Interoception in Bulimia Nervosa: Evidence at cortical and self-report levels

Bulimia nervosa (BN) is characterized by recurrent episodes of binge eating
and compensatory behaviors, such as self- induced vomiting. Body
image disturbance is also prominent in BN. Current research is trying to
determine which dimensions and sensory domains of body perception are
affected in BN. Regarding heartbeat perception, findings are inconclusive,
with some studies reporting reduced and others reporting unaltered interoceptive
accuracy in BN. The current study contributes further data
on heartbeat perception by using an indicator of the cortical processing
of cardio- afferent signals (heartbeat evoked potentials, HEPs). We investigated
22 women with current or partially remitted BN (BMI 23.94[3.61]; age
31.86[11.20]) and 22 healthy women (HC; BMI 24.24[3.37]; age 31.00[10.15]).
Participants performed a heartbeat perception task (according to Schandry)
with concurrent 64- channel- EEG and ECG recording. HEPs were calculated
as mean EEG amplitudes in the interval 455- 595ms after the R- peak
of the ECG. Results show no significant differences between the BN and HC
groups, neither for heartbeat perception, HEPs, or mean heartrate. These
results confirm previous findings of intact heartbeat perception in BN. In addition,
cortical processing of cardio- afferent signals is unaltered. Heartbeat
perception is particularly relevant for emotion processing and regulation.
The previously reported emotion- regulation deficits in BN appear not to be
based on altered CNS processing of cardiac signals