Our BPS is robust. While lesioning different components of BeCA (Gershenson,
Gonzalez and Negrete, 2000b), its functionality degrades “gracefully”.
BeCA is able to model reflex behaviours. External signals perceived by the reflex actions
internal behaviour will be directly sent to the Actions level of the cognitive node.
BeCA presents regulated reactive behaviours. The parameter (i in the attention to
preferences internal behaviour regulates how reactive a behavioural column will be. If ( is equal
to zero, then the behavioural column will not be reactive.
Our BPS has motivated behaviours: regulated and/or learned by reinforcement
(Gershenson and Gonzalez, 2000). The parameter " in the intero/extero/drive congruence
internal behaviour regulates the degree of the motivation of an external behaviour. If " is near
zero, the behaviour will be less motivated than if it is near one. The wealth or scarcity of the
environment is taken into account in the learning of this parameter. If the environment is
scarce, " will be increased. If the environment is rich, then " will be decreased.
BeCA has associative learning implemented within it. At this stage, primary and
secondary conditionings are present, and the following properties emerge from the interaction
of the different components of BeCA: blocking, decreasing of the stimulus activity in time,
overshadowing, extinction of the conditioning, reacquisition of the conditioning, temporal
interruption of the conditioning, inhibition of the conditioning, and the stronger conditioning
occurs for intermediate values of inter-stimuli intervals (Gonzalez, 2000). BeCA also exhibits
delay conditioning, in its two variants, and trace conditioning. The first variant of delay
conditioning consists in the length of the neutral stimulus (or the stimulus in conditioning
process) being equal to the inter-stimulus interval, whereas the second variant establishes that
the length of the neutral stimulus is equal to the inter-stimulus interval plus the length of the
unconditioned stimulus. In trace conditioning, the presentation of the neutral stimulus
terminates before the arrival of the unconditioned stimulus (Balkenius, 1994).
The following properties of BeCA are emergent:
Opportunism. The blackboard architecture allows the possibility of opportunistic
behaviour to arise. The elementary behaviours take the opportunity to execute their actions
when their conditions allow it.
Preactivation of internal behaviours. Once a competition is carried out at a motivational
level, the winning signal will be sent to the Consummatory Preferents level of the cognitive
node. If there is no external signal corresponding for the internal need represented by the
winning signal, then the attention to preferences internal behaviour will be “preactivated”,
focussing attention on the satisfaction of the need. If a corresponding signal appears, the
corresponding external behaviour will be executed, without the need for waiting for signals
from the motivational node.
Goal-directedness. If a behaviour is motivated, we can say that it is directed by the goals
(or needs) of the entity.
Non indecision in the action selection. The different competition processes assure that
there will be no indecision, or randomness, in the action selection. For example, if a creature
controlled by BeCA has the same degree of hunger and the same degree of thirst, and has food
and water in the same amount at the same distance, he will not decide randomly which
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