The Impact of Male Body Odor Perception on Motor Response Inhibition in Women: Investigating Facilitation Effects and the Role of Trait Impulsivity

This thesis explores the influence of strangers’ male body odor (BO) collected in an emotionally neutral context on motor response inhibition in a healthy group of women. Inhibitory control is one of the core executive functions that enable individuals to suppress prepotent actions inappropriate or impulsive responses, and behaviors. Inhibitory control encompasses interference control and response inhibition. While interference control refers to the capability to filter out distractions or irrelevant information, allowing an individual to maintain focus on a selected stimulus or task, response inhibition is about the ability to withhold or suppress an action that may be prepotent or habitual but is not appropriate for the situation. As a modulatory factor of response inhibition, trait impulsivity refers to the tendency to react and act on immediate urges or desires without considering the potential consequences for both oneself and others. The literature suggests that response inhibition deficiencies may be the underlying cause of trait impulsiveness. Prior research indicates that body odors can serve as potent, unconscious communication signals and may influence behavior and perception. It has been reported that the sender's gender is an important factor supported by exposure to male body odor, which influences moral choices and attractiveness judgments toward male faces among female participants. This study uses the Go/NoGo task to be randomly assigned version A or version B (i.e., in version A, the Go stimulus is the yellow-colored circle, whilst in version B the Go stimulus is the yellow-colored square), a generally used measure of response inhibition, to evaluate the potential facilitation effect of strangers’ male BO, given the evidence that opposite-sex receivers typically experience strangers’ male BO as an aversive stimulus. During the task, participants will be randomly assigned and exposed to three conditions; a common odor (i.e., cedarwood oil), clean air, and male BO masked with cedarwood oil. We hypothesize that exposure to male BO may induce a higher state of alertness in female perceivers, resulting in quicker and more accurate responses compared with female BO and masker condition. Additionally, the study aims to elucidate the role of trait impulsivity, often associated with deficits in response inhibition, by examining its moderating effect on the relationship between olfactory cues and task performance. By controlling for impulsivity as a confounding variable, the research seeks more nuanced insights into the neuropsychological mechanisms by which olfactory stimuli can modulate executive function. Lastly, during the entire Go/No-go task, electrocardiogram (ECG) data will be recorded to measure heart rate variability (HRV) to run an explanatory analysis.