Parietal Lobe Flashcards
What is the primary area of the parietal lobe and what does it do
Primary somatosensory cortex, i.e. the post-central gyrus, receives sensory information from the body
How is the Primary somatosensory cortex organised
Topographically organised – i.e. homunculus
What is the primary sensory region of the parietal lobe known as
post-central gyrus or somatosensory strip
Where is the Sensory homunculus mapped
somatosensory strip
what does the post-central gyrus do
receives sensory information about a particular region of the body, from the contralateral side of the body
moving out laterally along the cortex, the homunculus represents parts that are…
closer and closer to the head
what deficits/impairments does Lesion/disconnection of the primary, somatosensory strip result in
Leads to a primary sensory deficit.
Tactile discrimination impaired
Tactile thresholds reduced,
Reduced ability to detect object characteristics such as an edge or a curve
What is the secondary area of the parietal lobe
Unimodal Association area
What does the Unimodal Association of the parietal lobe area do
receives inputs from the primary somatosensory cortex and integrates these inputs so that the tactile stimulus can then be perceived.
What does Lesion/disconnection of unimodal association of the parietal lobe area result in
tactile perceptual deficits which may include:
- An inability to judge the orientation of a tactile stimulus - Tactile agnosia - an inability to recognise an object by touch. - This is an inability to perceive the object, not a primary inability to sense the object
What is the tertiary area of the parietal lobe
Multi-modal integration Area
What are the three main areas of the parietal lobe
- post-central gyrus or somatosensory strip
- Unimodal Association area
- Multi-modal integration Area
The Tertiary region of the parietal lobe is at the crossroads of what other areas
temporo-parieto-occipital crossroads
What does the Multi-modal integration Area of the parietal lobe do
multi-modal integration of sensory information including tactile, somatosensory, visual, auditory and vestibular information
Lesions that disrupt Multi-modal integration in the parietal lobe principally seem to effect what
understanding of spatial relations
much of the function of the parietal lobes involves understanding what
spatial properties of the world in which we live, including the spatial properties of our own body in that world
parietal lobes are essential in constructing what
mental maps of the world
Disorders of spatial attention result in what 7 impairments
(i) Disorders in the judgement of the location or orientation of stimuli, both with respect to each other and to the person
(ii) Impaired memory of location
(iii) Topographical disorientation and loss of topographical memory
(iv) Route finding difficulties – due to a difficulty in being able to synthesise and integrate spatial information, such as on maps
(v) Constructional apraxia
(vi) Unilateral spatial neglect
(vii) Disorders of body schema
What is visuospatial agnosia
difficulty in perceiving the spatial relationships between several objects in one’s visual field
What is a test of visuospatial agnosia
Benton Visual Retention Test
how does Impaired memory for location affect a persons understanding of objects
The patient can recall what the objects were, but can not recall where they were located
What is a test of Impaired memory for location
the REY Complex figure with and without a memory loading
When doing the REY Complex figure what is the difference between Frontal lobe patients and Parietal lobe patients
Parietal lobe patients can’t understand the spatial organization of the figure.
* Parietal lobe patients improve performance when guided with spatial information.
- Frontal lobe patients show disturbances in the plan to approach the copying of the figure.
- Frontal lobe patients improve performance if provided with a plan.
What is Topographical Disorientation
An inability to utilise landmark objects to orient and to localise everything within a spatial representation
Topographical Disorientation results from an inability to do what 2things?
- recall the spatial arrangement of familiar surroundings
2. recall and describe well-known geographical relationships with which the patient was formerly familiar.
What is suspected to be the fundamental problem behind Topographical Disorientation
seem to involve problems in the recall of visual images from long term memory
What are the 4 basic disorders that may explain Topographical Disorientation
- perceptual disorders (of the location and relative position of objects).
- failure of recognition of environmental feature
- topographical amnesia. i.e a specific inability to remember landmarks within the spatial representation, as opposed to the broader inability to utilise objects as landmarks in the spatial represenation.
- unilateral spatial neglect (i.e. impaired attentional processing.
What is a test of Route Finding Difficulties
Semmes Locomotor Map
Money’s Road Map
What is Constructional Apraxia
inability to construct/join/assemble parts of an object in order to form a unitary structure.
Where does Constructional Apraxia occur
patients with lesions at the overlapping parietal, temporal and occipital junction.
Constructional apraxia arising from parietal lobe lesions occurs mostly in which hemisphere
right hemisphere lesions
What are 2 tests of Tests for Constructional Apraxia
WAIS Block design
Rey Complex Figure
What is Contralateral neglect
inability to attend, perceive or process information from one side of your visual space.
The hemi-space that is neglected is contralateral to the side of the parietal lobe that is lesioned, hence it is usually referred to as contralateral neglect.
Where does Contralateral neglect occur and what does it effect
Contralateral neglect nearly always involves a right parietal lobe lesion, causing neglect to the left hemi-space
disorders of body schema and lack of awareness of body parts can occur as a result of damage to which lobe
Parietal lobe damage
What is a test of disorders of body schema and lack of awareness of body parts
simply involve asking patients to identify / point to parts of their own bodies or on a diagram.
How does the parietal lobe effect movement
parietal lobes to help us control our movements, if we don’t know anything about our position in our environment, can’t track our movements and understand them then it is hard to move with any confidence e.g., driving a car
Which other brain areas is the Multi-modal integration Area of the parietal lobe attached to and what is the result
Motor Cortex - information about our body position is crucial for our movements
Temporal Lobe - reading difficulties - spatial recognition of letters
What are two elements of spatial understanding
- determine the relationship between objects in extra-personal space
- understand where our body is, in relation to extra-personal space.
Topographical Disorientation is often seen is patients with what disease
Alzheimers
Disorders of location and orientation involve 2 things
- difficulty localising an object in a visual field
2. perceiving the spatial relationships between several objects in one’s visual field.
How can we differentiate between constructional apraxia in frontal and parietal patients
Frontal lesion - loss of planning and regulating sequential behaviour;
Parietal lesion - loss of spatial understanding of the elements
