dear dr. Liu
We had in the past similar problems with the assesment of a inter-stimulus
time. The problem with photo cells is the refresh rate of the
monitor. If the stimulus is short in time, you could have problems
with the refresh rate of the monitor if the response
rate photocell is too fast. You must consider a photocell with
a response time fastest than the stimulus duration but slower
than the refresh rate of the monitor. If you give me the details
of the stimulus duration of your experiment and monitor
I could evaluate if the experimental device we use could be useful
for you.
Dr. ALvaro Pons
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