The Effect of Neurofeedback on Eating Behaviour

Neuroimaging is becoming increasingly common to investigate the neural networks underlying eating behaviour and food preference in normal-weight and obese humans. It has been observed that obese in comparison to lean individuals display altered activation patterns in networks of brain areas involved in reward, emotion and cognitive control. Interestingly, obese individuals who are capable of losing weight appear to have a stronger connectivity between areas related to food value and to the control of eating behaviour. The same areas are also associated with healthy food choices. It has been suggested that activation in the prefrontal control areas indirectly modulate valuation-related activity. Based on this, brain-related intervention strategies to support weight loss and long-lasting weight maintenance are of particular interest. Hence, we first want to examine the effect on eating behaviour of neurofeedback training-induced up-regulation of functional connectivity between reward- and impulse-related brain areas as a pilot, and second we want to examine up-regulation of the activity of prefrontal control brain areas.

Primary objective: We want to investigate whether the training-induced up-regulation of the dorsal prefrontal cortex inhibits eating behaviour.

Study design: A parallel design. Half of the participants will learn to up-regulate activity of the dorsolateral prefrontal cortex (dlPFC), while the other participants will participate in sham-training sessions. Adherence to experimental conditions will be assigned randomly, based on the participants' enrolment in the study, balanced by gender and binge eating classification.

Study population: 50 overweight and obese (BMI 25-40 kg/m2), but otherwise healthy individuals, 18-65 years old.

Intervention: All participants will participate in a screening day, followed by one neurofeedback session day and a follow-up day. During the neurofeedback session, participants will undergo a 45 min real-time-fMRI-brain-computer-interface scan in order to learn to up-regulate dlPFC activation.

Main study parameters/endpoints:

1. The ability to up-regulate dlPFC activity.
2. Respective effects on eating behaviour. Nature and extent of the burden and risks associated with participation: Participants will be scanned once (fMRI). Functional MRI is a safe and non-invasive technique.

Eligibility Criteria:
Inclusion Criteria:

* Healthy male and female subjects
* Age 18-65 years at start of the study
* Body Mass Index (BMI) between 25 and 40 kg/m2
* Informed consent to study protocol
* Willingness to be informed about chance findings of pathology and approval of the disclosure of this information to the general physician (see Informed Consent)
* Fulfilment of the criteria for blood donors according to the "Richtlinien zur Gewinnung von Blut und Blutbestandteilen und zur Anwendung von Blutprodukten", in particular Hb ≥ 135 g/l (8,37 mmol/l; Bundesärztekammer 2010)

Exclusion Criteria:

* Subjects who have a non-removable metal object in or at their body, such as, for ex-ample:

  * Heart pace-maker
  * Artificial heart valve
  * Metal prosthesis
  * Metallic implants (screws, plates from operations, etc.)
  * Metal splinters / grenade fragments
  * Non-removable dental braces
  * Acupuncture needles
  * Insulin pump
  * Intraport, etc.
  * In field strengths of over 1.0 T also: tattoos, eye lid-shadow
* Current weight loss regimens
* Limited temperature perception and/or increased sensitivity to warming of the body
* Pathological hearing ability or an increased sensitivity to loud noises
* Claustrophobia
* Lack of ability to give informed consent
* Operation less than three month ago
* Simultaneous participation in other studies
* Acute illness or infection during the last 4 weeks
* Neurological disorder or injury
* Moderate or severe head injury
* Severe psychotic illness
* Intake of antidepressants / antipsychotics
* Participation in other studies with blood withdrawals or blood donation in previous and subsequent 2 months