Guardia Et Al (2012) [Anorexia Nervosa] contemp Flashcards
Guardia Et Al (2012) Contemp
Aims (3)
• To investigate if problems in judging body actions
– (e.g. if a body fits through a space)
– occurs only when judging your own body
– or if its overal judgment problems
• if AN is diff to Ctrl in judging whether a gap was large enough for their body to pass through
• Continue previous reseach showung AN patients misjudged their ability to fit through a door that was clearly too big
– test if this occurs when AN judge others abbility to fit througg a door
– (see if they also misjudge others sizes)
Guardia Et Al (2012) Contemp
ethic approved and Sample
• Study approved ny Independent Ethics Committee
• Each ppt given info sheet so they could give informed concent
– or parential concent for those under 18
SAMPLE
• 50 young Females (Gynocentric but most AN is fe so let it slide)
– 25 w/ AN from a Eating Dissorder clinic
– 25 Healthy ctrls
– All students from Lille, France (ethnol
– Matched on Age and Education lvl
– were checked to make sure there were no Percpetual problems
– AN ppts all fufilled DSM-IV-TR criteria for diagnosis
• A Psychiatrist carried out an interview to check there were NO CO-MORBILITIES
• Ctrls have BMI od 18.5-25
Guardia Et Al (2012) Contemp
How data gathered/ how sim groups were
Averages:
Age: AN: 23.84 Ctrl: 24.48
Ed Lvl (yrs after primary):
AN: 13.16 Ctrl: 13.8
Height (m): AN: 1.645 Ctrl: 1.649
BMI (Kb/cm³): AN: 15.645 Ctrl: 22.06
Sholder width (cm): AN: 37.66 Ctrl: 41.542
Body Shape Questionaire Score:
AN: 123.96 Ctrl: 66.708
BMI, Sholder width both smaller in AN (expected)
BSQ sig different ( AN larger than Ctrl) (expected) (^= neg perception of body/ shape)
Assessments in Height, sholder width and Weight = standardised
Measured changes over time in Nutritional status by looking at weight:
Before Dissorder, 6mth b4 study, 1mth b4 study and at start of Study
Gatherd data on Body disatisfaction and weight consern using questionaires:
Body Shape Questionaire (BSQ):
- 34 item self report
– Measure degree of body disatisfaction w/ weight and shape
Eating Disorder inventory-2 (EDI2):
– Measures AN ppts desire for thinness and body dissatisfaction score
– 91 item self report
– Likert Scale (aquences bias is possible)
Guardia Et Al (2012) Contemp
procedure
• 51 different openings were projected onto a Wall
– (30-80cm wide)
– from 5.5m away + projection reached the floor (to look like a 2m door)
– in random Order
– Each was Presented 4 times
2 conditions:
1) First person Perspective (1pp):
– PPTS judge if their own body can fit through the opening.
