PREFRONTAL CORTEX: ANATOMY, FUNCTIONS AND INJURIES - NEUROPSYCHOLOGY - 2025

The prefrontal cortex, also known as the prefrontal cortex, is a region of the brain that is located in the anterior part of the frontal lobes. Specifically, this structure is located in front of the motor and pre-motor areas of the frontal cortex, resulting in a basic region for planning cognitively elaborated behaviors.

Recent research has linked the prefrontal cortex with activities such as the expression of personality, decision-making processes, and the adequacy of appropriate social behavior at all times.

Prefrontal cortex (red)

Thus, this region of the brain is one of the basic structures that determines the qualities of human behavior, as well as the execution of the most complex activities.

This article reviews the main characteristics of the prefrontal cortex. The main theories about this brain region are discussed, as well as the activities it performs and associated disorders.

Characteristics of the prefrontal cortex

The prefrontal cortex is a region of the brain that makes up approximately 30% of the cerebral cortex. This structure is located in the frontal region of the brain, that is, in the area that is located in the forehead, and constitutes the anterior part of the frontal lobes of the brain.

More specifically, the prefrontal cortex lies just ahead of two other important areas of the frontal lobe: the motor cortex and the pre-motor cortex. There are currently three main ways to define the prefrontal cortex. These are:

1. Like the granular frontal cortex.
2. As the projection zone of the middorsal nucleus of the thalamus.
3. As the part of the frontal cortex whose electrical stimulation does not cause movements.

The prefrontal cortex can be distinguished from other areas of the frontal lobe through its cellular composition, its dopaminergic innervation, and its thalamic input. In this way, it constitutes today a well established and delimited region.

Frontal lobe

According to most authors, such as Miller and Cohen, the prefrontal cortex is the region that is most elaborated in primates, animals known for their diverse and flexible behavioral repertoire.

Thus, the prefrontal cortex constitutes a set of neocortical areas that sends and receives projections from practically all the sensory and motor cortical systems and many sub-cortical structures, and is a basic region for the development of behavior and personality.

Illustration of the prefrontal cortex

In this sense, Miller and Cohen determined that the prefrontal cortex is not a critical structure for the performance of simple or automatic behaviors, which are not generalized to new situations.

On the contrary, the prefrontal cortex is important in those activities that require top-down processing, that is, when behavior must be guided by internal states or when it is necessary to use social and environmental elements that determine behavior.

Anatomy

Subdivisions of the prefrontal cortex

The prefrontal cortex has been defined through its cytoarchitecture by the presence of a granular layer that corresponds to the fourth layer of the cerebral cortex.

At present, it is not entirely clear who was the first to use this criterion for distinguishing the prefrontal cortex. Many of the pioneering researchers in brain cytoarchitecture restricted the prefrontal term to a much smaller region.

However, in 1935, Carlyle Jacobsen used the term prefrontal cortex to differentiate the granular prefrontal areas from the non-granular motor and pre-motor areas of the frontal lobe.

In Brodmann's area terminology, the prefrontal cortex includes areas 8, 9, 10, 11, 44, 45, 46, and 47, resulting in a very large region with a large number of structures within it.

Brodmann areas

On the other hand, the prefrontal cortex stands out as a projection zone for the nuclei of the thalamus, according to the work of Rose and Woolsey. These authors demonstrated that in non-primate animals (which do not have a prefrontal cortex), these structures project to different regions. Specifically, towards the anterior and ventral areas.

Likewise, there are currently studies that have shown that the projections of the mediodorsal nucleus of the thalamus are not restricted to the prefrontal cortex in primates, but that they could also travel to other brain structures.

Finally, today the prefrontal cortex is also known as that area of ​​the frontal cortex whose electrical stimulation does not cause observable movements. However, this definition causes some controversy since the absence of observable movements after electrical stimulation can also be observed in non-granular regions of the cortex.

Features

The prefrontal cortex is a structure that is strongly interconnected with much of the brain. Inside it, abundant connections with other cortical and sub-cortical regions can be seen.

The dorsal prefrontal cortex is especially interconnected with brain regions involved in processes such as attention, cognition, and action. Instead, the ventral prefrontal cortex interconnects with brain structures related to and involved with emotion processes.

Finally, it should be noted that the prefrontal cortex receives information from the arousal systems of the brain stem, and its function is particularly dependent on its neurochemical environment.

Brainstem (orange)

More generally, there is currently a high scientific consensus that the prefrontal cortex is a region of the brain that is primarily involved in planning cognitively complex behaviors.

This type of functions implies the performance of activities such as the expression of personality, the development of decision-making processes or the adaptation of behavior to the social situations that occur at all times.

Thus, the prefrontal cortex is a fundamental region to coordinate thoughts and actions in accordance with internal goals and acquired knowledge.

To determine the functionality of the prefrontal cortex, the medical term executive function has been developed. This type of function refers to the ability to distinguish between conflicting thoughts, make moral judgments, predict consequences, etc.

Activity of the prefrontal cortex

Currently, there are many theories that try to define how the prefrontal cortex works through executive functions.

