Testing architectures of the decision-confidence relation.

Two experiments examined the effect of rendering confidence judgments on the properties of the comparative decision process. In Experiment 1, participants worked for 12 sessions that required two-alternative perceptual, line-length comparisons. For sessions 1-4 and sessions 9-12, confidence judgments were not required. For sessions 5-8, participants provided confidence reports following each comparative judgment. The requirement of confidence judgments significantly increased decisional response time, suggesting that some confidence processing occurs in parallel with the primary decision process. Concomitantly, an examination of the properties of the time to determine confidence during sessions 5-8 revealed clear evidence of postdecisional confidence processing. These results were replicated in a second experiment requiring two-alternative comparative judgments of Canadian city populations. We conclude that confidence processing occurs both during the decision process and postdecisionally, and we discuss the implications of the present findings for current theories of confidence in human judgment.     

The discriminability of remembered magnitudes

Psychometric functions and the associated indices of discriminative performance (i.e., the point of subjective equality [PSE], just noticeable difference, and Weber fraction) were obtained with the method of constant stimuli using perceptual and remembered line-length standards. Three important results were obtained. First, comparisons with a perceptual or a remembered standard were sensitive to variations of absolute stimulus differences with a common ratio; that is, Weber's law was violated. Second, relative to discriminative performance with the longest and shortest remembered standards, comparisons involving mid-range remembered standards displayed increased variability in the PSE and inflated Weber fractions, characteristic of a reduction in the quality of the memorial representation. Finally, large and negative time-order errors (TOE) were observed for successive line judgments but not for those involving remembered standards. The implications of these findings for research concerned with the relationships between perception and memory, as well as the TOE phenomenon, are discussed.     

Presentation order effects in duration discrimination

Three separate experiments indicate that the second of a pair of durations tends to be overestimated relative to the first. These negative time-order errors are discussed as reliable perceptual phenomena, not explainable in terms of simple response biases, criterion biases, assimilation, or fading traces.     

Long-term mediational processes

A general paradigm for studying the interplay between STM processing under conditions of divided attention and recently acquired cognitive structures is presented. The paradigm requires the acquisition of an n-tuple by the usual serial anticipation method. Subsequently, selected subspan subsets of these items or synonyms or homophones of the corresponding (position for position) serially ordered items are presented for ordered recall in the Brown-Peterson paradigm. Two preliminary experiments are presented. Both demonstrate mediated facilitation of STM processing. The degree of facilitation depends on such LTM variables as the direction of associations of adjacent items and the location of the items in the long-term serial order, as well as the similarity of the items in STM to those in corresponding LTM positions. The role of item availability in assessing mediated facilitation of order information is discussed.     

Anchoring effects in the judgment of confidence: Semantic or numeric priming?

Over the last decade, researchers have debated whether anchoring effects are the result of semantic or numeric priming. The present study tested both hypotheses. In four experiments involving a sensory detection task, participants first made a relative confidence judgment by deciding whether they were more or less confident than an anchor value in the correctness of their decision. Subsequently, they expressed an absolute level of confidence. In two of these experiments, the relative confidence anchor values represented the midpoints between the absolute confidence scale values, which were either explicitly numeric or semantic, nonnumeric representations of magnitude. In two other experiments, the anchor values were drawn from a scale modally different from that used to express the absolute confidence (i.e., nonnumeric and numeric, respectively, or vice versa). Regardless of the nature of the anchors, the mean confidence ratings revealed anchoring effects only when the relative and absolute confidence values were drawn from identical scales. Together, the results of these four experiments limit the conditions under which both numeric and semantic priming would be expected to lead to anchoring effects.     

Aggregating conclusive and inconclusive information: Data and a model based on the assessment of threat

This study examined the process of combining conclusive and inconclusive information using a Naval threat assessment simulation. On each of 36 trials, participants interrogated 10 pieces of information (e.g., speed, direction, bearing, etc.) about “targets” in a simulated radar space. The number of hostile, peaceful, and inconclusive cues was factorially varied across targets. Three models were developed to understand how inconclusive information is used in the judgment of threat. According to one model, inconclusive information is ignored and the judgment of threat is based only on the conclusive information. According to a second model, the amount of dominant conclusive information is normalized by all of the available information. Finally, according to a third model, inconclusive information is partitioned under the assumption that it equally represents both dominant and non‐dominant evidence. In Experiment 1, the data of novices (i.e., civilians) were best described by a model that assumes a partitioning of inconclusive evidence. This result was replicated in a second experiment involving variation of the global threat context. In a third experiment involving experts (i.e., Canadian Navy officers), the data of half of the participants were best described by the partitioning model and the data of the other half were best described by the normalizing model. In Experiments 1 and 2, the presence of inconclusive information produced a “dilution effect”, whereby hostile (peaceful) targets were judged as less hostile (peaceful) than the predictions of the Partitioning model. The dilution effect was not evident in the judgments of the Navy officers. Copyright © 2009 Crown in the right of Canada. Published by John Wiley & Sons, Ltd.     

SNARC effects with numerical and non-numerical symbolic comparative judgments: instructional and cultural dependencies

With English-language readers in an experiment requiring pairwise comparative judgments of the sizes of animals, the nature of the association between the magnitudes of the animal pairs and the left or right sides of response (i.e., the SNARC effect) was reversed depending on whether the participants had to choose either the smaller or the larger member of the pair. In contrast, such a dependence of the direction of the SNARC effect on the form of the comparative instructions was not evident for pairwise comparisons of numerical magnitude made by a similar group of participants. Furthermore, exactly the same configuration of findings was obtained for a single group of Israeli-Palestinian right-to-left reading and writing participants, except that the spatial direction of the SNARC effects for both the animal-size and number comparisons were completely reversed. In a final experiment with English readers, SNARC effects paralleling those for the animal-size comparisons were obtained for pairwise comparative judgments involving the just-learned height relations between 6 imaginary individuals. As will be discussed, such results serve to extend the generality of the SNARC effect far beyond the current modal view that it simply reflects culturally influenced, long-term learned associations between numerical magnitudes and the locations on a fixed mental number line. The implications that these results have for both the Proctor and Cho (2006) polarity correspondence view and the Gevers, Verguts, Reynvoet, Caessens, and Fias (2006) computational model of the SNARC effect will also discussed.     

Feedback versus an illusion in time

The accuracy of many perceptual comparisons depends greatly on the order in which the to-be-compared stimuli are presented. With comparisons of durations around 300 ms, these presentation-order effects do not diminish, even with extended practice, when feedback about response accuracy is withheld. Providing such feedback greatly diminishes presentation-order effects and coincidentally produces substantial increases in response accuracy. The feedback acts in part through inducing response biases and in part through changes in sensitivity. The contradiction between studies which report time-order errors in duration comparison and those which do not is attributable to differences in the use of information feedback.