This network can be trained to
develop more robust capacity for executive control. This, as we all experience,
is what parenting and schooling are about. Such training is especially crucial
in early childhood as the challenges of school are first encountered. Even so,
such training takes many years and for most of us may never be completed.
The question arises: can such
executive control training be expedited? One possibility has recently arisen
from several studies showing that working memory capacity can be expanded by a
relatively short training time, and in the process general intelligence may be
improved. Since the same system that determines intelligence is also operative
in executive control, Schweizer et al. (2013) reasoned that working memory
training might also enhance executive control. To pursue this possibility in a
specific context, the researchers hypothesized that inappropriate or
maladaptive behaviors might be reduced by effective working memory training
based on emotion-laded stimuli.
In this study, subjects in their
early 20s were assessed for affective control before and after 20 training days
of 20-30 minute sessions. The experimental groups received dual n-back training
with a simultaneously presented face and a word that was either emotionally
negative or neutral. After each picture-word pair, subjects were to press a
button to indicate if either or both members of the pair matched the stimulus
presented n-positions back. Tests began with n = 1 and increased as subjects
gain proficiency.
Not surprisingly, errors in both
trained and untrained subjects decreased at levels beyond n = 1, and the error
rate was comparable for both groups. Results indicated that subjects reported
less distress when they consciously willed to suppress it compared with the
null state of just attending to negative stimuli. But this distress reduction
occurred only in the emotional working memory training group.
No change in activity levels was
indicated in fMRI scans as a result of placebo training, but significant
increases occurred as a result of emotional working memory training
irrespective of the level of n-back achievement in the executive control
regions of interest.
The study also compared emotional
responsivity before and after training. Subjects were asked to just pay
attention or to pay attention and cognitively suppress their emotional
reaction. Subjects rated their emotions on a numerical scale from negative to
positive while viewing films that were emotionally neutral (such as weather
forecasts) or that were emotionally disturbing (such as war scenes, accidents,
etc.). Training caused no change in the group that viewed only neutral images,
but in the groups viewing disturbing scenes, training decreased the perceived
distress in a group told just to attend the scenes and was even more effective
in the group told to suppress emotional reaction.
The affective working memory
training produced benefits that transferred to the emotional response task.
Trained subjects not only generated enhanced emotional regulation but also
developed greater fMRI activity during the emotional task in the predicted
brain regions of interest, the executive control loci. It seems that working
memory training can do more than just expand the amount of information that can
be held in working memory. Emotional working memory training improves the
ability to suppress disturbing emotional responses and does so presumably
because the executive control network is more activated. Thus, such training
might also enhance many executive control functions, particularly responses to
emotionally disturbing circumstances.
Sources:
Banich, M. T., Mackiewicz, K. L., Depue, B. E., Whitmer, A.
J., Miller, G. A. , Heller, W. (2009) Cognitive control mechanisms, emotions
and memory: a neural perspective with implications for psychopathology. Neurosci. Biobehav. Rev. 33, 613-630.
Beck, A. T. (2008) The evolution of the cognitive model of
depression and its neurobiological correlates. Am. J. Psychiatry. 165, 969-977.
Schweizer, S., Grahn, J., Hampshire, A., Mobbs, D., and
Dalgleish, T. (2013). Training the
emotional brain: improving affective control through emotional working memory
training. J. Neurosci. 33(12),
5301-5311.
