Effects of intertrial interval, orientation, and adaptation on orientation discrimination measured with a yes-no signal detection paradigm.

Orientation discriminations were measured with a 3.8-cpd sinusoidal grating stimulus and a yes-no signal-detection procedure. Analysis showed that such discriminations are independent of light-adaptation conditions and of intertrial interval over the 2- to 8-sec. range of values explored. However, they are strongly influenced by the orientation where measurements are made (the "oblique effect").