. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 40 80 120' Interval 1 .0 to c Q) T3 0> N E o 0 5. 400 500 600 Wavelength (nm) 700 Figure 5. Scan technique. A. Results of a single ascending spectral scan. The scan began at 400 nm at interval 0, and each interval lasted 5 s. Whenever reflectance fell within (dotted lines) of the refer- ence level (O^r reflectance change), the wavelength and photon flux was recorded and the wavelength was driven to a value 10 nm greater. Whenever the reflectance differed from the reference by more than the density wedges were
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 40 80 120' Interval 1 .0 to c Q) T3 0> N E o 0 5. 400 500 600 Wavelength (nm) 700 Figure 5. Scan technique. A. Results of a single ascending spectral scan. The scan began at 400 nm at interval 0, and each interval lasted 5 s. Whenever reflectance fell within (dotted lines) of the refer- ence level (O^r reflectance change), the wavelength and photon flux was recorded and the wavelength was driven to a value 10 nm greater. Whenever the reflectance differed from the reference by more than the density wedges were rotated to alter the stimulation intensity and move the response towards the reference level. In general, each spike in the record occurred as a new wavelength was reached and the negative-feedback loop restored the reflectance to the reference level. The scan ended when the wavelength reached 650 nm. B. Average re- sults of 21 scans in 16 experiments. Vertical lines indicate standard errors of the mean. successive spikes tend to point upwards, as in the earlier part of the record. As the peak sensitivity is passed, the spikes begin to point downwards, so stimulus intensity must be increased to bring the response back to the refer- ence level. In the illustrated scan, the longest wavelengths contained insufficient light to bring the response to the reference level, and the trace trailed off to decreasing lev- els of reflectance. Sensitivity curves were analyzed and averaged as be- fore. The average curve and associated errors for 21 sepa- rate scans, taken from 16 individual presentations (some included multiple scans), are plotted in Figure 5B. Scans typically were completed within 15 to 25 min, once the initial 20-min stabilization period was passed (the scan of Fig. 5 A required 20 min, 19 s). Thus, starting with a fully dark-adapted eye, four complete scans (2 ascending and 2 descending) could be completed in 2 h or less. Though collecting the data of Figure 5B required a
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
