specific phobia
Etiology
Ranchmen (1977) and
Knight and Simon (2005) indicate that the reactions are essentially specific
phobias acquired through three possible ways such as: direct conditioning, transmission
of information and / or observational learning.
Research has shown
that aversive experiences direct and / or indirect are generating specific
phobias.
In response to
other questions on key variables or factors involved in the genesis of these
disorders, hypotheses are: a) The prepare atoriedad b) The vulnerability.
The prepare atoriedad
hypothesis attempts to answer the question why individuals acquire fear or
phobic responses to stimuli more easily than others? According Horse and Simon (2005),
this is because: "The human body is biologically prepared to acquire and maintain
phobic responses to stimuli that phyla genetically had threatened the survival
of the species." These ideas are based on the theory of preparation for
the acquisition of fear of Seligman (1971).
For its part, the
vulnerability hypothesis seeks to answer the question: why certain individuals
acquire fear responses more easily than others? This is due to the
characteristics of different factors that are involved in the genesis of phobic
state. These can be grouped into two types of vulnerability:
- The biological vulnerability: contains genetic
factors and activation of specific brain circuitry, neurotransmitters and
neurohormonal systems. On the first, teachers Sword, Olivares and Mendez (2005),
indicate that the genetic contribution can be: specific (higher heritability to
develop certain phobias) and / or non-specific (with autonomic nervous system (ANS)
unstable or labile ).
The second, the
significant activation (hyper) vegetative dependent autonomic nervous system (ANS),
as sympathetic branch, and the somatic nervous system (SNS), which will be
reflected in psycho physiological manifestations such as: increased heart rate, excessive
sweating, increased muscle tone, etc.. Likewise, trigger other systems such as:
the immune, hormonal or endocrine, etc.
- The psychological vulnerability: expressed as a
sense of uncontrollability of phobic stimuli and responses. Its causes triggers
include: maternal separation, lack of coping skills, maternal or paternal
overprotection, etc.
From behavioral
strategies emphasize the importance of learning processes in the origin and
maintenance of specific phobias or fears.
At present there
is much research material on acquisitions of specific phobias in children and
adolescents, and there the results differ significantly from each other.
On the other hand,
it has also sought to answer the question: why the alteration occurs in the
fear circuit activation in specific phobia? For this purpose, two groups have
raised etiological model: modified conditioning, and no associative.
The modified model
of conditioning associative learning is similar to classical conditioning, which
explains the appearance of phobias by this phenomenon.
Within your
content, try to answer the question: why in many patients do not cause any kind
of conditioning? Its explanatory answer is that these people have forgotten the
conditioning event and preserved emotional memory. There are two possible
reasons for this fact happens. The first is that there is a developmental delay
in the cortical circuit, which will lead to emotional memory encoding but not
explicit (Jacobs & Nadel, 1985; Stein, 2005). The latter, being under
stress, causing the release of cortical and CRH (or releasing hormone corticotrophin
releasing factor) which hippocampus function deteriorates (Beemer et al. 1995; Stein,
2005), but does not spoil the function of amygdale may even promote it (McCaughey
et al., 1993; Stein, 2005). In both cases, emotional memories are formed with
no explicit or declarative memory.
Given this model, Ranchman
et al. (1987) indicate that presents some drawbacks to consider. One of these
could be pointing Stein (2005), with the following words: "Many patients
experience aversive conditioning but have no phobias, suggesting that other factors
are involved. However, no evidence supporting the existence of indirect ways
and start vicariate phobias. "
Meanwhile, non-associative
models explain certain fears or intrinsic fears are beneficial for normal
development of the individual and adaptation to the environment. Also, postulate
that specific phobias are the result or product of the lack of habituation to
these intrinsic fears, as outlined Menses and Clarke (1995) and Stein (2005).
It has been found
that no habituation occurs in the individual by the lack of safe exposure to
the stimulus or for not properly learned from practical experience or
experiential.
On these models no
associative Stein (2005) also notes that Kindler et al. (2002), have been
working on and analyzing the mode of acquisition of fears in twins. After
several investigations, their conclusions have been that the vulnerability to
phobias is largely innate, and therefore away from support for a theory of
conditioning / learning.
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