TONA   |   ANOT h e r     d a y

Interesting science beyond lasers..

To continue the series (started by Miki) of interesting scientific problems going beyond our direct activities, I would like to draw your attention to the current issue of Nature (Vol 436 from 7 July 2005).

I would like to recommend the following articles:

The vocal tract and the sound of a didgeridoo
Acoustic measurements show how a player can extract a range of timbres from this primitive instrument.

When instability makes sense
Peter Ashwin and Marc Timme
Mathematical models that use instabilities to describe changes of weather patterns or spacecraft trajectories are well established. Could such principles apply to the sense of smell, and to other aspects of neural computation?

Dynamic predictive coding by the retina
Toshihiko Hosoya, Stephen A. Baccus & Markus Meister
Retinal ganglion cells convey the visual image from the eye to the brain. They generally encode local differences in space and changes in time rather than the raw image intensity. This can be seen as a strategy of predictive coding, adapted through evolution to the average image statistics of the natural environment. Yet animals encounter many environments with visual statistics different from the average scene. Here we show that when this happens, the retina adjusts its processing dynamically. The spatio-temporal receptive fields of retinal ganglion cells change after a few seconds in a new environment. The changes are adaptive, in that the new receptive field improves predictive coding under the new image statistics. We show that a network model with plastic synapses can account for the large variety of observed adaptations.

posted by ingo @ 17:39