LEC 9: spatial cognition Flashcards
anterior parietal lobe
somatosensory representations (not apart of dorsal stream proper)
posterior parietal cortex (PPC)
multisensory and crucial to spatial cognition
three pathways that project from dorsal stream
- PC to prefrontal cortex
- PC to premotor cortex
- PC to medial temporal cortex
parietal cortex to prefrontal cortex
supports spatial working memory
parietal cortex to premotor cortex
supports guided actions (like reaching and grasping)
parietal cortex to medial temporal
supports spatial navigation
cells in PPC are most responsive to and not sensitive to
responsive to:
- combination of retinal location of obj & position of eyes/head
- specific direction of motion
not sensitive to:
- color or form
- or central foveal focus
stereoscope
allows for 2 images to be presented to each eye separately
when images depict objs at slightly diff angles, it creates perecetion of depth
how is depth perception computed
binocular (2 eyes) and monocular (1 eye)
depth perception helps us
localize items in near-far plane
binocular disparity
(binocular depth cue) discrepancy btwn images seen by 2 eyes
motion parallax
(monocular cue) perceive motion of thinsg closer as faster
and motion of things farther as slower or staying put
egocentric reference frame
reference where something is relative to viewer
allocentric reference frame
maps relative to btwn objs
categorical spatial relations
position of one location relative to another (above vs below, etc)
left hem specialization
coordinate (or metric) spatial relations
distance btwn 2 locations
right hem specialization
corollary discharge theory
motor regions of brain could let visual system know when eye movements are planned
optic ataxia
damage to parietal lobe
impariment in visually guided reaching
3 diff characteristics of PPC developing reference frames
- spatial representations encoded in PPC go beyond eye-centered representations in primary visual cortex (PPC cells go beyond retinotopy - aka left visual field)
- diff subpopulations of PPC cells participate in coding space for diff functions (PPC cells show specialization for egocentric vs allocentric recognition)
- coding of location is dynamic process that must constantly take into account the changing position of eyes (constantly adapting and changing as eyes move)
2 types of spatial nav
cognitive map based or route based
map based navigation
constructing a map w/in your head
route based
based on directions like turn left
not based on mental map
parahippocampal place area PPA
encodes landmarks
strongly associated w spatial navigation
retrosplenial complex RSC
determine loation of self
damage leads to prbs of spatial navigation