Synthesis: The EMOCON Model
In an attempt to explain emotional consciousness, I developed the EMOCON model shown in figure
5.2, which depicts relations among many of the most important brain areas. The arrows indicate that
activity of neural populations in one area causes neural activity in other connected areas. The figure
shows perceptual information coming from sensory processes on the left, which is then
simultaneously communicated via the thalamus to cortical areas such as the dorsolateral prefrontal
cortex that make cognitive judgments, and to areas involved in bodily perception such as the
amygdala and the insula. Moreover, the thalamus also affects bodily processes such as heart rate via
the hypothalamus, not shown in the figure. If the brain were a serial processor like most computers, it
would have to alternate between processing the sensory inputs cognitively and doing so bodily, but
the power of parallel processing allows it to do both simultaneously.
Because of the large numbers of reciprocal connections between brain areas, the results of
processing in one part of the brain can easily affect processing in other parts. Figure 5.2 displays
many interactions among the dopamine system, which includes the nucleus accumbens, the cognitive
appraisal system in the prefrontal cortex, and the emotional perception system involving the amygdala
and the insula. There is no central processor that coordinates all the results and yields a decision.
Rather, the brain's reaction to a scary face or other sensory stimulus comes about through the dynamic
interaction of external sensory perception, internal sensory perception, cognitive appraisal, and
positive and negative valuation. Note that the connections between brain areas in the EMOCON
model are reciprocal, based on neural evidence that there is extensive feedback between neural
populations in each pair of regions.
The model in figure 5.2 incorporates the bodily perception theory of emotion by virtue of the role
played by the amygdala and the insula in collecting input from internal sensors that respond to bodily
changes. These changes are the result of both sensory input conveyed via the thalamus and the
feedback relations between physiological processes such as heartbeat and respiration and brain
processes in areas such as the amygdala and the insula. People have a penchant for simple linear
causal explanations: factor A causes factor B, which causes factor C. But biological systems often
involve extensive causal interactions based on feedback, so that A and B interact to cause C, which
then has a causal influence on A. For example, your liver function and diet both increase your
cholesterol level, which then induces your liver to produce less cholesterol. Understanding how the
brain produces emotions requires appreciating the complex of reciprocal connections shown in figure
5.2, producing highly nonlinear processes because of all the feedback that occurs.
Although bodily perception theories of emotion have become popular in recent years, they fail to
account for the full range of emotional phenomena. There are only weak correlations between
emotions such as anger and fear and physiological states such as facial behavior and autonomic
arousal. The subtle differences between diverse emotions have not been found to be closely related to
distinct physiological states, their magnitudes, or particular neurotransmitters. Surgical disruption of
bodily signals does not eliminate emotional reactions. Manipulations of physiology by injection of
epinephrine can produce different emotional reactions depending on how people interpret their social
situations. Social emotions such as guilt and pride require an appreciation of one's location in a
social network. Hence cognitive appraisal is needed to complement bodily perception to generate a
full range of emotional reactions. However, bodily perception remains a crucial part of the
EMOCON model, which assumes that appraisal alone would not produce the kinds of feelings that
occur in emotional consciousness.
shows how integration of cognitive appraisal and bodily perception might work by
virtue of the interactions among the amydgala, the insula, and several parts of the prefrontal cortex.
The dorsolateral prefrontal cortex, at the top and sides of the brain, is important for verbal processing
and working memory. The orbitofrontal prefrontal cortex, at the bottom of the brain behind your eyes,
contributes to assessment of value, in concert with the dopamine system. Positive and negative
valuations that are central to emotions occur because of coordination of the activity of neural
populations in these areas with neural activity in other areas supporting verbal or sensory
representations. The ventromedial part of the prefrontal cortex is important for communication
between the cortex and the amygdala. People with damage to this area have great difficulty making
good decisions.
Psychological and philosophical theories that take emotions to be based on cognitive appraisal
have had little to say about the brain mechanisms needed to evaluate the relevance of a situation to a
person's many goals. Evaluation of a simple sensory stimulus (a man with a gun aimed at you) may be
relatively simple, but reflection on a complex situation (a job offer in a far-off city) may require an
assessment with respect to many goals. In chapter 4, I described theory evaluation as involving a kind
of parallel evaluation of multiple constraints, and cognitive appraisal is also naturally conceived as
parallel constraint satisfaction. Hence the brain can accomplish cognitive appraisal of a situation
with respect to multiple goals using the same kind of mechanism described in chapter 4 for inference
to the best explanation.
For appraisal, different aspects of the situation and different goals are represented by different
neural populations. Positive and negative constraints between the aspects and the goals are captured
by excitatory and inhibitory synaptic connections between the neurons in the different populations.
Overall appraisal of how a situation fits or fails to fit with your goals comes about because of
parallel processing through the firing activity of the neural populations as they interact. Value
naturally enters the picture because the neural populations involved in the representation of the
situation and personal goals include ones in areas such as the amygdala, the nucleus accumbens, and
the orbitofrontal prefrontal cortex that help to encode positive and negative features. An overall
assessment of value comes about when parallel constraint satisfaction combines the features of the
situation, goals, and values to compute the overall emotional coherence of the situation.
Figure 5.2 shows how bodily perceptions can contribute to cognitive appraisal and assessment of
value through the interactions of the amygdala and the insula with cortical areas. Hence the parallel
constraint satisfaction that assesses the relevance of situations to goals includes bodily perception as
an important part. Emotions are not just gut reactions, because they also involve cognitive judgments.
But contrary to purely cognitive theories of emotions, gut reactions are a part of appraisal. This
combination would be very puzzling if you tried to think of the brain as operating in a series of steps,
and had to decide what it does first: cognitive appraisal or bodily perception? But the kinds of
dynamic interactions depicted in figure 5.2 show how emotion can be both representational and
embodied.
Like all models, EMOCON is oversimplified in many ways. There are many other relevant brain
areas—for example, the hippocampus, which plays a major role in memory and interpreting situations
in the context of previous experience. Figure 5.2 might be taken to suggest that the brain is a kind of
passive observer, waiting for sensory information to come in to be interpreted. But brains are much
more active, anticipating situations in ways that can lead to action. Chapter 6 will say much more
about how emotions contribute to decisions about how to act. We have already seen, in chapter 4, that
perception is a top-down as well as bottom-up process, so even processing of sensory information in
the thalamus is affected by expectations stored in the prefrontal cortex. Hence figure 5.2 should not be
interpreted as maintaining that emotions are just responses to stimuli, but rather as showing a
simplified part of more complex thought processes that include expectations and actions.