Melissa A. Cyders

Ventral frontal satiation-mediated responses to food aromas in obese and normal-weight women

BACKGROUND Sensory properties of foods promote and guide consumption in hunger states, whereas satiation should dampen the sensory activation of ingestive behaviors. Such activation may be disordered in obese individuals. OBJECTIVE Using functional magnetic resonance imaging (fMRI), we studied regional brain responses to food odor stimulation in the sated state in obese and normal-weight individuals targeting ventral frontal regions known to be involved in coding for stimulus reward value. DESIGN Forty-eight women (25 normal weight; 23 obese) participated in a 2-day (fed compared with fasting) fMRI study while smelling odors of 2 foods and an inedible, nonfood object. Analyses were conducted to permit an examination of both general and sensory-specific satiation (satiation effects specific to a given food). RESULTS Normal-weight subjects showed significant blood oxygen level-dependent responses in the ventromedial prefrontal cortex (vmPFC) to food aromas compared with responses induced by the odor of an inedible object. Normal-weight subjects also showed general (but not sensory-specific) satiation effects in both the vmPFC and orbitofrontal cortex. Obese subjects showed no differential response to the aromas of food and the inedible object when fasting. Within- and between-group differences in satiation were driven largely by changes in the response to the odor of the inedible stimulus. Responses to food aromas in the obese correlated with trait negative urgency, the tendency toward negative affect-provoked impulsivity. CONCLUSIONS Ventral frontal signaling of reward value may be disordered in obesity, with negative urgency heightening responses to food aromas. The observed nature of responses to food and nonfood stimuli suggests that future research should independently quantify each to fully understand brain reward signaling in obesity.

The interactive effects of affect lability, negative urgency, and sensation seeking on young adult problematic drinking.

Prior studies have suggested that affect lability might reduce the risk for problematic drinking among sensation seekers by compensating for their deficiencies in emotional reactivity and among individuals high on negative urgency by disrupting stable negative emotions. Due to the high prevalence of college drinking, this study examined whether affect lability interacted with sensation seeking and negative urgency to influence college student problematic drinking. 414 college drinkers (mean age: 20, 77% female, and 74% Caucasian) from a US Midwestern University completed self-administered questionnaires online. Consistent with our hypotheses, our results indicated that the effects of sensation seeking and negative urgency on problematic drinking weakened at higher levels of affect lability. These findings emphasize the importance of considering specific emotional contexts in understanding how negative urgency and sensation seeking create risk for problematic drinking among college students. These findings might also help us better understand how to reduce problematic drinking among sensation seekers and individuals high on negative urgency.

Problematic alcohol use and sexting as risk factors for sexual assault among college women

ABSTRACT Sexual assault is a major public health concern and college women are four times more likely to experience sexual assault than any other group. We investigated whether sexting is a mechanism by which alcohol use increases risk for college women to be targeted for sexual assault. We hypothesized that sexting would mediate the relationship between problem drinking and sexual assault, such that drinking (T1 = beginning fall semester) would contribute to increased sexting (T2 = end fall semester), and in turn increase the risk of being targeted for sexual assault (T3 = end spring semester). Results: Among 332 undergraduate women (M(SD)age = 19.15(1.69), 76.9% Caucasian), sexting (T2) predicted sexual assault (T3; b = 3.98, p = .05), controlling for baseline sexual assault (b = 0.82, p < .01). Further, sexting (T2) mediated the relationship between problem drinking (T1) and sexual assault (T3) (b = 0.04, CI[.004,.12]). Conclusion: Findings suggest that sexting is one mechanism through which drinking increases the risk of college women being targeted for sexual assault.