Work & Projects
Early days. One rotation project done, many more questions to go.
Do Microfluctuations Increase When Chromatic Aberration Cues Are Reduced?
Chromatic aberration is considered a directional cue that helps drive accommodation: because the eye focuses different wavelengths at slightly different depths, the resulting blur signal gives the visual system information about which way to adjust focus. This project asked what happens when that cue is degraded. By manipulating the red/blue ratio of a target, chromatic aberration information can be systematically reduced. At the extremes of the ratio (pure red or pure blue), there is very little wavelength contrast, meaning the chromatic cue is weakest. If microfluctuations serve as a search signal that helps the eye find the correct focal plane, then reducing chromatic information should force the system to rely more on them, and their power should rise. This predicts a U-shaped relationship between red/blue ratio and microfluctuation power, with the highest power at the edges where chromatic information is least available. Using data from a previous experiment, I analysed microfluctuation power across 10 chromatic conditions and 3 target distances (1.5D, 2.5D, 3.5D), with 180 trials per subject.
The results showed a significant effect of target distance on microfluctuation power (p<0.01): farther targets produced larger fluctuations. However, there was no significant effect of chromatic content (p=0.98). The U-shaped pattern was not observed across any distance condition. This suggests that, at least under these conditions, microfluctuation power does not appear to increase in response to reduced chromatic aberration cues in the way the hypothesis predicted.
