Olfactory information processing during the course of the menstrual cycle

Area of Science:

• Neuroscience
• Endocrinology
• Sensory Science

Background:

• The menstrual cycle involves hormonal fluctuations that may influence cognitive functions.
• Olfactory perception, a key sensory modality, has been less explored in relation to the menstrual cycle phases.

Purpose of the Study:

• To investigate the impact of the menstrual cycle phase on olfactory information processing.
• To correlate olfactory sensitivity and perception with hormonal levels, specifically cortisol.

Main Methods:

• Chemosensory (olfactory) event-related potentials (CSERP) were recorded in five female subjects across follicular, ovulatory, and luteal phases.
• Olfactory thresholds and hedonic tone of citral were assessed.
• Salivary cortisol levels were measured and correlated with olfactory data.

Main Results:

• Olfactory perception varied across menstrual cycle phases, with enhanced complexity and novelty (increased P3-1 amplitude) during the ovulatory period.
• Odor processing speed increased (reduced NI, P2, P3-2 latency) around ovulation and slowed during the follicular phase.
• Odors were described more differentially during the ovulatory phase, and olfactory sensitivity positively correlated with cortisol levels.

Conclusions:

• Olfactory processing is significantly modulated by the phase of the menstrual cycle.
• Hormonal changes, indicated by cortisol levels, are linked to olfactory sensitivity.
• These findings highlight the cyclical nature of sensory perception in women.