Functional Temperament Ensemble

The fact that people use drugs to change the balance of brain neurotransmitters in cases of depression, anxiety, schizophrenia and other psychiatric diseases shows that an imbalance in neurochemical systems can affect human behavior. All healthy people have a weak form of such an imbalance and is manifested in the form of constant character traits ( temperament ). In this sense, temperament (as individual differences based on neurochemical systems) and psychiatric diseases represent a weak and strong degree of severity of the same continuum of neurochemical imbalance. ^{[5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16]} And in fact, many features of temperament (impulsiveness, search for impressions, energetic traits, plasticity, sociability) turned out to be dependent on the activation of brain neurotransmitters and hormones . ^{[17] [18] [19] [20] [2] [1] [21]} . By the end of the 20th century, it became clear that the human brain is regulated by dozens of neurotransmitters , and a large number of neuropeptides and hormones . The relationship between these neurochemical systems is complex because they inhibit or activate the release of each other during neural activity. The complexity of these relationships devalues ​​the old approach to neurotransmitters dividing them only into “stimulating” and “inhibiting” ones. Now it has become clear to scientists that the impressive diversity of neurotransmitters and the diversity of their receptors is necessary for us so that we can adequately respond to a wide range of behavioral situations. However, the relationship between temperament traits and individual neurotransmitters is still the subject of controversy and research. Several attempts have been made to attribute certain features to the action of individual neurotransmitters. For example, it was suggested that dopamine be regarded as the neurotransmitter of the Extraversion trait; norepinephrine - as a mediator of anxiety, and serotonin was considered as a neurotransmitter of inhibitory processes. Such theories turned out to be a serious simplification of the functions of these neurotransmitters in regulating human behavior, because studies have shown their much broader functionality ^{[1] [2]} .

The architecture of the Functional Temperament Ensemble Model (FET) model was developed by Trofimova initially as the Compact Test version of the Temperament Structure Questionnaire (STQ-77) in 1997-2007. This model inherited the Activity-specific approach to the structure of temperament proposed by Rusalov in the mid-1980s. According to this approach, traits of temperament (and behavioral regulation) related to the motor-physical, socio-verbal and mental aspects of activity are based on various neurophysiological systems and must be analyzed / evaluated separately (in the Figure, this separation is seen as 3 rows of traits). Like Ost Rusalov, the version of Trofimova OST-STQ-77 has 12 temperamental scales that measure abilities in the physical, socio-verbal and mental aspects of behavior. In both models, the three upper (“cortical”) traits are considered as traits regulating behavior in more complex, probabilistic conditions, and the two series of traits below (physical and socio-verbal) are considered as the regulation of more specific, deterministic aspects of behavior ^{[22] [1] [2] [3] [4] [23] [24] [25] [10] [26]}

The differences in the structure of OST-77 Trofimova from the structure of OST-150 Rusalov are as follows:

• the choice of grouping traits according to the dynamic qualities of behavior: the OST-77 model uses the Energy Traits, Integration Speed, and Orientation groups, presented on the diagram as columns of the trait matrix;
• the inclusion of traits related to the behavioral orientation to certain types of values ​​- reinforcers of behavior: physical sensations (trait “Search for Feelings”), or the state of other people (“ Empathy ”), or knowledge about the cause-effect relationships of events and the exclusivity-frequency of their occurrence (Sensitivity to Probabilities, or Probabilistic Thinking) ^[4] ;
• in another structure of traits related to emotionality. Trofimova’s model combined the three features of the Rusalov model related to Emotionality into one scale ^{[22] [24] [26]} . The OST-77 model considers emotionality as a system that amplifies (strengthens) three dynamic aspects of behavior. The amplification of the orientation system is expressed in Neuroticism, the amplification of the behavior integration system (integration is too fast) is expressed in Impulsivity, and the strengthening of the subjective feeling of energy readiness is expressed in Self-confidence.
• The Impulsivity trait in OST-77 reflects the rate of initiation of a behavioral act during emotional regulation of behavior when the integration of the act is still immature and has not passed complete cognitive control. A more mature and complex integration of behavior manifests itself in the form of the Plasticity trait. The Activity tempo trait describes a mature and automatic type of action integration. Impulsivity, Tempo and Plasticity, therefore, belong to the group of traits regulating the speed (ease) of the integration of a behavioral act.

In 2007-2013, the temperament model STQ-77 was compared with work in the field of neurophysiology, neurochemistry, clinical psychology and kinesiology and was reduced by Irina Trofimova to the neurochemical FET model. ^{[1] [3]} . Trevor Robbins , from the University of Cambridge , England, who collaborated with Trofimova on this project in 2014-2016, proposed an audit of a part of the FET hypothesis that related to Intellectual Endurance ( voluntary attention ) ^[2] . This component of the FET hypothesis was updated in 2015, defining the main role in the voluntary retention of attention of the neurotransmitters acetylcholine and norepinephrine .

The final STQ-77 / FET model consists of 12 components ( temperament traits): 9 traits regulating formal functional aspects of behavior (energy, act initiation rate and behavior orientation, each taken in three aspects - physical, social, verbal and mental), as well 3 traits of emotionality (Neuroticism, Impulsivity and Contentment (previously called Self-Confidence)) (see. Figure). The FET hypothesis suggests that 9 functional traits that are not related to emotionality are regulated by monoamines (MA): ( norepinephrine , dopamine and serotonin ), as well as acetylcholine and neuropeptides , while 3 traits of emotionality manifest themselves as dysregulation in the opioid system receptors directly controlling the MA system.

It is important to note that the FET hypothesis suggests that there is no one-to-one correspondence between neurotransmitters and traits of temperament (or mental illness). Instead, special combinations between these neurotransmitters produce certain traits of temperament while working in an ensemble. ^{[1] [2] [3]} .

The FET hypothesis is conservative and based only on consensus in neurochemical studies of the functionality of neurotransmitters. It does not include controversial and unverified connections between neurochemical systems and traits of temperament (aspects of behavior regulation).

The FET model proposes to structure modern classifications of mental illness (DSM, ICD) based on 12 functional components of the model. Thus, studies of patients with depression have shown that the predictions of the model are consistent with the symptoms of depression, combined with low physical stamina and low physical pace in the temperamental profiles of patients ^{[10] [13] [15] [16] [27]} . In contrast to these profiles, patients with chronic anxiety had higher values ​​on the scales of Neuroticism and Impulsivity ^{[10] [13] [14]} . The developers of the FET model proposed the presentation of each of the 21 main diagnoses of the leading classifications of mental illness in the form of a FET code, i.e. a specific pattern in the regulation of 12 aspects of behavior that this model describes.

• https://en.wikipedia.org/wiki/Functional_Ensemble_of_Temperament
• / Structure of Temperament Questionnaire - history of validation, forms for testing a questionnaire corresponding to this model (in 18 languages).
• - Lecture 1 or - Lecture 2 on the FET model in Russian
• / Lecture on the FET model in English