John R. Vokey

Salience of Item Knowledge in Learning Artificial Grammars

Both the specific similarity of test items to study items and the grammaticality of test items were found to be major determinants of performance under task conditions common in the literature. Results bearing on the issue of how item-specific effects are coordinated with knowledge pooled across items are: (a) Better item memory resulted in smaller rather than larger effects of specific similarity on judgments of grammaticality, suggesting that items can be too well differentiated to support transfer to new items, (b) Variation in the effect of specific similarity did not result in compensatory variation in grammaticality, suggesting that any scheme that tightly links the effects of the two variables is insufficient, (c) Differential reliance on the 2 knowledge resources was not under good instructional control, which poses a problem for accounts that use functional task analyses to coordinate functionally different memories.

Familiarity, memorability, and the effect of typicality on the recognition of faces.

Typical faces are more poorly discriminated on tests of recognition than are atypical faces, an effect suggested to mediate similar findings for attractive or likable faces. We tested the hypothesis that the effect of typicality on recognition is a function of context-free familiarity and memorability, which function in opposition. Two orthogonal principal components were extracted from subjects’ ratings of faces for typicality, familiarity, attractiveness, likability, and memorability—one consisting of the ratings of familiarity, attractiveness, and likability, and reflecting context-free familiarity, and the other consisting of the memorability rating. As expected, typicality loaded equally (r ≈ .66), but with opposite sign, on both components. In subsequent experiments, both components were found to be significant and additive, predictors of face recognition with no residual effect of typicality. General familiarity decreased discrimination, and the memorability component enhanced it, supporting the hypothesis. The results are discussed in terms of the mirror effect.

Lifting the curtain on the Wizard of Oz: Biased voice-based impressions of speaker size.

The consistent, but often wrong, impressions people form of the size of unseen speakers are not random but rather point to a consistent misattribution bias, one that the advertising, broadcasting, and entertainment industries also routinely exploit. The authors report 3 experiments examining the perceptual basis of this bias. The results indicate that, under controlled experimental conditions, listeners can make relative size distinctions between male speakers using reliable cues carried in voice formant frequencies (resonant frequencies, or timbre) but that this ability can be perturbed by discordant voice fundamental frequency (F-sub-0, or pitch) differences between speakers. The authors introduce 3 accounts for the perceptual pull that voice F-sub-0 can exert on our routine (mis)attributions of speaker size and consider the role that voice F-sub-0 plays in additional voice-based attributions that may or may not be reliable but that have clear size connotations.

Illusory recollection and dual-process models of recognition memory.

Higham and Vokey (2000, Exps.1 & 3)demonstrated that a slight increase in the display duration of a briefly presented word prior to displaying it in the clear for a recognition response increased the bias to respond “old”. In the current research, three experiments investigated the phenomenology associated with this illusion of memory using the standard remember–know procedure and a new, independent–scales methodology. Contrary to expectations based on the fluency heuristic, which predicts effects of display duration on subjective familiarity only, the results indicated that the illusion was reported as both familiarity and recollection. Furthermore, manipulations of prime duration induced reports of false recollection in all experiments. The results—in particular, the implications of illusory recollection—are discussed in terms of dual–process, fuzzy–trace, two–criteria signal detection models and attribution models of recognition memory.

Beyond dissociation logic: evidence for controlled and automatic influences in artificial grammar learning.

Evidence for unconscious learning has typically been based on dissociations between direct and indirect tests of learning. Because of some inherent problems with dissociation logic, we applied the logic of opposition to 2 artificial grammar learning experiments. In Experiment 1, participants were exposed to 2 different sets of letter strings, generated from 2 different grammars, and later rated test strings for grammaticality with either in-concert (rate grammatical strings consistent with either structure) or opposition (rate grammatical only strings from 1 of the structures) instructions. Manipulating response deadline affected controlled, but not automatic influences. In Experiment 2, after similar training, a source-monitoring test was administered from which the in-concert and opposition conditions were derived. The test indicated that varying the retention interval affected controlled, but not automatic, influences. The results are discussed in terms of awareness, knowledge representation, and metacognitive processing.

The Face-Space Typicality Paradox: Understanding the Face-Space Metaphor

Some recent accounts of human face processing use the idea of “face space”, considered to be a multi-dimensional space whose dimensions correspond to ways in which faces can vary. Within this space, “typicality” is sometimes taken to reflect the proximity of a face to its local neighbours. Intuitions about the distribution of faces within the space may suggest that the majority of faces will be “typical” in these terms. However, when typicality measures are taken, researchers very rarely find that faces cluster at the “typical” end of the scale. In this short note we attempt to resolve this paradox and point out that reasoning about high dimensional distributions requires that some specific assumptions are made explicit.

Judgment heuristics and recognition memory: Prime identification and target-processing fluency

In three experiments, the effect of identification of a briefly presented word (prime) on a subsequent recognition response to that word (target) was investigated. Theories of current processing fluency (e.g., Jacoby & Whitehouse, 1989) suggest that prime identification should reduce P(old) relative to prime misidentification because awareness of the prime provides a source to which to attribute target fluency, rendering attributions to prior presentation less likely. However, counter to these predictions, Experiment 1 demonstrated that prime identification increased P(old) relative to misidentified primes. It is hypothesized that this reversed effect was due to participants’ using a heuristic that related prime identification success to prior presentation but was not based on current processing fluency. In Experiment 2, participants were induced to avoid using this heuristic by making an alternate source for prime identification success (display duration) highly available. Under these circumstances, prime identification reduced P(old) relative to prime misidentification, suggesting that participants now relied on current processing fluency rather than on prime identification success. Experiment 3 replicated the results of Experiments 1 and 2, but with fixed rather than variable prime displays.

Perceptual identification of visually degraded stimuli

In this article, we describe procedures, materials, and some representative results of a microcomputer-based approach to the degradation of visual stimuli for the investigation of perceptual identification. We discuss application of the procedures for the production of visually degraded picture, letter, and word stimuli, and of visual stimuli common to neuropsychological investigations.

On the preliminary psychophysics of fingerprint identification

For a century, the matching of images of fingerprints has been used for forensic identification. Despite that history, there have been no published, peer-reviewed studies directly examining the extent to which people can correctly match fingerprints to one another. The results of three experiments using naïve undergraduates to match images of fingerprints are reported. The results demonstrate that people can identify fingerprints quite well, and that matching accuracy can vary as a function of both source finger type and image similarity.

Opposition logic and neural network models in artificial grammar learning.

Following neural network simulations of the two experiments of, argued that the opposition logic advocated by was incapable of distinguishing between single and multiple influences on performance of artificial grammar learning and more generally. We show that their simulations do not support their conclusions. We also provide different neural network simulations that do simulate the essential results of Higham et al. (2000).