The theory of reinforcement sensitivity: summary, and what it proposes

This theory relates ideas about learning, about motivation and about neuroscience.

Personality is a complex dimension that describes the behavioral, cognitive and emotional pattern of an individual; through which he expresses himself as an independent being within the human multiplicity.

The scientific interest in knowing what personality is and how it manifests itself has led many researchers, over the years, to postulate different theoretical models for this purpose. One of them was Jeffrey Gray, who presented his theory of reinforcement sensitivity as an alternative to classical models (the as an alternative to classical models (that of Eysenck, for example), but starting from a fundamentally neuropsychological basis.

In this article we will discuss the author's theoretical postulates, which constitute a very important vision of the nature of acts and cognitions, from which we can better understand who we are and why.

Reinforcement sensitivity theory

The theory of sensitivity to reinforcement tries to explain what a human being is like on the basis of his or her motivation to move towards or away from the environmental stimuli or situations available to him..

While it is true that there are a series of appetitive stimuli for which there is an innate search that has not been mediated by learning (such as food with which to nourish ourselves), others have acquired their positive nuances through individual experience.

The theory contemplates both types of stimuliThe first ones are those that provoke an unconditioned approach or rejection (learning shared by the whole species throughout evolution) and those that generate similar responses but as a result of personal experiences (avoidance of dogs because we had an unpleasant encounter with one of them or because we saw a third one being the victim of an attack, for example).

The desire to approach and to reject/avoid (maintained by motivational states) would depend on the activation/inhibition of a series of neural networks, which would stand as the organic substrate of the basic dimensions of personality. According to this perspective, what we think, feel or do can be captured by a reduced set of attributes rooted in the brain (offering a parsimonious and clear explanation of behavior from its multiple interactions).

After a thorough study of the neural structures, and equipped with a broad theoretical background on their functions, Gray proposed three brain systems that would underlie approach and withdrawal behaviors, Gray proposed three brain systems that would underlie approach and withdrawal behaviors: the behavioral approach system (BAS), the behavioral inhibition system (BIS) and the behavioral inhibition system (BIS).These are the behavioral approach system (BAS), the behavioral inhibition system (BIS) and the fight or flight system (FFS). Every person would present a specific activity pattern for each of them, which would form the profile of how he/she acts and feels in his/her natural environment.

Based on these observations, he additionally proposed two personality dimensions: anxiety and impulsivity, different from those usually considered. Each of these would be linked to one of the systems outlined above and would also involve different emotional experiences.

As can be seen, Gray traced a direct relationship between brain and personality.The neurological model was based on the understanding that both behavior and thought could be explained on the basis of the activity of the structures involved in their systems. In the following we will connect these two phenomena, explaining in a simple way how neurology and psychology converge in this interesting integrated theoretical model.

1. The behavioral approximation system (BAS).

The BAS is a neurological mechanism that promotes approach behavior towards stimuli that have been conditioned in a positive way (i.e. that are associated with desirable results or that make it possible to avoid adverse consequences), thereby motivating the active search for their spatial and temporal proximity. Thus, it would be responsible for promoting the availability of what is perceived as desirable or that increases the probability of survival.

All this would translate into a voluntary motor and emotional approach behavior, mediated by coordinated brain structures.mediated by coordinated brain structures. Specifically, dopaminergic fibers that emerge from the midbrain (ventral tegmental area and nucleus accumbens) to limbic regions such as the basal ganglia, in addition to other neocortical regions (sensorimotor, motor and prefrontal cortex). The activation of this system would be manifested in positive affects associated with the impulsivity dimension.

The basal ganglia are responsible for the planning and integration of voluntary movement, as well as for motivation and emotion, while the motor and sensorimotor areas of the brain are responsible for the integration of voluntary movement, motivation and emotion. motor and sensorimotor areas are necessary for translating everything into explicit approach actions..

This is complemented by the function of the frontal lobe (which includes intention and projection at an executive level) and the reward system (which brings a positive tone to life experience through the production of dopamine).

