The traditional view of iconic memory as a precategorical, high-capacity, quickly decaying visible memory has recently come under attack (e.g., Coltheart, 1980). Specifically, distinctions have been drawn between visible persistence, or the phenomenal trace of an extinguished stimulus, and informational persistence, knowledge about the visual properties of the stimulus. In the present research we tested two alternative conceptions of informational persistence. One conception is that visual information persists in a visual memory that begins at stimulus offset and lasts for 150-300 ms, independently of exposure duration. The second is that informational persistence arises from a nonvisual memory that contains spatial coordinates for displayed items along with identity codes for those items. Three experiments were conducted in which 3X3 letter arrays were presented for durations ranging from 50 to 500 ms. A single character mask presented at varying intervals after array offset cued report of an entire row of the array. Comparison of the cued row's masked and unmasked letters revealed that spatially-specific visual (i.e., maskable) information persisted after stimulus offset, regardless of exposure duration. This result favors the visual conception of informational persistence. But there was also support for the nonvisual conception: Accuracy increased and item intrusion errors decreased as stimulus duration increased. The implications of these results for models of informational persistence and for transsaccadic integration during reading are discussed.It has been known at least since Aristotle's time (384-322 B.C.) that visual sensation persists after stimulus offset (Allen, 1926). Contemporary interest in this property of the visual system was revived by Sperling (1960). In Sperling's experiments, subjects were presented an array of letters for some brief time.Following stimulus offset, a subset of the information in the array was cued for report. Sperling found that subjects' recall performance for the cued information was very high if the cue was presented within about 100 ms or so of stimulus offset. Furthermore, recall accuracy decreased as the time between stimulus offset and presentation of the recall cue increased. These results contrasted with performance when subjects were asked to report the entire array of letters. In this case, recall performance was limited to only a few items from the array. Taken together, Experiments I and 2 were part of a senior honors thesis submitted by the second author, under the direction of the first author, to Cornell University. Experiment 2 was presented at the 25th annual meeting of the Psychonomic Society, San Antonio, lexas, November 1984. Experiment 3 and the preparation of the manuscript were supported by an AllUruversity Research Initiation Grant from Michigan State University to the first author, and also by National Science Foundation Grant BNS 85-19580 to the first author.We thank Kathryn Bock, Joseph Brown, Thomas Carr, Lester Hyman, James Zacks, and Rose Zac...

This paper investigates the effect of stimulus duration on partial report performance. Two experiments showed that variations in stimulus duration from 50 to 500 msec had little or no effect on partial report accuracy, decay, or error patterns. These results contrast with previous research demonstrating that increasing stimulus duration decreases visible persistence duration. Our findings thus provide support for the argument (Coltheart, 1980) that informational persistence (knowledge about the visual properties of a stimulus) is a separate phenomenon from visible persistence (the phenomenal persistence of a stimulus), and suggest that the traditional view of iconic memory, which conflates these two forms of persistence, is incorrect. Furthermore, our results indicate that informational persistence is not merely a function of unnaturally brief stimulus exposures, but exists even after exposure durations as long as 500 msec. Possible mechanisms of informational persistence, as well as its potential role in everyday perception, are discussed.It has been known for centuries that visual sensation persists after stimulus offset; the writings of Aristotle (384-322 B.C.) reportedly contain the first known reference to this phenomenon (Allen, 1926). The fairly recent rekindling of interest in visual persistence can, perhaps, be traced to the work of Sperling (1960). Sperling briefly presented subjects an array of letters and, following their offset, cued report of one row of the array. Sperling found that subjects' recall performance for the cued row was very high if the cue was presented within about 100 msec or so of stimulus offset. Furthermore, recall accuracy decreased as the time between stimulus offset and presentation of the recall cue increased. These results stood in contrast with what happened when subjects were asked to report the entire array of letters. In this case, recall performance was limited to only a few items from the array. Taken together, these results suggested that immediately following stimulus offset there was more information available about the array than could be normally reported, but this information disappeared quickly with the passage of time. This method of sampling a subset of the total information in an array has been called the partial-report technique, and the superior recall performance under these conditions, the partial-report superiority effect.

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Visible persistence refers to the phenomenal impression that a stimulus is still present after its offset. A dispute exists whether visible persistence is due to temporal sluggishness in the visual pathway (neural hypothesis) or whether it is a byproduct of information-extraction processes under cognitive control (process hypothesis). This was investigated by manipulating stimulus complexity in five temporal integration experiments and one recognition memory experiment. According to the process hypothesis, complex stimuli should persist longer than simple stimuli because they require more information extraction. This prediction was not confirmed; in all six experiments, complexity was found to have no reliable effect on the duration of visible persistence. By contrast, and in accordance with earlier findings, complexity was shown to have a significant effect on a short-lived, nonvisible form of memory known as schematic persistence. This pattern of results supports two major conclusions: First, that the effects of complexity reported in earlier research were probably on schematic-rather than visible-persistence; and second, that visible persistence must be regarded as a residual neural trace of an extinguished stimulus, rather than as a byproduct of information-extraction processes.Visible persistence refers to the phenomenal, lingering trace of a stimulus after its offset. Some investigators, such as Coltheart (1980) and Eriksen and Schultz (1978), have suggested that visible persistence is due to residual neural activity in the visual pathway. According to this neural view, visible persistence results from temporal sluggishness in the visual system. In other words, it is an automatic event initiated by stimulus onset whose duration is determined by physical characteristics of the stimulus such as its intensity and its duration. Other investigators, however, such as Erwin (19700, 1976b), Erwin and Hershenson (1974), Loftus andHanna (1989), andLoftus andHogden (1988), have challenged this view on the basis of experiments whose results suggest that the amount of information contained in a stimulus affects how long it appears to persist after its offset. This result has been taken as evidence for aprocess model of visible persistence in which persistence duration is determined by the processing demands of higher level cognitive operations, such as stimulus encoding. According to this view, visible persistence is a byproduct of ongoing informationThis article is based on a master's thesis submitted by thesecond author to Michigan State University. The research was supported by Grants BNS 85-19580 and BNS 89-08699 from the National Science Foundation to David E. Irwin. Portions of the data were presented at the annual meeting of the Midwestern Psychological Association, Chicago, IL in May 1986. We thank David Van Dyk and Jennifer Larys for assistance with data collection and Tom Carr and Jim Zacks for helpful comments regarding the research. Vince Di Lollo and two anonymous reviewers madehelpful comments on an earli...

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