– Had to imagine walking through at normal speed w/o turning sideways
2) Third Person Perspective (3pp):
– ppts had to imagine the Experimenter (Age: 28, 1.6m, 52kg, sholder: 38cm wide, stood 5.9m from wall projection) could fit through the opening
– ppts could move to get a better look at the experementer
– say wether she could move through w/o turning
• Opening was classed as a perceived critical opening (a space you could walk through) When it had:
– ‘yes’ response 50% of times it was shown (2/4+)
• A Ratio was Obtained
– Perceived critical opening (size) ÷ Sholder width of ppt
– when ratio = 1 then it opening = same size as sholder width and cannot pass through w/o turning
– ratio needs to be 1< for them to be able to pass through
Guardia Et Al (2012) Contemp
Results
• AN group= sig higher score on BSQ than Ctrl
• AN group = sig Overestimate own body size
– judging it unable to fit through an oppening considerably bigger than their actual body size
– In 1pp condition: Mean perceptual Ratios= Higher for AN than Ctrl (p=0.001 sig)
– Mean Ratio AN: 1.321
– Mean Ratio Ctrl: 1.106
• AN more accurate in 3pp w/ juding exp body size
– in 3pp the Mean Perceptual Rations were the same
– the AN Avg Ratio (1.227) = Higher than Ctrl (1.137) but NOT SIG DIFF
• was SIG DIFF in Mean Ratios in AN in 1pp and 3pp
– when AN rate own body for going through mean= 1.321
– When AN rate EXP body going through mean= 1.227
– Ctrls show NO SIG DIFF between 1pp and 3pp
• AN rate own body diff from how rate Exp body
– also AN rate own body diff from how Ctrl rate own body
• found CORRELATION between Judgments made by AN and their pre-illness body weight/size
– Those who lost weight in 6mth b4 study showed GREATER DIFF between own and exp perceptions
Guardia Et Al (2012) Contemp
(french AN)
conclusion
and Application / implecation
Aim 1)
– overestimation of Ratio between Opening size and Sholder width is thought to be due to own Body Schema issues
– as AN group better at Judging Exp size, so its not a General perceptual issue
– AN not adapted to their Internal Body image, to take into account ‘new’ body size after dev AN dissorder
– Their Brains still Perceive their bodys to be large despite Visual Info contradicting this
AIM 2
– AN sig Overestimate own body chance of fit in opening compared to Ctrl
– AN say they felt larger than they were
AIM 3
- Altho AN make Errors in own judgment of fitting through Opening
– Didn’t make these errors when judging Exp possibility of fitting through the opening
– The Ctrl’s Judgments were the same when judging own or Exp possibility of fitting through oppening
– So AN not misjudge other ppls body size
Therefore all 3 aims were answerd
• Not a general Perception issue a own perception issue
( due to not adapting internal bidy image to new body size after Dissorder developed and schema stil think its old body image despite visual contradictions)
• AN diff to Ctrl (think large gaps to small to fit through and Ctrl dont)
• dont misjudge others body size only their own
This study therefore overall thurthers the understanding of AN
meaning it is more likley sucsessfull treatments will be developed
as the study found:
the results that AN ptnts sig overestimate own body size but not others making AN’s body judging body actions issue an internal perception issue not an General One
therefore treatments will target the Schemas effecting this self perception issue
that are found to not use their new body image after the dissorder has developed, insted still viewing themselfs in their previous body image
despite visual info contredicting this
these new treatments should therefore be more effective than ones targeting issues in overal perception
aditionaly prexcistinv therapys can be adapted to this result to target that schema at this cause, and more effectivly attempt to resolve AN
and if these new treatments are not found then the study still thurthered the understanding of AN and its functioning and possibke cause
So good applications
Guardia Et Al (2012) Contemp
background
Some authors beleive the Body schema could be Disturbed in AN
As the Brains perceive their body as larger despite visual info contradicting this
In a Previous Study, Guarida found
The Antisipation of Action in AN patients:
They Judged they couldnt pass through an apature
despite it being easily wide enough
Guardia Et Al (2012) Contemp
controls put in place
• Ctrl Groups
– eliminates possibility of misjudgment of fitting through openings being a general judgmebt issue regardless of the results
• Ctrl Group matched on ED and Age reducing individual diff and ppts effects
e.g. higher Ed lvl allowing for better judgment and perception in the Ctrl group impacting on the Validity of the results and conclusion
decreasing these Ex variables allows Cause (AN) and Effect (Misjudge opening cuz own issues) to be accuratly established
– increasing Internal Validity
• Standardising Exp used in 3pp
– so all ppts dont have diff exp w/ diff body sizes and shapes
– which may of Disturbed or invalidated the results or made them incomparable due to these differences
