Response Inhibition to High Calorie Food Cues Among Adolescents Following Active and Sedentary Video Game Play
Condition: Obesity
Study type: Interventional

Summary: 
      Response inhibition is a cognitive process that helps individuals suppress or avoid unwanted
      actions and inappropriate behavior. In regards to food, response inhibition allows a person
      to resist eating, ignore poor food choices and poor behavior related to food choices.
      Previous research suggests that physical activity may play a role in the regulation of
      response inhibition to food in adults.

      The purpose of this study is to compare the effects of an acute bout of active video gaming
      versus passive video gaming on response inhibition to high calorie and low calorie food
      images among adolescents.

      The proposed study is a randomized cross-over study with counterbalanced design. Participants
      will come to the lab two times. Each subject will serve as their own control. There will be
      two conditions and all participants will complete both conditions. One condition will be
      completed each time the participants come to the lab. The two conditions will include (a) 60
      minutes of sedentary video game play and (b) 60 minutes of active video game play at
      moderate-intense levels. After each video game condition the participants will view pictures
      of high-calorie and low-calorie foods while being connected to an EEG machine. The EEG will
      measure the N2 and P3 event-related potentials, which will be used to index and analyze
      response inhibition. As participants view the pictures of high-calorie and low-calorie foods,
      they will be given a button pressing task where the press a button when they see pictures of
      the high-calorie or low-calorie foods. Immediately after each video game session participants
      will complete two cognitive measurement tasks. These tasks are (a) Stroop color-word task and
      (b) auditory verbal learning test. The Stroop color-word test requires the participants to
      read words typed in different colors on a sheet of paper and to say the name of the color of
      ink the words are printed in (ie to say "blue" when the word "red" is printed in blue ink).
      The auditory verbal learning test will require the researchers to read a list of 15 words and
      have participants repeat as many of the words back to the researcher as possible. This will
      be repeated 6 times. After the 5th time, there will be a 30 minute waiting period before the
      6th trial where participants will be allowed to eat ad libitum pre-weighed foods while they
      wait to complete the last trial of the verbal learning test.
    

Detailed description: 
      Design. A randomized crossover design with counterbalanced treatment conditions will be used
      to compare the amount of neural inhibition to high and low calorie food cues among
      adolescents between two conditions. These two conditions will include a 60-minute session of
      active video game play and a 60-minute session of sedentary video game play. The order of
      treatment conditions will be randomly assigned using a validated simple randomization
      technique. During each laboratory session EEG data will be recorded and then later analyzed
      to assess the individual event related potential (ERP) components following each of the two
      conditions. Participants will complete a go/no-go response inhibition viewing task with
      pictures of high calorie and low calorie foods displayed on a computer monitor. The response
      inhibition task will be administered immediately following the cessation of each video game
      condition.

      Video gaming conditions. The sedentary video game play condition will require participants to
      play in a seated position for 60 minutes. The active video game play condition will require
      participants to complete 60 minutes of active video gaming at moderate intense levels
      (3.0-5.9 metabolic equivalents (METs)) using a popular dance simulation game called 'Dance
      Dance Revolution' (DDR by Konami Digital Entertainment, Redwood City, CA). DDR elicits
      moderate intense (3.0-5.9 METs) levels of physical activity. Sixty minutes of active video
      game play has been shown to produce moderate intense levels of physical activity. Current
      guidelines recommend adolescents engage daily in 60 minutes or more of moderate-to
      vigorous-intense physical activity.

      Participants. Sixty two healthy adolescents (31 female and 31 male) will be recruited through
      advertisements and fliers in the local community. Participants will be adolescents between
      the ages of 12 and 15 years old.

      Procedures Screening. Candidates for the study and their guardians will be sent an email
      containing a link to an online survey. The online survey will be a 'yes or no' questionnaire
      to ensure participants meet inclusion criteria. Candidates must answer each question properly
      in order to qualify for the study. As part of the online survey, participants will be asked
      to report any food allergies and complete a food preference questionnaire. The food
      preference questionnaire will be used to prepare the standardized meals for each participant.
      Qualifying candidates will be invited to participate in the study.

