Cerebral Cortex: Lobes, Brodmann Areas, and Functional Regions

Complete anatomy of the cerebral cortex - the six lobes, Brodmann areas, primary sensory and motor areas, association cortices, and hemispheric specialization.

This content is for informational purposes only. Always consult a healthcare professional.

The cerebral cortex is the outermost layer of the cerebrum, responsible for higher cognitive functions, sensory processing, and motor command generation. It is characterized by its folded appearance (gyri and sulci) and layered cellular organization.

Gross Anatomy: Gyri and Sulci

Major Sulci and Fissures

Sulcus/Fissure Location Significance
Longitudinal fissure Midline, separates hemispheres Contains falx cerebri, anterior cerebral arteries
Lateral sulcus (Sylvian) Separates frontal/parietal from temporal Contains middle cerebral artery
Central sulcus (Rolando) Separates frontal from parietal Primary motor (anterior) and sensory (posterior)
Parieto-occipital sulcus Medial, separates parietal from occipital Visual cortex boundary
Calcarine sulcus Medial occipital Contains primary visual cortex (area 17)
Cingulate sulcus Medial frontal/parietal Above cingulate gyrus
Preoccipital notch Lateral temporo-occipital Visual association boundary

Major Gyri

Gyrus Location Function
Precentral gyrus Anterior to central sulcus Primary motor cortex (M1)
Postcentral gyrus Posterior to central sulcus Primary somatosensory cortex (S1)
Superior temporal gyrus Superior temporal lobe Primary auditory cortex (Heschl gyrus)
Middle temporal gyrus Middle temporal lobe Language, auditory association
Inferior temporal gyrus Inferior temporal lobe Object recognition, visual association
Fusiform gyrus Inferior temporal/occipital Face recognition (fusiform face area)
Parahippocampal gyrus Medial temporal Memory, scene recognition
Lingual gyrus Medial occipital Visual processing
Cuneus Medial occipital (above calcarine) Visual
Precuneus Medial parietal Visuospatial, self-awareness
Angular gyrus Posterior superior temporal Language, mathematical cognition
Supramarginal gyrus Parietal operculum Tactile perception, language
Straight gyrus (gyrus rectus) Orbitofrontal Olfactory, behavior

Lobes of the Cerebral Cortex

Frontal Lobe

The frontal lobe is the largest lobe, responsible for motor function, executive control, and language production.

Area Brodmann Function
Primary motor cortex (M1) 4 Voluntary movement (contralateral)
Premotor cortex 6 Motor planning, sequencing
Supplementary motor area 6 (medial) Motor initiation, bimanual coordination
Frontal eye field 8 Voluntary eye movements
Broca area 44, 45 Speech production (dominant hemisphere)
Dorsolateral prefrontal 9, 46 Executive function, working memory
Orbitofrontal cortex 10, 11, 47 Decision-making, reward, social behavior
Anterior cingulate (frontal portion) 24, 32 Error detection, motivation

Parietal Lobe

The parietal lobe integrates sensory information and spatial awareness.

Area Brodmann Function
Primary somatosensory (S1) 1, 2, 3 Touch, pain, temperature, proprioception
Secondary somatosensory (S2) 43 Tactile recognition
Posterior parietal cortex 5, 7 Spatial attention, visuomotor integration
Supramarginal gyrus 40 Tactile object recognition, language
Angular gyrus 39 Reading, arithmetic, semantic processing
Precuneus 7 (medial) Visuospatial imagery, episodic memory

Temporal Lobe

The temporal lobe processes auditory information, language comprehension, and memory.

Area Brodmann Function
Primary auditory cortex (A1) 41, 42 Hearing (tonotopic organization)
Auditory association 22 Sound recognition, language comprehension
Wernicke area 22 (posterior) Language comprehension (dominant)
Middle temporal gyrus 21 Auditory association, semantic memory
Inferior temporal cortex 20, 37 Object recognition, visual association
Fusiform face area 37 (lateral) Face recognition
Parahippocampal place area 36, 37 Scene recognition
Hippocampus (archicortex) Memory formation, spatial navigation
Amygdala Emotion, fear conditioning

Occipital Lobe

The occipital lobe is dedicated entirely to visual processing.