In this sense, the prefrontal cortex is a functionally very difficult region to analyze and study, since it has multiple connections with practically all the structures of the brain.

However, beyond the mechanism that it may present, the type of activities it carries out is currently well described. The activity of the prefrontal cortex falls on what is known as executive functions and is characterized by performing the following actions:

1. Development of capacities to formulate goals and design plans.
2. Development of powers involved in planning processes and strategies to achieve objectives.
3. Execution of skills involved in the execution of the plans.
4. Recognition of the achievement acquired through the behavior and the need to alter the activity, stop it and generate new action plans.
5. Inhibition of inappropriate responses.
6. Behavior selection process and its organization in space and time.
7. Development of cognitive flexibility in monitoring strategies.
8. Supervision of behaviors based on motivational and affective states.
9. Supervision of behaviors based on the particularities of the context at all times.
10. Decision making.

Prefrontal cortex and executive functions

MRI of the brain

Through the initial studies of Fuster and Goldman-Rakic, the term executive functions was developed to give a name to the capacity and activity that the prefrontal cortex develops.

Executive function thus refers to the ability to represent information that is not present in the environment at a given time, as well as the creation of a "mental notepad."

Thus, the concept of executive function of the prefrontal cortex encompasses the development of cognitive responses to complex or difficult-to-solve problems.

Current studies suggest that past experiences are represented in the prefrontal cortex to apply them to the present and, in this way, guide decision-making.

In general, through this function, the prefrontal cortex would be the brain structure that would give people the ability to reason and the ability to use knowledge and past experience to modulate behavior.

More specifically, the Goldman-Rakin works describe these types of functions as the way in which representational knowledge can be used to intelligently guide thoughts, actions and emotions.

Executive functions would be a process that would give rise to the ability to inhibit thoughts, behaviors and sensations that are considered inappropriate.

Theories of executive functions

At present, there are many different theories that try to explain the specific functioning of this activity carried out by the prefrontal cortex. One of them postulates that working memory would be a fundamental part of the process of attention and behavioral inhibition.

Specifically, working memory allows you to retain the new information captured and keep it for a few seconds in the mind of the person. The adaptation of this information with prior knowledge could be the process that gave rise to executive functions and determined the activity of the prefrontal cortex.

On the other hand, Shimamura proposed the theory of dynamic filtering to describe the role of the prefrontal cortex in executive functions.

In this theory it is postulated that the prefrontal cortex would act as a high-level filtering mechanism that would favor goal-oriented activations and inhibit activations that may be irrelevant.

Finally, Miller and Cohen proposed an integrative theory of the functioning of the prefrontal cortex. In this theory it is theorized that cognitive control arises from the active maintenance of activity patterns in the prefrontal cortex, which are aimed at creating representations of the goals to be achieved and the necessary means to achieve it.

Lesions in the prefrontal cortex

Phineas gage

The first finding about lesions in the prefrontal cortex was made through the documentation of the famous case of Phineas Gage, a railroad worker who, after an accident, experienced a serious injury to the frontal lobe of the brain.

Through brain damage that critically involved the prefrontal cortex, Phineas retained his memory, speech, and motor skills. However, his personality traits changed radically after the accident.

In fact, the damage experienced in the prefrontal cortex made him irritable, impatient and with high deficits in social and interpersonal relationships.

Subsequently, other studies carried out with patients with prefrontal damage have shown that people are able to correctly verbalize what would be the most appropriate social behaviors under certain circumstances.

Despite being able to correctly reason the behavior to follow, in practice they have difficulties in executing said behaviors. In fact, in everyday life they tend to carry out acts that bring immediate gratification despite knowing the negative consequences that they can carry in the long term.

Associated disorders

The data collected on the effects of direct damage to the prefrontal cortex indicate that this region of the brain is not only related to the abilities to understand the long-term consequences, but also involves the mental capacity to delay immediate gratification.

Today there is an abundant literature aimed at improving the understanding of the role of the prefrontal cortex in different neurological disorders, such as schizophrenia, bipolar disorder or attention deficit hyperactivity disorder.

These three psychopathologies have been related to a certain dysfunction of the cerebral cortex, a fact that would motivate the appearance of behavioral alterations in people.

Likewise, clinical trials with pharmacotherapy have now been initiated that have found that certain drugs, such as guanfacine, improve the function of the prefrontal cortex.

Finally, it is postulated that other pathological conditions such as depression, elevated stress responses, behaviors and suicide attempts, sociopathies or drug addictions could also be related to the functioning of the prefrontal cortex.

However, the scientific evidence on these hypotheses is limited and further investigation is required to determine the role of the prefrontal cortex in these types of psychopathological disorders.

References

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2. Javier Tirapu Ustárroz et al. (2012). Neuropsychology of the prefrontal cortex and executive functions. Editorial Viguer.
3. Lapuente, R. (2010). Neuropsychology. Madrid, Plaza edition.
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5. Bryan Kolb, Ian Q. Whishaw (2006): Human Neuropsychology. Editorial Médica Panamericana, Barcelona.
6. Jódar, M (ed). (2005). Language and memory disorders. Editorial UOC.