Human Neuropsychology - Lecture 10: Parietal Lobe & Networks

Precentral sulcus

The anterior anatomical boundary of the parietal lobe that separates it from the frontal lobe.

Parieto-occipital sulcus

The posterior anatomical boundary of the parietal lobe that separates it from the occipital lobe.

Lateral/Sylvian fissure

The ventral anatomical boundary of the parietal lobe that separates it from the temporal lobe.

Postcentral gyrus

The major anterior lateral parietal structure that serves as the primary somatosensory cortex.

Intraparietal sulcus (IPS)

A prominent sulcus within the posterior lateral parietal cortex that separates the superior parietal lobule from the inferior parietal lobule.

Inferior parietal lobule (IPL)

A functional division of the lateral parietal cortex composed of the supramarginal gyrus (SMG) and angular gyrus (AG).

Parietal reach region (PRR)

A parietal area involved in visually guided reaching and motor planning by encoding the desired outcome of a movement.

Lateral intraparietal (LIP) area

A region within the intraparietal sulcus that contributes directly to saccadic eye movements.

Anterior intraparietal (AIP) area

An intraparietal cortical area involved in the visual control of grasping motions.

Parieto-premotor pathway

A functional sub-stream of the dorsal visual processing stream designated as the "how" pathway.

Parieto-prefrontal pathway

A dorsal stream sub-pathway dedicated to supporting visuospatial working memory.

Parieto-medial-temporal pathway

A dorsal stream pathway that projects to the hippocampus and parahippocampal cortex via the posterior cingulate cortex and retrosplenial cortex for spatial memory and navigation.

Polysensory neurons

Neurons in the posterior parietal cortex that activate specifically when an individual interacts with or manipulates an object.

Efference copy

A copy of outgoing (efferent) motor commands duplicated and sent to sensory processing areas to anticipate the sensory consequences of action.

Sensorimotor transformation

The integration of movement intention with sensory feedback regarding how intended actions compare to actual execution to perform smooth movements toward a target.

Route knowledge

A spatial navigation strategy consisting of a list of specific actions executed at each decision point, mediated in humans by the medial parietal region (MPR).

Afferent paresis

Clumsy limb movements resulting from postcentral gyrus lesions due to the loss of sensory feedback about limb positions.

Astereognosis

A somatoperceptual disorder characterized by the loss of the ability to identify an object purely through touch.

Simultaneous extinction

A condition resulting from damage to the secondary somatosensory cortex or parietal lobe in which a patient reports only one object when presented with two simultaneously.

Numb touch

The somatosensory equivalent of blindsight, in which a patient reports an absence of conscious sensation in a body region but can accurately report where they were touched within that region.

Asomatognosia

A somatosensory agnosia characterized by the loss of knowledge or awareness about one's own body or condition, usually affecting the left side of the body following right hemisphere lesions.

Anosognosia

A subtype of asomatognosia characterized by an unawareness or denial of one's own illness or neurological deficits.

Anosodiaphoria

A subtype of asomatognosia defined by an abnormal indifference or lack of concern toward one's illness.

Autopagnosia

An inability to locate and name body parts, typically affecting the right side of the body following left hemisphere damage.

Finger agnosia

A specific autopagnosia where an individual cannot point to or identify their own fingers or an examiner's fingers, frequently co-occurring with dyscalculia.

Asymbolia for pain

A somatosensory agnosia manifested as an absence of normal avoidance and emotional reactions to painful stimuli.

Bálint syndrome

A rare neurological disorder caused by bilateral posterior parietal lesions, presenting with simultagnosia, optic ataxia, and an inability to voluntarily fixate targets.

Optic ataxia

An inability to accurately reach for a specified target under visual guidance, commonly caused by damage to superior posterior parietal areas.

Contralateral neglect

A disorder resulting from right parietal damage (including the right IPS and angular gyrus) where a patient ignores or fails to attend to stimuli on the left side of space and their own body.

Allesthesia

The first recovery stage of contralateral neglect, wherein a patient begins responding to stimuli presented on the neglected side as if they were located on the attended side.

Gerstmann syndrome

A syndrome caused by damage