Temporal summation and reaction times for detecting gratings.

The effects of the duration of presentation of stimuli on the reaction time for detection of gratings of different spatial frequencies were studied. The product of contrast and duration (the contrast "energy") was kept constant for each duration. These experiments showed that at near-threshold "energies," reaction times did not change with increases in the duration to 15 and 30 msec at low and high spatial frequencies respectively.

[Temporal summation and reaction time for grid detection].

We studied the stimulus-duration effect on the reaction time (RT) to gratings with different spatial frequencies. At each duration value, the product of the contrast and the duration, i.e.