Page 131 - Designing Sociable Robots

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112 Chapter 8

if the robot has not been engaged with a toy for a long time. The sorrowful expression is
intended to elicit attentive acts from the human caregiver. Another class of affective re-
sponses relates to behavioral performance. For instance, a successfully accomplished goal
is reflected by a smile on the robot’s face, whereas delayed progress is reflected by a stern
expression. Exploratory responses include visual search for desired stimulus and/or main-
taining visual engagement of a desired stimulus. Kismet currently has several protective
responses, the strongest of which is to close its eyes and turn away from “threatening”
or overwhelming stimuli. Many of these emotive responses serve a regulatory function.
They bias the robot’s behavior to bring it into contact with desired stimuli (orientation or
exploration), or to avoid poor quality or “dangerous” stimuli (protection or rejection). In
addition, the expression on the robot’s face is a social signal to the human caregiver, who
responds in a way to further promote the robot’s “well-being.” Taken as a whole, these
affective responses encourage the human to treat Kismet as a socially aware creature and
to establish meaningful communication with it.

Components of Emotion
Several theories posit that emotional reactions consist of several distinct but interrelated
facets (Scherer, 1984; Izard, 1977). In addition, several appraisal theories hypothesize that
a characteristic appraisal (or meaning analysis) triggers the emotional reaction in a context-
sensitive manner (Frijda, 1994b; Lazarus, 1994; Scherer, 1994). Summarizing these ideas,
an “emotional” reaction for Kismet consists of:
• A precipitating event
• An affective appraisal of that event
• A characteristic expression (face, voice, posture)
• Action tendencies that motivate a behavioral response
Two factors that are not directly addressed with Kismet are:

• Subjective feeling state
• A pattern of physiological activity
1
Kismet is not conscious, so it does not have feelings. Nor does it have internal sensors that
might sense something akin to physiological changes due to autonomic nervous activity.
Kismet does, however, have a parameter that maps to arousal level, so in a very simple
fashion Kismet has a correlate to autonomic nervous system activity.

1. Several emotion theorists posit that consciousness is a requirement for an organism to experience feeling (see
Damasio, 1999). That Kismet is not conscious (at least not yet) is the author’s philosophical position.