Related Experiment Video
Updated: Mar 10, 2026

04:47
Olfactory Context Dependent Memory: Direct Presentation of Odorants
Published on: September 18, 2018
7.1K
A probabilistic approach to demixing odors.
Agnieszka Grabska-Barwińska1,2, Simon Barthelmé3, Jeff Beck4
1Gatsby Computational Neuroscience Unit, University College London, London, UK.
Nature Neuroscience
|December 6, 2016
Summary
The olfactory system deciphers complex odors by using approximate Bayesian inference. This computational model explains how the brain demixes overlapping olfactory signals for accurate odor perception.
Area of Science:
- Neuroscience
- Computational Neuroscience
- Sensory Systems
Background:
- The olfactory system must identify individual odors from noisy and overlapping signals from olfactory receptor neurons.
- Odor perception is challenging due to the high number of possible odors and the non-isolated nature of odorant molecules.
Purpose of the Study:
- To propose a computational model for how the early olfactory system demixes odor inputs.
- To investigate the role of approximate Bayesian inference in olfactory processing.
Main Methods:
- Modeling the olfactory system using a dynamical loop between the olfactory bulb and piriform cortex.
- Simulating the cortex's role in explaining olfactory receptor neuron activity as a mixture of odors.
Main Results:
- The proposed model successfully demixes overlapping olfactory receptor neuron activity.
- The model aligns with known olfactory system anatomy and physiology, including pattern decorrelation.
Conclusions:
- Approximate Bayesian inference is a viable mechanism for the olfactory system to solve the odor demixing problem.
- The proposed model offers a functional explanation for olfactory processing and outperforms existing models in odor demixing.
Related Concept Videos
Olfaction
49.4K
The sense of smell is achieved through the activities of the olfactory system. It starts when an airborne odorant enters the nasal cavity and reaches olfactory epithelium (OE). The OE is protected by a thin layer of mucus, which also serves the purpose of dissolving more complex compounds into simpler chemical odorants. The size of the OE and the density of sensory neurons varies among species; in humans, the OE is only about 9-10 cm2.
The olfactory receptors are embedded in the cilia of the...
The olfactory receptors are embedded in the cilia of the...
49.4K
Mass Spectrometry: Complex Analysis
2.0K
Mass spectrometry is an important technique for the identification of pure compounds. However, it has some limitations for the analysis of complex mixtures, often due to excessive fragmentation making the spectrum too complicated to decipher. Mass spectrometry can be combined with suitable separation methods in sequence, forming hyphenated methods, which are useful in the analysis of complex mixtures.
GC–MS is a powerful hyphenated method commonly used in forensics and environmental...
GC–MS is a powerful hyphenated method commonly used in forensics and environmental...
2.0K
Physiology of Smell and Olfactory Pathway
13.6K
Humans detect odors with the help of specialized cells located in the upper part of the nasal cavity, called olfactory receptor neurons (ORNs). ORNs possess hair-like structures called cilia, which are receptive to sensations from the inhaled air. When an odorant molecule binds to a specific receptor on the cell of the cilia, it leads to a series of events that ultimately cause the ORN to send electrical signals to the olfactory bulb in the brain through the olfactory nerves.
The olfactory...
The olfactory...
13.6K
The Thermodynamics of Mixing
48
Mixing is a fascinating phenomenon in thermodynamics, particularly when considering the Gibbs energy of a mixture at constant temperature and pressure. This energy, denoted as G, tends to decrease during spontaneous mixing processes, offering insights into the composition changes that occur.Imagine two ideal gases, initially separated in different containers, with amounts nA and nB, respectively, both at a temperature T and pressure p. The chemical potentials of these gases have their 'pure'...
48

