Reinforcement Sensitivity Theory: Summary, And What It Proposes
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 human multiplicity.
The scientific interest in knowing what personality is and how it manifests 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 (Eysenck’s, for example), but starting from a fundamentally neuropsychological base.
In this article we will address 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.
The theory of sensitivity to reinforcement tries to explain what a human being is like based on his or her motivation to approach or move away from environmental stimuli or situations at your disposal.
While it is true that there are a series of appetitive stimuli in which an innate search is displayed 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 stimuli: those that provoke an unconditional approach or rejection (learning shared by the entire 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 party being the victim of an attack, for example).
The desire to approach and to reject/flight (maintained by motivational states) would depend on the activation/inhibition of a series of neural networks, which would arise 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 group of attributes that have their roots in the brain (offering a parsimonious and clear explanation of behavior based on its multiple interactions).
After the meticulous study of the neural structures, and equipped with extensive theoretical background on their functions, Gray proposed three brain systems that underlie approach and distance behaviors: the behavioral approach system (CAS), the behavioral inhibition system (SIC) and the fight or flight system (SLH). Every person would present a specific activity pattern for each of them, which would form the profile of how he acts and feels in his natural environment.
Based on these observations, he additionally proposed two personality dimensions: anxiety and impulsivity, different from those usually considered. Each of them would be linked to one of the systems reviewed and would also involve different emotional experiences.
As can be seen, Gray drew a direct relationship between brain and personality, understanding that both behavior and thought could be explained from the activity of the structures involved in their systems. From now on 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 approach system (CAS)
The SAC is a neurological mechanism that promotes approach behavior towards stimuli that have been conditioned in a positive way (that is, they are associated with desirable results or that allow us to avoid adverse consequences), thereby motivating the active search for their proximity. spatial and temporal. Thus, it would be responsible for promoting the availability of what is perceived as desirable or that increases the probability of survival.
All of this would translate into voluntary motor and emotional approach behavior, 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, as well as other neocortical types (sensorymotor, motor and prefrontal cortex). The activation of this system would manifest itself in positive affects associated with the dimension of impulsivity.
The basal ganglia are responsible for the planning and integration of voluntary movement, as well as motivation and emotion, while the motor and sensorimotor areas are necessary to translate everything into explicit approach actions.
The above is complemented by the function of the frontal lobe (which includes intention and projection at an executive level) and the reward system (which provides a positive tone to the life experience through the production of dopamine).
The SIC is understood, in the context of reinforcement sensitivity theory, as a response that opposes that of the SAC. In this case would be activated by stimuli that have been negatively conditioned (because they generate harm or prevent the achievement of something desirable), or that have been established throughout the development of the species as objects or situations that must be avoided. For this reason, they promote behaviors whose purpose is active distancing.
Likewise, it also extends to novel or overly 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 more precise knowledge was available about the nature of the events being faced, and from that moment on a series of proximity behaviors (mediated by the SAC) or avoidance behaviors (mediated) would be articulated. mediated by the SIC and the SLH).
The brain structures that form the SIC are the hippocampus and its projections to the prefrontal cortex. The hippocampus would actively participate in memory and spatial orientation, while the prefrontal cortex would be in charge of attention and prospective reasoning. All of them would coordinate to explore the immediate environment and predict what may happen at that 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 appearance of adverse events that we fear. or that we consider should be avoided.
3. The fight or flight system (SLH)
SLH is related to the escape of adverse events of which one is a participant (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 the 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’s known that The simultaneous hyperactivation of this system and the SAC triggers approach and escape behavior at the same time and towards the same object, a contradiction that would have to be resolved through the participation of the SIC. 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?
To explain personality according to the theory of sensitivity to reinforcement, the SAC and SIC systems are especially considered. Both work independently, so the high or low activation of one of them would not influence that of the other. Thus, there would be people with hyperactivation/hypoactivation of both systems, and others in which one would be hyperactivated and the other hypoactivated.
As previously stated, the SAC would be related to impulsivity and the 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 activation spectrum of the SAC would be associated with the extraversion/introversion continuum (tendency towards sociability or preference for solitude or individuality) while the SIC would do the same with that of neuroticism/stability (vulnerability to emotional discomfort or regularity in affective states).
Currently the theory of sensitivity to reinforcement is the subject of numerous investigations, from which both favorable and contrary results emerge. Some of them suggest that the SAC and SIC systems could be related in some way (so they would not work independently) and the study of anxiety/depression is also being approached from this same prism. Time is still needed, however, to know the real scope of Gray’s model.
