Frontal lobe in the context of "Language processing in the brain"

The human brain is the central organ of the nervous system, and with the spinal cord, comprises the central nervous system. It consists of the cerebrum, the brainstem and the cerebellum. The brain controls most of the activities of the body, processing, integrating, and coordinating the information it receives from the sensory nervous system. The brain integrates sensory information and coordinates instructions sent to the rest of the body.

The cerebrum, the largest part of the human brain, consists of two cerebral hemispheres. Each hemisphere has an inner core composed of white matter, and an outer surface – the cerebral cortex – composed of grey matter. The cortex has an outer layer, the neocortex, and an inner allocortex. The neocortex is made up of six neuronal layers, while the allocortex has three or four. Each hemisphere is divided into four lobes – the frontal, parietal, temporal, and occipital lobes. The frontal lobe is associated with executive functions including self-control, planning, reasoning, and abstract thought, while the occipital lobe is dedicated to vision. Within each lobe, cortical areas are associated with specific functions, such as the sensory, motor, and association regions. Although the left and right hemispheres are broadly similar in shape and function, some functions are associated with one side, such as language in the left and visual-spatial ability in the right. The hemispheres are connected by commissural nerve tracts, the largest being the corpus callosum.

The parietal lobe is one of the four major lobes of the cerebral cortex in the brain of mammals. The parietal lobe is positioned above the temporal lobe and behind the frontal lobe and central sulcus.

The parietal lobe integrates sensory information among various modalities, including spatial sense and navigation (proprioception), the main sensory receptive area for the sense of touch in the somatosensory cortex which is just posterior to the central sulcus in the postcentral gyrus, and the dorsal stream of the visual system. The major sensory inputs from the skin (touch, temperature, and pain receptors), relay through the thalamus to the parietal lobe.

The sensory cortex can refer sometimes to the primary somatosensory cortex, or it can be used as a term for the primary and secondary cortices of the different senses (two cortices each, on left and right hemisphere): the visual cortex on the occipital lobes, the auditory cortex on the temporal lobes, the primary olfactory cortex on the uncus of the piriform region of the temporal lobes, the gustatory cortex on the insular lobe (also referred to as the insular cortex), and the primary somatosensory cortex on the anterior parietal lobes. Just posterior to the primary somatosensory cortex lies the somatosensory association cortex or area, which integrates sensory information from the primary somatosensory cortex (temperature, pressure, etc.) to construct an understanding of the object being felt. Inferior to the frontal lobes are found the olfactory bulbs, which receive sensory input from the olfactory nerves and route those signals throughout the brain. Not all olfactory information is routed to the olfactory cortex: some neural fibers are routed to the supraorbital region of the frontal lobe, while others are routed directly to limbic structures. The direct limbic connection makes the olfactory sense unique.

The brain cortical regions are related to the auditory, visual, olfactory, and somatosensory (touch, proprioception) sensations, which are located lateral to the lateral fissure and posterior to the central sulcus, that is, more toward the back of the brain. The cortical region related to gustatory sensation is located anterior to the central sulcus.

The motor cortex comprises interconnected fields on the posterior frontal lobe—chiefly Brodmann area 4 (primary motor cortex, M1) and area 6 (premotor cortex and supplementary motor areas)—that plan, select and execute voluntary movements. These regions transform goals into patterned activity in descending pathways to brainstem and spinal motor circuits, enabling dexterous eye, face and limb actions. Modern work shows overlapping, action‑type representations rather than a strictly point‑to‑point "homunculus," and highlights direct cortico‑motoneuronal projections that underwrite fine finger control. Clinically, motor‑cortical organization shapes deficits after stroke and neurodegenerative disease and guides mapping for neurosurgery and neurotechnology.

