A bias interpretation of facilitation in perceptual identification.

In a typical perceptual identification task, a word is presented for a few milliseconds and masked; then subjects are asked to report the word. It has been found that an earlier presentation of the test word will improve identification of the test word by as much as 30%. In addition, this facilitation has been shown to be preserved under amnesia. In this article we examined a fundamental question: Is the facilitation the result of bias toward the earlier presented item, an improvement in perceptual sensitivity, or both? The experiments presented here use a forced choice procedure to show that prior presentation of an item biases the subject to choose that item but does not improve discriminability. This result is obtained when the distractor items are visually similar to the target items. When distractors are dissimilar, earlier presentation affects neither bias nor discriminability. Two models of word identification are examined in light of the bias effects, and implications for understanding savings in amnesia are also examined. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Bayesian model for implicit effects in perceptual identification.

Retrieving effectively from memory (REM; R. M. Shiffrin & M. Steyvers, 1997), an episodic model of memory, is extended to implicit memory phenomena, namely the perceptual identification studies reported in R. Ratcliff and G. McKoon (1997). In those studies, the influence of prior study was greatest when words were presented most briefly and when forced-choice targets and foils were most similar. R. Ratcliff and G. McKoon use these data to argue against models in which prior study changes a word's representation. A model in which prior study changes a word's representation by adding context information is fit to their data; at test, the model uses a Bayesian decision process to compare the perceptual and context features associated with the test flash to stored traces. The effects of prior study are due to matching extra context information and are larger when alternatives share many features, thereby reducing noise that attenuates these effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attention and perceptual priming in the perceptual identification task.

Prior research indicates that manipulations of attention during encoding sometimes affect perceptual implicit memory. Two hypotheses were investigated. One proposes that manipulations of attention affect perceptual priming only to the extent that they disrupt stimulus identification. The other attributes reduced priming to the disruptive effects of distractor selection. The role of attention was investigated with a variant of the Stroop task in which participants either read words, identified their color, or did both. Identifying the color reduced priming even when the word was also overtly identified. This result held regardless of whether color and word were presented as a single object (Experiments 1 and 2) or as separate objects (Experiment 4). When participants read and identified a color, the overt order of the responses did not matter; both conditions reduced priming relative to reading alone (Experiment 3). The results provide evidence against the stimulus-identification account but are consistent with the distractor-selection hypothesis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The nature of word frequency effects on perceptual identification.

Four experiments, using a study–test paradigm, examined the effects of event presentation frequency on perceptual identification. In each cycle, subjects studied a list with different items presented from one to four or more times, then received identification tests of studied and nonstudied items. Pseudoword repetition (Experiments 1 and 4) produced a priming effect, that is, enhanced identification for presented items, and a repetition effect, that is, incremental improvements in identification for repeated items. In contrast, word repetition (Experiment 2, 3, and 4) produced priming but not repetition effects, a pattern that was not due to learning asymptotes or scaling distortions. We conclude that presentation frequency effects act on at least two distinct processing paths, selected on the basis of processing and task demands. Under conditions of simple exposure, perceptual enhancement is mediated, for codified events like words, primarily by nodal activation, and, for noncodified events like pseudowords, by information accumulation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aggregation bias in estimates of perceptual agreement.

Discusses the need to demonstrate agreement among individuals' perceptions of climate prior to averaging climate scores from the perspective of aggregation. It is shown that estimates of agreement based on group mean scores have been incorrectly interpreted as perceptual agreement among individuals. Of initial importance is a study by J. A. Drexler (see record 1977-22375-001), who concluded that a considerable proportion of the variance in climate perceptions was accounted for by organizational membership. This conclusion has been employed recently by other authors to support the assumption that individuals in the same environment tend to agree with climate perceptions (e.g., J. R. Hackman and E. E. Lawler, Hackman and G. R. Oldham, and Oldham et al—see PA, Vols 46:9858, 54:2031, and 57:2102, respectively). It is demonstrated that Drexler's analysis provided inflated estimates of agreement among individuals, and the logic of the approach is extended to other studies in which inflated estimates of agreement appeared likely. (54 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developmental sex differences in global-local perceptual bias.

