Abstract
Di Lollo, Enns, & Rensink (2000) have demonstrated that four small dots can produce substantial masking when they surround the target in a visual search task. Vogel, Woodman, & Luck (in press) have shown that the presentation of pattern masks in a change-detection task can interrupt the process of transforming perceptual representations into durable working memory representations (consolidation masking). Both types of masking effects increases as set size increases. The present study was designed to determine whether these two types of masking are really the same. One potential difference is that consolidation masking is quite effective for simple features whereas four-dot masking is not. However, the lack of four-dot masking with simple-feature targets observed in previous studies may have been caused by pop-out of the targets, leading to a rapid deployment of attention. In contrast, all of the objects must be attended in the consolidation masking paradigm. In the present study, we assessed whether four-dot masks are effective or ineffective at masking simple-feature objects when all the objects must be attended. To accomplish this, we conducted a change-detection experiment with arrays of 1–4 oriented lines. Each of the items in the sample array was surrounded by four dots that began at the same time as the sample array and persisted for a variable amount of time after the offset of the sample array. Very little masking was observed, and the masking effects did not increase as set size increased. A follow-up experiment showed that extensive masking was present when the same stimuli were used in the context of a perceptually demanding visual search task. Thus, four-dot masks do not impair performance for simple-feature targets, even when attention cannot be rapidly deployed to a single pop-out target. We conclude that four-dot masks interfere with the formation of perceptual representations, not with the consolidation of information in working memory.
This research was made possible by grants R01 MH63001 and R01 MH65034 from the National Institute of Mental Health.