Study

The sense of touch in the star-nosed mole: from mechanoreceptors to the brain

Catania, Kenneth C.

Philosophical Transactions of the Royal Society B, 2011

Peer-reviewednarrative reviewmixed

What they did

Reviews the anatomy of the mole’s twenty-two fleshy appendages and the roughly twenty-five thousand Eimer’s organs distributed over them, the disproportionate cortical representation of the star, and high-speed behavioural work on how prey are found, identified and eaten.

Studied in: Condylura cristata
Sample size: synthesis of anatomical, electrophysiological and behavioural work on one species

What they found

The star is a tactile organ of extreme resolution, with one small pair of appendages functioning as a tactile fovea that the animal moves onto anything of interest, and prey identification and consumption completed in well under a quarter of a second.

What it means

The authors' reading, and ours. Where they differ, that difference is the point.

How the authors put it

The star-nosed mole’s star is a touch analogue of a visual system, including a fovea, saccade-like movements and a magnified cortical map.

How NatureHQ reads it

The best available answer to what a sense would look like if touch, rather than vision, were an animal’s primary way of examining the world — and the answer is that it looks remarkably like vision. There is a high-resolution region the animal aims at things, rapid movements that bring targets into it, and a brain map in which that region occupies far more space than its size warrants. The convergence is the finding; the eleven-appendages-per-side anatomy is the memorable part.

Limitations

One species, and one so specialised that generalising from it is unwise.
A review; the behavioural timings come from a small number of individuals.
The comparison with vision is an analogy supported by structure, not an identity.