Previous developmental studies have indicated that boys tend to perform better than girls on tasks associated with the right hemisphere (e.g., spatial tasks), whereas girls perform better on tasks associated with the left hemisphere (e.g., verbal tasks). Extending this body of literature to what is known about hemispheric specialization of visuospatial processing, we predicted that boys would be more global than girls in their perception of visual hierarchical stimuli. Forty girls and 39 boys between the ages of 4 and 12 years were administered a perceptual judgment task previously used by Kimchi and Palmer (see record 1983-02534-001). Boys were significantly more global in their perceptual judgments than girls at all ages. Younger children of both sexes were less global than older children. Results were consistent with developmental models that suggest an early left-hemisphere advantage for girls and a right-hemisphere advantage for boys. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The interplay of memory and judgment processes in effects of aging on hindsight bias.

Hindsight bias is the phenomenon that after people are presented with the correct answer to a question, their judgment regarding their own past answer to this question is biased toward the correct answer. In three experiments, younger and older adults gave numerical responses to general-knowledge questions and later attempted to recall their responses. For some questions, the correct answer was provided during recall (Experiment 1) or before recall (Experiments 2 and 3). Multinomial model-based analyses show age differences in both recollection bias and reconstruction bias when the correct judgment was in working memory during the recall phase. The authors discuss implications for theories of cognitive aging and theories of hindsight bias. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Form-specific priming and functional brain asymmetries in perceptual identification

Word form representations in intact cerebral hemispheres were studied by a lateralized perceptual identification priming task. During the study phase, word forms were primed by displaying words visually in uppercase or lowercase letters. During the test phase, perceptual identification of non-studied baseline words and studied words (presented in same or different lettercase as studied) was tested by displaying targets in the left or right visual field. Experiment 1 showed that the hemispheric pattern of priming effects was dependent on the lettercase at test. For uppercase test items, only the left visual field/right hemisphere was sentitive to study-test changes in lettercase, replicating an earlier result obtained in word-stem completion (Marsolek, Kosslyn and Squire, 1992). However, lowercase test items did not reveal any asymmetries in the form-dependent priming component indicating that in some conditions form-specific representations are computed in the left hemisphere also. No asymmetries were found in the abstract, form-independent component of priming. Experiment 2 revealed that use of explicit memory in the perceptual identification task eliminated the form-specific priming effects and suggested that the results of Experiment 1 were uncontaminated by explicit memory.     

Semantic effects in naming perceptual identification but not in delayed naming: Implications for models and tasks.

Previous research has demonstrated that the subjective danger and usefulness of words affect lexical decision times. Usually, an interaction is found: Increasing danger predicts faster reaction times (RTs) for words low on usefulness, but increasing danger predicts slower RTs for words high on usefulness. The authors show the same interaction with immediate auditory naming. The interaction disappeared with a delayed auditory naming control experiment, suggesting that it has a perceptual basis. In an attempt to separate input (signal to ear) from output (brain to muscle) processes in word recognition, the authors ran 2 auditory perceptual identification experiments. The interaction was again significant, but performance was best for words high on both danger and usefulness. This suggests that initial demonstrations of the interaction were reflecting an output approach/withdraw response conflict induced by stimuli that are both dangerous and useful. The interaction cannot be characterized as a tradeoff of speed versus accuracy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Base-rate effects in multidimensional perceptual categorization

The optimality of human performance when category base rates differ was investigated in 2 multidimensional perceptual categorization tasks. All participants were sensitive to differences in base rate, even during their 1st experimental session. Nearly half of the participants learned the optimal decision bound by their final experimental session. Little evidence for conservative cutoff placement was found (i.e., an underestimation of category base-rate differences). In fact, participants who did not learn the optimal decision bound tended to use a decision bound that overestimated the base-rate difference. Across all conditions participants showed a clear shift toward the optimal decision bound with experience. These data suggest that experienced participants are highly sensitive to differences in category base rate. The model-based analyses suggest that the decision-bound model of categorization (Ashby, 1992a; Ashby & Maddox, 1993; Maddox & Ashby, 1993) provides a powerful tool for investigating the limits of human categorization performance.     

