Thank you Dr. XXXX; I am going to be talking briefly about my EMA study of attention training in cigarette smokers.

Transcription

1 Thank you Dr. XXXX; I am going to be talking briefly about my EMA study of attention training in cigarette smokers. 1

2 This work is a result of the combined efforts of myself and my research advisor, Dr. Andrew Waters. 2

3 As you ve already heard today both theory and data suggest a link between attentional bias and addiction. In particular, the theoretical rationale for the current study is Franken s 2003 model. Seen here. 3

4 I won t go into all the details, but this section here is important. Franken hypothesized that attentional bias causes craving and craving causes relapse. Interventions that target attentional bias may be able to reduce craving and relapse. 4

5 The question then becomes, How can we reduce attentional bias? Researchers have been attempting to do exactly this using a modified version of an experimental task originally used to assess attentional bias, the visual probe task. 5

6 The assessment version of the visual probe task that we used in this study looks like this: Imagine this rectangle in the middle of the screen is the screen of the participants desktop computer or PDA. The boxes at the bottom are meant to indicate where the participants will place their fingers during this task. One finger on the left key and one finger on the right key. Instructions are given to the participant to press the left key if they see a probe on the left side of the screen and to press the right key if they see a probe on the right side of the screen. 6

7 The first screen of the task is a fixation cross in the center of the screen towards which participants are instructed to direct their gaze. This fixation cross stays on screen for 500 ms or half a second. 7

8 The fixation cross is replaced by a neutral and negative stimulus on the right and left hand side for an additional 500 ms. 8

9 One of the stimuli is then replaced by a probe which stays on screen until the participant responds to the location of the probe with a key press. 9

10 In this case a left key response is indicated. 10

11 In the visual probe assessment task the probe will replace the neutral and the smoking stimuli with equal frequency as can be seen in this real time video. 11

12 Reaction time data from the assessment version of the visual probe task can be used to compute an attentional bias index score by subtracting mean reaction times in responding to those probes replacing smoking stimuli from mean reaction times in responding to probes replacing neutral stimuli. Thus, higher values reflect an attentional bias toward smoking cues and lower values reflect an attentional bias away from smoking cues. 12

13 An attentional bias toward smoking stimuli means that participants are automatically attending toward smoking stimuli and away from neutral stimuli as reflected in faster reaction times in responding to probes replacing the smoking stimuli. 13

14 The modified visual probe task used for attentional retraining proceeds in the same fashion as the assessment visual probe task except that the probe replaces neutral stimuli on 100% of trials as can be seen in this video. 14

15 The idea is that when participants are exposed to a sufficient number of trials they will learn to automatically attend away from the smoking stimuli and to attend towards the neutral stimuli. 15

16 Other groups have successfully used the modified visual probe task to alter attentional biases and reduce anxiety reactivity in nonclinical participants and to reduce GAD symptoms. In the addictions Field and Eastwood used the task to alter drinking behavior and Attwood et al used the modified visual probe task to alter cue reactivity (craving) in cigarette smokers. 16

17 One way that attentional retraining has been conceptualized is that participants implicitly learn a generic production rule in the form of an If-Then statement: If there are both drug cues and neutral stimuli in the environment, Then attend toward the neutral stimuli to maximize efficient performance. The assumption then, is that this retraining will generalize to stimuli outside of the laboratory in the participants natural environment. One can imagine a smoker trying to quit smoking and heading out one evening for a night on the town with friends. As the smoker approaches the bar his or her attention is drawn automatically towards every smoking related stimuli in sight thus increasing the risk of relapse. However, if before going out the smoker underwent attentional retraining, upon approaching the bar his or her attention is drawn away from smoking stimuli thus decreasing craving and reducing the likelihood of relapse.

18 As already mentioned there are many advantages to using EMA.

19 Specifically, for this study EMA methodology can allow us to deliver more doses of attentional retraining. Researchers have found that it is more difficult to train addicts to attend away from alcohol related cues than to train them to attend towards these cues; so more doses may be necessary. Also, researchers have demonstrated that distributed practice is more effective than massed practice. Finally, other forms of cognitive training, such as that used in ADHD, utilize extensive training regimens in excess of 5 weeks. Furthermore, using EMA methodology we are able to administer attentional retraining in a real-world setting while participants are going about their lives; potentially improving the generalizability of the training. Perhaps most importantly, it may allow us to administer attentional retraining when participants are most in need of it. Like when that smoker trying to remain abstinent is in a cue laden environment. 19

20 We conducted a pilot study to test the feasibility of our attentional retraining and EMA procedures. Partcipants were randomly assigned to an AR group or Control group. 20

21 Over 7 days of EMA the pilot participants completed nearly 77% of presented RAs. This compliance rate gave us confidence in the AR procedures we had developed. 21

22 We then began main study using the same procedures utilized for the pilot study. 22

23 We delineated 3 specific aims in conducting this study. Our primary outcome variable was attentional bias as that is the most proximal variable to our retraining protocol, Second was self-reported craving, and finally, our tertiary and more exploratory outcome variable was self-reported smoking behavior. 23

24 Participants were smokers not wishing to quit who were randomly assigned to an Attentional Retraining group or no-training control group. All participants completed attentional bias assessments using the visual probe assessment task on the PDA throughout the week of training and in the laboratory. 24

25 Participants had to be between the years of 18 to 65 and smoke at least 10 cigarettes per day. Expired carbon monoxide was required to be above 10 ppm to reflect at least a moderate level of recent smoking. 25

