The Parietal Lobes Flashcards
What area of the parietal lobes controls saccadic eye movements?
-Intraparietal sulcus (cIPS)
What is the function of the somatosensory strip?
- To area PE - tactile recognition
- To motor regions - sensory information about limb movement and position
What is the function of area PE?
- Somatosensory
- Input from somatosensory strip
- Outputs to primary motor cortex, supplementary motor cortex, premotor regions, and area PF
What is the function of area PF?
-Input from somatosensory, primary motor cortex, premotor cortex, and small visual input through area PE
What is the function of area PG?
-Receives complex connections including visual, somesthetic, proprioceptive, auditory, vestibular, oculomotor, and cingulate connections
What is the function of the connections between posterior parietal (PF and PF) and the prefrontal cortex?
-Controlling spatially guided behaviour
What is the general theory of parietal lobe function? (What do the anterior and posterior zones do?)
- Anterior - process somatic sensations and perceptions
- Posterior - integrate information from vision with somatosensory information for movement
- Spatial map in the brain?
What can spatial information be used for?
- Object recognition (details of object are important; posterior parietal cortex)
- Guidance of movement (sensitive to eye movements; posterior parietal cortex)
- Sensorimotor information (relative position of body with respect to sensory feedback from movements being planned and made; posterior parietal cortex)
- Movement planning (desired goal of movement)
- Spatial navigation (cognitive spatial map - unconscious knowledge of how to reach a destination; medial parietal region)
What do lesions to the post-central gyrus produce?
- Abnormally high sensory thresholds
- Impaired position sense
- Deficits in stereogenesis, or tactile perception
- Afferent paresis (clumsy finger movements due to lack of feedback about finger position)
What is astereognosis?
-Inability to recognize an object by touch
What is simultaneous extinction?
-Failure to report stimuli on one side of the body
What is blind touch?
-Cannot feel stimuli, but can report location
What are the agnosias?
- Asomatognosia (loss of knowledge or sense of one’s own body)
- Anosognosia (unaware/denial of illness)
- Anosodiaphoria (indifference for illness)
- Asymbolia for pain (absence of normal reactions to pain)
- Finger agnosia (unable to point to fingers or show them to examiner)
What are some symptoms of posterior parietal lobe damage?
- Balint’s syndrome (can’t fixate on visual stimulus; neglect of objects; optic ataxia)
- Contralateral neglect (right parietal lesions; neglect for visual, auditory, and somesthetic stimulation on one side of the body or space; caused by defective sensation or perception or defective attention or orientation)
- Poor object recognition
- Perceptual classification deficit
- Gerstmann syndrome (finger agnosia, right-left confusion, agraphia, acalculia; results from left parietal lobe lesion)
What is apraxia?
- Movement disorder in which loss of movement is not caused by any other disorder of movement
- Left parietal lobe damage
