Anatomy and Functions of the Parietal Lobes

Parietal Lobe

Processes and integrates sensory information.

Angular Gyrus

Region involved in language and spatial awareness.

Supramarginal Gyrus

Integrates sensory information for language processing.

Postcentral Gyrus

Primary somatosensory area for tactile information.

Posterior Parietal Cortex

Integrates sensory and visual information for movement.

Precuneus

Involved in visuospatial processing and self-awareness.

Dorsal Visual Stream

Processes 'how' to interact with objects.

Area PE (Brodmann's Area 5)

Secondary somatosensory area guiding limb movement.

Area PF (Brodmann's Area 7)

Receives somatosensory input, projects to motor areas.

Area PG

Integrates multiple sensory inputs for spatial behavior.

Parieto-Premotor Pathway

Primary pathway for motor control actions.

Parieto-Prefrontal Pathway

Involved in working memory for visuospatial tasks.

Parieto-Medial-Temporal Pathway

Important for spatial recognition and navigation.

Multisensory Map

Combines sensory inputs for interaction with the environment.

Spatial Information

Guides actions and understanding of object significance.

Object Recognition

Focuses on object-centered information for identification.

Movement Guidance

Requires attention to parietal spatial maps.

Viewer-Centered Movements

Controlled by eye position for accurate targeting.

Limb Control

Based on joint positions for movement execution.

Sensorimotor Transformation

Integrates intention with sensory feedback for movement.

Area PRR

Involved in planning movements and desired outcomes.

Spatial Neglect

Inability to attend to one side of space.

Visually Guided Movement

Movement directed by visual stimuli and attention.

Neuronal Activity

Depends on visual stimulation and ongoing behaviors.

Brain-Computer Interface

Uses neural recordings for controlling devices.

Higher Cognitive Functions

Complex processes often lacking in experimental animals.

Spatial Navigation

Internal mapping for successful movement in environment.

Alocentric View

Navigation based on external reference points.

Egocentric View

Navigation based on personal perspective and orientation.

Medial Parietal Region

Brain area crucial for route knowledge.

Aphantasia

Inability to visualize mental images.

Acalculia

Inability to perform arithmetic calculations.

Posterior Parietal Damage

Impaired spatial organization and left-right discrimination.

Astereognosis

Loss of object identification by touch.

Simultaneous Extinction

Neglect of one object when presented with two.

Numb Touch

Loss of sensation but accurate location reporting.

Asomatognosia

Loss of awareness about one's own body.

Anosognosia

Unawareness of one's illness or condition.

Balint Syndrome

Bilateral parietal lesions causing visual and movement issues.

Contralateral Neglect

Neglect of one side of body/environment after stroke.

Transcranial Magnetic Stimulation (TMS)

Induces neglect by targeting specific brain areas.

Gerstmann Syndrome

Left parietal damage causing finger agnosia and confusion.

Apraxia

Loss of skilled movement execution.

Ideomotor Apraxia

Inability to imitate movements of others.

Construction Apraxia

Difficulty with spatial organization and assembly tasks.

Somatosensory Symptoms

Impaired sensation due to parietal cortex damage.

Afferent Paresis

Loss of feedback about limb positions.

Optic Ataxia

Inability to reach targets using visual guidance.

Dyscalculia

Difficulty with numerical concepts and calculations.

Language Difficulties

Problems with spatial organization in language processing.

Simultagnosia

Inability to perceive multiple objects simultaneously.

Right Parietal Lobe Damage

Leads to neglect of the left side in drawings.

Left Parietal Lobe Damage

Results in fewer recognizable drawings and lines.

Spatial Attention

Brain's ability to focus on relevant stimuli.

Parietal Cortex Role

Shifts attention between different stimuli.

Visuomotor Guidance System

Resets to switch focus from one target to another.

Mental Rotation

Requires forming and manipulating mental images.

Unilateral Neglect

Common in right parietal lobe lesions, 67% affected.

Dressing Disability

Difficulty dressing due to right parietal damage.

Cube Counting

86% of subjects with right parietal deficits struggle.

Paper Cutting

90% of subjects with right parietal deficits struggle.

Topographical Loss

50% of subjects with right parietal deficits experience.

Right-Left Discrimination

63% of subjects with left parietal deficits struggle.

Weigl's Sorting Test

83% of subjects with left parietal deficits struggle.

Tactile Agnosia

Inability to recognize objects by touch, linked to Area PE.

Constructional Apraxia

Impaired ability to construct or draw objects.

Two-Point Discrimination Test

Measures somatosensory threshold for touch perception.

Tactile Form Recognition Test

Identifies shapes by touch, involving areas PE and PF.

Line Bisection Test

Assesses contralateral neglect by drawing lines.

Visual Perception Assessment

Tests drawing of incomplete images, sensitive to right damage.

Right-Left Differentiation

Identifying body parts' orientation, sensitive to left damage.

Token Test

Assesses language comprehension using colored shapes.

Kimura Box Test

Evaluates apraxia through sequence of movements.

Inferior Parietal Lobule

Active in default mode network for various behaviors.

Temporoparietal Junction

Involved in attention, language, memory, and social processing.

Parietal Memory Network

Includes precuneus, angular gyrus for learning and memory.

Dorsolateral Parietal Network

Connects prefrontal and temporal cortex for spatial functions.