RT Journal Article
SR Electronic
T1 Impact of Photon Noise on the Reliability of a Motion-Sensitive Neuron in the Fly's Visual System
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 10776
OP 10783
DO 10.1523/JNEUROSCI.23-34-10776.2003
VO 23
IS 34
A1 Grewe, Jan
A1 Kretzberg, Jutta
A1 Warzecha, Anne-Kathrin
A1 Egelhaaf, Martin
YR 2003
UL http://www.jneurosci.org/content/23/34/10776.abstract
AB Variable behavioral responses to identical visual stimuli can, in part, be traced back to variable neuronal signals that provide unreliable information about the outside world. This unreliability in encoding of visual information is caused by several noise sources such as photon noise, synaptic noise, or the stochastic nature of ion channels. Neurons of the fly's visual motion pathway have been claimed to represent perfect encoders, with photon noise as the main noise source limiting their performance. Other studies on the fly's visual system suggest, however, that internal noise emerging within the nervous system also affects the reliability of motion vision. To resolve these contradictory interpretations, we performed an electrophysiological investigation, inspired by the “equivalent noise” paradigm applied in psychophysics, on the fly's motion-sensitive H1 neuron. Noise-like brightness fluctuations of different strength were superimposed on the motion stimuli. Because the noise level found to affect the temporal properties of the spike responses is much larger than the estimate of photon noise under the experimental conditions, our results indicate that motion vision is more likely to be limited by internal sources of variability than by photon noise.