Cingulate rotation (brain): anatomy and functions
The cingulate gyrus, also known as cingular gyrus, cingulate gyrus , cingulum or gyrus cinguli it is a very important part of the brain, since it plays an essential connecting role between the limbic system and the neocortex. The cingulate gyrus forms an arcuate convolution, close to the surface of the corpus callosum.
In simplistic terms, the cingulate turn is like a "passing" structure, like a bridge, that differentiates us to a large extent from animals that have evolved differently from ours.
It connects the structures that equate us with the rest of animals (the limbic system: remember the importance of the hippocampus and the amygdala) and those that give us the ability to plan, reason, perform conceptual abstractions: the higher cognitive functions located in the neocortex.
Functions of the cingulate gyrus
The anterior cingulate region has important connections with the amygdala, hippocampus, septum, anterior hypothalamus, caudate and putamen, dorso-medial nucleus of the thalamus, inferior parietal lobe, lateral convexity and medial frontal lobes.
- It performs a connecting role between the volitional aspects, cognitive, emotional and mnesic motors.
- It deals with modulating and processing the expression of subtle emotional nuances
- It intervenes in the modulation of the voice (sadness, happiness).
- It is responsible for the learning of emotional vocalization, which facilitates the formation of long-term attachments, especially the attachment between mother and child.
- Its stimulation produces feelings of anxiety, pleasure and fear.
- It is responsible for initiating the behavior oriented to significant motivational goals for the subject.
- The subcallose region is responsible for the regulation of autonomic functions such as respiration and heart rate.
- Participates in the movements of hands and other movements in difficult tasks, or that imply recent memory, and in the spontaneous beginning of the action.
- It is activated in situations that demand executive control, divided attention, resolution of conflicts, detection of errors, supervision of responses and initiation and maintenance of appropriate responses.
- It plays a basic role in the selective attention involved in the correct resolution of the Stroop test and in other attentional tasks guided by motivation. The function would be to monitor the conflict between stimulus and response to select the appropriate behavior.
- It plays an important role related to the motivation in the functioning of the pre-frontal cortex for the performance of voluntary actions.
The Papez circuit
Papez (1929) affirmed that the communication between the hippocampus and the neocortex is carried out reciprocally . They are constantly connected by means of the cingulate gyrus, and would be carried out in the following way: the hippocampal formation processes the information that comes from the cingulate gyrus, and carries it to the mammillary bodies of the hypothalamus (through the fornix). At the same time, the hypothalamus sends information to the cingulate gyrus via the mamillary bodies-anterior thalamic nucleus and from here to the frontal cortex.
The processing of the conflict
Posner and other authors (2007) have ensured that the anterior cingulate gyrus is part of an executive attentional network, which is responsible for regulating the processing of information from other sensory and emotional networks. This is important in order to perform a task, especially those that involve effort or those that are new (not routine). Some authors, such as Posner and Botvinick, propose the conflict monitoring hypothesis, which defends that when there is a conflict detection in a task (as in the Stroop test), the anterior cingulate turn triggers a set of strategic adjustments in cognitive control and in planning the response. Its objective is to reduce the conflict in the task and, on the next occasion, to succeed. It's like a mechanized controlled evaluation of the results. If these are not satisfactory, information is sent to other structures of the planning system (frontoparietal system and cerebellum) that are responsible for establishing strategies for action and learning from error.
Emotional control mechanism
According to Kandel (2000), the emotional state of humans is composed of physical sensations and specific feelings, and are regulated by different anatomical structures. Concrete feelings are regulated by the cingulate cortex and the orbitofrontal cortex, and the emotional states (peripheral, autonomic, endocrine, and skeletal-motor responses) involve subcortical structures such as the amygdala, hypothalamus, and brainstem.For example, when we watch a horror movie and feel fear, at the same time we experience an increase in heart rate, the mouth dries up, the muscles tense, and so on. The rostral anterior cingulate cortex can help inhibit the activity of the amygdala, resolving emotional conflicts. This phenomenon is called "emotional top-down" . In patients with depression there is a hyperactivation of the anterior cingulate cortex in the processing of negative self-referential words. More specifically, there is a positive correlation between the amygdala, the medial prefrontal cortex and the rostral cingulate cortex between the self-referential negative emotional information processing. People with Posttraumatic Stress Disorder show hypoactivity of the rostral anterior cingulate cortex when they try to evoke the trauma and during its reexperimentation. In addition, the severity of PTSD symptoms correlates with the hypoactivity of the rostral anterior cingulate cortex. In people with anxiety, there is no suppression of activity of the amygdala, which correlates negatively with the activity of the rostral anterior cingulate cortex. Changes in such activity will depend on the perceived threat, the degree of defenselessness that the person feels and the anticipation of adverse stimuli. .
What happens if the cingulate turn is injured?
His injury produces several disorders and syndromes, such as mutism, imitation behaviors (echopraxia) and compulsive use of objects.
Lesions in the anterior and medial cingulate regions generate disorders of exploratory, attentional or action motivation. Patients with lesions show hypokinesia, apathy, abulia without depression, lack of spontaneity, akinetic mutism and flattened emotional response.
The bilateral cingulate lesions generate incontinence of sphincters, tendency to distractibility , docility and fabulation.
The most common alteration when the cingulate gyrus is injured is the frontal medial syndrome or the anterior cingulate syndrome, characterized by lack of initiative, akinesia or hypokinesia, apathy and mutism. There is a reduction in goal-oriented activities, patients show no interest or concern for anything (neither for their family, nor for themselves or the future).
It would also have to do with the syndrome of dependence on the environment, which entails the loss of personal autonomy (involves a tendency to distraction, hyperreactivity, decreased motivation and apathy).