Rikard Frederiksen
I became a PhD-student in the Lund Vision Group in November 2003. I worked on dim light vision, in particular on nocturnal and crepuscular insects.
Information capacity in nocturnal vision
When photons are rare, photoreceptor signal-to-noise ratios becomes low. This leads to a less accurate detection of contrast and lower visual acuity. In other words, vision becomes less reliable in dim light. Much of the noise comes from the stochastic nature of light, but a significant amount is due to the cellular mechanisms of phototransduction and the electrical properties of the photoreceptor cell membrane. This noise directly affects the amount of information the photoreceptor can code since the information capacity is dependent on the signal-to-noise ratio.
In my work I want to understand if nocturnal insects have a way to improve the signal-to-noise ratio and the amount of information coded in the photoreceptors in dim light. I am also interested in the mechanisms and costs of information. For instance, does a single bit of information cost more to code, in terms of energy, for a nocturnal animal than for a day-active animal and what are the underlying cellular mechanisms that allow the photoreceptors of nocturnal insects to maintain a high information capacity in very dim light?
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Publisher: Department
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Last modified 1 Dec 2009
Phone:
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E-mail:
Rikard.Frederiksen@cob.lu.se
Supervisor Eric Warrant