Not provided
Not provided
Not provided
Not provided
Coronavirus pandemic
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
In this study the investigators aim to assess whether transcranial direct current stimulation (tDCS; a safe non-invasive method for modulating the activity of specific brain regions) when applied over the orbitofrontal cortex (OFC) is able to modulate impulsivity in obese participants.
In this single-blind, sham controlled study, the investigators will assess whether transcranial direct current stimulation (tDCS; a safe non-invasive method for modulating the activity of specific brain regions) when applied over the orbitofrontal cortex (OFC) is able to modulate impulsivity in obese volunteers. The investigators hypothesize that tDCS applied to the OFC, in comparison to sham tDCS, will significantly reduce impulsivity and enhance decision making as measured by computerized neurocognitive tasks. For this study the investigators will enroll 30 obese individuals aged 18-65 years. Participants will be assessed with a battery of computerized tasks as well as self-reported questionnaires on eating, impulsivity, mood and anxiety. Assessments will be carried out before, during, and after a single 20-minute 2mA tDCS session.
Not provided
Not provided
Not provided
Not provided
Not provided
| Label | Type | Description | Intervention Names |
|---|---|---|---|
| Experimental: Active Left OFC Group | Active Comparator | 2mA will be applied for 20 minutes with the tDCS anode applied to the left OFC and Cathode applied to the right primary motor cortex. |
|
| Sham Comparator: Sham left OFC Group | Sham Comparator | Current will be ramped up for 30s followed by a 30s ramp down to mimic the physical sensation of stimulation and habituation. The anode placed over the left OFC and cathode placed over the right primary motor cortex. |
|
| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| Transcranial Direct Current Stimulation | Device | Anode placed over the OFC and cathode placed over the right primary motor cortex. |
|
| Measure | Description | Time Frame |
|---|---|---|
| Probabilistic Decision Making | Net score of the Iowa Gambling Task The net score ranges from -20 to 30. Higher values represent a better outcome (i.e., enhanced decision-making) | Before and after a 20-minute tDCS session |
| Measure | Description | Time Frame |
|---|---|---|
| Cognitive Control | Interference index in the Stroop Color-word Task. Interference index is the reaction time computed between the presentation of the stimulus and the response of the participant. It typically ranges from 0 to 300 millisecond, with smaller values of reaction time indicate better outcome (i.e., better cognitive control). | Before and after a 20-minute tDCS session |
Not provided
Inclusion Criteria:
Exclusion Criteria:
Not provided
Not provided
Not provided
Not provided
Not provided
| Name | Affiliation | Role |
|---|---|---|
| Alexander McGirr, MD, MSc | University of Calgary | Principal Investigator |
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| University of Calgary | Calgary | Alberta | T2N 1N4 | Canada |
| PubMed Identifier | Type | Citation | Retractions |
|---|---|---|---|
| 8039375 | Background | Bechara A, Damasio AR, Damasio H, Anderson SW. Insensitivity to future consequences following damage to human prefrontal cortex. Cognition. 1994 Apr-Jun;50(1-3):7-15. doi: 10.1016/0010-0277(94)90018-3. | |
| 16136173 | Background | Kringelbach ML. The human orbitofrontal cortex: linking reward to hedonic experience. Nat Rev Neurosci. 2005 Sep;6(9):691-702. doi: 10.1038/nrn1747. |
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
| ID | Term |
|---|---|
| D007175 | Impulsive Behavior |
| ID | Term |
|---|---|
| D001519 | Behavior |
Not provided
Not provided
| ID | Term |
|---|---|
| D065908 | Transcranial Direct Current Stimulation |
| ID | Term |
|---|---|
| D004599 | Electric Stimulation Therapy |
| D013812 | Therapeutics |
| D003295 | Convulsive Therapy |
| D013000 | Psychiatric Somatic Therapies |
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
|
| Food-specific cognitive control | The interference index in the Food-Stroop Color-Word test. Interference index is the reaction time computed between the presentation of the stimulus and the response of the participant. It typically ranges from 0 to 300 millisecond, with smaller values of reaction time indicate better outcome (i.e., better Food-specific cognitive control). | Before and after a 20-minute tDCS session |
| Delayed discounting | The discount rate for delayed monetary rewards. This rate is quantified by the hyperbolic discounting function using the following equation: V = A/(1+kD), where A presents the value of the delayed reward A at delay D, and k is a free parameter that determines the discount rate, with higher values of k indicate worse outcome (i.e., greater discounting of rewards as a function of time). | Before and after a 20-minute tDCS session |
