None listed
Conditions
Brief summary
Study objectives: to observe the effects of specific frequencies of median nerve stimulation on food attention and subjective and physiological appetite. Intervention: use of non-invasive electrical stimulation (Transcutaneous electrical nerve stimulation) on the median nerve at the inner forearm region for ten minutes using a frequency of 40hz, 80hz or 120hz and placebo (electrodes placed but no stimulation passed) on four different days for males and eight different days for females(four days per menstrual period of follicular and luteal stages). Hypothesis: median nerve stimulation using different frequencies will reduce subjective and physiological measures of appetite and reduce the effect of odour on the food attention task.
Interventions
Healthy adult participants, male and female of age 21-39 years, were tested on an appetite questionnaire and a simple probe-dot, attention task with food imagery and odour delivery, before and after non-invasive, stimulation of the median nerve for ten minutes, with the recording of an ECG throughout the whole experiment.
The participants will perform a simple reaction time task and fill in subjective ratings of appetite, before- and after median nerve stimulation. There is a baseline period of
Healthy adult participants, male and female of age 21-39 years, were tested on an appetite questionnaire and a simple probe-dot, attention task with food imagery and odour delivery, before and after non-invasive, stimulation of the median nerve for ten minutes, with the recording of an ECG throughout the whole experiment. The participants will perform a simple reaction time task and fill in subjective ratings of appetite, before- and after median nerve stimulation. There is a baseline period of 5mins of ECG recording, followed by 15-20minutes of pre-stim tests then a 10 min stimulation period then again 15-20mins post-stim tests, total of approx. 45-55 minutes. The TENS electrodes are placed on the left forearm, and the stimulation is set to be above the motor threshold but not inducing any pain or discomfort for the participant. The duration of each session is roughly 45-55minutes and each session occurs on different days. The sessions are not required to be consecutive. The intervention will be applied by a member of the research staff and each intervention will be identified by a key of P1-12. ECG recordings, probe-dot tests and VAS scales (where participants rate subjective appetite) also have raw data files which can be checked for fidelity if needed. Visual analogue scales (VAS) are used for subjective appetite and hunger scales, which are very well-validated in the literature. Probe-dot test is also stable in food-attention research and is considered superior to the previously used Stroop test design. Our only modification with the probe-dot test is the delivery of odour throughout some of the probe-dot test blocks with the use of an olfactometer. The only change in the four different sessions (male) and eight different sessions (female) was the frequency of stimulation (40Hz, 80Hz, 120Hz, control-placebo). Females were tested on both stages of the menstrual cycle (follicular and luteal stages).
Sponsors
University of Otago
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject, Caregiver, Outcomes Assessor)
Eligibility
Sex/Gender
All
Age
21 Years to 39 Years
Healthy volunteers
Yes
Inclusion criteria
Inclusion criteria for the study include healthy (no neurological or cognitive impairments, no impairments in smell, vision or hearing) male and females (not on hormonal contraceptives) of 21-39 years of age, non-smokers, of Caucasian (NZ-European descent), of a healthy BMI range (18.5-24.9). In the screening form before each session, participants are also asked to disclose any medication use, physical fitness levels, computer use levels, following of any specific diets, alcohol intake (if within 48 hours of the experiment), caffeine intake (if any within 2 hours of the experiment) and food intake (if any within 2 hours of the experiment).
Exclusion criteria
No consumption of food or caffeine within two hours of the experiment, no use of deodorant on the day of experiment and no consumption of alcohol or performance of weight training/heavy exercise on the day or within 24 hours of the experiment.
Outcome results
None listed