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3 Biological Foundations of the Reactive Paradigm

Figure 3.5 Action-Perception Cycle. 7

then used for a variety of functions, including both cognitive activities like
planning for what to do next as well as reacting. The term cognitive activity
includes the concepts of feedback and feedforward control, where the agent
senses an error in what it attempted to do and what actually happened. An
equally basic cognitive activity is determining what to sense next. That ac-
tivity can be something as straightforward as activating processes to look for
releasers, or as complex as looking for a particular face in a crowd.
Regardless of whether there is an explicit conscious processing of the senses
or the extraction of a stimulus or releaser, the agent is now directed in terms
of what it is going to perceive on the next update(s). This is a type of selective
attention or focus-of-attention. As it perceives, the agent perceptually sam-
ples the world. If the agent actually acts in a way to gather more perception
before continuing with its primary action, then that is sometimes referred to
as active perception. Part of the sampling process is to determine the poten-
tial for action. Lorenz and Tinbergen might think of this as the agent having
a set of releasers for a task, and now is observing whether they are present
in the world. If the perception supports an action, the agent acts. The ac-
tion modifies the environment, but it also modifies the agent’s assessment of
the situation. In the simplest case, this could be an error signal to be used
for control or a more abstract difference such as at the level of those used in
STRIPS/MEA.
In some regards, the action-perception cycle appears to bear a superficial
resemblance to the Hierarchical Paradigm of SENSE, PLAN, ACT. However,
note that 1) there is no box which contains ACT, and 2) the cycle does not
require the equivalent of planning to occur at each update. Action is implicit