Repetitive Olfactory Exposure to the Biologically Significant Steroid Androstadienone Causes a Hedonic Shift and Gender Dimorphic Changes in Olfactory-Evoked Potentials

Abstract

The function of a sensory system is to transduce and relay sensory information in a constant and reproducible manner. However, in the olfactory processing of certain steroids this precept of sensory constancy does not appear to apply. Using threshold testing, psychometrics, and electrophysiological techniques, we investigated the effects of a repetitive exposure protocol on the response to androstadienone. Androstadienone is a steroid found in human secretions that has been widely proposed as a candidate for a human pheromone. The detection threshold, hedonic perception, and evoked potential response all changed following repetitive exposure to androstadienone and not to a control odorant, benzaldehyde. Furthermore, the exposure-dependent changes in evoked potentials exhibited a gender dimorphism in which there were changes in the later components of the evoked potentials specific to women. These components have been associated with cognitive and perceptual operations. This 'learning' to smell a compound found in sweat may be related to biological signaling.

Environmental Effects Exceed Genetic Effects on Perceived Intensity and Pleasantness of Several Odors: A Three-Population Twin Study

“…Whatever the mechanisms are, it is likely that olfactory plasticity is not restricted to the perception of androstenone. Exposure-induced sensitization has also been demonstrated for benzaldehyde and citralva (Dalton et al 2002), and androstadienone (Boulkroune et al 2007). …”

Evidence that androstadienone, a putative human chemosignal, modulates women’s attributions of men’s attractiveness

“…Women exposed to androstadienone in the laboratory environment tend to experience positive affective modulation, including fewer feelings of boredom and frustration associated with the laboratory testing session, maintenance of positive moods despite exposure to negative stimuli, and increased feelings of focus (Bensafi et al, 2004a;Grosser et al, 2000;Jacob and McClintock, 2000;Jacob et al, 2001a;Lundström et al, 2003a;Lundström and Olsson, 2005;Villemure and Bushnell, 2007). At the physiological level, androstadienone inhalation precedes measurable changes in endocrine state (Wyart et al, 2007) and autonomic activations (Bensafi et al, 2004a;Grosser et al, 2000;Jacob et al, 2001a;Monti-Bloch and Grosser, 1991) that may be specific to women (Boulkroune et al, 2007). Neurologically, female response to androstadienone extends beyond the olfactory system, activating areas of the brain associated with attention, social cognition, emotional processing, and sexual behavior Jacob et al, 2001b;Savic et al, 2001;Savic et al, 2005).…”

Human Olfactory Perception

“…189 The exposure-induced enhancement of responses to androstadienone (28) has been replicated with both psychophysical methods and odour-evoked potentials to show a gender-specific effect of repeated exposure on late components of the odour-evoked potential response. 190 The genetic and environmental factors contributing to the perceived pleasantness of androstenone (27) have recently been clarified in a study involving 917 twin subjects. 191 The data suggest that both intensity and pleasantness of androstenone are moderately influenced by genetic factors (21-28% heritability) and that the traits are modified by an overlapping set of genes.…”