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What
are cognitive biases?
Current
cognitive theories on emotional disorders are not only addressed to the content
of cognitions, but also intend to study the information processing strategies
and structures that could be playing a role in the explanation and description
of these disorders. One of the basic assumptions maintained by
cognitive-experimental
perspectives within the psychopathology field is that there are differences on
how the emotional information is processed as a function of the presence or lack
of pathology. However, one of the most important issues still unsolved is to
know whether these biases are a vulnerability factor to suffer from these
disorders or whether they are part of the clinical characteristics of the
disorder. Beck’s cognitive model (1967, 1976, 1987), articulated around the
concept of schema, has been the starting point for most of these studies. Bower’s
theory (1981) also tries to explain cognitive biases. Both of them predict that
in all levels of processing (perception, attention, and memory), mood congruent
biases are manifested, and that they are present in all emotional disorders.
Regarding to
attention, it is affected in many psychological disorders.
In mood and anxiety disorders concentration difficulties and distractibility are
two of the most frequent complains that these patients show, and they appear in
the DSM-IV criteria as symptoms for the diagnoses of major depression, dysthymic
disorder and some anxiety disorders. Nevertheless, from the cognitive psychology
perspective attentional biases do not refer to distractibility in general, but
to a change in the subject’s focus of attention, so that the person notices
one specific part or aspect of the environment (Williams, Watts, MacLeod, &
Mathews, 1988; 1997).
As for
memory, many theories point out that there exists a mood congruent
memory bias in emotional disorders. This bias has been defined as the tendency
to remember information that is consistent with the individual’s mood.
How are cognitive biases
evaluated?
Two
main strategies have been employed in the experimental study of attentional
biases: the first one consists of testing how this tendency to attend certain
stimuli of the environment facilitates the person's performance; the second one
tests how the same tendency may deteriorate performance. The Emotional Stroop
task is probably the most frequently used task for the study of attentional
biases. It has got into the main experimental paradigm in the literature on
cognition and emotion, and belongs to the second type of strategy. When
performing the Stroop the person is shown a series of words whose emotional
content is representative of the topics that characterizes the disorder under
study. Words are written in different colors and the person’s task is to name
the colors without paying attention to the word content, which has a disturbing
effect on the person's cognitive functioning since it is related to her/his main
worry (Williams et al., 1988). The
attentional bias is shown by the interference effect produced in the Stroop task
(Stroop, 1935) consisting of the competition between the task the person is
asked to do (color-naming the words) and the automatic and preconscious
processing of the printed words (attentional bias). Many studies that have used
the Stroop task have shown that latencies in color-naming emotional words are
higher in persons with emotional disorders (Williams et
al., 1997).
With respect to memory
biases, multiple evaluation techniques have been used. They can be clustered in two
groups: explicit memory and implicit memory.
For the first one, free recollection, guided recollection or recognition
paradigms are used. In all of them the person is explicitly asked to remember
the information that is going to be presented. It is predicted that memory of
the mood congruent information will be facilitated or increased. Regarding
implicit memory, the person is asked to realize several tasks (to complete
words,
to form anagrams, etc.) with no direct instructions on remembering the
information; however such information is used in a nonconscious way. In this
case it is also predicted that the mood congruent emotional information will be
facilitated or increased.
Cognitive biases in
Emotional
and
Anxiety disorders
Empirical
data supporting the presence of an attentional bias towards emotional
information are more consistent for anxiety than for depression. In the case of
anxiety disorders, it has been found that these individuals attend
preferentially to information related to their fears (e.g., Mathews & MacLeod, 1985), and that this bias is produced
without the intervention of conscious strategies (e.g., MacLeod & Rutherford, 1992).
In
the case of anxiety disorders it’s have been found that these people pay
attention mainly to information about theirs fears (and terrors) (Mathews and
McLeod, 1985) and that these “attention biases” play an important role in
the etiology and maintenance of the disorder. The facts obtained until today
have been consistent enough, and several theories have been developed to try to
understand these disorders, and they have given an eminent role to attention
system. However, there are still some questions to solve, central questions to
understand the role of attention in etiology, maintenance and treatment of this
kind of disorders. Some of these questions are:
A)
Are attention biases produced out of selective attention?
B)
Does anxiety influence the same way in all aspects of anxiety disorders?
C)
Do the attention biases manifest “towards” the threat, in all anxiety
disorders?
D)
Can the psychological treatments remove or reduce the attention biases?
Part
of the difficulties to obtain answers to these questions come from the
strategies used to evaluate attention biases. The tasks used until now present
an important limitation : verbal materials (words) that represent the person
fears are used in these tasks. However, it is possible that the answers to these
words would not be the same than the answers to the threats in real life.
Therefore, it is necessary to improve the ecological validity of these tasks (Mogg
and Bradley, 1999; Thorpe and Salkovskis, 1998). That is the reason why some
works have used stimulus like drawings or photos of the feared object (Mayer et
al., 1999; Öhman and Soares, 1994, etc.). However these works still have
generalization problems (they are static representations, in two dimensions, out
of context,…) We believe that Virtual Reality technology could help to improve
these limitations, because it permits to recreate environments that simulate
situations the person fears. So, to study the functions of attention in the
presence of the feared situation, VR would permit to evaluate the attention
performance “inside” this situation. Moreover, it would be able to evaluate
what is happening along all the attention process too, because “Eye –
tracker” systems, that can be installed in VR helmet, record in every moment
and in a reliable way what the person is looking at (the accurate point) and for
how long. At last, the stimulus presentations could be made without the person’s
conscious warning, using as a whole subliminal perception strategies.
Actually,
we are investigating the presence of attention biases in people with spider fear
and talk-in-public fear, in virtual environments that simulate real situations,
how these biases are produced, if they act before conscious warning of the
feared stimulus and we are also studying if the biases get manifest in different
ways in function of every concrete anxiety problem. At last, we also want to
check if these biases get disappeared or reduced after a “virtual exposition”
psychological treatment.
Regarding to memory
biases, data point out that they seem to be found in depression, but not in anxiety
disorders.
In order to explain these
discrepancies, Williams, et al. (1988) developed an alternative theory for emotional
disorders. The theory predicts that anxiety is related to a facilitation of the
processing of the fear-related information in the operation of integration,
while in the case of depression the bias appears in the operation of
elaboration.
The distinction between integration and elaboration is closely related to the
concept of implicit and explicit memory. Explicit memory mainly depends on
elaboration, while implicit memory depends on the integration/activation
operation. Therefore, it is maintained that mood congruent implicit memory
biases are typical of depression.
What are we
doing?
Within
this research line, we have carried out several studies (most of them sponsored
by public funds) addressed to the study of the presence of attentional and
memory biases in several disorders: specific phobias (phobia to storms in
children), agoraphobia, panic disorder, social phobia, depression, and eating
disorders. Moreover, we have studied whether these biases change (decrease or
disappear) after the application of a cognitive-behavioral treatment for social
phobia and panic disorder. In general, our data point out that it is necessary
to use tasks with higher ecological validity than those that use simple verbal
material (words). On the other hand, it is also considered the necessity of
including therapeutic elements specifically addressed to change these biases.
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