Who Needs Emotions? The Brain Meets the Robot

260 robots
Mean distance to attachment object
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
-1.0 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0
Comfort level
No Attachment Behavior
With Attachment Behavior
Figure 9.6. (Top) Nomad robot conducting 5-minute explorations. The object
of attachment is the tree. (Bottom) Results showing how average distance
from attachment object increases as robot’s comfort level increases.
in Breazeal’s Chapter 10). Takanishi’s (1999) approach is also used to reduce
the overall internal state space into three dimensions: pleasantness,
arousal, and confidence. The six basic emotional states are located within
this three-dimensional space. By establishing predefined levels of internal
variables, such as hunger and thirst, and determining how the current state
of the robot relates to those thresholds, pleasantness can be assessed. If these
variables remain within the regulated range, the pleasantness is high. Arousal
is controlled by both circadian rhythm and unexpected stimuli, while confidence
is determined by the certainty of recognized external stimuli.
The resulting emotional values affect the action-selection process for
behavior eligibility for execution. Drawing on aspects of both McFarland’s