Emotion, Learning, Attention and Perception
If you were forced at gunpoint
to choose the part of the brain that plays the most important role in emotion,
you might well plump for the amygdala. The amygdala is an almond shaped
structure in the medial temporal lobe, roughly in the centre of the brain.
While certainly not the only structure involved in emotional processes, it is
the most extensively researched. Generally speaking, the amygdala is thought to
play a role in mediating cognitive responses to emotional stimuli. Phelps
(2006), in an Annual Review of Psychology article, provides an overview of the
findings that have emerged.
Emotional Learning
If someone really did point a
gun at your head, you’d probably be afraid, even if you are used to that sort
of thing happening. But for some people with damage to their amygdala, this
might reveal itself in a rather odd disconnect between what their body ‘feels’
and what they ‘know’.
Phelps (2006) describes a
patient with this type of amygdala damage who, while being able to conceptually
understand immediate physical danger, cannot seem to understand it in what the
rest of us might consider the most obvious way: bodily. Responses that can be
conditioned physiologically into normal controls, cannot be elicited in this
patient. When you point a gun at her head, she is afraid, but she doesn’t start
sweating like the rest of us would.
So there seems to be at least
two different ways of ‘being afraid’. Similarly, there is certainly more than
one way of learning to be afraid. You can see someone else have a gun held to
their head and that’s enough to clue you in that it might not be a pleasant
experience. Or someone can simply tell you. These have been investigated in
so-called ‘instructional’ and ‘observational’ fear conditioning paradigms. As
Phelps (2006) points out, the amygdala has been found to be important in both
of these processes.
Emotion and Memory
Perhaps the most famous
connection between emotion and memory is the idea that arousal enhances
episodic memory. Reassuringly (for research psychologists at least) patients
with damage to their amygdala do not show this particular enhancement of
memory. So, again, the amygdala seems to be important in some way in mediating
how memories are layed down.
More recent work, though, has
suggested that it’s not the memory that’s actually being enhanced. Instead it
might just be the perceived clarity of the event that’s being increased, while
the memory for the event itself remains unenhanced. Phelps (2006) uses the
example of research examining people’s memories of 9/11. Crucially, people’s
recall was not actually improved despite their significantly raised arousal at
that time. Clearly there’s something more complicated going on here.
Emotion, Attention and
Perception
So, imagine that the guy with
the gun is back again. Now the revolver is so close to your face that you can
see the bullets loaded into the individual chambers. But it’s dark and you’re
emotional so how can you see that? Phelps (2006) explains that there is some
evidence that fear can actually enhance perception. One study carried out by
Phelps herself found an increased sensitivity to contrast when subjects were
primed with fearful faces (Phelps, Ling & Carrasco, 2006). It seems, then,
that emotional situations can send your visual cortex into overdrive.
In the same way, there is also
evidence that emotional situations can enhance your attention. Some research
has suggested that normal cognitive processes like the attentional blink can be
reduced when emotions are running high. Again, patients with certain types of
damage to their amygdala do not show this enhancement, lending further weight
to the amygdala’s claim to emotional fame.
Emotions and Social Stimuli
You stare back into your
assailants eyes, trying to work out whether he’s actually more scared than you
are. If you challenge him to shoot you, as they do in all the best cop shows,
will he meekly hand you the gun or will he put a bullet in your brain? Phelps
(2006) reports evidence examining the amygdala’s role in processing fear on
other people’s faces. There is some evidence that the amygdala could once again
come to your rescue. It seems to have a specialised role in processing fear,
especially as, again, those with amygdala damage tend to have difficulties in this
area.
But, Phelps (2006) points out
that while there’s some interesting research being produced on the amygdala’s
role in fear responses, this area is still wide open and there are still
considerable controversies.
Down the Barrell
If you’re looking down the
barrell of a gun, the traditional dividing line in cognitive science between
emotion and cognition is not so clear. Your emotional state can have marked
effects on basic cognitive processes like learning, attention, perception and
memory. And it’s the amygdala that seems to play an important role in mediating
these processes.
About the author
Psychologist, Jeremy Dean, PhD is the founder and author of PsyBlog. He holds a doctorate in psychology from University College London and two other advanced degrees in psychology.
He has been writing about
scientific research on PsyBlog since 2004. He is also the author of the book
“Making Habits, Breaking Habits” (Da Capo, 2003) and several ebooks.
SOURCE: PSYBLOG
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