the parietal lobes Flashcards
identify the name of the border between the frontal lobe and the parietal lobe
central sulcus
identify the name of the border between the occipital lobe and the parietal lobe
parieto-occipital fissure
identify the name of the border between the temporal lobe and the parietal lobe
lateral sulcus
identify the two parts of the parietal lobe
1/ postcentral gyrus
2/ posterior parietal lobe
describe the postcentral gyrus
- contains the central sulcus
- contains postcentral sulcus
describe the posterior parietal lobe
- behind postcentral gyrus
- top part = superior parietal lobe
- intraparietal lobe = separates the superior parietal lobe with the inferior parietal lobe
- bottom part = inferior parietal lobe
identify major functional subdivisions of the parietal lobe
- primary somatosensory cortex (S1)
- posterior parietal cortex
- Intraparietal sulcus and superior parietal lobule
- Right inferior parietal lobule
- Left anterior parietal lobule
- Left posterior inferior parietal lobule
explain the function of the primary somatosensory cortex (S1)
- main role = processing sensory information (touch, pain, perception of awareness, NOT thermal regulation)
- input = from thalamus and motor cortex
- output = motor cortex and posterior parietal cortex
outline Penfield and Boldrey (1937) study into the primary somatosensory cortex
- inserted electrodes in somatosensory cortex of epileptic patients
- stimulated different parts of the somatosensory cortex
- recorded sensations reported by patients
- led to somatotopic map
what has studying the somatosensory cortex led to research in?
- learning more about brain reorganisation
- especially after injuries
- phantom limbs and phantom pain after amputation
describe what phantom limbs are
- sensations in limbs that are no longer there
outline a study looking into functional reorganisation
(Kolasinski et al., 2016)
- functional reorganisation of primary somatosensory cortex can occur within 24 hours
- shown in Kolasinski et al. (2016)
- stuck little finger and ring finger together
- waited 24hrs and conducted fMRI
- found that activity in little finger and ring finger overlapped in fMRI
explain the function of the Intraparietal sulcus and superior parietal lobule
- main function = vision for action
- is there an object that I can interact with?
- where is body in relation to object?
- anterior areas = main role in coding hand-centred (hand movement)
- posterior areas = main role in coding vision-centred coordinate system
explain Bálint syndrom
- an inability to visualise more than one object in the visual field at a time
explain optic ataxia
deficit in visually guided reaching movement (grasping)
explain oculomotor apraxia
- looking straight at something
- then something comes into peripheral field
- difficulty going to that periphery
- difficulty voluntarily shifting fixation to other objects
explain simultanagnosia
- impaired ability to perceive multiple items in visual display
- not being able to see things as a whole
- i.e.: can see trees but not a forest
what pathway is there a problem with if people experience Balint Syndrome?
dorsal stream problem
(where/how pathway)
what other cognitive functions might derive from the principles of the Intraparietal sulcus and superior parietal lobule?
visuospatial working memory
- link to representing location of objects, coding what is relevant
mental rotation/imagery
- link to manipulating objects
arithmetics
- link to moving eyes/hands to count
- spatial layout
explain the function of the right inferior parietal lobule
- detect noticeable events in the environment
- and then shifting attention to noticeable event
outline evidence from Singh-Curry & Husain (2009) on the role of the right inferior parietal lobule
- suggests that detection and encoding from salient/novel events = bottom-up processing
- role of RIPL = sustaining attention on current task goals whilst simultaneously encoding salient events
- allows task-sets to be rapidly reconfigured to deal with new challenges
what does lesions in the RIPL show?
- lesions causes hemispatial neglect
- reduced awareness of stimuli on one side of space, even though there may be no sensory loss.
explain the function of the left anterior inferior parietal lobule
- use objects in appropriate way
- pantomime object use (miming object use)
how did Reynaud et al. (2016) explain the role of the LAIPL?
- suggested the role of the LAIPL was understanding tool-use actions
what does lesions to the LAIPL lead to?
- apraxia with possible impairments
apraxia impairments effects:
- imitation of gestures
- communicative gestures
- real tool use (might not use tool how it was intended)
explain the function of the left posterior inferior parietal lobule
- detect salient events in one’s thoughts
outline what Seghier (2012) lists as what the LPIPL does
Semantic processing.
Reading and comprehension.
Default mode processing (mind wandering).
Number processing.
Memory retrieval.
Theory of mind.
what does Cabeza et al. (2012) suggest about the LPIPL?
- we have bottom-up attention to internally generated stimuli
- RIPL relies on bottom-up processing information from environmental stimuli
identify a difference in bottom-up processing between the LPIPL and the RIPL
- bottom-up attention for internally generated stimuli
- bottom-up attention for environmental stimuli
