ROLE OF KNOWLEDGE IN HUMAN VISUAL TEMPORAL INTEGRATION IN SPATIOTEMPORAL NOISE

Previous studies have shown how human observers' knowledge about the s ignal's spatial frequency, spatial phase, and spatial locations affect s human performance in detecting and identifying signals in spatial no ise. These results have led to the idea that human observers can be mo deled as suboptimal Bayesian observers that use a priori information t o generate probabilities or likelihoods for hypothesis. This approach has also been applied more recently to object recognition. We investig ate whether human observers have the ability to use information about the temporal profile of a temporally modulated signal in temporal info rmation processing. We measure human performance in detecting a time-v arying signal embedded in spatiotemporal (dynamic) noise with and with out a cue that contains information about the temporal phase of the si gnal. Results show improvement in performance in the phase-cued condit ion, suggesting that human observers act as if they have the ability t o use knowledge about the temporal shape of the signal when performing temporal information processing. Human performance is consistent with a suboptimal Bayesian observer and a newly proposed Max-Min observer. The results also suggest that models based solely on the integration of the early temporal filters in the human visual system and/or any fu rther integration (e.g., probability summation), which do not make use of knowledge about the signals' temporal profile, are incomplete mode ls of human visual detection in spatiotemporal noise. (C) 1996 Optical Society of America.