the sensory systems and perception Flashcards
What does illusion show us?
They show us that sensation is actually different from perception
why do we see illusions
brain making sense of the world
Take in information, make mental representation of it
Is the brain making a mistake? No
Perception is a three stage process
Analysis
Synthesis
Perception
what about sensation and perception
Sensation and perception are two separate things
what is a signal
Something that is generated
Something that ‘travels’ to the sense organs
Something that innovates the sense organ
Light sound, chemicals these are signals … energy that arrives at out perceptual organs
whats a modality
A mode of perceptual processing
Hearing, seeing, ‘touch’ are all modalities
When there are two modalities (audiovisual) we refer to multimodal perception
what is sound
A compression of air molecules
Remove the medium and there is no ‘sound’
Medium in this case – air
Where there is no air molecules there’s nothing to innovate the sound
what does a sine wave sound like
whistle
what if its spread out
The more spread out the lower the sound is, closer together more high pitched
more than one sine wave =
complex wave
sensation
what happens at the sense organ
whats perception
involves the brain, thinking, experience, opinion, emotion
what is hearing for?
Speech and other things
parse?
split the world into individual components
sensory threshold
the weakest stimulus that an organism can detect
absolute threshold
the lowest level at which a stimulus can be detected
recognition threshold
the level at which a stimulus can not only be detected but also recognized
terminal threshold
the level beyond which a stimulus is no longer detected
sensory adaptation
when does it happen
The levels of absolute threshold can be influenced by factors such as individual motivations, expectations and adaptation to the stimulus
happens when our senses no longer percieve a stimulus because of our sensory receptors continuous contact with it
light
waves of electromagnetic energy between 380 and 760 nanometers
Humans can only see wavelengths between 400 and 750
what do photoreceptor cells allow
allow for the primary processing these visible wavelengths
visual pathway
Core pathway for vision: retina-geniculate-striate pathway
Signals proceed from each retina via the optic nerve, optic chiasm, optic tract and lateral geniculate nuclei of the thalamus and pulvinar to the primary visual cortex
is there an auditory pathway for visiosn
There is no major auditory pathway like for vision, instead, there is a network of auditory pathways
Axons of auditory pathways synapse in the cochlear nuclei and proceed via the superior olives, lateral lemniscus, inferior colliculi, medial geniculate nuclei in the thalamus to the primary auditory cortex
The primary auditory cortex is located at the transverse temporal gyri, also called the Heschl’s gyri
