Who Needs Emotions? The Brain Meets the Robot

212 robots
different varieties of mental states in general—just as some computeroperating
system architectures support states like “thrashing,” where more
time is spent swapping and paging than doing useful work, whereas other
architectures do not, for instance, if they do not include virtual memory or
multi processing mechanisms.
So, to understand the full variety of types of emotions, we need to study
not just human-like systems but alternative architectures as well, to explore
the varieties of mental states they support. This includes attempting to understand
the control architectures found in many animals and the different
stages in the development of human architectures from infancy onward.
Some aspects of the architecture will also reflect evolutionary development
(Sloman, 2000a; Scheutz & Sloman, 2001).
VARIETIES OF AFFECT
What are affective states and processes? We now explain the intuitive affective/nonaffective
distinction in a general way. Like emotion, affect lacks any
generally agreed upon definition. We suggest that what is intended by this
notion is best captured by our architecture-based notion of a desire-like state,
introduced earlier in contrast with belief-like and other types of nonaffective
state. Desire-like and belief-like states are defined more precisely below.
Varieties of Control States
Previously, we introduced the notion of a control state, which has some
function that may include preserving or preventing some state or process.
An individual’s being in such a state involves the truth of some collection of
counterfactual conditional statements about what the individual would do
in a variety of possible circumstances.
We define desire-like states as those that have the function of detecting
needs so that the state can act as an initiator of action designed to produce
or prevent changes in a manner that serves the need. This can be taken as a
more precise version of the intuitive notion of affective state. These are states
that involve dispositions to produce or prevent some (internal or external)
occurrence related to a need. It is an old point, dating at least back to the
philosopher David Hume (1739/1978), that an action may be based on many
beliefs and derivatively affective states but must have some intrinsically
affective component in its instigation. In our terminology, no matter how
many beliefs, percepts, expectations, and reasoning skills a machine or organism
has, they will not cause it to do one thing rather than another or even