Base-rate and payoff effects in multidimensional perceptual categorization

The optimality of multidimensional perceptual categorization performance with unequal base rates and payoffs was examined. In Experiment 1, observers learned simultaneously the category structures and base rates or payoffs. Observers showed conservative cutoff placement when payoffs were unequal and extreme cutoff placement when base rates were unequal. In Experiment 2, observers were trained on the category structures before the base-rate or payoff manipulation. Simultaneous base-rate and payoff manipulations tested the hypothesis that base-rate information and payoff information are combined independently. Observers showed (a) small suboptimalities in base-rate and payoff estimation, (b) no qualitative differences across base-rate and payoff conditions, and (c) support for the hypothesis that base-rate and payoff information is combined independently. Implications for current theories of base-rate and payoff learning are discussed.     

A further study of the relationship between response bias and perceptual defense.

Ss were exposed to tachistoscopically-presented pairs of words and asked to report whether a particular word was on the left or right of a fixation point. A non-statistically-significant trend showed that Ss tended to demonstrate a response bias in terms of reporting anxiety or neutral words on one or the other side whether or not they were in fact on the stated side of the point. A 2nd phase of the experiment presented S with blank stimulus fields although S was expecting words. A response bias was not demonstrated. "… it is suggested that the use of a forced-choice spatial indicator of perception may undermine the motivational basis for perceptual defense." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Limiting lexical activation limits perceptual priming in masked word identification

Four experiments tested the hypothesis that perceptual priming of a word depends on the prior lexical processing of the word (Rajaram & Roediger, 1993; Weldon, 1991). Experiment 1 showed that first-letter naming reduced priming relative to reading a whole word on two tests: word fragment completion and masked word identification. In Experiment 2, naming the first letter of a word took longer than naming the letter presented alone, and led to better masked word identification. Experiment 3 showed that masked word identification was enhanced by prior word processing more for low frequency words than for high frequency words, but only when words had been read aloud. Experiment 4 tested whether the auditory input accruing from reading a word aloud was the source of facilitation and frequency effects. Participants judged either the frequency of the whole display or the positional frequency of the first letter in the display, and indicated their decisions manually. The major findings from Experiment 3 were replicated, ruling out the cross-modal source of those effects. It was concluded that activation of a lexical unit, one component of word processing (Vriezen, Moscovitch, & Bellos, 1995), is a critical determinant of the perceptual priming of that word.     

Priming and baseline perceptual identification performance in amnesia: A comment on Hamann, Squire, and Schacter.

There is evidence that stimulus processing deficits, some of which may be due to striatal damage, are prevalent in memory-impaired patients. The deficits often result in impaired baseline performance in implicit memory tasks, which in turn is associated with increased priming effects. When priming scores were corrected for such processing deficits, the authors found a relationship between priming and both recognition memory and mesial temporal lobe damage. On the basis of 4 tachistoscopic word identification experiments, S. B. Hamann et al (see record 1995-14158-001) challenged the notion that either processing deficits or striatal damage is prevalent in amnesia patients. They claim that both priming and baseline word identification are normal in amnesia patients, except that patients with Korsakoff amnesia show deficits under certain restricted circumstances. The authors argue that the results of the Hamann et al study are entirely consistent with their previous reports. When Hamann et al did not find differences between amnesia patients and controls in word identification, the results were contaminated by ceiling effects, and there was poor control over the effective exposure duration of the stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Competitive activation model of perceptual interference in picture and word identification.

Perceptual interference is the finding that prior exposures to a target item's partial features inhibit its later identification. This study tests a competitive activation model of perceptual interference that attributes interference to the activation of competing responses generated by prior cues. The authors examined 2 sets of data that seemed to be inconsistent or incompatible with the model. The first is the observed positive effect of viewing time of stimuli (J. S. Bruner and M. C. Potter, 1964). The second is the finding that interference occurs only for studied or primed words (Z. F. Peynircioglu, 1987; Peynircioglu and M. J. Watkins, 1986). Exps 1 and 2 showed paradoxical effects of viewing time and found evidence supporting the competitive activation model. Exps 3–6 failed to replicate Peynircioglu and Watkins's finding and showed that a performance level explanation compatible with the competitive activation model can account for all related results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Time-course contingencies in perceptual organization and identification of fragmented object outlines.

