ABSTRACT
Results from extrinsic-uncertainty, primary-with-probes, and concurrent experiments using near-threshold visual patterns differing in spatial frequency or spatial position suggest: (a) Typical observers can attend to and give direct reports from selected ranges of spatial frequency and spatial position in the sense of basing their responses on appropriate subsets of visual mechanisms, (b) This selective attention may sometimes occur early enough to block the unmonitored mechanisms’ outputs from influencing conscious perception, (c) Observers in these near-threshold tasks can also attend to the whole range without losing any information from any subpart of the range. (The largest number of far-apart spatial frequencies or spatial positions used was five or three, respectively, however.)
