Cortex

What is the Cortex?

Here, cortex means the cerebral cortex, the outer gray-matter covering of the cerebrum. It supports perception, language, memory, decision-making, and voluntary movement. Neocortex is its largest subdivision, not another name for all cerebral cortex.

Structure and Function of the Cortex

• Cortical Structure and Layers

  The cortex is a highly folded and convoluted structure, consisting of gyri (ridges) and sulci (grooves), which increases its surface area and allows for a larger number of neurons to be packed into a relatively small space. The neocortex has six cellular layers with different cell populations and connections. Other cortical types have different laminar organization. The thickness of these layers varies across different regions of the cortex, reflecting the functional specialization of each area.

• Lobes

  Four prominent surface lobes are the frontal, parietal, temporal, and occipital lobes. The insula lies deeper within the lateral sulcus. Broad functional associations include:
  • Frontal Lobe: Responsible for higher cognitive functions, including reasoning, decision-making, planning, and voluntary motor control.
  • Parietal Lobe: Processes sensory information from the body and integrates it with visual and spatial information.
  • Temporal Lobe: Involved in auditory processing, language comprehension, and memory formation.
  • Occipital Lobe: Processes visual information and is responsible for various aspects of visual perception.

• Functional Specialization

  Cortical areas have specialized contributions within wider networks. For example, the primary motor cortex in the frontal lobe contributes to voluntary movement, while the primary visual cortex in the occipital lobe processes visual information. Other regions, such as the prefrontal cortex, are involved in complex cognitive tasks, such as decision-making, problem-solving, and social behavior.

Cortex in Neuroscience Research

• Brain Mapping

  Neuroscientists use various techniques, such as functional magnetic resonance imaging (fMRI), electroencephalography (EEG), and magnetoencephalography (MEG), to map the functional organization of the cortex and investigate the relationships between specific cortical areas and cognitive processes.

• Neural Plasticity

  Research on the cortex has contributed to our understanding of neural plasticity – the brain's ability to change and adapt in response to experience. Studies have shown that the cortex can reorganize itself following injury or sensory deprivation, and that its structure and function can be modified through learning and training.

• Neuropsychology

  The study of the cortex has also informed the field of neuropsychology, which examines the relationship between brain function and behavior. By investigating the cognitive and behavioral effects of damage to specific cortical regions, neuropsychologists have gained insights into the neural mechanisms underlying various cognitive functions and disorders.

Sources and evidence

• Dale Purves et al., editors: An Overview of Cortical Structure, Neuroscience 2nd edition. Histological subdivisions and functions overlap; a cortical area is not the sole site of a complex mental process.