Title: Effects of brief mindfulness training on the neural activity associated with processing food cues
Supervisor: Lawrence Barsalou
Date: June 2019
Universities: The University of Glasgow supported the research performed in this dissertation, with data collected in the fMRI scanner in the Institute for Neuroscience and Psychology. Emory University awarded the PhD, where Jing Chen was a PhD student.
Abstract: A functional magnetic resonance imaging experiment assessed effects of a brief mindfulness intervention on the neural mechanisms that underlie food cue processing. In a blocked design, an initial training phase asked participants to either normally view or mindfully attend to images of tasty and healthy foods. In a fast event-related design, a subsequent choice phase asked participants to make speeded choices about whether to eat pictured foods (both tasty and healthy, half from the training phase, half novel). The results largely supported our hypotheses. Using the breadth of activation relative to well-matched active baselines (rather than signal intensity relative to resting state baselines), we established a large distributed neural network for food processing that grounds the diverse aspects of food consumption simulations, including the ventral food reward network (taste, olfaction, reward, attention), mentalizing (along the cortical midline), and embodiment including action (across the motor system). This distributed network was active for both training and choice, for both tasty and healthy foods, for both repeated and novel foods. Left-hemisphere language areas were also active (although not predicted), implicating linguistic processing of food cues, especially during the training phase for the mindful attention group. As predicted, tasty foods produced greater neural activity across food processing areas than healthy foods during the training phase. Surprisingly the choice phase exhibited the opposite pattern, with healthy foods producing larger activations. Most importantly, mindful attention, relative to normal viewing, produced more neural activity while processing foods during the training phase, but much less neural activity during the subsequent choice phase. Increased up-front processing for mindful attention during training later led to a large processing off-load during food choice. Moreover, this effect of mindful attention was much larger for tasty foods than for healthy foods, perhaps because tasty foods offer more conceptual content for mindful attention to process. Finally, mindful attention operated both as a general cognitive set (generalizing to novel foods) and also via food-specific memories (repetition effect), suggesting two mechanisms that underlie mindful attention effects. These results shed new light on the mechanisms that underlie early mindfulness practice, while raising many issues for future research.
Source: Emory University Libraries, https://etd.library.emory.edu/concern/etds/bn9997608?locale=en