Jacoby and Dallas (1981) found that if an object "jumps out" at a person and is readily perceived, then they have likely seen it before even if they do not consciously remember seeing it.
[3] a) cities in the U.S with more than 100,000 inhabitants b) the 100 German companies with the highest revenue in 2003 c) the top 106 music artists in the U.S. in terms of cumulative sales of recordings from 1958 to 2003 d) the highest paid athletes of 2004 e) the 100 wealthiest people in the world Hertwig et al. measured response time latencies for participants presented with each object.
They observed three results: First, people prove to be quite good at discriminating between recognition latencies whose differences exceeds 100 ms. Second, even when taking less-than perfectly accurate discriminations into account, subjective fluency judgments are a moderately good predictor of the criterion, except in environments in which ecological validity of fluency information is too low to begin with (e.g. music artist's environment).
Hertwig et al. also found that the larger the difference between recognition latencies (for two objects), the greater the likelihood that the actual inference adheres to that predicted by the fluency heuristic.
[3] Neural correlates of the fluency heuristic: Volz, Schooler, and von Cramon (2010) used functional magnetic resonance imaging to isolate fluency-heuristic-based judgments to map the use of fluency onto specific brain areas that might give a better understanding of the heuristic's underlying processes.