Study
Integration of visual and infrared information in bimodal neurons of the rattlesnake optic tectum
Newman, Eric A.; Hartline, Peter H.
Science, 1981
Single-unit recordings from the optic tectum of rattlesnakes while presenting visual stimuli, infrared stimuli, and both together, mapping the receptive fields of the cells that responded.
- Studied in
- Crotalinae
- Sample size
- single-unit recordings from rattlesnake optic tectum
Cells responding only to light, only to infrared, and to both were found in the same structure, with the infrared and visual maps in spatial register and some bimodal cells responding more strongly to the two together than to either alone.
What it means
The authors' reading, and ours. Where they differ, that difference is the point.
How the authors put it
Infrared and visual information are integrated rather than processed in parallel, producing a combined representation of the space around the animal.
How NatureHQ reads it
This is the recording that licenses the phrase "see heat", and it licenses it in one specific sense: the information is spatial, it is mapped onto the same structure as vision, and individual cells combine the two. That is integration. It is not evidence about what a snake experiences — the same recording would look identical either way — and this corpus treats the difference between the two as the point rather than a quibble.
- Convergence in the tectum shows the signals meet; it does not establish a unified percept.
- Rattlesnakes only; boid pit organs have a different and less thoroughly studied arrangement.
- Recording under anaesthesia in a restrained animal, which is the standard method and is not free behaviour.
Finding the cells that answer to both heat and light
A pit viper has eyes and it has heat-sensing pits. Are those two separate senses, or one?
What this study is used for on NatureHQ
One study can inform several subjects. Here is everywhere this one is cited.
Infrared sensing
A pit viper does not detect infrared light the way an eye detects visible light. It suspends a very thin membrane in air, lets radiant heat warm it, and measures the warming with a temperature-sensitive channel.
Infrared sensing
In the snake’s midbrain there are cells that answer to light, cells that answer to heat, and cells that answer to both — with the two maps of space lined up.
Published by: American Association for the Advancement of SciencePublished in Science or Science Advances (AAAS).
doi.org/10.1126/science.7256281
Checked against Crossref on 2026-09-28, and they agree on the title, the authors and the year.
NatureHQ summarises research in its own words and does not reproduce published text. Reviewed 2026-09-02.