      Orientation. Participants for the study will be asked to complete the assent and consent
      forms prior to the first lab session. Participants and their guardians will come to the
      Clinical Neuroscience lab at least one day prior to their first lab session to pick up their
      standardized meals. Each participant will be informed of the main purpose of the study and
      familiarized with the testing procedures. Participants will be instructed to avoid consuming
      caffeine and other stimulants on the testing day as well as avoiding vigorous-intense
      physical activity for the 24-hour period prior to testing. Participants will be given a copy
      of these testing instructions.

      Standardized Meals. Participants will be given a standardized breakfast and lunch for each of
      the testing days. The energy needs for each participant will be estimated using the World
      Health Organization equations for predicting basal metabolic rates. This equation uses height
      (cm), weight (kg) and age (years) to predict basal metabolic rates and has been validated for
      accuracy and reliability. An activity factor of 1.6 for boys and 1.5 for girls will be used
      to estimate total daily energy requirements.

      Meals will be standardized based on macronutrient content (60% carbohydrate, 20% fat, 20%
      protein), age, gender and physical activity level (light, moderate or high activity).
      Participants will be given 25% of their daily caloric requirements for breakfast and 25% for
      lunch. The same foods will be given on both test days and participants will be instructed to
      consume all the food for both meals. Meal adherence will be assessed at the beginning of each
      session. Any non-compliance (not eating all food and/or eating other foods) will require
      participants to redo that particular lab session on a different day when they have followed
      food protocols.

      Meals are designed to represent a reasonable amount of food to provide participants with
      adequate food intake. Participants will be given both of their standardized meals prior to
      the first testing day along with instructions to consume only standardized meals on testing
      days, avoid caffeine consumption and vigorous-intense physical activity 24-hours prior to
      testing. Participants will be instructed to consume their breakfast and lunch at the same
      time of day and at least two hours before arriving for each testing day.

      Video Gaming Sessions. Each participant will complete two separate lab sessions. Demographic
      and anthropometric information will be collected at the beginning of the first lab session.
      Participants will be asked to rate their hunger at the beginning of each lab session. Hoffman
      et al compared P3 and N2 components between fed (1 hour postprandial) and fasted (17 hour
      fast) states and found no significant differences in P3 or N2 component amplitude or latency
      among young adults. Testing procedures and protocols will be reviewed with each participant
      prior to initiation of each video gaming session. Participants will then be taken to the
      video game lab to complete a 60-minute video gaming session. At the beginning of the video
      game session, participants will be fitted with the K4b2 (Cosmed, Rome, Italy) metabolic
      system, Polar heart rate monitor (Polar, Helsinki, Finland) and GT3X activity monitor
      (Pensicola, FL) to measure energy expenditure. Metabolic information for each participant
      will be measured and recorded for analysis.

      Immediately following each video gaming condition, participants will be brought into an
      adjacent room containing the EEG equipment where they will complete the response inhibition
      tasks. After the second video gaming session participants will be asked to classify each food
      image as either high- or low-calorie to ensure the participants were correctly identifying
      food images during the response inhibition tasks. Upon completion of the response inhibition
      task, participants will be led to a separate room to complete the Stroop-Color Word test.

      Response Inhibition Task. Immediately following both the active and passive video game
      conditions, participants will complete two go/no-go active viewing tasks. The go/no-go task
      will include pictures of high-calorie and low-calorie foods. Pictures for the viewing tasks
      will be selected based on findings from Blechert et al who recently reported normative
      ratings of 568 high- and low-calorie food images. The first viewing task will use a total of
      150 pictures, 100 of these will include high-calorie pictures and 50 low-calorie pictures;
      the low-calorie images will be the target stimuli. The second viewing task will include 100
      low-calorie pictures and 50 high-calorie pictures; the high-calorie images will be the target
      stimuli. Each of the viewing tasks will be shown in a different random order for each
      participant. Images will be shown for 500 milliseconds (ms) with an inter-trial interval of
      1300 ms between images. Following the second response inhibition task, participants will be
      asked to subjectively rate the pictures according to pleasantness and arousal by using a
      picture rating scale from 1-9 (with 1 being the lowest and 9 the highest). To determine
      participant understanding of low vs high calorie foods, participants will be asked to
      complete a short task in which they will categorize each food picture as either low calorie
      or high calorie.

