PSYB65H3 Study Guide - Final Guide: Posterior Parietal Cortex, Superior Frontal Sulcus, Parietal Lobe

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PSYB65 ~ Final Textbook Notes
spatial ability: processing position, direction, or movement of objects or points in space
space is construct that includes real space (what you can sense right now) and imagined space (space you can think
about when though can’t directly experience it right now)
when factory analysis used to define spatial ability, made up of 6 skills that correspond to ways we interact with
targeting: how well you can throw object at target
spatial orientation: how well you can recognize items even when they’re placed in different orientations, or
spatial location memory: how well you can remember location of objects
spatial visualization: how well you can imagine how well pieces of an object would go together
disembedding: how well you can find figures hidden within other pictures
spatial perception: how well you can determine where horizontal or vertical is in real world even if given
distracting info
most basic spatial ability is ability to locate point in space
to localize point in space, need to know where point is absolutely and relative position of that point; to know
whether point occupies same location as another point requires depth perception
neurologically normal people can identify location of dot more readily when it occurs in left visual field; interpreted
as being indicative of superiority of RH (right hemisphere) for processing spatial location
RH (especially right pre-frontal cortex) appears to be involved with recall of spatial location info
depth perception: ability to determine relative position of object; another very basic spatial ability; 2 types:
local depth perception: ability to use detailed features of objects point by point to asses relative position
global depth perception: ability to use difference between information reaching each eye to compute entire
visual scene
RH better at determining global depth perception
determination of which object in front of another shows left VF (visual field) advantage in normals; both left and RH
legions disrupt local depth perception
line orientation: ability to localize a line and identify its orientation
RH advantage for both tactile and visual assessment of line orientation
if lines can be described verbally (“horizontal”, “vertical”), often LH advantage emerges
object geometry: whether or not item shares spatial properties with another
RH advantage for judgement of similarity between curved lines when using either visual or tactile modalities
decisions regarding whether or not complex novel figure had been viewed previously more accurate when figure
presented in left VF; RH superior at this task
motion detection and prediction of trajectory are fundamental and complex spatial abilities
in humans, detection of motion related to increased activity in RH; particularly in occipital, temporal, and parietal
areas associated with processing of visual info
mental rotation: rotation that does not occur overtly; abilities rely on RH, as measured by enhanced accuracy in left
VF or tasks of mental rotation that result in greater activation of RH
visual info received in primary visual area (area V1 of occipital lobe or striate cortex), transferred to other areas of
occipital lobe
beyond occipital lobes, info appears to be divided into complementary dorsal and ventral streams
ventral visual stream considered “what” pathway useful for identifying objects
dorsal visual stream considered “how pathway”; one role is to know how motor acts must be performed to
manipulate object; supports spatial processing of info; projects from primary visual areas to parietal regions
properties of cells within areas 5 and 7 sensitive to certain attributes that allow stable cognitive maps to be made
don’t receive much info about colour of object or fine details of object, needed to identify object
seem to respond to movements that occur in specific directions, allowing objects to be tracked in space
respond best to movements similar in speed to walking or running
sensitivity in movement allows area 7 to analyze space and update positions of objects in space
cells in inferior parietal region sensitive to retinotopic representations of space as well as head position, movement,
and speed of movement
monkeys with parietal lobe lesions appear to be quite impaired at computing spatial relations among objects;
human brains work similarly
discrimination of form involves ventral stream, discrimination of spatial location involves dorsal stream
greater activation in right parietal lobes when participants asked to perform tasks that required processing of spatial
some cells in parietal lobe sensitive to visual qualities of object (ex. texture); influence how hands manipulate an
properties of dorsal stream of parietal lobe well suited to processing info about how to interact with objects and
where they are in space
reciprocal connections of parietal lobes with frontal lobes that make dorsal stream important for coordinating
movements with spatial locations of objects
system of parietal cells that project to areas of frontal lobes, to both premotor and prefrontal cortex
these areas receive massive inputs from somatosensory, auditory, and visual association areas of parietal lobes
associative nature of inputs to this system suggest that one of functions is to provide accurate coordinate system of
visual space and to locate objects in space
neurons in posterior parietal cortex respond to stimuli within grasping space and project to frontal motor system to
guide movements
within frontal lobes, also nuclei responsible for directing head and eye movements toward stimuli in grasping space
communicate extensively with parietal lobes, further enhancing our ability to program motor movements aimed
at reaching and grasping objects in space
visuospatial working memory: short-term visuospatial memory; reflected by activation of dorsal premotor cortex
studies also found parietal lobe activation, with activation in other, more frontal areas, including inferior,
