On the dimensionality of odor space
- California Institute of Technology, United States
Figures
Figure 1
Model of olfaction in a toy microbe.
(A) This 3-state olfactory system counts how many odors in the mixture are attractants vs repellents, and converts the result into three response categories (see text). Two odor mixtures are …
Figure 2
Model of human color vision.
(A) The RGB color cube with three of the 128 primary colors represented by vectors from the origin. Tick marks represent just noticeable differences, for example, along the R-axis. (B) The fraction …
Figure 3
A model simulation of the human smell experiments.
(A) Left: Each primary odor gets mapped into a unit vector (e.g., red, green, blue). Mixtures of odors get mapped into the normalized sum vector (gray). Right: When a subject sniffs an odor vial, …
Figure 4
Coloring close-packed spheres in 2 dimensions so no nearest neighbors have the same color.
(A) All colors different. (B) Three colors suffice. (C) Progression of colors in one dimension only.
Tables
Table 1
Number of dimensions of various spaces involved in sensory discrimination
| Toy microbe | Ring model | Human color | E. coli smell | Human smell | |
|---|---|---|---|---|---|
| Stimuli | ∞ | ∞ | ∞ | ∞ | ∞ |
| Receptors | ∞ | ∞ | 3 | 5 | ∼400 |
| Percepts | 1 | 1 | 3 | 1 | 1–20? |
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The symbol ∞ stands for ‘very large or infinite’.
Additional files
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Source code 1
Annotated Igor (Wavemetrics) code.
- https://doi.org/10.7554/eLife.07865.008
