Page 130 - Designing Sociable Robots

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The Motivation System 111

Table 8.1
Summary of the antecedents and behavioral responses that comprise Kismet’s emotive responses. The antecedents
refer to the eliciting perceptual conditions for each emotion. The behavior coloumn denotes the observable
response that becomes active with the emotion. For some, this is simply a facial expression. For others, it is a
behavior such as escape. The column to the right describes the function each emotive response serves for Kismet.
Antecedent Conditions Emotion Behavior Function
Delay, difficulty in achieving goal anger, display- Show displeasure to caregiver to modify
of adaptive behavior frustration displeasure his/her behavior
Presence of an undesired stimulus disgust withdraw Signal rejection of presented stimulus
to caregiver
Presence of a threatening, fear, escape Move away from a potentially
overwhelming stimulus distress dangerous stimuli
Prolonged presence of a desired calm engage Continued interaction with
stimulus a desired stimulus
Success in achieving goal of joy display- Reallocate resources to the next
active behavior, or praise pleasure relevant behavior (eventually to
reinforce behavior)
Prolonged absence of a desired sorrow display- Evoke sympathy and attention from
stimulus, or prohibition sorrow caregiver (eventually to
discourage behavior)
A sudden, close stimulus suprise startle Alert
Appearance of a desired stimulus interest orient Attend to new, salient object
Need of an absent and desired boredom seek Explore environment for desired stimulus
stimulus

Emotive Responses

This section begins with a high-level discussion of the emotional responses implemented
in Kismet. Table 8.1 summarizes under what conditions certain emotions and behavioral
responses arise, and what function they serve the robot. This table is derived from the evolu-
tionary, cross-species, and social functions hypothesized by Plutchik (1991), Darwin (1872),
and Izard (1977). The table includes the six primary emotions proposed by Ekman (i.e.,
anger, disgust, fear, joy, sorrow, surprise) along with three arousal states (i.e.,
boredom, interest, and calm). Kismet’s expressions of these emotions also can be seen
on the included CD-ROM in the “Readable Expressions” demonstration.
By adapting these ideas to Kismet, the robot’s emotional responses mirror those of bio-
logical systems and therefore should seem plausible to a human (please refer to the seventh
CD-ROM demonstration titled “Emotive Responses”). This is very important for social in-
teraction. Under close inspection, also note that the four categories of proto-social responses
from chapter 3 (affective, exploratory, protective, and regulatory) are represented within this
table. Each of the entries in this table has a corresponding affective display. For instance, the
robot exhibits sadness upon the prolonged absence of a desired stimulus. This may occur