This section has described the organization and structure of the CE optical system. The CE is basically a visual sampling array, rather than a camera with a single lens and film. The two CEs are generally built on the curved surface of an insect's head. The maximum response axis of each ommatidium diverges from each of its neighbors so that a whole eye responds to objects lying in about a hemisphere of visually sampled space (2n steradians of solid angle).
Each ommatidium is seen to be effectively a light-gathering and transducer assembly of retinula photoreceptor cells, rather than an imaging system. The entire CE with its thousands of ommatidia is the imaging system. The directional sensitivity function of each ommatidium is analogous to a spatial low-pass filter. Thus, the entire ommatidial array samples an analog low-pass-filtered image and converts the intensity information to retinula cell depolarization voltages. Interneurons in the OLs process these analog voltages and perform spatial filtering (edge enhancement) and feature extraction operations. The outputs of OL neurons are "coded" in terms of spike frequency.
Was this article helpful?
This guide will help millions of people understand this condition so that they can take control of their lives and make informed decisions. The ebook covers information on a vast number of different types of neuropathy. In addition, it will be a useful resource for their families, caregivers, and health care providers.