DISTRACTOR VERSUS FOCUSED CUE – CRITICAL IMPORTANCE WHEN ASSESSING THE EFFECT OF BUPROPION ON THE LATE POSITIVE POTENTIAL

Author

Matthew Gunn, Southern Illinois University CarbondaleFollow

Date of Award

6-1-2021

Degree Name

Master of Arts

Department

Psychology

First Advisor

Gilbert, David

Second Advisor

Habib, Reza

Abstract

Bupropion (BUP) is an efficacious pharmacologic aid for individuals attempting to quit tobacco smoking (Wilkes., 2008), yet little is known about the effects of BUP on neural responses to either smoking cues (SC) or affective cues (AC), stimuli that are known to promote smoking and relapse to smoking for those attempting to quit. In fact, only one published study has assessed BUP’s effects on neuroelectrical event-related responses (ERPs) to SC or AC (Versace, Stevens, Robinson, Cui, Deweese, Engelmann, et al., 2019), and this study did not detect any neural effects of BUP, relative to placebo. It is important to note that Versace et al. (2019) study’s smokers were instructed to focus their attention solely on large color pictures of SC or AC that were presented for several seconds, something that may differ from conditions in which BUP might alter brain responses to SC. In contrast, several studies have assessed the effects of BUP on functional magnetic resonance imaging (fMRI)-assessed brain activity, with several finding that BUP enhanced activation of the nucleus accumbens during the anticipation of a brief (140-460ms) monetary target (Ikeda et al., 2019) and in the right middle and inferior frontal gyri, right caudate, and bilateral precuneus during AC presentation (Robertson et al 2007), while several others found reductions in activation in the left ventral striatum, right medial orbitofrontal cortex, and bilateral anterior cingulate cortex during presentation of SC (Culbertson et al., 2011), and reductions in the activation of right orbitofrontal cortex, left dorsomedial prefrontal cortex, right ventromedial prefrontal cortex, right anterior cingulate cortex, right inferior frontal cortex, right amygdala/parahippocampal area, right caudate, right fusiform gyrus, and left posterior cingulate during AC presentation (Robertson et al 2007). The inconsistencies across these studies may reflect underlying effects of the task used to assess the participant (i.e., context of the task). Thus, it is reasonable to hypothesize that the effects of BUP SC and AC on brain reactivity depend on assessment context and task demands. Few studies have assessed the effects of BUP on brain responses to SC and AC when they are briefly presented distractors, as opposed to the primary focus of sustained attention. This study demonstrates the importance of task context for SC and AC presentation to detect the effects of BUP. By neglecting context-specific effect, the field is missing measurable targets for drug efficacy. This is the 1st study to find an BUP induced LPP reduction. The data is obtained from smokers who were randomly assigned to a BUP (n=24) group or a placebo group (n=66) and assessed prior to and after 14 days on BUP or PLA capsules while still smoking at their typical rate.