The primary objective of the current study is investigating whether AN patients and controls differ how they experience the shape and size of a rubber hand that during the Rubber Hand Illusion is incorporated in their body image, compared to how…
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Source
Brief title
Condition
- Eating disorders and disturbances
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
The main study parameter of the current study is the difference in size
estimation of the rubber hand before and during the RHI. This measure allows us
to test whether AN patients experience the rubber hand as more different in
size during the RHI illusion than controls. The main endpoints of this measure
are the differences in size estimations of the rubber hand before and during
the RHI. To determine this endpoint we will subtract the size estimation of the
1) width of the rubber hand; 2) width of the index finger of the rubber hand;
and 3) width of the wrist of the rubber hand during the RHI from the size
estimation of 1) the width of the rubber hand; 2) the width of the index finger
of the rubber hand; and 3) the width of the wrist of the rubber hand before the
RHI. These three difference score allow us to test whether the size estimations
of the rubber hand before and during the RHI differ within and between
participant groups in the synchronous and a-synchronous condition.
Secondary outcome
In order to investigate the first secondary objective of the present study
eating disorder related pathology will be assessed with two questionnaires; the
Body Shape Questionnaire and the Eating Disorder Inventory II (four subscales),
and by a measure of perceptual body image. The main endpoints of the
questionnaires are sum of the items on both questionnaires. The main eindpoint
of perceptual body image is the difference between size estimation of the own
hand and the actual size of the own hand. These measures enable us to test
whether there is a relation between the difference in size estimation of the
RHI before and after the RHI and eating disorder related pathology.
In order to investigate the second secondary objective of the current study
(i.e. replicate the findings by Eshkevari, et al (2011), we will measure
proprioceptive drift. This variable consists of the estimated location of the
left index finger before the RHI and the estimated location of the left index
finger during the RHI. In addition the embodiment score will be measured. The
embodiment score consists of the sum of the ten-item embodiment questionnaire,
which measure the extent of embodiment of the rubber hand during the RHI. Both
variables will be calculated for both the synchronous and a-synchronous
condition of the RHI.
To test the third secondary objective of the study, i.e. investigate whether AN
patients show a greater temperature-drop than controls, we will measure the
temperature of the left hand before and after inducing the RHI. The difference
score between these measurements allows us to test whether the temperature drop
differs between AN patients and controls. This variable will be calculated for
both the synchronous and a-synchronous condition of the RHI.
Background summary
Anorexia Nervosa (AN) is one of the most invasive psychosomatic disorders with
a relatively high mortality rate. In order to ensure successful treatment it is
crucial to understand the underlying mechanisms of AN. One of the central
symptoms of AN is a disturbed experience of the own body. To date, not all
aspects of this so-called body image disturbance have been investigated fully.
Though, research shows that body image disturbances appear to be the key to
full recovery of AN. Therefore the current study will focus on the stability of
body image. Previous research indicated that AN patients are more suciptible
for the Rubber Hand Illusion (RHI), which is a measure of body image stability.
This increased susceptibility indicates that AN patients have a less stable
body image than controls. It is however still unknown whether this decreased
stability of body image also influences how the body is perceived in terms of
size and shape.
Study objective
The primary objective of the current study is investigating whether AN patients
and controls differ how they experience the shape and size of a rubber hand
that during the Rubber Hand Illusion is incorporated in their body image,
compared to how they experienced the rubber hand before the RHI. A secondary
objective of the current study is investigating whether there is a relation
between how the rubber hand is experienced and eating disorder related
pathology. A second secondary objective of the present study is to replicate
the findings by Eshkevari et al (2011). Specifically we aim to replicate their
findings on perceptual drift and embodiment during the RHI. Eshkevari et al
(2011) found that AN patients experience higher levels of perceptual drift and
embodiment in both the synchronous and a-synchronous condition of the RHI.
Also, it will be checked whether AN patients have a larger temperature drop
during the illusion than controls. It has been found in the literature that
during the RHI the temperature in the hand involved in the illusion drops,
compared to a pre-RHI measure. Eshkevari et al (2012) did not assess
temperature, but they did show that AN patients are more sensitive to the RHI.
Based on previous findings in healthy populations it may be expected that those
more sensitive to the RHI (here AN patients) show a larger drop in temperature
during the illusion.
Study design
Quasi-experimental
Study burden and risks
It is not expected, but theoretically possible that the participants experience
negative emotions during the study, for example due to experiencing the rubber
hand as belonging to the own body. However, the chance of experiencing negative
emotions is thought to be minimal, since before participation takes place the
participants will be informed of the procedures during the study and what will
happen during the experiment. From experience with previous (AN) studies we
learned that participants understand why certain methods are important for the
study, and that explaining these methods to the participants reduces concerns.
In addition, the knowledge that will be gained in the current study will not
only increase our understanding of body representation disturbances in AN, but
will might have implication for treatment of AN.
Heidelberglaan 2
Utrecht 3584 CS
NL
Heidelberglaan 2
Utrecht 3584 CS
NL
Listed location countries
Age
Inclusion criteria
Patients: Female, between 18 and 35 years of age, diagnosed with Anorexia Nervosa, physically non-disabled (i.e. able to perform tasks involving arm and hand movements).;Healthy controls: Female, between 18 and 35 years of age, BMI between 18.5 and 25, no current severe mental health problems, physically non-disables (i.e. able to perform tasks involving arm and hand movements).
Exclusion criteria
Patients: Use of medication that may influence task performance due to sedative effects, drowsiness or (psycho)motor impairments, comorbid Borderline personality disorder or contact disorder, recent start of treatment, pregnancy.
Healthy controls: Use of medication that may influence task performance due to sedative effects, drownsiness, or (psycho)motor impairments, pregnancy.
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL40376.041.12 |