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Painfully thin but locked inside a fatter body: abnormalities in both anticipation and execution of action in anorexia nervosa.

Metral M, Guardia D, Bauwens I, Guerraz M, Lafargue G, Cottencin O, Luyat M - BMC Res Notes (2014)

Bottom Line: This bias is linked to weight variations.Moreover, these results prompt us to suggest that emotional burden during weight recovery could also alter sensorimotor aspects of body representation.New therapeutic methods should take account of body schema alterations in AN as adjuncts to psychotherapy.

View Article: PubMed Central - PubMed

Affiliation: LNFP (Laboratory of Functional Neuroscience and Pathology) EA4559, F-59000 Lille, France. marion.luyat@univ-lille3.fr.

ABSTRACT

Background: People with anorexia nervosa (AN) usually report feeling broader than they really are. The objective of the present study was to better understand the body schema's involvement in this false self-representation in AN. We tested the potential for correction of the body schema impairment via the sensorimotor feedback provided by a real, executed action and relative to an imagined action. We also took account of the impact of the AN patients' weight variations on the task outcomes.

Methods: Fourteen inpatient participants with AN and fourteen control participants were presented with a doorway-like aperture. The participants had to (i) judge whether or not various apertures were wide enough for them to pass through in a motor imagery task and then (ii) actually perform the action by passing through various apertures.

Results: We observed a higher passability ratio (i.e. the ratio between the critical aperture size and shoulder width) in participants with AN (relative to controls) for both motor imagery and real action. Moreover, the magnitude of the passability ratio was positively correlated with weight recovery.

Conclusion: The body schema alteration in AN appears to be strong enough to affect the patient's actions. Furthermore, the alteration resists correction by the sensorimotor feedback generated during action. This bias is linked to weight variations. The central nervous system might be locked to a false representation of the body that cannot be updated. Moreover, these results prompt us to suggest that emotional burden during weight recovery could also alter sensorimotor aspects of body representation. New therapeutic methods should take account of body schema alterations in AN as adjuncts to psychotherapy.

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Related in: MedlinePlus

The mean action ratio as a function of the series (i.e. the first series vs. the second series) and the group. AN = patients suffered from anorexia nervosa. The vertical bars represent the 95% confidence interval.
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Fig4: The mean action ratio as a function of the series (i.e. the first series vs. the second series) and the group. AN = patients suffered from anorexia nervosa. The vertical bars represent the 95% confidence interval.

Mentions: In order to establish whether the AN group's ratio could be improved by repeating the action, we performed a 2×2 analysis of variance with repeated measures on the series factor and with group as a categorical predictor for the action ratio. This ANOVA revealed a significant effect of group (F(1,26) = 27.76, p < 0.0001). The AN group had significant higher action ratio (Mean = 1.32) than the control group (Mean = 1.16). Moreover, the effect of series was not statistically significant (F(1,26) = 3.80, p = 0.06). The first series yielded a lower action ratio (Mean = 1.23) than the second series (Mean = 1.26). The interaction between series and group was not statistically significant: F(1,26) = 1.40, p = 0.25 (see Figure 4). However, an a priori comparison revealed that the lower action ratio in the AN group was significantly lower in the first series (Mean = 1.29) than in the second series (Mean = 1.35). In contrast, no such difference was observed for the control group when comparing the first series (Mean =1.16) with the second series (Mean = 1.18; F(1,26) < 1).Figure 4


Painfully thin but locked inside a fatter body: abnormalities in both anticipation and execution of action in anorexia nervosa.

Metral M, Guardia D, Bauwens I, Guerraz M, Lafargue G, Cottencin O, Luyat M - BMC Res Notes (2014)

The mean action ratio as a function of the series (i.e. the first series vs. the second series) and the group. AN = patients suffered from anorexia nervosa. The vertical bars represent the 95% confidence interval.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4201671&req=5

Fig4: The mean action ratio as a function of the series (i.e. the first series vs. the second series) and the group. AN = patients suffered from anorexia nervosa. The vertical bars represent the 95% confidence interval.
Mentions: In order to establish whether the AN group's ratio could be improved by repeating the action, we performed a 2×2 analysis of variance with repeated measures on the series factor and with group as a categorical predictor for the action ratio. This ANOVA revealed a significant effect of group (F(1,26) = 27.76, p < 0.0001). The AN group had significant higher action ratio (Mean = 1.32) than the control group (Mean = 1.16). Moreover, the effect of series was not statistically significant (F(1,26) = 3.80, p = 0.06). The first series yielded a lower action ratio (Mean = 1.23) than the second series (Mean = 1.26). The interaction between series and group was not statistically significant: F(1,26) = 1.40, p = 0.25 (see Figure 4). However, an a priori comparison revealed that the lower action ratio in the AN group was significantly lower in the first series (Mean = 1.29) than in the second series (Mean = 1.35). In contrast, no such difference was observed for the control group when comparing the first series (Mean =1.16) with the second series (Mean = 1.18; F(1,26) < 1).Figure 4

Bottom Line: This bias is linked to weight variations.Moreover, these results prompt us to suggest that emotional burden during weight recovery could also alter sensorimotor aspects of body representation.New therapeutic methods should take account of body schema alterations in AN as adjuncts to psychotherapy.

View Article: PubMed Central - PubMed

Affiliation: LNFP (Laboratory of Functional Neuroscience and Pathology) EA4559, F-59000 Lille, France. marion.luyat@univ-lille3.fr.

ABSTRACT

Background: People with anorexia nervosa (AN) usually report feeling broader than they really are. The objective of the present study was to better understand the body schema's involvement in this false self-representation in AN. We tested the potential for correction of the body schema impairment via the sensorimotor feedback provided by a real, executed action and relative to an imagined action. We also took account of the impact of the AN patients' weight variations on the task outcomes.

Methods: Fourteen inpatient participants with AN and fourteen control participants were presented with a doorway-like aperture. The participants had to (i) judge whether or not various apertures were wide enough for them to pass through in a motor imagery task and then (ii) actually perform the action by passing through various apertures.

Results: We observed a higher passability ratio (i.e. the ratio between the critical aperture size and shoulder width) in participants with AN (relative to controls) for both motor imagery and real action. Moreover, the magnitude of the passability ratio was positively correlated with weight recovery.

Conclusion: The body schema alteration in AN appears to be strong enough to affect the patient's actions. Furthermore, the alteration resists correction by the sensorimotor feedback generated during action. This bias is linked to weight variations. The central nervous system might be locked to a false representation of the body that cannot be updated. Moreover, these results prompt us to suggest that emotional burden during weight recovery could also alter sensorimotor aspects of body representation. New therapeutic methods should take account of body schema alterations in AN as adjuncts to psychotherapy.

Show MeSH
Related in: MedlinePlus