tectorial membrane?
rests on the hair cells
What does the basilar membrane have?
a base and an apex
Where do natural sounds excite the hair cells?
across the membrane
Where do you hear low frequency sounds?
excites hair cells near the apex
Where do you hear high frequency sounds?
excited hair cells near the base
Describe the 2 steps of transduction of auditory information:
- stimulation of hair cells triggers action potentials in the auditory nerve
- activated by mechanical movements of the stapes against the oval window
How much movement is needed to cause an action potential that will generate a noticeable sound?
around 1-100 piccometres
What are tonotopic maps?
cochlea and auditory cortex arranged according to sound frequencies that most effectively stimulate the cells
Where are the two areas of the association areas where auditory signals are conducted?
- prefrontal cortex
2. posterior cortex
Which auditory pathway is more involved in identifying WHAT a sound is?
anterior auditory pathway
Which auditory pathway is more involved in identifying WHERE the sound is?
the posterior cortex
What are odorants?
molecules that give off a smell
Where do odorant binds to?
receptors in olfactory cilia
What are glomeruli?
Clusters of convergent olfactory sensory neurons
What is gustation?
receptors in tongue and oral cavity in clusters of about 50 called taste buds
What are the 4 different primary tastes?
sweet, sour, salty, bitter
What is the 5th primary taste?
umami, meat or savoury
Do salty and sour have their own receptors?
no, they merely act on ion channels
What is the gustatory pathway?
receptors
solitary tract
thalamus
cortex
Somatosensory system is actually 3 separate and interacting systems. What are they?
- exteroceptive
- proprioceptive
- interoceptive
What is the exteroceptive somatosensory system?
external stimuli
What is the proprioceptive somatosensory system?
body position
What is the interoceptive somatosensory system?
internal body conditions (e.g, temperature and blood pressure)
What is Merkel’s disks as a somatosensation
regular touch
What is meissner’s corpuscles, which is a somatosensation receptor?
light touch
What is pacinian corpuscles, which is a somatosensation receptor?
deep pressure (gradual skin indentation)
What is ruffini corpuscles, which are a somatosensation receptors?
temperature
What is a nociceptors, which is a somatosensation receptor?
pain
What is the dorsal column medial lemniscus system?
a somatosensory pathway associated with mainly touch and proprioception
What is the anterolateral system?
a somatosensory pathway which is mainly associated with pain and temperature. Goes straight up to the thalamus, which is one of the reasons that we feel pain and temperature so quickly.
What is hue perceiving?
wavelength
What is brightness perceiving?
intensity
What is saturation perceiving?
purity
What are found only at the fovea?
cones
What are cones responsible for?
photopic (daytime) vision
high acuity colour information in good lighting
What are rods responsible for?
scotopic (nighttime) vision high sensitivity (allowing to see in low light but lacking detail)
What are found only at the fovea?
cones
How many rods are retinal ganglion cells representing?
multiple rods
What is the characteristic response of a lateral geniculate nucleus when light is fully hitting it?
The neurons begin firing like crazy
What is the flow of visual information?
receptor-visual cortex (striate)-visual cortex (prestriate)- visual association cortex
As visual information flows through hierarchy, receptive fields become what?
larger and respond to more complex and specific stimuli.
What is PPC in monkeys?
LIP
As visual information flows through hierarchy, receptive fields become what?
larger and respond to more complex and specific stimuli.
What has stronger connectivity in synesthesia patients?
White matter
