Frontal lobe functions

The frontal lobe has a number of important function.

Function
In the human brain, the precentral gyrus and the related cortical tissue that folds into the central sulcus comprise the primary motor cortex, which controls voluntary movements of specific body parts associated with areas of the gyrus.

Executive control
Frontal lobes assist in planning, coordinating, controlling and executing behavior. People that have damaged frontal lobes may experience problems with these aspects of cognitive function, being at times impulsive; impaired in their ability to plan and execute complex sequences of actions; perhaps persisting with one course of action or pattern of behavior when a change would be appropriate (perseveration).

The executive functions of the frontal lobes involve the ability to recognize future consequences resulting from current actions, to choose between good and bad actions (or better and best), override and suppress unacceptable social responses, and determine similarities and differences between things or events.Therefore, it is involved in higher mental functions.

Memory
The frontal lobes also play an important part in retaining longer term memories which are not task-based. Memories associated with emotions of input from the brain's limbic system are modified by the higher frontal lobe centers to generally fit socially acceptable norms (see executive functions above). The frontal lobes have rich neuronal input from both the alert centers in the brainstem and the limbic regions.

Role in mental health
A report from the National Institute of Mental Health says a gene variant that reduces dopamine activity in the prefrontal cortex is related to poorer performance and inefficient functioning of that brain region during working memory tasks, and to slightly increased risk for schizophrenia.

Theories of function
Theories of frontal lobe function can be differentiated into four categories:
 * Single-process theories. Posit "that damage to a single process or system is responsible for a number of different dysexecutive symptoms” (Burgess, 2003, p. 309).
 * Multi-process theories. Propose "that the frontal lobe executive system consists of a number of components that typically work together in everyday actions [(heterogeneity of function)]" (Burgess, 2003, p. 310).
 * Construct-led theories. Assume "that most if not all frontal functions can be explained by one construct (homogeneity of function) such as working memory or inhibition" (Stuss, 1999, p. 348; cf. Burgess & Simons, 2005).
 * Single-symptom theories. Suggest that a specific dysexecutive symptom (e.g., confabulation) is related to the processes and construct of the underlying structures (cf. Burgess & Simons, 2005).

Stuss (1999) suggests a differentiation into two categories according to homogeneity and heterogeneity of function.

Further theoretical approaches to frontal lobe function include:
 * Grafman's managerial knowledge units (MKU) / structured event complex (SEC) approach (cf. Wood & Grafman, 2003)
 * Miller & Cohen's integrative theory of prefrontal functioning (e.g. Miller & Cohen, 2001)
 * Rolls's stimulus-reward approach and Stuss's anterior attentional functions (Burgess & Simons, 2005; Burgess, 2003; Burke, 2007).

It may be highlighted that the theories described above differ in their focus on certain processes/systems or construct-lets. Stuss (1999) remarks that the question of homogeneity (single construct) or heterogeneity (multiple processes/systems) of function "may represent a problem of semantics and/or incomplete functional analysis rather than an unresolvable dichotomy" (p. 348). However, further research will show if a unified theory of frontal lobe function that fully accounts for the diversity of functions will be available.

Assessment of funtioning
Psychological tests that measure frontal lobe function include finger tapping, Wisconsin Card Sorting Task, and measures of verbal and figural fluency.