DEVICE
NEUROSCENT
Reading the brain’s response to smell – objective, non-invasive olfactory assessment from EEG.
NEUROSCENT detects whether a person is perceiving an odour directly from brain activity. Calibrated odours are delivered under controlled conditions while 64-channel EEG is recorded, and a deep-learning model returns, on a sliding window, the probability that an odour is being perceived. In parallel, cortical source reconstruction (eLORETA over 68 cortical regions) maps where the response arises, separates the olfactory component from the trigeminal one, and relates both to clinical olfactory scores. The goal is an objective readout of a sense whose loss is among the earliest signs of neurodegenerative and metabolic disease — one that complements, and does not depend on, the patient’s own report.
Project Status
Status: NEUROSCENT is in the clinical data-collection phase, within a multicentre study run with hospital partners. On the cohort acquired so far, source-level analyses show a reproducible cortical signature of trigeminal stimulation and a cortical network that tracks the presence of an odour, with the frontal response related to clinical olfactory scores. A patent application covering the technology has been filed and is currently under examination. The decoding pipeline is being extended towards real-time streaming.
Inside the analysis
Three views of what NEUROSCENT measures, taken from the ongoing multicentre study. They are shown here to illustrate the method; the underlying results are exploratory and not yet peer-reviewed.
Where the cortex responds to smell. The EEG is projected onto the cortical surface with eLORETA and summarised over 68 anatomical regions. Each brain shows how theta-band power changes while an odour is present, compared with the washout period that follows it — blue a decrease, red an increase. The five odours are those used in the clinical protocol. Eucalyptus, which also stimulates the trigeminal nerve, produces the most widespread change, one of the reasons it is treated as a separate axis in the analysis.
Smell is a network event, not a single spot. The same recordings are described by how strongly pairs of cortical regions co-vary in the theta band. Each line is one of the twenty connections that change most between odour and washout: blue where coupling decreases with the odour present, red where it increases. Yellow nodes mark regions classically associated with olfaction — orbitofrontal cortex, anterior cingulate, parahippocampal cortex, insula.
The brain measurement tracks the clinical one. For each participant the cortical response is compared with their Sniffin’ Sticks TDI score, the standard clinical measure of olfactory function. Colour shows the strength and direction of that relationship across the cortex: the frontal and orbitofrontal regions in dark blue are where people with better olfactory scores show a smaller theta response to the odour. The effect holds after controlling for age and for recording quality.
Frequently asked questions
What does NEUROSCENT do?
NEUROSCENT reads the brain’s response to smell. Odours are delivered under controlled conditions while 64-channel EEG is recorded, and a machine-learning model returns the probability that the person is perceiving an odour at each moment. It is developed at the Metabolic Intelligence Lab of Università Cattolica del Sacro Cuore in Rome.
Why measure olfaction from the brain?
Because the standard clinical tests are psychophysical: they depend on the person recognising and reporting what they smell. An EEG readout is objective and needs no verbal response, which matters for patients who cannot report reliably. It matters clinically because olfactory loss is one of the earliest signs of neurodegenerative disease, often years before other symptoms appear.
What is the trigeminal axis, and why does it matter?
Some odorants — the 1,8-cineole in eucalyptus, for instance — also stimulate the trigeminal nerve and are felt as pungent or cooling, not only smelled. NEUROSCENT separates that somatosensory component from olfaction proper. In our cortical data the trigeminal response is the component that reads out most reliably, over sensorimotor cortex, cingulate and insula — exactly the network expected for trigeminal processing.
Is NEUROSCENT available, and is it a medical device?
Neither yet. NEUROSCENT is a research project in the clinical data-collection phase; a patent application has been filed and is under examination, and the decoding models are still being validated. It is not a certified diagnostic device and is not on the market.
What do the brain maps on this page show?
They show where cortical activity changes while an odour is present, compared with the washout period between odours. The EEG is projected onto the cortical surface with eLORETA and summarised over 68 anatomical regions of the Desikan–Killiany atlas. Eucalyptus, which also stimulates the trigeminal nerve, produces the most widespread change — which is why the trigeminal component is analysed as a separate axis.
Does the EEG measurement agree with standard clinical smell tests?
In part, and in a specific way. Across 80 participants, a stronger theta response in frontal and orbitofrontal cortex goes together with a lower Sniffin’ Sticks TDI score, the standard clinical measure of olfactory function (threshold, discrimination, identification). The relationship holds after controlling for age and for EEG recording quality. It is an exploratory result from the ongoing study, not yet peer-reviewed.
The full publication list behind this work is on the Publications page.