Science & tech · 2012
How can scientists separate the two binocular signals that help us see motion in depth?
Model simulations suggest that uncorrelated random dot patterns—0% correlation between the two eyes—are useful for isolating either signal. Contrast-reversed, anticorrelated patterns may not be.
Details
Random dot patterns (RDPs) have been used to stimulate separately two binocular mechanisms for perceiving motion in depth: interocular velocity difference (IOVD) and changing over time (CDOT).
The researchers first examined how these stimuli isolate either mechanism using computational models based on motion/disparity energy detection. In the model, the IOVD mechanism calculates the difference in motion signal between the two eyes. The CDOT mechanism calculates the difference in disparity signal between sequential stereo images.
The simulation revealed that uncorrelated RDPs, with 0% correlation, are useful for isolating either mechanism, whereas contrast-reversed RDPs, described as anticorrelated, may not be.
Next, the researchers compared the IOVD model's predictions with experimental data from a previous study of motion in depth that varied contrast, displacement, and vertical shift between the two eyes. The simulation showed that the model predicts the general trends in the effects of contrast, displacement, and vertical shift found in those data.
These findings suggest that the energy-based model of motion in depth is physiologically plausible.
What do you think?
Good conversations begin with curiosity.
You can read comments without an account. Sign in to write.
Loading comments…