      Go/No-Go Paradigm. For the high-calorie portion of the go/no-go task, participants will be
      instructed to press a button with their right index finger when they see images of
      low-calorie foods, which will be the target stimuli. The low calorie foods will be the target
      stimulus and the participants must commit their response by pressing the appropriate button.
      This portion of the task will be called "go". The "no-go" portion of the task will require
      the participants to withhold pressing the button when images of high-calorie foods are
      presented. The second go/no-go task will use the opposite instructions of the first task.
      Participants will be instructed to "go" or press a button when pictures of high-calorie foods
      are presented and to withhold, or "no-go", when the images of the low-calorie foods are
      presented, the high-calorie foods will be the target stimuli. Images for both tasks will be
      presented random order using 150 pictures displayed for 500 ms with an inter-trial interval
      of 1300 ms. Participants will be instructed to remain as still as possible and to minimize
      their eye blinks to reduce the amount of artifacts (disruptions or noise) while EEG data is
      recorded.

      To further examine the effects of moderate intense physical activity on response inhibition,
      participants will be given several food choices while completing an auditory verbal learning
      test, the Rey auditory verbal learning test (AVLT). The Rey AVLT will be administered
      according to the protocol validated by Vakil et al which is described previously. After the
      6th trial of the Rey AVLT, participants will be given 30 minutes before the final portions of
      the learning test to consume high and low energy dense foods ad-libitum. During the 30 minute
      delay period, foods which have been pre-measured and weighed to the nearest 0.1 gram
      beforehand will be given to each participant as they wait for the delay period of the Rey
      AVLT. High calorie foods will include high energy dense food items. Low calorie foods will
      include low energy dense food items, such as fruit slices and vegetables. The test will
      include 8 trials and allow appropriate time for participants to consume pre-measured foods.
      Completion of the Rey AVTL test will conclude the entire session.

      After completion of the first video gaming session, participants will return after 7 days to
      complete the second video gaming session. Participants will be contacted 24 hours before
      their second video gaming session to remind participants of the upcoming testing session.
      Participants who complete both video gaming sessions and the accompanying tests will receive
      $40 dollars for completing the study.

      Power Analysis. The number of participants was estimated based on a meaningful shift in N2
      amplitudes. Since exercise has been shown to have a moderate effect on neural responses to
      food cues among adults, an estimated mean difference of 0.50 microvolts was used. A mean
      standard error of 0.63 microvolts was also used in this analysis based on previous research
      which helped establish a test-retest reliability of N2 amplitudes using EEG techniques.197
      Thus, based on a mean N2 difference of 0.5 microvolts, a mean standard error of 0.63
      microvolts and an alpha of 0.05, a sample of 55 participants is needed to have 90% power. In
      addition, based on previous experience measuring ERPs we expect to lose 10% of the EEG
      measurements due to poor or incomplete data. To account for this loss we will recruit an
      extra 7 participants, for a total of 62 total participants.

      Statistical Analysis. Analysis will be completed using SAS statistical software (version 9.4;
      SAS Institute, Inc. Cary NC). Participant data will be reported as means and standard
      deviations. To evaluate the main and interaction effects within each subject, a 2-condition
      (active and passive) x 2-neural inhibition (Go and No/Go) x 2-calorie (high calorie and low
      calorie) repeated measures ANOVA will be used. An alpha level of 0.05 will be used for this
      analysis. Post hoc t-tests will be performed if significant effects are observed to identify
      significant differences. Bonferroni adjustments will be conducted for multiple comparisons.
    

Intervention name(s): Active Video Game Play; Passive Video Game Play
Intervention type(s): Behavioral; Behavioral
Intervention description(s): 60 minutes of active video game play at a moderate intensity; 60 minutes of passive video game play
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: None (Open Label)
Primary purpose: Other
Keywords: Exercise; Video Games; Physical Activity; Children; Appetite