Who Needs Emotions? The Brain Meets the Robot

eware the passionate robot 363
responses, or controls for food and water intake. The more caudal segment of
the column is involved in general foraging/exploratory behaviors.
Kelley notes that the lateral hypothalamus is not specifically included
in Swanson’s behavioral control column scheme but probably plays a critical
role in arousal, control of behavioral state, and reward-seeking behavior.
It includes what Olds (1977) referred to as the “pleasure center” because
rats will press a lever thousands of times per hour to deliver electrical stimulation
to this region.
We may distinguish drive signals—energy deficits, osmotic imbalance,
visceral cues (including pain, temperature, and heart rate), metabolic and
humoral information, etc.—from external cues about objects and other animals
in the world. Following Risold, Thompson, & Swanson (1997), Kelley
reviews the many paths whereby both kinds of information reach the hypothalamus,
with much specificity as to which kinds of information affect which
nuclei.
Amygdala, Orbitofrontal Cortex, and their Friends
Kelley notes that the amygdala’s role in reward valuation and learning, particularly
in its lateral and basolateral aspects (which are intimately connected
with the frontotemporal association cortex) can influence and perhaps bias
lateral hypothalamic output, citing literature on ingestive behavior which
complements the emphasis of Fellous and LeDoux (Chapter 4) of certain
nuclei of the amygdala in fear behavior.
Figure 12.4 summarizes the evolutionary perspective of Fellous and
LeDoux on fearful behavior. The role of the hippocampus in conditioning
to contextual cues can be usefully compared to its “you are here” function
in the Figure 12.2 model of motivated spatial behavior. The crucial element
from an evolutionary point of view is the set of reciprocal interactions between
the amygdala and cerebral cortex: the amygdala can influence cortical
areas by way of feedback either from proprioceptive or visceral signals
or hormones, via projections to various arousal networks (these are discussed
extensively in Kelley’s Chapter 3), and through interaction with the medial
prefrontal cortex. This area has widespread influences on cognition and behavior
and sends connections to several amygdala regions, allowing cognitive
functions organized in prefrontal regions to regulate the amygdala and
its fear reactions.
This, for fear behavior, provides but one example of the major principle
for organization of the behavioral control columns—namely, that they project
massively back to the cerebral cortex/voluntary control system directly or
indirectly via the dorsal thalamus (Risold, Thompson, & Swanson, 1997;