Area Brodmann Function
Primary visual cortex (V1) 17 Initial visual processing (retinotopic)
Visual association (V2) 18 Contour, orientation processing
Visual association (V3, V4, V5) 19 Motion (V5/MT), color (V4), form
Lateral occipital complex 19, 37 Object recognition

Insula

The insula is a hidden lobe deep within the lateral sulcus.

Region Function
Anterior insula Interoception, emotion, taste, pain
Posterior insula Visceral sensation, sensorimotor

Limbic Lobe

The limbic lobe forms a ring on the medial surface of the cerebrum.

Structure Function
Cingulate gyrus Emotion, pain, attention
Parahippocampal gyrus Memory, scene recognition
Isthmus (bridge between cingulate and parahippocampal) Visual memory

Brodmann Areas

Brodmann areas are numbered regions of the cerebral cortex defined by their cytoarchitecture (cellular organization). The numbering system includes 52 areas.

Key Brodmann Areas by Category

Motor areas:

Area Name Function
BA 4 Primary motor cortex (M1) Voluntary movement
BA 6 Premotor cortex, SMA Motor planning
BA 8 Frontal eye field Eye movements
BA 44 Pars opercularis Broca area (speech)
BA 45 Pars triangularis Broca area (language)

Somatosensory areas:

Area Name Function
BA 1 Primary somatosensory Texture perception
BA 2 Primary somatosensory Proprioception, joint position
BA 3 Primary somatosensory Cutaneous sensation

Visual areas:

Area Name Function
BA 17 Primary visual (V1) Initial visual processing
BA 18 Visual association (V2) Contour, orientation
BA 19 Visual association (V3, V4, V5) Motion, color, form

Auditory areas:

Area Name Function
BA 41 Primary auditory (A1) Hearing
BA 42 Auditory association Sound recognition

Association areas:

Area Name Function
BA 9, 10 Dorsolateral prefrontal Executive function
BA 11, 47 Orbitofrontal Decision-making, reward
BA 22 Superior temporal Wernicke area (language comprehension)
BA 39 Angular gyrus Reading, arithmetic
BA 40 Supramarginal gyrus Tactile recognition, language
BA 37 Fusiform gyrus Face/object recognition

Cortical Layers

The neocortex has six layers (laminae):

Layer Name Cells Connections
I Molecular Few neurons, mainly dendrites Apical dendrites of pyramidal cells
II External granular Small pyramidal and stellate cells Corticocortical connections
III External pyramidal Medium pyramidal cells Commissural and association fibers
IV Internal granular Stellate cells Main input layer (thalamic afferents)
V Internal pyramidal Large pyramidal (Betz cells in M1) Output to subcortical structures
VI Multiform Fusiform cells Output to thalamus

Cortical types by layer prominence:

Type Prominent Layer Location
Granular (koniocortex) Layer IV Primary sensory areas
Agranular Layer IV absent (layers II/III/V prominent) Primary motor, premotor
Dysgranular Layer IV thin Association areas

Hemispheric Specialization

Function Dominant Hemisphere (usually left) Non-Dominant Hemisphere (usually right)
Language Comprehension and production Prosody, emotional tone
Motor praxis Skilled movement planning
Visuospatial Spatial attention, navigation
Face recognition Holistic face processing
Emotion Emotional recognition
Music Rhythm Pitch, melody
Arithmetic Calculation Estimation

White Matter Tracts

Tract Type Examples Function
Association fibers (within hemisphere) Superior longitudinal, inferior longitudinal, uncinate, arcuate, cingulum Connect cortical regions in same hemisphere
Commissural fibers (between hemispheres) Corpus callosum, anterior commissure, hippocampal commissure Connect corresponding cortical areas
Projection fibers (to/from subcortex) Internal capsule, corona radiata, fornix Connect cortex to brainstem, spinal cord, basal ganglia, thalamus