Differential motivational responses to food and pleasurable cues in anorexia and bulimia nervosa: a startle reflex paradigm.
BACKGROUND
Abnormal perceptions of food and shape underpin the cognitive behavioural model of eating disorders (EDs). The aim of this study was to investigate motivational processing of disorder-specific and standard emotional cues in anorexia (AN) and bulimia nervosa (BN) using startle eyeblink modulation (SEM). SEM was used because it is sensitive to motivational states of approach (appetitive response) and withdrawal (aversive response), which are independent of conscious intentional control.


METHODS
Acoustically elicited SEM and subjective anxiety ratings were measured in 30 female patients with an ED (n=15 AN, n=15 BN) and 30 female control subjects while they viewed ED-relevant stimuli (food, female bodies) and standardized emotional pictures.


RESULTS
BN subjects showed an appetitive response (startle inhibition) to food relative to neutral cues that differed significantly from AN subjects. By contrast, self-reports indicated significantly increased anxiety related to food cues across both ED groups. To female body picture (relative to neutral) cues, no significant between-group differences were found for SEM. ED subjects unexpectedly showed an aversive response (startle potentiation) to positive cues, in contrast to controls, who showed the established startle attenuation.


CONCLUSIONS
These preliminary results suggest that BN patients demonstrated an exaggerated appetitive response to food but not to standardized positive cues, whereas SEM in AN patients points to a generalized failure to activate the appetitive motivational system. Differences in motivational salience to food cues are in line with distinctions between AN and BN in eating behaviour and food consumption and support differential treatment requirements.
Friederich
Hans-Christoph
HC
Eating Disorders Unit, Institute of Psychiatry, King's College London, London, UK. hans-christoph.friederich@med.uni-heidelberg.de
Kumari
Veena
V
Uher
Rudolf
R
Riga
Marianthy
M
Schmidt
Ulrike
U
Campbell
Iain C
IC
Herzog
Wolfgang
W
Treasure
Janet
J
D000328:Adult; D000339:Affect; D000856:Anorexia Nervosa / Q000453:epidemiology / Q000503:physiopathology* / Q000523:psychology*; D001828:Body Image; D015992:Body Mass Index; D052018:Bulimia Nervosa / Q000453:epidemiology / Q000503:physiopathology* / Q000523:psychology*; D003072:Cognition Disorders / Q000175:diagnosis / Q000453:epidemiology; D003463:Cues; D003710:Demography; D005260:Female; D005502:Food; D006801:Humans; D009042:Motivation; D013216:Reflex, Startle / Q000502:physiology*; D012720:Severity of Illness Index