To study the dynamic interplay between different component processes involved in the identification of fragmented object outlines, the authors used a discrete-identification paradigm in which the masked presentation duration of fragmented object outlines was repeatedly increased until correct naming occurred. Survival analysis was used to investigate whether and when different types of information—such as contour integration cues (proximity, collinearity, and fragment density), fragment properties (low vs. high curvature), stimulus complexity (global symmetry, number and saliency of the parts), and memory factors (natural vs. artifactual)—influenced the timing of identification. The results show that the importance of these different types of information can change over the time course of object identification, indicating so-called time-course contingencies. Most important, the straight segments of a contour played a larger role for complex outlines with high part saliency during early (bottom-up) grouping processes, whereas the curved segments of object outlines were more important during later (top-down) matching processes for simpler outlines with lower part saliency. This new insight can explain why different studies on shape-based object identification have produced seemingly contradictory results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Functional anatomy of human odor sensation, discrimination, and identification in health and aging.

Aging of cerebral olfactory regions was studied in 5 younger and 6 older healthy adults, matched by odor discrimination and identification scores, with positron emission tomography during odor sensory stimulation, discrimination, and identification tasks. Sensory stimulation engaged bilateral piriform and orbitofrontal regions, but neither discrimination nor identification evoked added temporal or orbital activity. Discrimination involved the hippocampus, implicating its role in serial odor comparisons (olfactory working memory). Left inferior frontal activity during identification may reflect semantic associations. Older participants deactivated the left gyrus rectus/medial orbital gyrus (GR/MOG) during sensory stimulation but activated GR/MOG during discrimination and identification. Adjusting for detection threshold eliminated GR/MOG group differences during sensory stimulation. Diminished threshold may lead to reduced engagement of olfactory association areas. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Camera perspective bias in videotaped confessions: Experimental evidence of its perceptual basis.

The camera perspective from which a criminal confession is videotaped influences later assessments of its voluntariness and the suspect's guilt. Previous research has suggested that this camera perspective bias is rooted in perceptual rather than conceptual processes, but these data are strictly correlational. In 3 experiments, the authors directly manipulated perceptual processing to provide stronger evidence of its mediational role. Prior to viewing a videotape of a simulated confession, participants were shown a photograph of the confessor's apparent victim. Participants in a perceptual interference condition were instructed to visualize the image of the victim in their minds while viewing the videotape; participants in a conceptual interference condition were instructed instead to rehearse an 8-digit number. Because mental imagery and actual perception draw on the same available resources, the authors anticipated that the former, but not the latter, interference task would disrupt the camera perspective bias, if indeed it were perceptually mediated. Results supported this conclusion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Accuracy of feeling-of-knowing judgments for predicting perceptual identification and relearning.

The feeling of knowing (FOK) refers to predictions about subsequent memory performance on previously nonrecalled items. The present research explored predictive accuracy with 2 new FOK criterion tests (in addition to recognition): relearning and perceptual identification. In 2 experiments, Ss attempted to recall the answers to general information questions, then made FOK predictions for all nonrecalled answers, and finally had a criterion test to assess the accuracy of the FOK predictions. Exp I, conducted with 32 undergraduates, demonstrated that perceptual identification can be employed successfully as a criterion test for the feeling of knowing FOK. This opens a new way for metamemory research via perception. Moreover, the FOK accuracy for predicting perceptual identification was not significantly correlated with the FOK accuracy for predicting recognition, in accord with the idea that these 2 tests assess memory differently. Exp II, conducted with 77 undergraduates, demonstrated that relearning performance can also be predicted by FOK judgments. Overall results show that there is a positive relationship between the FOK and the amount of time elapsing before a memory search is terminated during recall. (76 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prejudice, stereotypes, and labeling effects: Sources of bias in person perception.

A preliminary study and 3 experiments compared predictions generated by contrasting models of how group labels bias person perception. An affective model assumed that how much perceivers like different groups mediates bias; a cognition model assumed that perceivers' beliefs regarding different groups mediates bias; and a third model assumed that both affect and cognition are necessary to mediate bias. Perceivers evaluated behavior samples provided by targets who were labeled as either rock music performers or child abusers in the preliminary study and the first 2 experiments; homosexuals or heterosexuals in the third experiment. In all studies, controlling for liking eliminated bias. The preliminary study and Study 3 also showed that controlling for beliefs about the groups eliminated bias. Structural equation modeling provided support for the affect model in Studies 1 and 2, and mixed support for the affect model and the cognition model in Study 3. These studies suggest an important role for affect in judgmental biases. (PsycINFO Database Record (c) 2010 APA, all rights reserved)