Association cortex: space, faces, reading and executive function

Concept
Exam priority: medium

Most of the cortex does not see, feel or move directly; it combines those signals to map space, recognize faces, read and plan.

Updated Nov 13, 2026

Also called: Hemineglect, Prosopagnosia, Split brain, Prefrontal cortex

See it in 3D: Frontal lobe · Parietal lobe · Temporal lobe · Occipital lobe · Corpus callosum

Key points

Non-dominant (usually right) parietal lesion → hemineglect of the left side of space and body, often with denial of the deficit.
Dominant angular gyrus lesion → alexia with agraphia; left occipital lobe plus splenium of the corpus callosum → alexia without agraphia (patient writes but cannot read it back).
Prosopagnosia (inability to recognize familiar faces) comes from lesions of the ventral occipitotemporal (fusiform) cortex, usually on both sides or on the right.
Prefrontal cortex: dorsolateral = working memory, planning, set shifting; orbitofrontal = social behavior and impulse control; damage gives apathy or disinhibition.
Split brain: an object felt with the left hand cannot be named, because the right hemisphere cannot speak and the callosal route to language areas is cut.

What it is

Association areas receive input from several primary and secondary areas and turn it into meaning: where the body is in space, whose face this is, what a written word says, and what to do next. The parieto-occipito-temporal cortex handles perception and language; the prefrontal cortex handles planning, working memory and social control. Lesions cause striking, highly localizing deficits.

Key facts

The dominant hemisphere (left in about 95% of right-handers and most left-handers) carries language; the other hemisphere is not 'minor', it leads in spatial and emotional processing.
Working memory holds a few items for seconds while they are used; it depends on sustained firing in prefrontal–parietal networks.
The anterior commissure links parts of the temporal lobes, including the amygdalae; it may let some emotional information cross after callosal section.

Association areas and what a lesion shows

Area	Normal role	Typical lesion sign
Posterior parietal (non-dominant)	Maps body and space, directs attention	Left hemineglect, dressing apraxia
Angular gyrus (dominant)	Links seen words to language; naming, calculation	Alexia with agraphia, acalculia, left–right confusion
Fusiform (ventral occipitotemporal)	Face and object recognition	Prosopagnosia
Non-dominant hemisphere (general)	Prosody, music, spatial skill, emotional tone	Flat, monotone speech; poor spatial construction
Dorsolateral prefrontal	Working memory, planning, flexibility	Perseveration, poor planning
Orbitofrontal	Social rules, reward evaluation	Disinhibition, poor judgement
Corpus callosum	Links the two hemispheres	Disconnection: left-hand naming failure, left-hand apraxia

Clinical notes

Asking a patient to bisect a line or copy a clock exposes left neglect after a right parietal stroke.
Frontotemporal dementia often begins with changes in personality and social conduct (orbitofrontal and anterior temporal), before memory loss.
Alexia without agraphia is a classic sign of left posterior cerebral artery stroke.

Test yourself

Think of the answer, then tap the question to see it.

After a right parietal stroke, a patient eats only from the right half of the plate and shaves only the right side of his face. What is this deficit?

Left hemineglect: the non-dominant posterior parietal cortex directs attention to both sides of space, so its loss leaves the left side ignored.

Why can a patient with a left occipital and splenium lesion write a sentence but not read it?

Visual input reaches only the right occipital cortex, and the splenium route to the left angular gyrus is cut; the writing pathways from the language areas are intact (alexia without agraphia).

A man with a cut corpus callosum holds a key in his left hand out of sight. Why can he not name it?

Touch from the left hand reaches the right hemisphere, which cannot produce speech, and the callosal route to the left-hemisphere language areas is cut.

Which prefrontal region is linked with disinhibited, socially inappropriate behavior after injury?

The orbitofrontal (ventromedial) cortex, which weighs rewards and social rules to control impulses.

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Connections

See it in 3D5

The structures of Durgical's 3D anatomy where it happens.

← All of physiology

Educational physiology content; not a diagnostic or treatment guide and no substitute for a health professional's advice. Values are approximate references. No doses are given.

Sources: Neuroanatomy, Cerebral Cortex (StatPearls (NCBI Bookshelf), 2025); Neuroanatomy, Corpus Callosum (StatPearls (NCBI Bookshelf), 2025); Neuroanatomy, Frontal Cortex (StatPearls (NCBI Bookshelf), 2025).

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