2. The behavioral inhibition system (BIS)

The BIS is understood, in the context of reinforcement sensitivity theory, as a response that is opposed to that of the BMS. In this case would be activated in response to stimuli that have been negatively conditioned (because they generate (because they generate a harm or prevent the achievement of something desirable), or that have been fixed throughout the development of the species as objects or situations to be avoided. For this reason, they promote behaviors aimed at active distancing.

Likewise, it also extends to novel or too ambiguous situations, in which it is necessary to act in a considered manner and paying special attention to the environment. Consequently, the action of approaching would be inhibited until a more precise knowledge of the nature of the events being confronted is available, at which point a series of proximity behaviors (mediated by the SAC) or avoidance behaviors (mediated by the SIC and SLH) would be articulated.

The brain structures that form the SIC are the hippocampus and its projections to the prefrontal cortex.. The hippocampus is actively involved in memory and spatial orientation, while the prefrontal cortex is responsible for attention and prospective reasoning. All of them would coordinate to explore the immediate environment and predict what may occur at that very moment or as a consequence of it at a later time.

The system, therefore, is directly associated with anxiety and is responsible for continuously assessing (monitoring) the situation in which we are immersed and what could happen in the future, with the aim of anticipating the occurrence of adverse events that we fear or that we believe should be avoided.

3. The fight or flight system (FWS)

The SLH is related to the escape from adverse events in which one is involved. (which differentiates it from avoidance) and with fight or flight behaviors.

The brain structures involved are the amygdala (in which various emotional experiences are processed, but particularly fear) and the hypothalamus (which mediates stress responses and activation of the autonomic nervous system). Anger and fear would depend on it, emotions that have the purpose of preparing the body to give an immediate response.

It is known that the simultaneous hyperactivation of this system and of the SAC detonates a behavior of approach and escape at the same time and towards the same object, a contradiction that would be solved by means of the participation of the SIC. and towards the same object, a contradiction that would have to be resolved through the participation of the CIS. This dissonance between the appetitive and the aversive would be responsible for anxiety as a symptom within a disorder.

How would personality be understood from this model?

In order to explain personality according to the reinforcement sensitivity theory, the SAC and SIC systems are considered in particular. Both function independently, so that the high or low activation of one of them would not influence the other. Thus, there would be people with hyperactivation/hypoactivation of the two systems, and others in which one would be hyperactivated and the other hypoactivated..

As previously stated, SAC would be related to impulsivity and SIC would be related to anxiety, these being the basic personality dimensions according to Gray's model (thoughts or acts of approach and inhibition, respectively). In this sense, subjects with hyperactive SAC would be impulsive, and those with hyperactive SIC would be anxious.

Some authors have drawn analogies to explain that the SAC activation spectrum would be associated with the extraversion/introversion continuum (tendency to sociability or preference for solitude or individuality) while the SIC would be associated with the neuroticism/stability continuum (vulnerability to emotional discomfort or regularity in affective states).

The theory of reinforcement sensitivity is currently the subject of much research. is currently the subject of numerous investigationsThe results of which are both favorable and contrary. Some of them suggest that the SAC and SIC systems could be related in some way (so that they would not function independently) and the study of anxiety/depression is also being approached from this same perspective. Time is still needed, however, to know the real scope of Gray's model.

Bibliographical references:

• Bijttebier, P., Beck, I., Claes, L. and Vandereycken, W. (2009). Gray's Reinforcement Sensitivity Theory as a framework for research on personality-psychopathology associations. Clinical Psychology Review, 29(5), 421-430.
• Colder, C.R., Trucco, E.M., Lopez, H.I., Hawk, L.W., Read, J.P., Lengua, L.J. ... Eiden, R.D. (2011). Revised Reinforcement Sensitivity Theory and Laboratory Assessment of BIS and BAS in Children. Journal of Research on Personality, 45(2), 198-207.