Emotions and psychotherapy as novel targets for neuroimaging
Hasse Karlsson
Modern functional neuroimaging methods have made it possible to study phenomena
traditionally considered as subjective and difficult to approach scientifically. Such
phenomena include eg. cognitions, hallucinations, beliefs, emotions and pain. Also the
effects of psychotherapy are now open for scientific research using neuroimaging.
Especially, research in emotions has flourished (see eg. Damasio 1996, LeDoux 1996).
These studies (for a review, see Phan et al. 2002) are usually done by either showing the
subjects emotion eliciting pictures or film clips, or by asking them to recall an emotionally
important event while obtaining an image of the concurrent brain activations. The most
common methods used are radiowater-PET and fMRI. These studies have shown that
many different brain areas are activated during the experiencing of emotions. It seems that
the medial prefrontal cortex has a general role. Sadness is associated with activity of the
subcallosal cingulate, and fear with the amygdala. There seems to be differences also
according to the method of emotion induction. Visual stimuli activate the occipital cortex
and the amygdala, whereas induction by recall or imagery activate the anterior cingulate
and insula. Emotional tasks with cognitive demand involve the anterior cingulate and
insula (Phan et al. 2002). My group has found activations in the occipitotemporal and
anterior temporal cortices and cerebellum during amusement and sadness (Aalto et al.
2002).
Alexithymia is a defect in experiencing and communicating affect. So far two studies
directly looking at brain function during affect in people with alexithymia have been
published (Berthoz et al. 2002, Huber et al. 2002) and one is under preparation (Karlsson
et al., manuscript under preparation). In the study by Berthoz et al. (2002) the alexithymic
men showed less activation in the left mediofrontal – paracingulate cortex in response to
negative stimuli. However, they showed more activation in the anterior cingulate,
mediofrontal cortex and middle frontal gyrus in response to positive stimuli. No differences
between the groups were found in response to neutral stimuli. The authors conclude that
alexithymia may be linked to structures involved in the appraisal of the emotional content
of the stimuli rather than in lower levels of processing during the passive viewing of these
stimuli. They state that their results are in line with the idea that alexithymia is associated
with a deficit in the cognitive evaluation of emotion because they found no differences
between the groups in limbic structures. Both the mediofrontal and the anterior cingulate
cortices have been postulated to participate in the experience of emotion and in affect
regulation, but also in pain modulation. Accordingly, one study has shown that the
perception of unpleasant visceral sensation and the perception of emotion both are
associated with activation of the insula and dorsal and ventral regions of the anterior
cingulate gyri (Phillips et al. 2003). The other alexithymia study (Huber et al. 2002) showed
greater activation in normal controls in cingulate areas, corpus callosum and right superior
and inferior frontal gyrus whereas in alexithymic subjects more activation was found in
cuneus and precuneus, thalamus, left medial frontal, right inferior temporal, left superior
temporal regions, left precentral gyrus and the cerebellum. The authors conclude that the
areas activated by alexithymic persons largely comprise of language related regions
leaving out limbic and paralimbic areas. My group has also performed a similar experiment
(Karlsson et al., manuscript under preparation). We have used short film clips as the
emotion eliciting stimuli and radiowater-PET as the imaging method. The results are
currently being analyzed.
So far seven studies and one case report on the outcome of psychotherapy using
neuroimaging has been published. The therapies used have been behavioral therapy,
cognitive-behavioral therapy or interpersonal therapy and the outcome has been change in
blood flow or glucose metabolism. Usually psychotherapy has resulted in similar brain
changes that drug treatments have, although also some small differences have been
found. So far no studies looking at receptor level changes, or using psychodynamic
psychotherapy have been published, but two studies using such an approach are ongoing
in Finland (Lehtonen J, personal communication, Karlsson H, personal communication).
Functional neuroimaging allows us to approach questions raised at different levels
(biological, psychological and interpersonal), and, thus, helps us to integrate various
approaches contributing to a more holistic view of man in the future.
References
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Berthoz S, Artiges E, Van De Moortele PF, Poline JB, Rouquette S, Consoli SM, Martinot JL. Effect of
impaired recognition and expression of emotions on frontocingulate cortices: an fMRI study of men with
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