Perception/neuropsychology Flashcards
sensation is…
receiving sensory information from the environment from sensory organs (such as nose, eyes, ears).
These translate energy into language for the brain
Perception is…
the interpretation of the information receiving from the sensory organs
process of perception
- sensory organs absorb energy
- that energy is transduced into a neutral signal
- the neutral signal is sent throughout the brain for further processing
primates are only responsive to a small part…
of the electromagnetic spectrum
what does the cornea do?
it is transparent and focusses images onto the retina
Cones VS Rods
Cones: colour, daytime, high resolution
Rods: no colour, night time, low resolution
what does the ventral system do?
responsible for ‘what’
- pattern perception
- in the temporal lobe - damage to this causes decreased performance on object tasks
what does the dorsal system do?
responsible for ‘where’
- spatial location
- parietal lobe - damage to this decreased performance on landmark tasks
steps of information processing of visual neurons
simple to complex (builds a picture by breaking down objects into different stages)
1. rods/cones
2. retinal ganglion cells
3. lateral geniculate neurons (LGN)
4. V1 cells
5. V2 cells
6. Beyond V1
Rods and cones are responsible for?
detecting changes in illuminations
V1 cells are responsible for?
lines
retinal ganglion cells are responsible for?
spots of light/dark
V2 cells are responsible for?
specific lines of length
LGN is responsible for?
spots of light
Beyond V1 are responsible for?
complex shapes/stimuli
retinotopic mapping is… and what is … it mapped onto
the point - to - point mapping of the external/visual world onto photo-receptors
retina, LGN, V1(up to V1)
Receptive field
the area of the retina which, when stimulated by light, causes a change in the neural activity of the cell
Lateral Inhibition
neuron sending units forward BUT while doing so it is inhibiting its neighbour
lateral inhibition increases….
contrast allowing for increased sensory perception and reduced work for neighbouring cells
the capacity for excited neurons…
to reduce the activity of their neighbours
‘small light in a dark room’ is an example of what?
lateral inhibition
receptors on the retina central to the stimulus are activated/ excited
receptors peripheral to the retina send inhibitory signals
this therefore enhance the perception of the surrounding darkness
herman grid illusion can be explained by
lateral inhibition
less black surrounding, creating emphasis on the brightness between intersections - creating illusion of the grey dots.
how many rods / cones
rods: 120 mil
cones 7 mil
What two structures in the eye are responsible for focusing the image on the retina?
cornea and lens
monosynaptic stretch reflex
reflex that only contains one space for an action potential
polysynaptic stretch reflex
complex reflex that contains many connections between neurons
