scholarly journals Information content of visual scenes influences systematic search of desert ants

2012 ◽  
Vol 216 (4) ◽  
pp. 742-749 ◽  
Author(s):  
P. Schultheiss ◽  
A. Wystrach ◽  
E. L. G. Legge ◽  
K. Cheng
Keyword(s):  
Information Content ◽  
Systematic Search ◽  
Desert Ants ◽  
Visual Scenes

Information content of visual scenes influences systematic search of desert ants (Melophorus bagoti)

2012 ◽  
Author(s):  
Eric L. G. Legge ◽  
Patrick Schultheiss ◽  
Antoine Wystrach ◽  
Marcia L. Spetch ◽  
Ken Cheng
Keyword(s):  
Information Content ◽  
Systematic Search ◽  
Desert Ants ◽  
Visual Scenes ◽  
Melophorus Bagoti

scholarly journals Effects of phase correlations in naturalistic stimuli on quantitative information coding by fly photoreceptors

2018 ◽  
Vol 119 (6) ◽  
pp. 2276-2290 ◽  
Author(s):  
Irina I. Ignatova ◽  
Andrew S. French ◽  
Roman V. Frolov
Keyword(s):  
Information Content ◽  
Information Transfer ◽  
Early Stage ◽  
Higher Order ◽  
Calliphora Vicina ◽  
Local Contrast ◽  
Time And Space ◽  
Random Signals ◽  
Visual Scenes ◽  
Phase Randomization

Natural visual scenes are rarely random. Instead, intensity and wavelength change slowly in time and space over many regions of the scene, so that neighboring temporal and spatial visual inputs are more correlated and contain less information than truly random signals. It has been suggested that sensory optimization to match these higher order correlations (HOC) occurs at the earliest visual stages, and that photoreceptors can process temporal natural signals more efficiently than random signals. We tested this early-stage hypothesis by comparing the information content of Calliphora vicina photoreceptor responses to naturalistic inputs before and after removing HOC by randomizing phase. Forty different, 60-s long, naturalistic sequences (NS) were used, together with randomized-phase versions of the same sequences to give pink noise (PN) so that each input pair had identical means, variances, mean contrasts, and power spectra. We measured the information content of inputs and membrane potential responses by three different methods: coherence, mutual information, and compression entropy. We also used entropy and phase statistics of each pair as measures of HOC. Responses to randomized signals generally had higher gain, signal-to-noise ratio, and information rates than responses to NS. Information rate increased with a strong, positive, linear correlation to phase randomization within sequence pairs. This was confirmed by varying the degree of phase randomization. Our data indicate that individual photoreceptors encode input information by Weber’s law, with HOC within natural sequences reducing information transfer by decreasing the number of local contrast events that exceed the noise-imposed threshold. NEW & NOTEWORTHY Natural visual scenes feature statistical regularities, or higher order correlations (HOC), both in time and space, to encode surfaces, textures, and object boundaries. Visual systems rely on this information; however, it remains controversial whether individual photoreceptors can discriminate and enhance information encoded in HOC. Here we show that the more HOC the stimulus contains, the lower the information transfer rate of photoreceptors. We explain our findings by applying the Weber’s paradigm of differential signal perception.

scholarly journals How flexible is the systematic search behaviour of desert ants?

2009 ◽  
Vol 77 (5) ◽  
pp. 1051-1056 ◽  
Author(s):  
Tobias Merkle ◽  
Rüdiger Wehner
Keyword(s):  
Systematic Search ◽  
Search Behaviour ◽  
Desert Ants

Applications of Scanning Microscopy in Biomedical Research

1968 ◽  
Vol 26 ◽  
pp. 354-355
Author(s):  
T. L. Hayes
Keyword(s):  
Information Content ◽  
Biomedical Research ◽  
Biomedical Applications ◽  
Three Dimensional ◽  
Dental Enamel ◽  
Resolving Power ◽  
Whole Mount ◽  
Two Parameters ◽  
Content Information ◽  
Sectioned Tissue

Biomedical applications of the scanning electron microscope (SEM) have increased in number quite rapidly over the last several years. Studies have been made of cells, whole mount tissue, sectioned tissue, particles, human chromosomes, microorganisms, dental enamel and skeletal material. Many of the advantages of using this instrument for such investigations come from its ability to produce images that are high in information content. Information about the chemical make-up of the specimen, its electrical properties and its three dimensional architecture all may be represented in such images. Since the biological system is distinctive in its chemistry and often spatially scaled to the resolving power of the SEM, these images are particularly useful in biomedical research.In any form of microscopy there are two parameters that together determine the usefulness of the image. One parameter is the size of the volume being studied or resolving power of the instrument and the other is the amount of information about this volume that is displayed in the image. Both parameters are important in describing the performance of a microscope. The light microscope image, for example, is rich in information content (chemical, spatial, living specimen, etc.) but is very limited in resolving power.

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