Finding lung nodules with and without comparative visual scanning

The effect of a pretarget (TS1) masked by a noise mask (MS) upon the recognition of a posttarget (TS2) was examined in a TS1-MS-TS2 paradigm. The results clearly showed that the presentation of TS1 masked completely by MS reduced the recognition of a subsequent TS2 to a much greater extent if TS2 was the same as TS1 than when it was not. The results suggest that a TS1 that is perceptually masked by an MS nevertheless continues to have an effect within the visual system. A possible explanation of this reductive effect is described briefly.