Werner Reichardt

[KOCH@IAGO.CALTECH.EDU]

I would like to second what Jack wrote about the importance of Werner
Reichardt's work. His second-order, correlation model (know today simply
as the Reichardt model) for motion detection in bettles and flies (first
postulated in 1956 in a joint publication with Hassenstein) is, together
with the Hodgkin-Huxley equations, one of the oldest and most successful
models in neurobiology. He and his group over the last 30 years amassed
both behavioral and electropyhysiological evidence supporting such a model
for the fly. More recent work on the intensity-based, short-range
motion perception system in humans (Adelson-Bergen, Watson-Ahumada,
Van Santen-Sperling) uses the same formalism as does the fly correlation
model. Furthermore, at the electrophysiological level, a number  of
studies support the notion of such detectors in area 17 in cats.

One could therefore argue that we have good evidence that Reichardt's
correlation model---in which the linearly filtered output of one
receptors is multiplied by the spatially offset and temporally delayed
filtered output of a neighbouring receptor---describes the first stage in
the motion pathway, from flies to humans.  That's quite a legacy to leave
behind.

Christof