Who Needs Emotions? The Brain Meets the Robot

eware the passionate robot 361
insist that the origins of emotional states are based on the cognitive construal
of events, with cognition being presupposed by the physiological, behavioral,
and expressive aspects of emotion. However, is the addition of a cognitive
evaluation, unlinked to a physiological structure, enough to convert information
processing into emotion? While I find great value in the attempt of
Ortony, Clore, and Collins to see how different cognitive structures may
relate to different emotional states, it gives no sense of the “heat” of emotion
that I tried to convey in my short narrative. I argue here that the “heat”
is added to the appraisal because the cerebral cortex is linked to basic motivational
systems, while human emotions are so much more varied and subtle
than mere hunger or thirst because basic motivational systems are integrated
with cortical systems that can provide varied appraisals.
My approach will be to integrate insights from chapters by Kelley, Rolls,
and Fellous & LeDoux with the evolutionary perspective provided above
while confronting the personal data set of my emotional narrative.
Behavioral Control Columns
To start, we must note that a full analysis of motivated behavior must include
not only the somatomotor behavior (e.g., feeding and fleeing; other
forms relevant to the study of motivation-related behavior include orofacial
responses and defensive and mating activities) but also autonomic output
(e.g., heart rate and blood pressure) and visceroendocrine output (cortisol,
adrenaline, release of sex hormones). In general, behavior will combine
effects of all three kinds. Kelley (Chapter 3) places special emphasis on
Swanson’s (2000) notion of the behavioral control column (Fig. 12.3). This
is a column of nuclei arrayed along the brain stem. Swanson proposes that
very specific and highly interconnected sets of nuclei in the hypothalamus
are devoted to the elaboration and control of specific behaviors necessary
for survival: spontaneous locomotion, exploration, ingestive, defensive, and
reproductive behaviors. Animals with chronic transections above the hypothalamus
can more or less eat, drink, reproduce, and show defensive behaviors,
whereas if the brain is transected below the hypothalamus, the animal
displays only fragments of these behaviors, enabled by motor pattern generators
in the brain stem. As Kelley notes, many instances of motivated behavior—eating,
drinking, grooming, attacking, sleeping, maternal behavior,
hoarding, copulating—have been evoked by direct electrical or chemical
stimulation of the hypothalamus.
The behavioral control column contains a rostral and a more caudal segment.
The former contains nuclei involved in ingestive and social (reproductive
and defensive) behaviors such as sexually dimorphic behaviors, defensive