| Motor impulsivity | The stop-signal reaction time in the Stop-Signal Task. The stop signal reaction time ranges from 50 to 250, where greater values represent worse outcome (i.e, increased motor impulsivity). | Before and after a 20-minute tDCS session. |
| Moderation of effect by self-reported measures of impulsivity and dysregulated eating | Individuals with high levels of impulsivity, impulsive eating, binge eating, self-reported food addiction will show greater moderation by tDCS on our primary and secondary outcomes. Barrat's impulsiveness scale-11 with a range of scores from 0 to 120, with higher scores indicating greater impulsivity. Reward-based eating drive scale-13 with a range of scores from 0 to 54, with higher scores indicating greater uncontrolled eating. Binge eating scale with a range of scores from 0 to 46: minimal binge eating ( >17), moderate binge eating (18-26), and severe binge eating (<27)). Yale Food Addiction Scale with a range of symptom severity from 0 to 7: mild (2-3 symptoms), moderate (4-5 symptoms), severe (6 or more symptoms)). | Before and after a 20-minute tDCS session. |
| 28611698 | Background | Mason AE, Vainik U, Acree M, Tomiyama AJ, Dagher A, Epel ES, Hecht FM. Improving Assessment of the Spectrum of Reward-Related Eating: The RED-13. Front Psychol. 2017 May 30;8:795. doi: 10.3389/fpsyg.2017.00795. eCollection 2017. |
| 17655972 | Background | Finlayson G, King N, Blundell J. The role of implicit wanting in relation to explicit liking and wanting for food: implications for appetite control. Appetite. 2008 Jan;50(1):120-7. doi: 10.1016/j.appet.2007.06.007. Epub 2007 Jun 28. |
| 17187897 | Background | Nijs IM, Franken IH, Muris P. The modified Trait and State Food-Cravings Questionnaires: development and validation of a general index of food craving. Appetite. 2007 Jul;49(1):38-46. doi: 10.1016/j.appet.2006.11.001. Epub 2006 Dec 21. |
| 11879657 | Background | O'Doherty JP, Deichmann R, Critchley HD, Dolan RJ. Neural responses during anticipation of a primary taste reward. Neuron. 2002 Feb 28;33(5):815-26. doi: 10.1016/s0896-6273(02)00603-7. |
| 26343591 | Background | Ouellet J, McGirr A, Van den Eynde F, Jollant F, Lepage M, Berlim MT. Enhancing decision-making and cognitive impulse control with transcranial direct current stimulation (tDCS) applied over the orbitofrontal cortex (OFC): A randomized and sham-controlled exploratory study. J Psychiatr Res. 2015 Oct;69:27-34. doi: 10.1016/j.jpsychires.2015.07.018. Epub 2015 Jul 17. |
| 20539296 | Background | Phelan S, Hassenstab J, McCaffery JM, Sweet L, Raynor HA, Cohen RA, Wing RR. Cognitive interference from food cues in weight loss maintainers, normal weight, and obese individuals. Obesity (Silver Spring). 2011 Jan;19(1):69-73. doi: 10.1038/oby.2010.138. Epub 2010 Jun 10. |
| 25988110 | Background | Pursey KM, Stanwell P, Callister RJ, Brain K, Collins CE, Burrows TL. Neural responses to visual food cues according to weight status: a systematic review of functional magnetic resonance imaging studies. Front Nutr. 2014 Jul 9;1:7. doi: 10.3389/fnut.2014.00007. eCollection 2014. |
| 28572072 | Background | Ray MK, Sylvester MD, Osborn L, Helms J, Turan B, Burgess EE, Boggiano MM. The critical role of cognitive-based trait differences in transcranial direct current stimulation (tDCS) suppression of food craving and eating in frank obesity. Appetite. 2017 Sep 1;116:568-574. doi: 10.1016/j.appet.2017.05.046. Epub 2017 May 29. |
| 17566768 | Background | Rothemund Y, Preuschhof C, Bohner G, Bauknecht HC, Klingebiel R, Flor H, Klapp BF. Differential activation of the dorsal striatum by high-calorie visual food stimuli in obese individuals. Neuroimage. 2007 Aug 15;37(2):410-21. doi: 10.1016/j.neuroimage.2007.05.008. Epub 2007 May 18. |
| 12946886 | Background | Rush AJ, Trivedi MH, Ibrahim HM, Carmody TJ, Arnow B, Klein DN, Markowitz JC, Ninan PT, Kornstein S, Manber R, Thase ME, Kocsis JH, Keller MB. The 16-Item Quick Inventory of Depressive Symptomatology (QIDS), clinician rating (QIDS-C), and self-report (QIDS-SR): a psychometric evaluation in patients with chronic major depression. Biol Psychiatry. 2003 Sep 1;54(5):573-83. doi: 10.1016/s0006-3223(02)01866-8. |
| 9881538 | Background | Sheehan DV, Lecrubier Y, Sheehan KH, Amorim P, Janavs J, Weiller E, Hergueta T, Baker R, Dunbar GC. The Mini-International Neuropsychiatric Interview (M.I.N.I.): the development and validation of a structured diagnostic psychiatric interview for DSM-IV and ICD-10. J Clin Psychiatry. 1998;59 Suppl 20:22-33;quiz 34-57. |
| 19828708 | Background | Swinburn B, Sacks G, Ravussin E. Increased food energy supply is more than sufficient to explain the US epidemic of obesity. Am J Clin Nutr. 2009 Dec;90(6):1453-6. doi: 10.3945/ajcn.2009.28595. Epub 2009 Oct 14. |
| 21111829 | Background | van der Laan LN, de Ridder DT, Viergever MA, Smeets PA. The first taste is always with the eyes: a meta-analysis on the neural correlates of processing visual food cues. Neuroimage. 2011 Mar 1;55(1):296-303. doi: 10.1016/j.neuroimage.2010.11.055. Epub 2010 Nov 25. |
| D004191 | Behavioral Disciplines and Activities |
| D004597 | Electroshock |
| D011580 | Psychological Techniques |