How much is an icon worth?

Perception & Psychophysics

Busey

Senders

1993

Self Cite

Our major goal is to account for some simple digit-recall data with a theory that integrates two models from two scientific traditions. The random-sampling model, founded in the memory and attention literature, holds that (1) stimulus features are randomly sampled throughout the course of stimulus presence and (2) proportion correct recall is equal to the ratio of sampled features to total features. The linear-filter model, founded in the vision and sensation literature, holds that the initial stages of the visual system act as a low-pass temporal filter on the input stimulus, resulting in a time-varying sensory response in the nervous system. We report two experiments in which a variable-duration, masked, four-digit string had to be immediately recalled. Experiment 1 was designed principally to replicate past data confirming the basic randomsampling model. Like others, we were able to confirm the model only by endowing it with an additional processing-delay assumption: that feature sampling does not begin until the stimulus has been physically present for some minimal duration. Experiment 2 was an extension of Experiment 1 in which the target stimulus was preceded, 250 msec prior to its onset, by a 50-msec pre-presentation of the same stimulus called a prime. The Experiment 2 results allowed the following conclusions. First, the initial processing delay found in Experiment 1 is immutably tied to stimulus onset; that is, if there are two stimulus onsets, separated even briefly in time, there are two associated processing delays. Second, processing rate is essentially unaffected by the prime's presentation. Third, being presented with a 50-msec prime is equivalent, in terms ofmemory performance, to increasing unprimed stimulus duration by approximately 30 msec; the prime can thus said to be worth 30 msec of additional exposure duration. This third conclusion seems superficially paradoxical, in the sense that one would expect that having seen a 50-msec prime would be equivalent to increasing exposure duration by at least the same 50 msec. However, both the initial processing delays and the 30-msec prime's worth are natural consequences of our theory that conjoins the random-sampling model with the linear-filter model. Two fundamental questions in perception are, What is the nature of information acquisition that follows the onset of a stimulus, and how is such information acquisition influenced by other priming stimuli presented prior to the stimulus? In this article, we report two experiments that bear on both of these questions as they apply to a digitrecall task in which a four-digit string is presented for varying durations to an observer who must immediately recall as many of the digits as possible.Such tasks have often been accounted for by one form or another of a random-sampling model. Variants of random-sampling models have long enjoyed popularity, both in the learning literature (e.g., Neimark & Estes, 1967) and in the attention and perception literature (e.g., This research was supported by an NIMH gran...

Section: Default Prediction Of the Basic Modelmentioning

confidence: 99%

Section: Stimuli and Apparatusmentioning

confidence: 99%

Providing a sensory basis for models of visual information acquisition

Perception & Psychophysics

Busey

Senders

1993

Self Cite

“…They then observed that performance curves for the immediate-mask and delayed-mask conditions were horizontally parallel, with the immediate-mask curve shifted to the right by 100 ms. That is, performance for a d-ms stimulus followed by an icon was identical to performance to a (d ϩ 100)-ms stimulus not followed by an icon. Loftus et al (1985) concluded that irrespective of the duration of the physical stimulus that it follows, "an icon is worth 100 ms of additional physical exposure duration" (p. 1). Reinitz, Wright, and Loftus (1989) used similar logic to investigate priming effects.…”

Section: Experiments 2: Primingmentioning

confidence: 99%

“…These conditions allow testing of a strong and unambiguous interactive GtL theory prediction that uses methodology and associated logic introduced by Loftus, Johnson, and Shimamura (1985; see also Loftus, Duncan, & Gehrig, 1992) for investigating the contribution to memory of an iconic image. Loftus et al (1985) presented stimuli at varying durations that were followed either by an immediate mask (which did not allow an icon) or by a 300-ms delayed mask (which did allow an icon).…”

Section: Experiments 2: Primingmentioning

confidence: 99%

“…Loftus et al (1985) presented stimuli at varying durations that were followed either by an immediate mask (which did not allow an icon) or by a 300-ms delayed mask (which did allow an icon). They then observed that performance curves for the immediate-mask and delayed-mask conditions were horizontally parallel, with the immediate-mask curve shifted to the right by 100 ms. That is, performance for a d-ms stimulus followed by an icon was identical to performance to a (d ϩ 100)-ms stimulus not followed by an icon.…”

Section: Experiments 2: Primingmentioning

confidence: 99%

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How Different Spatial-Frequency Components Contribute to Visual Information Acquisition.

Journal of Experimental Psychology: Human Perception and Perfor

Harley

2004

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We test 3 theories of global and local scene information acquisition, defining global and local in terms of spatial frequencies. By independence theories, high-and low-spatial-frequency information are acquired over the same time course and combine additively. By global-precedence theories, global information acquisition precedes local information acquisition, but they combine additively. By interactive theories, global information also affects local-information acquisition rate. We report 2 digit-recall experiments. In the 1st, we confirmed independence theories. In the 2nd, we disconfirmed both independence theories and interactive theories, leaving global-precedence theories as the remaining alternative. We show that a specific global-precedence theory quantitatively accounted for Experiments 1-2 data as well as for past data. We discuss how their spatial-frequency definition of spatial scale comports with definitions used by others, and we consider the suggestion by P. G. Schyns and colleagues (e.g., D. J. Morrison & Schyns, 2001) that the visual system may act flexibly rather than rigidly in its use of spatial scales.Since the time of Neisser's (1967) classic Cognitive Psychology, visual scenes have been conceptualized as being decomposable into global and local information: Global information corresponds to overall scene structure, whereas local information corresponds to fine details (see Morrison & Schyns, 2001, pp. 454 -456, for a summary). This article is about the relations between global information and local information-the relative time courses over which they are acquired and the means by which they combine into an overall perception of the scene. Spatial-Frequency InformationGlobal and local information can be operationalized in many ways. One of them is in terms of spatial frequencies. From the visual system's perspective, the world is made up of different spatial frequencies. An example is provided in Figure 1, the top of which shows a typical real-world scene. The two bottom panels show the same picture filtered to pass only the low spatial frequencies (LSFs; bottom left) or high spatial frequencies (HSFs; bottom right). It is evident that the two spatial-frequency components carry different kinds of information that accord well with the general conceptualization of global information and local information: The bottom left Figure-1 picture carries a global representation of the scene, whereas the bottom right picture conveys information about edges and details, such as the writing on the dollar bill. There is indeed ample evidence that the visual system decomposes the visual scene into separate spatial-frequency components (Blakemore & Campbell, 1969;Campbell & Robson, 1968;De Valois & De Valois, 1980, 1988Graham, 1989;Olzak & Thomas, 1986). Accordingly, a correspondence between global-local on the one hand and LSF-HSF on the other has been hypothesized by numerous investigators (e.g., Hughes, Nozawa, & Ketterle, 1996;Schyns & Oliva, 1994), and we shall use it in the remainder of this article....

Analysis, Interpretation, and Visual Presentation of Experimental Data

Stevens' Handbook of Experimental Psychology

2002

This chapter has two main purposes: the first is to discuss serious problems with two generally accepted and widely used foundations of current statistical analysis in psychology, the linear model and null hypothesis significance testing; the second purpose is to describe some alternative valuable techniques. The alternatives are grouped into six categories: (1) use of sophisticated pictorial and graphical techniques for data display, (2) use of confidence intervals in numerous situations, (3) use of planned comparisons, emphasizing contrasts , (4) use of percent total variance accounted for, (5) representation of theoretical fits to data, and (6) use of equivalence techniques to investigate interactions. Detailed hypothetical numerical examples along with associated calculations and graphs are constructed to illustrate each of the techniques.