Guardia et al (AN)

Question 1

AIM (1)

Answer 1

To investigate whether problems in judging body actions, such as deciding whether a body fits through a space, occurred only when judging ones own body or whether it was an overall judgement/perception problem.

Question 2

AIM (2)

Answer 2

Would people with AN be different from a control group in judging whether a gap was large enough for their body to pass through.

Question 3

Who approved of the study?

Answer 3

An independent ethics committee.

Question 4

SAMPLE

Answer 4

50 young female participants, 25 with AN from an eating disorder clinic and 25 healthy controls.
They were all students from Lille, France and were matched for age and education.

Question 5

Were the groups similar?

Answer 5

Their BMI differs of course and the width of AN patients was smaller. The body shape questionnaire scores were significantly different, as expected.

Question 6

PROCEDURE

Answer 6

• They gathered data about body dissatisfaction and concern about weight using a questionnaire, including the body shape questionnaire and eat disorder inventory-2 (which showed the drive for thinness and the body dissatisfaction scores.
• 51 different openings ranging from 30cm-80cm were projected onto a wall in random orders.
• Each opening was presented 4 times and this was to maintain ecological validity.

Question 7

What were the 2 conditions?

Answer 7

1) The first person perspective (1PP): ppts judged whether their own body would fit through the opening. They had to image themselves walking through and say whether they could walk through at normal speed without turning sideways.
2) The third person perspective (3PP): ppts had to imagine the experimenter going through the opening. They could move to get a better view of the experimenter and had to say whether the experimenter could walk through the opening at normal speed without turning.

Question 8

How was data collected?

Answer 8

Ratios were calculated for each participant based on ‘critical openings’ (this is the opening which they responded ‘yes’ to on at least 2 out of the 4 presentations).
If the ppts overestimated their size, their ratio would be over 1. If they underestimated their size, it would be under one.
A score of 1 would mean there is no chance of them fitting through the opening as they are the exact same size of the opening.

Question 9

What was the critical opening for all ppts?

Answer 9

The smallest door size in which they would be able to fit through.

Question 10

RESULTS

Answer 10

The AN group has a significantly higher score on the body shape questionnaire.
The AN group showed significant overestimation of their own body size, judging that they would be unable to fit through an opening that was considerably bigger than their actual body size.

Question 11

Results for the 1PP

Answer 11

The mean perceptual ratios were higher for the AN group then the controls. The mean ratio for the AN group was 1.321 and for the controls it was 1.106.

Question 12

Results for 3PP

Answer 12

They were much more accurate in predicting the body size of the experimenter. The mean perceptual ratios were the same. Although the average ratios for the AN group was higher (1.227) than the controls (1.137) it was not a significant difference.

Question 13

Comparing the 1PP to the 3PP in AN

Answer 13

There was a significant difference between the mean ratios for those with AN in the 1PP and 3PP condition. When the patients with AN rated their own body for going through the opening the mean ratios was 1.321 and when those with AN rated the experimenter’s body going through the opening the mean ratio was 1.227. The controls showed no significant difference between the 1PP and the 3PP.

Question 14

CONCLUSIONS

Answer 14

• Those with AN significantly overestimate their own ‘possibility’ in relation to the control group. The patients also said they felt larger than they were.
• Although AN patients made errors in judging their own ‘possibility’, they didn’t make errors in judging the experimenters body size i relation to the opening.
• The overestimation of the ratio between size of the opening and shoulder width is thought to be because of their own body schema issue. As the AN group were better at judging the experimenters size, this is not a perceptual issue, its more cognitive.
• Patients have not adapted their internal body image to take into account their ‘new’ body size after developing the disorder. Their brains still perceive their bodies to be larger despite the visual information contradicting this.

Question 15

Generalisibility (weakness)

Answer 15

There was a small sample consisting of only 25 fairly young AN females and not all of them had reported history of weight change. They were all students. Researcher may not generalise to older people or male sufferers as both can suffer with AN.

Question 16

Generalisibility (strength)

Answer 16

The majority of sufferers are females as it affects between 0.5% and 1%of women whereas its a much smaller percentage in men.

Question 17

Internal validity (strength)

Answer 17

They were diagnosed with AN using the DSM 4-R. A psychiatrist also carried out an interview to check there were no co-moralities Therefore any perceptual differences between the two groups could be attributed to AN not other factors.

Question 18

Internal validity (strength)

Answer 18

Matched design was used - matched on age, sex, education etc. This allows for a stronger cause and effect to be established suggesting that mis-judgements of their own body size was due to their AN not other factors.

Question 19

Ecological validity (weakness)

Answer 19

Body action task lacks ecological validity - it is a simulation task where ppts imagine performing the actions involved in passing through an opening.The researchers recognised this is not identical to the real activity of actually passing through a doorway and changing body orientation if necessary. Therefore the ratios dont measure true behaviour.