These results have the practical implication for future studies that stimulus intensity will not have to be adjusted for two or more different populations. Women appear to be more sensitive to detecting simulated blood scent than men.
This study shows that simulated blood scent is not an exception. There are a variety of possible reasons for this generally higher sensitivity, most explanations favor fundamental biological differences, rather than differences of upbringing or hygiene [ 1 ]. People can be sensitized to an array of different scents with repeated exposure, even if they are initially anosmic to them and this capability seems to be especially pronounced in women [ 51 ], especially for biological scents e.
Trivia About Blood Scent Junk Kirschbaum C, Platte P, Pirke KM, Hellhammer D Adrenocortical activation following stressful exercise: Further evidence for attenuated free cortisol responses in women using oral contraceptives. According to Amazon, all the novellas are prequel to the action in "Junkyard Druid" series, so I'm not sure what the 0. However, even if it were the case, universal perception of this particular scent is nevertheless highly likely. It is not known why this is the case. The story contains plenty of interesting supernatural creatures.
For the ratings of simulated blood scent, the most conspicuous result was the bimodality of valence ratings of blood scent, such that people either liked it or did not. This was the case for both genders. For women, the difference could be associated with differences in OC and the phase of their fertility, namely women who were not taking OC and who were in a point in their cycle corresponding to their fertile phase, showed a clearly more positive rating of the simulated blood scent. Previous research has shown that women vary significantly across the course of their cycle in their ratings of odors [ 1 , 26 , 53 , 54 ], indeed more intensive processing of scents has also been observed in ERPs [ 26 ].
It is not known why this is the case. It cannot be attributable to circulating ovarian hormones or gonadotrophic pituitary hormones. This is because women typically vary in their sensitivity and hedonic ratings of scents regardless of whether they are taking OC or not. Though research shows a generally more positive rating of scents in the time of ovulation, regardless of OC [ 1 ], data from this experiment cannot evaluate this, as the variety of different contraception methods have different effects upon the cycle.
Additionally, women found the simulated scent of blood more arousing than men, but this was only for those women who rated the scent as negative.
Thus, although the literature suggests that women can be more sensitive to withdrawal cues [ 22 ], including olfactory cues [ 23 , 24 ], our findings limit this specifically to women taking OC. Women without OC rate it more positively, and this is further potentiated by the fertile phase of the menstrual cycle. Oral OC is known to have effects on the hypothalamic-pituitary axis [ 54 ], and women taking OC show less cortisol response to stress, suggesting that they might have less stress adaptability over the long term [ 55 , 56 ].
Additionally women taking OC have a greater emotional memory for emotional pictures, positive and negative [ 57 ].
One could interpret the results in this context as demonstrating that women taking OC are primed to interpret stimuli as alarm signals, and that blood scent in particular is interpreted as such. We have no explanation for why men display a similar split in their hedonic ratings of blood scent. Through one rating it is as yet not possible to say whether it is a state or trait rating. Future experiments will clarify a possible contextual dependency [ 3 ].
An extreme example of the latter is in sexual response: Disgust and sexual arousal are two motivational states that are opposed to one another [ 58 , 59 ]. The former involves protection against contamination, the latter, fundamentally procreation. They often take the same stimuli: Mouths, genitalia, saliva, sexual effluvia, and body odors.
The desire for sex is thus predicated on overcoming disgust. Studies have shown that sexual arousal diminishes disgust generally in both women [ 58 ] and men [ 59 ].
Nell [ 7 ] describes the way chimpanzees hunting their prey switch from moment to moment from excitement at overwhelming the prey to fear as it defends itself. Future studies need to examine the interplay of these two motivational systems. The fact that responses to blood scent varies across the menstrual cycle of women, peaking at a point of maximum fertility, could open up the possibility that it is somehow related to sexuality.
Another potentially interesting lifestyle relation to the scent of blood was whether people eat meat or not.
