Hypothesis #1: 53% in an experiment that has 36 trials? Really? 50% is 18/36, but 19/36 is 52.7%, and 19/35 is 54.3%. Depending on experimental design, if it

Hypothesis #1: 53% in an experiment that has 36 trials? Really? 50% is 18/36, but 19/36 is 52.7%, and 19/35 is 54.3%. Depending on experimental design, if it just so happens that near the end of the 20 minutes, the subject has a tendency stop on one of the last erotic pictures they're like to guess and let the time run out. Hypothesis #2: Depending on how the computer's random number generator was seeded (and they might have a relatively short repeating sequence), subjects may have, however unconsciously, "learned" to predict the randomness, something they would have insufficient motivation to do in the other set of pictures. [We can test for this by seeing if they were getting better at it over the course of a session.]