Who Needs Emotions? The Brain Meets the Robot

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by the amygdala might be related in working memory to immediate sensory
information and long-term memories processed in other areas of the cortex
(see also Chapter 5, Rolls).
Attention and working memory are closely related, and recent studies
have shown that amygdala damage interferes with an important aspect of
attention (Anderson & Phelps, 2001, 2002). Normally, if we are attending
to one stimulus, we ignore others. This selective attention allows us to focus
our thoughts on the task at hand. However, if the second stimulus is
emotionally significant, it can override the selection process and slip into
working memory. Damage to the amygdala, though, prevents this from
occurring. The amygdala, in other words, makes it possible for implicitly processed
(unattended) emotional stimuli to make it into working memory and
consciousness.
In addition, the amygdala can influence working memory indirectly by
way of projections to the various amine cell groups that participate in cortical
arousal, including cholinergic, dopaminergic, noradrenergic, and serotonergic
systems (see Fig. 4.4; see also Chapter 3, Kelley). These arousal
pathways are relatively nonspecific since they influence many cortical areas
simultaneously. Specificity comes from the fact that the effects of arousal
are most significant on circuits that are active. As a result, if the cortex is
focused on some threatening stimulus, the circuits involved will be facilitated
by the arousal systems. This will help keep attention focused on the
threatening situation.
Finally, once the outputs of the amygdala elicit alarm-related behaviors
and accompanying changes in body physiology (fight/flight kinds of response),
the brain begins to receive feedback from the bodily responses.
Feedback can be in the form of sensory messages from internal organs (visceral
sensations) or from the muscles (proprioceptive sensations) or in the
form of hormones or peptides released by bodily organs that enter the brain
from the bloodstream and influence neural activity. Although the exact
manner in which bodily feedback influences working memory is not clear, it
is likely that working memory has access to this information in one form or
another. The feedback from these responses is relatively slow, on the order
of seconds, when compared to the feedback that occurs by way of synaptic
transmission within the brain, which transpires within a matter of milliseconds.
Bodily feedback adds at least intensity and duration but may also help
refine our interpretation of the emotion we are experiencing once the episode
has been triggered (James, 1890; Damasio, 1999; Cacioppo, Hawkley,
& Bernston, 2003). Bodily feedback in the form of stress hormones can either
enhance or impair long-term memory functions of the temporal lobe
memory system, which will in turn influence the content of working memory.