Answer:
A miss
Explanation:
In signal detection theory, when a signal is present but an individual fails to detected it, it is referred to as a miss. The participants inability to detected the rightward motion even though it was present is a miss. Other possible outcomes are a hit (being able to detect a present signal correctly, correct rejection (inability to detect a signal even when the signal is in fact absent), false alarm (when a signal is absent but detected as present).