Biology subjects

Bensafi, M.

Publications and source records attributed to Bensafi, M..

4 recordsLinked to original sources

bioRxiv2026

The formation and content of odor memory from childhood

As illustrated by Marcel Prousts madeleine, childhood olfactory autobiographical memory carries a stronger positive emotional valence than memories associated with other senses. However, little is known about its content or the conditions of encoding and maintenance. Here, we asked 647 participants to freely recall and characterize their earliest childhood olfactory memory. We found that this memory is typically encoded around age six, involves pleasant odors embedded within rich multisensory contexts, and retains a strong positive emotional valence despite age-related declines in some experiential qualities. The most frequently reported scenes took place at home, in the presence of the mother, and were predominantly associated with food-related odors, although natural-vegetation odors were also commonly reported. By contrast, the non-olfactory memory is encoded earlier, visually dominated, less multisensory, less pleasant, and more frequently associated with institutional settings and friends. These findings characterize childhood olfactory memory and highlight its distinctive content among autobiographical memories.

neuroscience↗

bioRxiv2026

The preference of a fragrance created by a perfumer is associated with one single-nucleotide polymorphism in OR5A1 gene

From ancient incense to Chanel No. 5, perfumes are almost ubiquitous across the world and across history yet highly diverse. While they reflect the artistry of the creator and the personality of the wearer, the neurobiological processes driving fragrance preference are unknown. Recent research demonstrated that genetic variability in olfactory receptors modulates odor perception; however, regarding the preference for complex real-world stimuli, the relative importance of peripheral sensory encoding versus top-down cognitive evaluation--shaped by individual life history--remains a subject of debate. Here, we evaluate whether the perception of a commercially available fragrance depends on genetics, using the example of beta-ionone, a molecule routinely used in perfume composition, whose perception and appreciation have been linked to a single-nucleotide polymorphism in the OR5A1 gene (rs691536). A total of 168 participants rated their preference for three versions of a perfume designed by a professional perfumer, differing only in the concentration of {beta}-ionone used in the formula. Results showed that carriers of the G allele rated the 0% {beta}-ionone fragrance significantly higher than the 10% and 50% versions, while AA homozygotes showed no discrimination between the perfumes. By focusing on just one SNP (among hundreds of olfactory genes) and a single molecule, this study offers a proof of concept regarding the influence of genetics on aesthetic fragrance appreciation, advocating for the integration of genomic data to better understand the global diversity of perfume preferences.

genetics↗

bioRxiv2023

A pilot study of the impact of smells on the behavior of level 3 autistic children and adolescents during an ongoing task

The present pilot study aims to perform a first evaluation of the effect of smells on the behavior of autistic children and adolescents (level 3) while they are performing a routine task and are going through a more or less intense crisis situation. To do this, we developed a protocol adapted for a field study in the familiar environment (specialized school) of 8 autistic children and adolescents, where the effect of odors on the behaviors of screaming, agitation, and aggression was assessed. First, it was possible to carry out this protocol on this level 3 autistic population. Second, the results acquired on subjective data collected by the experimenter suggest that odors may reduce certain behavioral traits such as agitation or screaming. These data should be considered as proof-of-concept, with results that need to be confirmed in a larger sample of autistic individuals.

neuroscience↗

bioRxiv2020

Cognitive regulation of multimodal food perception in the human brain

The ability to regulate appetite is essential to avoid food over-consumption. The desire for a particular food can be triggered by its odor before it is even seen. Using fMRI, we identify the neural systems modulated by cognitive regulation when experiencing appetizing food stimuli presented in both olfactory and visual modalities, while being hungry. Regulatory instruction modulated bids for food items and inhalation patterns. Distinct brain regions were observed for up and down appetite-regulation, respectively the dorsomedial prefrontal cortex (dmPFC) and dorsolateral PFC. Food valuation engaged the ventromedial PFC and bilateral striatum while the amygdala was modulated by individual food preferences, indexed by rank-ordered bids. Furthermore, we identified a neurobiological marker for up-regulating success: individuals with higher blood levels of ghrelin were better at exercising up-regulation, and engaged more the dmPFC. This characterizes the neural circuitry regulating food consumption and suggests potential hormonal and neurofunctional targets for preventing eating disorders.

neuroscience↗