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E E Johns

Publications and source records attributed to E E Johns.

6 recordsLinked to original sources
PubMed2003

The effect of feature frequency on short-term recognition memory.

We report two experiments using Sternberg's (1969) multitrial recognition-memory paradigm. We used colored shapes as stimuli and manipulated the frequency of the shapes (but not of the colors) across trials. For lures containing an extralist shape (i.e., a shape not studied in the current study list), responses were faster if the shape had occurred infrequently than if it had occurred frequently in the preceding trials. For lures containing an extralist color and a studied shape, by contrast, the frequency of the shape in the preceding trials was irrelevant. We conclude that correct rejections depend solely on contradictory evidence. Furthermore, low-frequency target items were recognized more easily than high-frequency targets. Both the interaction of frequency with the features of the lures and the main effect of frequency for the targets are problematic for current accounts of recognition.

Form Perception↗
PubMed2002

What information underlies correct rejections in short-term recognition memory?

We propose that correct rejections are based on information that contradicts the study set, rather than on insufficient familiarity. Using two-dimensional stimuli, we varied the featural overlap between lures and the study set so that one feature of the lure had occurred during study and the second feature of the lure had not occurred. Familiarity varied with the number of times the studied feature had occurred, whereas detectability of the extralist feature varied with the number of studied alternatives on the same dimension. Lures increased in difficulty with familiarity only when familiarity of the studied feature was confounded with the number of alternatives to the extralist feature. Hence, the difficulty in rejecting the lure was controlled by the number of alternatives to the extralist feature, not by the familiarity of the lure. Current theory requires additional representation assumptions and a new comparison process to accommodate these data.

Adult↗
PubMed2000

The extralist-feature effect: evidence against item matching in short-term recognition memory.

The authors varied the similarity between negative probes and study items in a short-term item-recognition task. Current models treat similarity as a function of the number of occurrences of the probe's features in the study set, a factor that is often confounded with the number of the probe's features occurring in the study set. Unconfounded comparisons showed that performance reflected only the latter factor, with response time a linear function of the number of probe features in the study set. The effect was obtained for both stimuli with manipulated features (colored shapes) and words. Number of presented features is a global property of the study list, but existing global models calculate familiarity by averaging across item matches and cannot readily accommodate the data. The authors proposed that the probe's features are compared with a global representation of the study set's features.

Adult↗
PubMed1991

Early and late selection in partial report: evidence from degraded displays.

In studies of iconic memory using the bar-probe task, subjects see a brief display of target letters and are probed by an arrow to report one of them. According to the classic early-selection account, subjects use the probe to select material for perceptual analysis from a precategorical (iconic) memory, but according to late-selection theories, subjects first identify the letters and then use the probe to select one letter for report from the set of categorized items. Pashler (1984) based his test for the locus of selection on a manipulation of display quality in previewed displays. He presented a target for 200 msec and then added a probe, together with the target, for an additional 150 msec. Reducing the target's stimulus quality increased response latency. If the subjects identified the characters before the probe appeared and then selected an item for report, the clarity of the original array should not have affected response latency. Hence, Pashler concluded that his subjects used the probe to select from a precategorical store (early selection). Pashler's experiment did not force subjects to rely on memory of the target; hence, although his experiment documented a situation in which subjects used early selection, it did not rule out late selection in studies of information persistence. We replicated Pashler's findings and, using his logic, showed that when subjects are forced to rely on memory of the target, they select from a categorized store.

Adult↗
PubMedDate not supplied

Sharpening the echo: an iterative-resonance model for short-term recognition memory.

We present an iterative-resonance model for recognition memory. On successive iterations, the probe is compared against a feature-by-feature profile of the study set. Yes decisions depend on the similarity of the probe to the profile; No decisions depend on a count of elements in the probe that are not in the profile. Successive iterations sharpen the evidence, and response latency is a function of the number of iterations needed to obtain a sufficiently clear result. The model successfully simulates classic data as well as recent data problematic for alternate models.

Algorithms↗