middle, and precentral gyri and superior frontal sulcus
also activation within motor areas of frontal lobes, particularly those involved in moving head, such as frontal
eye fields and presupplementary motor area
appears to reflect potential planning of motor movements required if imagined task were real
particularly evident in patients with dorsolateral prefrontal lesions; most impaired when visuospatial
working memory required to guide motor responses
performance of visuospatial working memory tasks engage dorsal stream, and its connections to frontal lobe
evidence suggests dorsal stream involved in identifying where object is in space and guiding motor movements
evidence suggests ventral stream involved in identifying of object (deciding what object it)
studies that implicated parietal and frontal lobes playing role in spatial localization of objects have found that these
tasks resulted in increased activity in temporal lobes
temporal lobes, specifically hippocampal formation, also involved in tasks that require spatial learning
hippocampal formation located within temporal lobes; includes dentate gyrus, specific areas of hippocampus, and
hippocampus receives info from entorhinal cortex, which receives major inputs from various cortical association
areas; hippocampus well placed to integrate info from variety of cortical and subcortical areas
hippocampus appears to engage in processing memory for places; damage to hippocampal formation results in
inability to form new memories for places and difficulty in utilizing spatial info to produce memories about places
place cells within hippocampus respond when rat moving through space; some cells respond only to certain
locations, other cells respond only to other locations
cells within hippocampus respond preferentially and selectively to spatial locations; these cells may form basis of
hippocampus to form memories about space
when we interact with spatial locations of objects, can utilize 3 types of info about object:
position responses: made with movements using body as referent; don’t need any cues external to body,
relatively automatic
cued responses: movements guided by cue(changes in how we perceive stimulus); rely on perception of info
external to body
place responses: made toward particular location or object; can be made when stimulus not currently present;
tend to be relational
intrapersonal space: space immediately around your body, including body
extrapersonal space: space more than 5 feet away from you
position responses performed in intrapersonal space because they require monitoring of space with respect to body
Acredolo test: participant seated at chair in room with table, window, and door; blindfolded and walked around
room; furniture moved without their knowledge; blindfold removed and participant asked to return to original
position; test of spatial ability that can rely on knowledge of intrapersonal space
many of basic spatial abilities performed in extrapersonal space; including targeting, spatial orientations, spatial
location memory, and navigational tasks including both place and cued responses
most studies of extrapersonal spatial abilities require participant to navigate through environment, often mazes
water maze: circular pool filled with milky water, platform submerged just below water’s surface; no identifying
feature within pool or water
must learn spatial relationship between objects in room outside of pool; unlesioned rats do task quickly, rats
with hippocampal lesions can’t find platform
people navigating in virtual make had enhanced activity in right hippocampus; greater activation of right
hippocampus associated with better learning of maze
when taxi drivers performing imagined navigation, enhanced activity in right hippocampus; posterior portion of
hippocampal formation larger than of control group
longer time as taxi driver, larger hippocampus; reflects brain’s ability to change in response to daily demands
that placed on brain; could reflect that only people with large hippocampi stay employed as taxi drivers
dead reckoning: short cuts; ability to use dead reckoning demonstrates place response, indicates good knowledge of
spatial configuration of environment
hippocampus essential for learning spatial configuration on environment or creating map of space
visual info in environment not required for development of map
ability for humans to dead reckon controversial; dead reckoning in complex paths may be skill learned over multiple
ability to learn how to use relational positions of stars or to use sun as compass appears to rely on hippocampal
hippocampus responsible for creation of cognitive maps and for performance of novel complex spatial tasks
caching: hiding food and retrieving it later; hippocampi of birds that cache larger than those that don’t
species who perform complex spatial tasks, like caching, tend to have larger hippocampi; brains of these species
appear to be quite plastic, reducing volume of hippocampus when not in use
spatial ability varies across menstrual cycle in women and across seasons in men

Document Summary

When factory analysis used to define spatial ability, made up of 6 skills that correspond to ways we interact with space: Targeting: how well you can throw object at target. Spatial orientation: how well you can recognize items even when they"re placed in different orientations, or directions. Spatial location memory: how well you can remember location of objects. Spatial visualization: how well you can imagine how well pieces of an object would go together. Disembedding: how well you can find figures hidden within other pictures. Spatial perception: how well you can determine where horizontal or vertical is in real world even if given distracting info. Neurologically normal people can identify location of dot more readily when it occurs in left visual field; interpreted as being indicative of superiority of rh (right hemisphere) for processing spatial location. Rh (especially right pre-frontal cortex) appears to be involved with recall of spatial location info.