Path integration
Path integration is the method thought to be used by animals for dead reckoning.
History
mole rat) can give path integration.[2]
Mechanism
Studies in
Sahara desert ant (Cataglyphis bicolor), reveal the existence of highly effective path integration mechanisms that depend on determination of directional heading (by polarized light or sun position) and distance computations (by monitoring leg movement or optical flow).[3]
In mammals, three important discoveries shed light on this.
The first, in the early 1970s, is that neurons in the hippocampal formation, called place cells, respond to the position of the animal.
The second, in the early 1990s, is that
head direction cells
, respond to the head direction of the animal. This enables a much more fine-grained study of path integration since it is possible to manipulate movement information and see how place and head direction cells respond (a much simpler procedure than training an animal, which is very slow).
The third finding was that neurons in the dorso-medial
hexagonally organized sheet of graph paper
, and suggest a possible metric system that place cells can use to compute distances. Whether place and grid cells actually compute a path integration signal remains to be seen, but computational models exist suggesting this is plausible. Certainly, brain damage to these regions seems to impair the ability of animals to path integrate.
David Redish states that "The carefully controlled experiments of Mittelstaedt and Mittelstaedt (1980) and Etienne (1987) have demonstrated conclusively that this ability [path integration in mammals] is a consequence of integrating internal cues from vestibular signals and motor efferent copy".[4]
See also
References
- Retrieved 28 February 2012
- ^ Tali Kimchi, Ariane S. Etienne‡, and Joseph Terkel, 2004. A subterranean mammal uses the magnetic compass for path integration. PNAS, January 27, vol. 101, no. 4, 1105–1109.
- S2CID 4571290.
- ^ Redish, 1999. p 69.
Bibliography
- Best PJ, White AM, Minai A (2001). "Spatial processing in the brain: the activity of hippocampal place cells". Annu Rev Neurosci. 24: 459–486. PMID 11283318.
- Etienne AS, Jeffery KJ (2004). "Path integration in mammals" (PDF). Hippocampus. 14 (2): 180–192. S2CID 1646974.
- McNaughton BL, Battaglia FP, Jensen O, Moser EI, Moser MB (2006). "Path integration and the neural basis of the 'cognitive map'". Nat Rev Neurosci. 7 (8): 663–678. S2CID 16928213.
- Redish, A David (1999). Beyond the Cognitive Map. MIT Press. PDF
- Taube JS (1998). "Head direction cells and the neurophysiological basis for a sense of direction". Prog Neurobiol. 55 (3): 225–256. S2CID 38083940.