The frontal lobe is the main site of cognitive, emotional and behavioral processing. The prefrontal cortex, because of heavy bidirectional connections with all the other associative areas of the brain has long been assumed to have functions of control over other cognitive functions. This function has been termed
“executive”, meaning that rather than performing primary cognitive operations, such as memorizing, speaking and seeing, the frontal regions control the deployment of such capabilities, which are carried out elsewhere in the brain.
Therefore, the role of the frontal lobes is regarded as “supervisory” or “managerial” rather than being limited to the performance of any specific cognitive function. The frontal lobe is “the master and commander” of our brains. As per cognitive functions the frontal areas (as consistently demonstrated by fMRI studies) play a central role in working memory tasks. Working memory is the faculty that is responsible for the transient holding, associating and processing of new and already stored information, a fundamental process for reasoning, comprehension, learning and memory updating. Intelligent people or people gifted with the so called “fluid intelligence” generally have high capabilities of working memory.
As per the cognitive deficits patients with frontal lobe lesions show working memory deficits, poor logic and judgment, diminished sustained attention and mental speed, poor capacities of planning and organizing, poor abstraction, mental inflexibility, difficulties to control automatisms and task-switching,
The frontal lobes are the “master and commander” of emotional and behavioral processing too.
Evidence of the role of the prefrontal cortex in behavior and personality changes comes from the description of patients with frontal lobe damage. Such patients tend to be emotionally impulsive and poorly affectively regulated. Their behaviors include decreased concern with social propriety, environmental dependency, utilization, imitation and stereotyped behaviors, restlessness, exuberance, euphoria, facetiousness, extroversion, lack of restraint, purposelessness, childish behavior, distractibility, egocentricity, grandiosity, capriciousness and instability, social and sexual disinhibition, poor judgement, diminished foresight, social withdrawal, absence of tact, concreteness, acting on simple motivations, impulsiveness, self-centeredness, immorality, inertia, lack of ambition, indifference to the environment, satisfaction with inferior performance, slowness in thinking, bradypsychism, lack of emotional expression, decreased self-concern, shallow affect, depressed outwardly directed behavior and social sense, indifference, and alexithymia, lack of empathy and impaired theory of the mind (the ability to attribute mental states to others and to oneself), ritualistic or compulsive behaviors. Furthermore, several of these conditions may often occur together in the same patient.
Damasio and Stuss suggested that all behavioral and emotional changes due to frontal system damage might be a personality disorder where lack of control and self-reflectiveness (vulnerability to interference, impoverished judgment, and inability to self-correct and self-monitor) are the key features.
Hence, the DSM taxonomy of personality disorders (paranoid, schizotypic, antisocial, borderline, histrionic, narcissistic, avoidant, and obsessive–compulsive) seems to fit well with the so-called “frontal” behaviors.
The rehabilitation of the individual with a dysexecutive/frontal syndrome is a true challenge for the clinician and requires complex multidisciplinary approaches.