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Carl J Bassi

Publications and source records attributed to Carl J Bassi.

5 recordsLinked to original sources
PubMed2006

Driver contrast sensitivity and reaction times as measured through a salt-covered windshield.

BACKGROUND: The objective of this study was to use contrast sensitivity measurements to determine the effect of windshield salt film on driver vision. This effect simulates road salt spray that dries in place on a vehicle windshield during winter driving conditions. METHODS: Ten emmetropic subjects were tested to assess contrast sensitivity functions through windshields that were clear compared with the same stimuli as viewed through windshields coated with salt film. Achromatic stimuli were generated by a VisionWorks system and were presented at 4 spatial frequencies (0.5, 3, 10, and 20 cycles per degree). RESULTS: A significant reduction in contrast sensitivity through the salt film was found at all spatial frequencies. In addition, reaction time to detect the stimuli was also found to be increased significantly at 2 of the 4 spatial frequencies through the saline-covered windshield. CONCLUSION: The results of this study indicate that windshield salt film reduces the ability to detect high and low contrast objects in a simulated driving environment as well as increases the subjects' reaction times.

Adult↗
PubMed2005

Evaluation of the new web-based "Colour Assessment and Diagnosis" test.

PURPOSE: The purpose of the study was to determine the sensitivity, specificity, and repeatability of the web-based Colour Assessment and Diagnosis (CAD) test in comparison to current tests of color vision. METHODS: Thirty color normals and 30 color deficients, identified and diagnosed by the Nagel anomaloscope, were tested. The results of the CAD test were compared with standard tests like Nagel anomaloscope, Ishihara (concise version, 2001), Hardy, Rand and Rittler (HRR; 4 ed) pseudoisochromatic test, and the Farnsworth Munsell 100 (FM-100) hue test. RESULTS: Using the Nagel anomaloscope as the "gold standard," the sensitivity with the CAD test was 93.33%, Ishihara 96%, HRR 100%, and the FM-100 hue 100%. The specificity was 100% with CAD and the Ishihara color plates, whereas it was 33% with the HRR and 83% with the FM-100 hue test. The concurrent validity of the CAD test for color normals was 93.75%. The concurrent validity of CAD test for color deficiency was 100%. Thus, anyone failing the CAD test has a color defect. The coefficient of agreement for the Nagel anomaloscope and the CAD test was 0.93, with Ishihara it was 0.96, with the HRR it was 0.33, and with FM-100 hue it was 0.83. CONCLUSION: These results showed that the CAD test is a valid test for identifying congenital red-green color deficiency. Further testing is required in a larger population of anomalous trichromats.

Adult↗
PubMed2005

Limits of learning enhancements with nicotine in old male rats.

Findings with young adult humans and animal models suggest that nicotine may serve both neuroprotective and cognition enhancing roles in old animals. A pair of experiments was conducted to examine drug-induced modification of the cholinergic nicotinic receptor subtype on rates of learning by young and aged rats. In experiment I males (4-7 months or 20-25 months old) were administered nicotine (0.0, 0.3 or 0.7 mg/kg injected s.c. daily) and tested in both a T-maze non-spatial discrimination paradigm and a hole board spatial task. Nicotine failed to improve acquisition by young animals on either task. Nicotine also failed to improve non-spatial learning by old animals. However, both dosages of nicotine improved performance by the old males in the spatial paradigm. In experiment II, a 5-choice serial discrimination paradigm designed to better evaluate visual attention and spatial working memory in aging was used. Groups of old male rats were administered nicotine or mecamylamine (2 or 8 mg/kg), an antagonist of the nicotinic cholinergic receptor. Results were that the 0.3 mg nicotine group learned the task fastest and achieved the highest learning asymptote. Both learning rates and final levels of performance were worst in the 8 mg mecamylamine group. However, the 2 mg mecamylamine rats were the equals of the control group and both reached a higher asymptote than the 0.7 mg nicotine group. These data suggest that healthy old animals can accrue benefits from nicotinic activation but that the benefits are complex, being limited to certain dosages and to specific cognitive skills.

Age Factors↗
PubMed2005

Luminous efficiency and the measurement of daytime displays, signals, and visors.

PURPOSE: Measurements concerning the usability or safety of optical equipment are based on assumptions regarding luminous efficiency. The current luminous efficiency functions are derived from human sensitivity experiments taken at low light levels compared with the outdoor daytime environment. The amount of error induced by extrapolating from low light level data to high light level applications is not known. We sought to determine whether standard luminous efficiency curves CIE V(lambda) and CIE Heterochromatic Brightness Matching are appropriate for measuring day-use optical equipment such as display phosphors, lasers, LEDs, and laser eye protection, which are becoming more common in aviation. METHODS: Flicker photometry and successive heterochromatic brightness matching were used to measure changes in luminance efficiency functions with increasing levels (1, 10, 100, and 1000 fL) of light adaptation. RESULTS: Luminous efficiency was found to depend on both the method and the reference intensity with which the measurements were taken. For heterochromatic brightness matching, luminous efficiency increased for longer wavelengths as reference intensity increased. Peak luminous efficiency shifted from approximately 540 nm to greater than 600 nm with increasing intensity. Peak luminous efficiency was constant for flicker photometry across all intensities, but the function narrowed slightly at 100 fL. CONCLUSION: Luminous efficiency curves measured at high reference intensities are substantially different from the standard luminous efficiency functions. Caution should be used when measuring spectrally narrow and bright sources such as lasers and LEDs with a V(lambda) corrected photometer because the measured luminance may correlate poorly with perceived brightness.

Adult↗