26 Participants were first screened by telephone to ensure they met the inclusion criteria and were enrolled if eligible to complete the first lab session where they completed questionnaire measures and AB was assessed on a PDA in the lab using the visual probe assessment task. After this first session participants completed 7 days of EMA wherein they completed 4 random assessments (or RAs) per day; which consisted of 3 training or control sessions and 1 AB assessment. After the 7 days of EMA were completed participants returned to the lab, completed many of the questionnaire measures again, an assessment of AB on the PDA and a novel AB assessment utilizing mobile eye tracking. 26

27 For the EMA portion of the study there were 4 RAs, 3 of which were attentional retraining tasks using the modified visual probe as previously described or 3 control tasks. All of these assessments (both the AR and the control) included 160 trials each. The 1 assessment task administered daily was the typical visual probe task and only included 80 trials to assess day to day changes in AB. 27

28 As a reminder the attentional retraining task includes a probe that will always replace the neutral stimuli. 28

29 In the non-training control condition the task is the same as the AR task except that the probe replaces the neutral and the smoking stimuli with equal frequency. 29

30 This is an example of a day in the life of both a control participant and an attentional retraining participant during this study. Notice that the Random Assessments are occurring throughout the day at random times, but most importantly notice that the control participant is completing 3 control assessments per day and the attentional retraining participant is receiving 3 attentional retraining tasks per day. Both participants are completing one attentional bias assessment per day. The RAs are programmed to occur at random times throughout the day. 30

31 For the field measures we assessed attentional bias toward smoking stimuli using the visual probe task on the PDA. We also assess self-reported craving assessed 4 times a day on the PDA. Two craving items were used, a typical uncued craving item and a cued or cue provoked craving item which we will discuss shortly. Also, smoking behavior was assessed through the use of a paper and pencil smoking diary completed at the end of each day in which the participants would log the number of cigarettes smoked that day. 31

32 For the craving measures used in the field there were two. One of these measures was a typical uncued craving measure requiring the participant to respond on a 1 7 scale with higher scores reflecting more craving. 32

33 This is an example of the typical craving measure.

34 However, the other craving measure administered on the PDA is a cued or cueprovoked craving item which is the same as the previous typical craving question except that it is immediately preceded by a smoking cue in this case an image. 34

35 This is what one of the craving cues used in this study looks like. Notice that the participant has the option of looking at the individuals smoking in this picture or to look at any of a number of nonsmoking cues.

36 Immediately following this cue, the craving measure is administered. The rationale for these two craving items is that if attentional retraining is working we would expect that when presented with a stimulus that contains both smoking stimuli and neutral stimuli the participant undergoing retraining would attend less to smoking stimuli and thus experience less elevation of craving.

37 This table presents the feasibility data from the main study. These data are very similar to the pilot study and most importantly, participants completed nearly 79% of presented RAs. 37

38 To analyze the data that I am about to present we used Linear Mixed Models analyses which allow for the fact that subjects will differ in the number of observations available for analysis and also take into account that data will cluster within subjects. We will look at the main effects of group and day and the group by day interaction effects as well. Baseline measures will be used as a covariate. 38

39 This first graph is looking at our primary outcome variable of attentional bias assessed on the PDAs during the EMA portion of the study. The reported values here are the mean attentional bias index scores by day for the participants in each group at baseline and over the 7 days of EMA. Of note is that there is a significant attentional bias toward smoking cues at baseline for both groups as their AB index scores are significantly greater than zero but there is no significant difference between the two groups at baseline. There was a significant group by day interaction. When analyzed further we found that the linear effect of day was only significant for the retraining group and not the control group. Over all days the control group exhibited a significant attentional bias toward smoking stimuli as their AB index score was significantly greater than zero. Finally, after day 5 the two groups separated as indicated in a significant between group difference in AB index scores. 39

40 In this graph we are looking at the mean cue-provoked craving reported by participants in each group at baseline and by day. At baseline there was no significant difference between the two groups. Over all days of EMA there is a significant main effect of group with the retraining group reporting less cue provoked craving than the control group. This effect persists even when controlling for the non-cue provoked typical craving measure. However, there was no significant group by day interaction for cue provoked craving. 40

41 These participant level data comparing the cue provoked craving over all days of EMA to the cue provoked craving at baseline corroborate the main effect of group we just saw in the data presented by day. 41

42 In all we have seen that there is a reliable change in attentional bias as a result of AR administered in an EMA setting. Cigarette smokers exhibited an attentional bias towards smoking cues at baseline and the attentional bias in the retraining group decreased over time. There were more mixed effects of AR on craving. We found that the cue-provoked craving but not typical craving was reduced in the retraining group versus controls. However, this effect did not become stronger over time. Finally we found no effects of AR on our measures of smoking behavior. 42

43 Ultimately we found that it is feasible to administer cognitive retraining on a PDA in an EMA setting. Given what we ve found in the current study and in previous abbreviated laboratory studies it may be the case that longer periods of AR may be warranted to achieve a significant attentional bias away from smoking cues. Further research is clearly needed to examine the effect of protracted periods of AR on craving and smoking behavior in individuals attempting to quit smoking. 43

44 Finally, I d like to acknowledge the people that made this project possible including Dr. Waters and the staff and graduate students in the Waters lab. 44

45 I will take any questions anyone may have now and, of course, any follow up questions can be addressed to me here. 45