– as Diff interpritations cant be compared when on Diff ppl directly and validly
therefore this ctrl reduces this Confoundimg variable, giving it good Internal Validity
Guardia Et Al (2012) Contemp
gen + matched ppts + women sk represent AN pop
Ppts mached for Age and Ed Lbl
the results that AN ptnts sig overestimate own body size but not others making AN’s body judging body actions issue an internal perception issue not an General One
can be generalised to Girls of those Ages and Education Levels with AN
Making it Partialy Generalisable
Its also Possible its Gynocentric due to the sample consisting of only (50) women, but AN mainly Affects Women so Its representive of AN population
Guardia Et Al (2012) Contemp
gen– Ethno age and ed
The Sample is Ethnocentric with all Ppts coming from Lille France
meaning that
the results that AN ptnts sig overestimate own body size but not others making AN’s body judging body actions issue an internal perception issue not an General One
cant be Generalised to Other Cultures Due to being unrepresented in the sample and different to Frances
and Also cant be Generalised to Other ages and Education levels that were not represented in the sample due to all being Matched between AN and Ctrl
this gives Guardia et al 2012 low generalisability as it cant be generalised to other Ages, Ed lvls and Cultures
Guardia Et Al (2012) Contemp
Reliabile + Stand Pro
Guardia et al 2012 has a standardised procedure of
51 oppenings shown 4 times in a Random order from a projector 5.5m away to make it look like a 2m tall door
in 2 conditions
1 where the ppts judge the possibility of them fitting through the Gap w/o turning
and 1 where they judge an Experimenters possibility of fitting through w/o turning ( age: 28, Height 1.6, 52kg, 38cm sholders and 5.9m from wall)
with the BSQ and EDI2 both being standardised self report Questionaires on Body image, size, disatisfaction, desire for thinness and weight conserns)
aswell as Standardised Equasion on perceptual ratios being:
Size of opening ÷ sholder width
This therefore makes the Procedure highly replicatable for other Experimenters to replicate the study and test the results
Giving Guardia et al 2012 high Reliability due to this standardised procedure
Guardia Et Al (2012) Contemp
Reliability – Order effects unreplicatable
due to the 51 Openings being displaed in RANDOM ORDER 4 times
the order they were displayed may have affected ppts judgments
therefore to replicate the Experiment accutatly the order of oprenings would need to be the same for each of the 50 ppts to atempt to find simular results
this may be impossible to do as it requires finging 202 oppenings for 50 ppts in 2 conditions, and impossible if all of them were not noted
thurthermore
to replicate the study accuratly by doing this and replicating the oppenings order
it breaks the standardised procedure as its no longer random
therefore either way of being more accurate with replicating the order
or replicating the standardused orocedure is unreliable
either because the order to makesure the order’s effect on judgment is replicated, breaking standardised procedure
or following the procedure and the different/inaccurate order of the openings are shown differently effecting ppts judgment on the chance of them/exp fitting through the opening
making Guardia Et Al 2012 Unreliable due to being Unreplicatbale accuratly
Guardia Et Al (2012) Contemp
External Val + Mundane realism
High mundane realism
as everyone (usualy internaly) judges wether they can fit through a door without turning when they approach a door they wish to pass through
meaning thus study’s task of ppts judging if they can pass through or others passing through (as if you are in a queue you also internalt do this)
is representive of everyday life
Giving Guardia et al 2012 high Mundane realism
Guardia Et Al (2012) Contemp
External Validity – Eco
Low Ecological Validity
as its an artificial Enviroment (in a lab by a wall)
and its not a real door only a projection of a opening
its therefore not reppresentitive of real Life door judging
or the results that AN ptnts sig overestimate own body size but not others making AN’s body judging body actions issue an internal perception issue not an General One
may not occur in Real life
Giving Guarida Et Al 2012 Low Ecological Validity
Guardia Et Al (2012) Contemp
+ Internal Validity Objective Measures (construct validity)
The Study used Objective measurments that are calculated which are high in Construct validity
such as mean perceptional Ratio
( Perceived Critical Opening (say yes they can walk through [whats being measured] 2+/4 times its shown) Size ÷ sholder width)
therefore the Ratio is Objecive
as both widths are measured in cm
and the Mean of these values is found by adding all 25 per group and dividing that number by the number of ppts ler group (25)
this gives the mean Perceptual Ratio High constructive Validity as its an valid measure of the accuracy of perception of what openings the ppts belive they can fit through
and therefore Guardia Et Al 2012 has High internal Validity
