by a signal on the Drive/Perception Congruents level; or this signal by itself will be able to
invoke an external behaviour.
The role of the perceptual persistence internal behaviour continues to be the
representation of the external signals in the Perceptual Persistents level, although its activity
has been refined. This means that for the persistence of a signal in Perceptual Persistents, this
will be taken into account if a signal associated with this one has been created at the
Drive/Perception Congruents level. This last signal participates in the competition among the
perceptual persistence elementary behaviours, reinforcing the persistence of the corresponding
signal at the Perceptual Persistents level. Expression (3) shows this refinement in the perceptual
persistence internal behaviour.
⅛√=∣>jjc⅛⅞r+ ⅛⅛+ς,,j+fli<ΓoΓ (3)
where FaiiI is the coupling strength of the signal OiI of the Drive/Perception Congruents level.
The rest of the notation is the same as used in expression (1), and AT is still determined by
expression (2.
The signals placed at the Consummatory Preferents level are combined with signals
placed at the Perceptual Persistents level to decide the possible external actions to execute. This
task is carried out by the attention to preferences internal behaviour. At this level, we can see
how the internal needs mediate the selection of the external behaviour to be executed. The
elementary behaviours encapsulated in this internal behaviour work as operators AND or
operators OR depending of the value of ( in expression (4). This parameter is used to
modulate the reactivity degree in the observed behaviour of the entity. The final action of the
elementary behaviour i consists in the creation of the solution element OI at the
Drive/Perception Congruents level. The value of solution element OI is given by expression (4).
, τ τ( ∑i4oΓl
(4 (( ) '4' ( + f4^, ( (4)
к Ч J
where OI is the value to be inscribed in the Drive/Perception Congruents level; OT is the signal
from the Perceptual Persistents level and FaT its corresponding coupling strength; O C is the
signal from the Consummatory Preferents level and Fa C its corresponding coupling strength;
and ( and N modulate the reactivity degree in the observed behaviour of the agent.
When the value of N equals one, the total value of the signals from the Consummatory
Preferents level, representing the most imperative internal needs, is taken. This makes the
external behaviour motivated. As N decreases, less importance is given to the signals from the
Consummatory Preferents level, making the external behaviour less motivated. If N is equal to
zero, there will be no flow of signals from the Consummatory Preferents level, and the agent
will not have any knowledge of its internal needs. Therefore, by modifying the value of N we
can produce a motivational lesion in the BPS.
39