Abstract
In humans, stress can be contagiously transmitted via chemosignals on a subconscious level. This study investigates how pregnancy affects neural responses to anxiety chemosignals. Using cotton pads, 28 men donated axillary sweat immediately before an academic examination (anxiety sweat) and during ergometer training (control). Via a constant-flow olfactometer, samples were presented (oddball paradigm) to 12 non-pregnant (NP) women, 14 women in their first (T1), and 18 in their third (T3) trimester of pregnancy. Chemosensory event-related potentials and current source densities (CSD) were analysed (60 electrode setup). Compared to NP-women, pregnant women display diminished evaluative processing of the sweat samples (targets; P3-1/ P3-2 amplitudes) and delayed evaluative processing of the anxiety sweat (targets; P3-2 latency). T3-women show attenuated early processing (targets; N1 amplitude) compared to NP-women, and reduced evaluative processing compared to T1-women (standards; P3-2 amplitude). CSDs (P3-1/ P3-2 latency ranges) reveal that T1- and T3-women show an atypical activation distribution to anxiety sweat. Most participants were unable to detect the sweat samples (anxiety sweat: 79.5%, sport sweat 88.6%). The results demonstrate that the processing of anxiety chemosignals progressively vanishes during pregnancy. This effect is likely to occur without any cognitive control.
Highlights
In humans, stress can be contagiously transmitted via chemosignals on a subconscious level
The current study is the first to show diminished automatic and evaluative brain responses in pregnant women to the exceptionally significant social signals deriving from human anxiety sweat
The current results contrast reports of pregnant women being overly sensitive to social signals of threat or harm
Summary
Stress can be contagiously transmitted via chemosignals on a subconscious level. Activation in empathy-related brain areas in response to chemosensory anxiety signals[21] suggests that these signals are contagious This emotional contagion hypothesis is confirmed by the findings that fear chemosignals induce fearful facial expressions[22] and increased state anxiety in the perceiving individuals[23]. In line with such emotional contagion, human social perception appears sensitized to detect social signals of threat through chemosensory anxiety signals[19, 24,25,26,27], and adaptive responses such as withdrawal-related motor behaviour are primed[28, 29], similar to effects demonstrated in rodents[30, 31]. It was hypothesized that during pregnancy, in line with a stress protection mechanism a progressive attenuation of the processing of chemosensory anxiety signals would be observed
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
