The motivating effect that rewards
have on behaviour is universally recognized, though the exact
role of pleasure is still debated. Is pleasure a determining
factor in whether an individual evinces a particular behaviour,
or simply a concomitant of the behavioural response? Either
way, the motivations that drive our behaviour appear to be
intimately linked to pleasure.
AND AVOIDING PAIN
Our most powerful motivations come from behaviours
that have proven beneficial to our species from an evolutionary
systems in the brain have thus evolved to give us pleasure
when we engage in these behaviours.
The brain has two major pathways that help
behaviours: the reward circuit, which is part of the medial
forebrain bundle (MFB); and the punishment circuit, or periventricular
MFB, through the desire/action/satisfaction cycle, and the
PVS, through the successful fight or flight response, lead
the organism to behave in a way that preserves its homeostasis.
Together, they form the behavioural approach system (BAS).
Opposing the BAS is the behavioural
inhibition system (BIS), characterized by Henri Laborit in
the early 1970s. Stimulation of the BIS causes an overall inhibition
of behaviour, thus working against the BAS.
Under natural conditions, the BIS is activated
when we observe that our actions will be ineffective. When fight
or flight appears impossible, very often the only choice left to
ensure survival is to submit and accept things as they are. The
BIS is the result of an evolutionary history in which this system
made itself useful by operating intermittently, temporarily preventing
any useless actions that could only have made matters worse.
For example, consider a small mammal in the
middle of a field who suddenly sees a bird of prey flying overhead.
The best thing to do is not to move, in the hope of not being seen.
In human societies based on competition, many people activate their
behavioural inhibition system continually, to avoid reprisals.
In such cases, the inhibition of behaviour
is no longer merely an adaptive interval between approach and avoidance
behaviours, but instead becomes a chronic source of anxiety. This
sense of uneasiness gradually undermines the individual’s
health. Indeed, the inhibition of behaviour has many negative consequences,
and they have been abundantly documented. The most obvious ones
are psychosomatic illnesses, stomach ulcers, and arterial hypertension.
But prolonged activation of the BIS can also lead to more serious
genetic disorders such as cancers and all of the pathologies associated
with impaired immune function.