Though this lifestyle is often chosen for ethical or health reasons, whether this position is reflected in a visceral response to blood scent is an open question. Though we did find a significantly lower arousal in people who were vegetarian or vegan, this is difficult to interpret, and a future study with a larger sample is required. When asked to identify the blood scent, the student participants named a host of different associated scents: Cleaning materials, forest, mushrooms, hospitals, iron, swimming pools, two people mentioned blood, and one mentioned hemoglobin.
In contrast, in a lecture, we described the rationale of our experiment, making it clear from the outset that we were running an experiment on the scent of blood, and gave the listeners a chance to smell the simulated scent. Many of these people confirmed that yes, this scent smells like e. One could speculate that verbal cue, providing the context that this smells of blood, seems to alter conscious attributions.
Visual cues could also have an effect, redness is itself a powerful environmental cue, and blood phobia fear responses are triggered by visual cues [ 13 ]. The underlying neurophysiological structures suggest that perception of visual and olfactory cues is holistically integrated [ 62 ]. Future studies will test this for blood scent. The hypothesis was that the response to simulated blood scent was evolutionarily conditioned and independent of life-experiences. Future experiments can broaden the examination from the emotional aspects of motivation: Would it have a potentiating effect upon either appetitive or fearful responses, respectively, that is not found for other scents?
Alternately, if the same people are measured over different time periods, will they show trait-like stability in their ratings of blood scent? The simulated blood scent mixture employed here provides a specific element of the scent of fresh blood that is convenient and safe for laboratory studies.
This mixture is postulated to represent the scent of fresh blood as it mixes with the lipid peroxides on the skin [ 30 ]. However we do no yet know if this individual stimulus is comparable to the complexity of the real-life stimulus. Glindemann et al.
get link On the other hand, predatory animals have been shown to react to an individual volatile component of blood itself trans-4,5-epoxy- E decenal in the same appetitive way as with real blood [ 6 ]. At a theoretical level, identifying a biologically important environmental scent cue from one of its components could provide an advantage in sensitivity.
But, configural perception of multiple elements of a scent is advantageous in the complex changing natural environment, moreover, if it were dependent only upon only one receptor, there is the possibility of a specific anosmia, which could be disastrous for an animal [ 63 ]. Blood is a complex stimulus, and this experiment shows complex responses in people to a major distinctive component of this.
In sum, this experiment examines the novel question concerning the effects of the scent of blood on humans. This preliminary data affirm the idea that its olfactory perception represents an important chemosensory signal requiring further investigation.
Browse Subject Areas? Click through the PLOS taxonomy to find articles in your field. Abstract The scent of blood is potentially one of the most fundamental and survival-relevant olfactory cues in humans. This is an open access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited Data Availability: All relevant data are within the paper and its Supporting Information files.
Introduction The scent of blood as a motivational driver Human biological scents, including sweat, breath, breast milk and sexual effluvia appear to have a major influence upon human chemical communication, bonding and partner selection [ 1 — 3 ]. Blood as approach vs.
Gender differences Gender is an essential variable in assessing the response to the scent of blood. Chemical characteristics of the scent of blood The scent of blood is a complex stimulus. Materials and Method Participants An experimental population of 89 people 44 women was drawn from the student population at the University of Konstanz.
Ethics Statement The safety of the blood scent mixture vide infra was evaluated by an accredited toxicologist, who was part of the project co-author DRD. Simulated blood scent solution Using an artificial blood scent mixture based upon the analysis of [ 30 ] has many practical advantages.
Threshold test We used the threshold test created by Doty and colleagues [ 45 ] to determine the absolute perceptual threshold of the blood scent and butyric acid. Procedure Odors were presented in brown 50ml bottles, with 30ml of the respective odor solution in each. Download: PPT. Emotion ratings The distributions for all dilutions of simulated blood scent, butyric acid, water and floral odor are shown in Fig 3. Fig 5. Valence vs. Fertility effects Threshold.