frontal and parietal lobe Flashcards
What is the boundary between parietal lobe and frontal lobe?
-Central sulcus (Rolandic Fissure)
What is the boundary between parietal lobe and occipital lobe?
-Parieto-occipital fissure
What is the boundary between parietal lobe and temporal lobe?
-Lateral sulcus (Sylvian fissure)
What does macro-anatomical mean?
-Based on sulci and gyro
What is a longitudinal fissure?
-Separates right and left hemisphere
What is a fissure?
-Deep sulci and gyri
What is posterior to the central sulcus?
-Post central sulcus
-Post central gyrus
PARIETAL
PARIETAL
What are the 3 parts of the posterior parietal lobe?
-Superior parietal lobule
-Intraparietal sulcus
-Inferior parental lobule
Describe what the somatosensory cortex (S1) is for?
-Helps to process information around body sensations e.g. touch, pain and proprioception
What 4 divisions can the somatosensory cortex be divided into?
-Areas 1,2,3a and 3b
Where does the input come from?
-Thalamus and motor cortex
Where does the output come from?
-Motor cortex and posterior parietal cortex
What did Penfield and Bolder (1937) find in regards to the primary somatosensory cortex?
-Inserted electrodes in somatosensory cortex of epileptic patients
-Patients under local anaesthesia just before surgery
-Stimulated different regions of this
-Recorded sensations
-Led to creation of simplified somatotopic map
Define what is meant by somatosensory homunculus
-Some body parts have a larger area dedicated than others
Why should we be interested in the somatosensory cortex?
-We can learn about brain reorganisation
-Help patients with deficits
-Assist patients through learning e.g. learning to play an instrument
Describe the study conducted by Kolasinki et al., 2016
-Mapped 4 finger digits
-Glued little finger and ring finger together
-See how quickly the body would accept this as 4 fingers rather than 5 fingers
What were the results of this study?
-Found that after 24 hours, the 2 fingers that were glued together would begin acting as one
What is the function of the intraparietal sulcus and superior parietal lobule?
-Vision for action
-Looks at object relevance
-Reaching/grasping objects
What are the more anterior areas responsible for?
-Coding in hand-centred coordinate system
What are the more posterior areas responsible for?
-Coding in vision-centred coordinate system
What lesions can occur in the intraparietal sulcus and superior parietal lobule?
-Baliant syndrome (Jackson et al., 2009)
What can Baliant syndrome be split into?
-Optic ataxia
-Oculomotor apraxia
-Simultanagnosia
Define what optic ataxia is
-Anderson et al., (2014)
-Deficit in visually guided reaching movements
-E.g. they can see a pen, but when they go to grasp it they completely miss it
Define what oculomotor apraxia is
-Inappropriate fixation of gaze and difficulties in voluntarily shift fixation to other objects
-E.g. they get stuck on the red dot, and can’t change gaze to different purple dots
Define what simultanagnosia is
-Impaired ability to perceive multiple items in a visual display
-E.g. can see all separate 7s but can’t see that it makes up a big 7
What is the function of right inferior parietal lobule?
-Detect salient events in environment
-Shift attention
Describe the study conducted by Singh-Curry and Husain (2009)
-Have to sustain first task
-Deal with salient events
-Means you have to reconfigure what you were originally going to do.
-E.g. basketball analogy of going to shoot hoop (first task) but a defender gets in the way (salient) and so you have to reevaluate
What happens if there is lesions in right inferior parietal lobule?
-Hemispatial neglect
-Tends to occur
-Deficit always tends to occur on the left side
-E.g. only draw half of an image
What is the function of the left anterior parietal lobule?
-Use objects in appropriate way
-Pantomime object use
-Tool-use actions
What did Reynaud et al. (2016) find in regards to lesions in this area?
-Apraxia with possible impairments
-Imitation of gestures
-Communicative gestures
What did Seghier (2012) find to do with ‘what things affect detecting bottom-up information’
-Semantic processing
-Reading and comprehension
-Mind wandering
-Number processing
-Theory of mind
What did Cabeza et al., (2012) find?
-Attention occurs internally rather than what is going on in the environment, which is the right inferior parietal lobule
What are the two sulci and gyri within the frontal lobe?
-Cingulate sulcus
-Cingulate gyrus
FRONTAL
FRONTAL
What are the 3 main subdivisions within the frontal lobe?
-Primary motor cortex
-Premotor cortex
-Prefrontal cortex
What are they cytoarchitectonics (cell structures) of these?
-M: giant Betz cells in layer V
-PM: no granular cells in layer IV
-PF: granular cells in layer IV
What is the function of the motor cortex?
-Controls skeletal muscles together with basal ganglia, thalamus and cerebellum
-Somatotopically organised
What is the function of the premotor cortex?
-Planning movement
-Movement selection
-Movement sequencing
What tests are conducted on patients with frontal lobe lesions?
-Verbal fluency (Milner, 1964)
-E.g. write down as many words beginning with F as possible
-Can get around 13 lesions max
-Wisconsin Card Sorting Test
-E.g. ignore shape, just sort by colour etc.
-Find that individuals with lesions can’t shift attention
-Tower of London (Shallice, 1982)
-Had to conduct this within 7 moves
What were issues with the traditional approach?
-Poor sensitivity
-Poor specificity
-Tasks weren’t pure enough
What is the more basic approach?
-Stuss and Alexander (2007)
-Devise simple tests
-Manipulate difficulty and context
What conclusions did Stuss come to?
-Lateral PFC = left (task setting) and right (monitoring)
