Biology subjects

Kypriotakis, G.

Publications and source records attributed to Kypriotakis, G..

3 recordsLinked to original sources

bioRxiv2022

Individual differences in late positive potential amplitude and theta power predict cue-induced eating

Both the brains affective and cognitive systems are known to regulate cue-induced behaviors. Although it is established that individual differences in affective processing of food-related cues predict cue-induced eating, we have yet to investigate how both affective and cognitive mechanisms act in tandem to regulate cue-induced eating. We recorded electroencephalogram (EEG) from 59 adults while they viewed emotional & food-related images that preceded the delivery of food rewards (candies) or nonfood objects (beads). We measured the amplitude of the late positive potential (LPP) in response to images and power in the theta (4-8 Hz) frequency band after the candy or bead was dispensed to the participant. We found that individuals with larger LPP responses to food cues than to pleasant images (C>P group) ate significantly more during the experiment than did those with the opposite response pattern (P>C group, p < 0.001). Furthermore, we found that individuals with higher theta power after dispensation of the candy than of the bead ({theta}CA>{theta}BE) ate significantly more than did those with the opposite response pattern ({theta}BE>{theta}CA, p < 0.001). Finally, we found that the crossed P>C and {theta}BE>{theta}CA group ate less (p < 0.001) than did the other three groups formed by crossing the LPP and theta group assignments, who exhibited similar eating behavior on average (p = 0.662). These findings demonstrate that motivational salience and cognitive control converge to independently confer vulnerability or resilience to cue-induced behaviors, underscoring the need for individualized treatments to mitigate maladaptive behaviors. HIGHLIGHTSO_LILPP responses to motivationally salient stimuli predict cue-induced eating. C_LIO_LITheta power in the presence of food rewards predicts cue-induced eating. C_LIO_LIThe LPP & theta may inform the development of personalized weight-loss interventions. C_LI

neuroscience↗

bioRxiv2022

Neuroaffective profiles are associated with e-cigarette use

IntroductionIdentifying the psychophysiological underpinnings of cue-induced compulsive nicotine use will provide new targets for relapse prevention treatments. We tested whether neuroaffective responses to motivationally relevant stimuli are associated with cue-induced nicotine self-administration. We hypothesized that smokers with stronger neuroaffective responses to nicotine-related cues than to pleasant stimuli (C>P) are more vulnerable to cue-induced nicotine self-administration than smokers with stronger neuroaffective responses to pleasant stimuli than to nicotine-related cues (P>C). MethodsSmokers (N=36) looked at pleasant, unpleasant, neutral, and nicotine-related images signaling that an electronic nicotine delivery system (ENDS) was immediately available for use. We measured event-related potentials (a direct measure of cortical activity) and computed the amplitude of the late positive potential, a robust index of motivational salience. We used k-means cluster analysis to identify individuals characterized by the C>P or the P>C neuroaffective profile. We compared the ENDS use frequency in the two groups using quantile regression for counts. ResultsCluster analysis assigned 18 smokers to the C>P profile and 18 smokers to the P>C profile. Smokers with the C>P neuroaffective profile used the ENDS significantly more often than smokers with the P>C profile. Significant differences in the number of puffs persisted across different quantiles. ConclusionsThese results support the hypothesis that individual differences in the tendency to attribute motivational salience to drug-related cues underlie vulnerability to cue-induced drug self-administration. ImplicationsBy linking brain reactivity profiles to nicotine self-administration, we identified a neuroaffective biomarker that could guide the development of personalized treatments to prevent smoking relapse.

neuroscience↗

bioRxiv2019

Estimating statistical power for event-related potential studies using the late positive potential

The late positive potential (LPP) is a common measurement used to study emotional processes of subjects in event-related potential (ERP) paradigms. Despite its extensive use in affective neuroscience, there is presently no gold standard for how to appropriately power ERP studies using the LPP in within-subject and between-subjects experimental designs. The present study investigates how the number of trials, number of subjects, and magnitude of the effect size affect statistical power in analyses of the LPP. Using Monte Carlo simulations of ERP experiments with varying numbers of trials, subjects, and effect sizes, we measured the probability of obtaining a statistically significant effect in 1,489 different experiments repeated 1,000 times each. Predictably, our results showed that statistical power increases with increasing numbers of trials and subjects and at larger effect sizes. In addition, we found that higher levels of statistical power can be achieved with lower numbers of subjects and trials and at lower effect sizes in within-subject than in between-subjects designs. Furthermore, we found that, as subjects are added to an experiment, the slope of the relationship between effect size and statistical power increases and shifts to the left until the power asymptotes to nearly 100% at higher effect sizes. This suggests that adding more subjects greatly increases statistical power at lower effect sizes (<1 {micro}V) compared with more robust (>1.5 {micro}V) effect sizes.

neuroscience↗