Who Needs Emotions? The Brain Meets the Robot

asic principles for emotional processing 99
sory processing areas, so anything that alters how these areas process sensory
stimuli will affect what working memory works with. By way of connections
with sensory processing areas in the cortex, amygdala arousal can
modify sensory processing. While only the latest stages of sensory processing
in the cortex send connections to the amygdala, the amygdala sends connections
to all stages, allowing the amygdala to influence even very early
processing in the neocortex (Amaral, Price, Pitkanen, & Carmichael, 1992).
Sensory cortex areas are influenced by activity in the amygdala, as suggested
by studies showing that the rate at which cells in the auditory cortex fire to a
tone is increased when that tone is paired with a shock in a fear-conditioning
situation (Weinberger, 1995). Other studies show that damage to the amygdala
prevents some of the cortical changes from taking place (Armony, Quirk, &
LeDoux, 1998). Because the sensory cortex provides important inputs to
working memory, the amygdala can influence working memory by altering
processing there.
The sensory cortex is crucially involved in activation of the medial temporal
lobe memory system. By influencing the sensory cortex, the amygdala
can have an impact on the long-term memories that are active and available
to working memory. However, the amygdala also influences the medial temporal
lobe memory system (through the rhinal cortex) and, thus, the memories
available to working memory.
The amygdala can also act directly on working memory circuits. Although
it does not have direct connections with the lateral prefrontal cortex, it does
have connections with other areas of the prefrontal cortex involved in working
memory, including the medial (anterior cingulate) and ventral (orbital) prefrontal
cortex (Groenewegen, Berendse, Wolters, & Lohman, 1990; McDonald,
1998; Uylings, Groenewegen, & Kolb, 2003). Damage to the medial prefrontal
cortex in rats leads to a loss of fear regulation, and studies of monkeys and
humans have implicated the medial orbital region in processing emotional cues
(rewards and punishments) and in the temporary storage of information about
such cues (Everitt & Robbins, 1992; Gaffan, 1992; Rolls, 1998; Rogers et al.,
1999). The orbital region is connected with the anterior cingulate, and like
the anterior cingulate, it also receives information from the amygdala and hippocampus
(Fuster, 1990; Petrides & Pandya, 1999, 2002). Humans with orbital
cortex damage become oblivious to social and emotional cues, have poor
decision-making abilities, and may exhibit sociopathic behavior (Damasio,
1994). In addition to being connected with the amygdala, the anterior cingulate
and orbital areas are intimately connected with one another, as well as
with the lateral prefrontal cortex, and each of the prefrontal areas receives
information from sensory processing regions and from areas involved in various
aspects of implicit and explicit memory processing. The anterior cingulate
and orbital areas thus provide a means through which emotional processing