Phrenology is a pseudoscience that involves the measurement of bumps on the skull to predict mental traits. It is based on the concept that the brain is the organ of the mind, and that certain brain areas have localized, specific functions or modules. It was said that the brain was composed of different muscles, so those that were used more often were bigger, resulting in the different skull shapes. This provided reasoning for the common presence of bumps on the skull in different locations. The brain "muscles" not being used as frequently remained small and were therefore not present on the exterior of the skull. Although both of those ideas have a basis in reality, phrenology generalizes beyond empirical knowledge in a way that departs from science. The central phrenological notion that measuring the contour of the skull can predict personality traits is discredited by empirical research. Developed by German physician Franz Joseph Gall in 1796, the discipline was influential in the 19th century, especially from about 1810 until 1840. The principal British centre for phrenology was Edinburgh, where the Edinburgh Phrenological Society was established in 1820.

Phrenology is today recognized as pseudoscientific. The methodological rigor of phrenology was doubtful even for the standards of its time, since many authors already regarded phrenology as pseudoscience in the 19th century. There have been various studies conducted that discredited phrenology, most of which were done with ablation techniques. Marie-Jean-Pierre Flourens demonstrated through ablation that the cerebrum and cerebellum accomplish different functions. He found that the impacted areas never carried out the functions that were proposed through phrenology. Paul Broca also discredited the idea when he discovered and named the "Broca's area": the patient's ability to produce language was lost while their ability to understand language remained intact, due to a lesion on the left frontal lobe. He concluded that this area of the brain was responsible for language production. Between Flourens and Broca, the claims to support phrenology were dismantled. Phrenological thinking was influential in the psychiatry and psychology of the 19th century. Gall's assumption that character, thoughts, and emotions are located in specific areas of the brain is considered an important historical advance toward neuropsychology. He contributed to the idea that the brain is spatially organized, but not in the way he proposed. There is a clear division of labor in the brain but none of which even remotely correlates to the size of the head or the structure of the skull. It contributed to some advancements in understanding the brain and its functions.

The insular cortex (also insula and insular lobe) is a portion of the cerebral cortex folded deep within the lateral sulcus (the fissure separating the temporal lobe from the parietal and frontal lobes) within each hemisphere of the mammalian brain.

The insulae are believed to be involved in consciousness and play a role in diverse functions usually linked to emotion, interoception, or the regulation of the body's homeostasis. These functions include compassion, empathy, taste, perception, motor control, self-awareness, cognitive functioning, interpersonal relationships, and awareness of homeostatic emotions such as hunger, pain and fatigue. In relation to these, it is involved in psychopathology.

In neuroanatomy, the central sulcus (also central fissure, fissure of Rolando, or Rolandic fissure, after Luigi Rolando) is a sulcus, or groove, in the cerebral cortex in the brains of vertebrates. It is sometimes confused with the longitudinal fissure.

The central sulcus is a prominent landmark of the brain, separating the parietal lobe from the frontal lobe and the primary motor cortex from the primary somatosensory cortex.

The lateral sulcus (or lateral fissure, also called Sylvian fissure, after Franciscus Sylvius) is the most prominent sulcus of each cerebral hemisphere in the human brain. The lateral sulcus is a deep fissure in each hemisphere that separates the frontal and parietal lobes from the temporal lobe. The insular cortex lies deep within the lateral sulcus.

The premotor cortex is an area of the motor cortex lying within the frontal lobe of the brain just anterior to the primary motor cortex. It occupies part of Brodmann area 6. It has been studied mainly in primates, including monkeys and humans.

The functions of the premotor cortex are diverse and not fully understood. It projects directly to the spinal cord and therefore may play a role in the direct control of behavior, with a relative emphasis on the trunk muscles of the body. It may also play a role in planning movement, in the spatial guidance of movement, in the sensory guidance of movement, in understanding the actions of others, and in using abstract rules to perform specific tasks. Different subregions of the premotor cortex have different properties and presumably emphasize different functions. Nerve signals generated in the premotor cortex cause much more complex patterns of movement than the discrete patterns generated in the primary motor cortex.