3.8.2.Dynamic adjustment of the motivation degree
The other type of learning included in BeCA consists in the dynamic adjustment of the
parameter " in the model for combination of internal and external stimuli, used by the
intero/extero/drive congruence internal behaviour, presented in Section 3.7. This parameter
allows to regulate the dependence degree of the external behaviour executed by the agent from
his internal state. We have named this parameter “motivation degree”. The effects produced
by values of " equal to zero or " near to one in the observed external behaviour were already
discussed in Section 3.7. We will rewrite again expression (7) taking into account that there is
a different parameter " for each intero/extero/drive congruence elementary behaviour.
Expression (11) incorporates this change.
4c= (alCf∖a2 + (∑.Fafθfy (afθf (11)
The learning model that controls the dynamic adjustment of the motivation degree
(parameter " in expression (11)) can be explained in the following terms: when for a strong
internal state (e.g. need, goal), if the external signal able to satisfy this need is not present, then
parameter " is reinforced, so that the external behaviour related with column i begins to be
more motivated. Therefore, after this adjustment, the BPS will begin to attach more
importance to the internal state which has not been satisfied. In this case, the default
exploratory behaviour can be activated for not so strong values of the internal need, although
other external signals may have already been perceived. When an external signal is perceived
and the value of the associated internal state to this signal is irrelevant, then the parameter "
of expression (11) is decreased, and the behaviour production begins to become less motivated.
Therefore, in later situations with this adjustment, the BPS will begin to give more importance
to the available external signal, although the associated internal state is not a strong one. In this
case, the default exploratory behaviour will need stronger values of the internal need to be
activated. In any other case the parameter " is not modified. These cases are represented in
expression (12).
(12)
ι∙⅞, (ґ) in othsr cass
where O E is the value of the internal signal from the Internal Perceptions blackboard level,
3 Fa SO S represents the value of all the external signals that are associated to the internal state
i, and 2 is a threshold value.
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