3.4.4 Frontal lobes and cingulate gyrus

The Internal Anatomy and Function of the Frontal Lobes and Cingulate Gyrus

Frontal lobes:

The frontal lobes are a critical part of the brain, located at the front of the cerebral cortex. They are responsible for a wide range of functions, including higher cognitive processes such as problem-solving, decision-making, and language. The frontal lobes also play a role in movement and emotion.

The anatomy of the frontal lobes is complex, with multiple subregions and connections to other areas of the brain. The prefrontal cortex, located in the frontal lobes, is involved in executive function and has been found to be essential for abstract thought and flexibility in decision-making (Goldman-Rakic, 1987). The motor cortex, also located in the frontal lobes, controls voluntary movement (Penfield & Rasmussen, 1950).

Frontal lobes can be divided into several regions, each of which has specific functions:

Region of Frontal Lobe:	Function:
Prefrontal cortex	The prefrontal cortex is involved in higher cognitive functions such as planning, decision-making, and problem-solving.
Motor cortex	The motor cortex is responsible for controlling voluntary movement.
Premotor cortex	The premotor cortex is involved in the planning and organization of movement.
Orbitofrontal cortex	The orbitofrontal cortex is involved in the regulation of emotional responses and decision-making.

Frontal lobe injury:

Damage to the frontal lobes can have significant consequences on cognitive function and behaviour. For example, a study by Eslinger and Damasio (1985) found that individuals with damage to the frontal lobes had difficulty with tasks requiring problem-solving and decision-making abilities, as well as impaired social judgement and behaviour. Other research has shown that damage to the frontal lobes can lead to impairments in memory and language, as well as changes in personality and emotional functioning (Stuss et al., 2001). In addition, frontal lobe damage can impact motor function. For example, a study by Alexander et al. (1990) found that damage to the frontal lobes can lead to difficulties with voluntary movement and a condition known as “spastic hemiparesis,” in which one side of the body is weak and stiff. Overall, the frontal lobes are a critical part of the brain, and damage to this region can have wide-ranging effects on cognitive, behavioural, and motor function.

There are several potential causes of damage to the frontal lobes, including trauma, stroke, and neurological conditions such as brain tumours or degenerative diseases like Alzheimer’s disease. The specific symptoms and severity of impairment can vary depending on the location and extent of the damage.

Overall, the frontal lobes play a crucial role in multiple aspects of brain function, and their proper functioning is essential for daily life.

Cingulate Gyrus:

The cingulate gyrus is a region of the brain located in the medial aspect of the cerebral cortex. It is part of the limbic system, which plays a role in emotion and memory, and is connected to the prefrontal cortex, which is involved in higher cognitive functions such as decision-making and problem-solving.

The cingulate gyrus is divided into two main regions: the anterior cingulate cortex (ACC) and the posterior cingulate cortex (PCC). The ACC is involved in a range of functions, including the regulation of attention and emotional processing (Bush et al., 2000). The PCC is involved in memory and spatial navigation, as well as the default mode network, a network of brain regions that is active during rest and is thought to be involved in self-referential thought (Gusnard et al., 2001).

Studies have shown that the cingulate gyrus is also involved in pain processing, with the ACC specifically being activated in response to painful stimuli (Rainville et al., 1997). It has also been suggested that the cingulate gyrus may be involved in the development of mental health conditions such as depression and anxiety (Drevets, 2001).

Overall, the cingulate gyrus plays a complex and multifaceted role in brain function, with a wide range of connections to other brain regions and functions.

References:

(1) Bush, G., Luu, P., & Posner, M. I. (2000). Cognitive and emotional influences in anterior cingulate cortex. Trends in Cognitive Sciences, 4(6), 215-222.

(2) Drevets, W. C. (2001). Neuroimaging and neuropathological studies of depression: Implications for the cognitive-emotional features of the disorder. Current Opinion in Neurobiology, 11(2), 240-249.

(3) Goldman-Rakic, P. S. (1987). Circuitry of the prefrontal cortex and the regulation of behavior by representational memory. In M. S. Gazzaniga (Ed.), The Handbook of Cognitive Neuroscience (pp. 273-295). New York: Plenum Press.

(4) Gusnard, D. A., Akbudak, E., Shulman, G. L., & Raichle, M. E. (2001). Medial prefrontal cortex and self-referential mental activity: Relation to a default mode of brain function. Proceedings of the National Academy of Sciences, 98(7), 4259-4264.

(5) Penfield, W., & Rasmussen, T. (1950). The cerebral cortex of man. New York: Macmillan.

(6) Rainville, P., Duncan, G. H., Price, D. D., Carrier, B., & Bushnell, M. C. (1997). Pain affect encoded in human anterior cingulate but not somatosensory cortex. Science, 277(5328), 968-971.

(7) Stuss, D. T., Gallup, G. G., Jr., & Alexander, M. P. (2001). The frontal lobes are necessary for “theory of mind”. Brain, 124(Pt 10), 279-286.