Are Morphs a Valid Substitute for Real Multiracial Faces in Race Categorization Research?

The rise of the multiracial population has been met with a growing body of research examining multiracial face perception. A common method for creating multiracial face stimuli in past research has been mathematically averaging two monoracial "parent" faces of different races to create computer-generated multiracial morphs, but conclusions from research using morphs will only be accurate to the extent that morphs yield perceptual decisions similar to those that would be made with real multiracial faces. The current studies compared race classifications of real and morphed multiracial face stimuli. We found that oval-masked morphed faces were classified as multiracial significantly more often than oval-masked real multiracial faces (Studies 1 and 2), but at comparable levels to unmasked real multiracial faces (Study 2). Study 3 examined factors that could explain differences in how morphs and real multiracial faces are categorized and pointed to the potential role that unusualness/distinctiveness might play.

Chicago Face Database: Multiracial expansion.

Multiracial individuals represent a growing segment of the population and have been increasingly the focus of empirical study. Much of this research centers on the perception and racial categorization of multiracial individuals. The current paper reviews some of this research and describes the different types of stimuli that have been used in these paradigms. We describe the strengths and weaknesses associated with different operationalizations of multiracialism and highlight the dearth of research using faces of real multiracial individuals, which we posit may be due to the lack of available stimuli. Our research seeks to satisfy this need by providing a free set of high-resolution, standardized images featuring 88 real multiracial individuals along with extensive norming data and objective physical measures of these faces. These data are offered as an extension of the widely used Chicago Face Database and are available for download at www.chicagofaces.org for use in research.

The Confidence Database.

Understanding how people rate their confidence is critical for the characterization of a wide range of perceptual, memory, motor and cognitive processes. To enable the continued exploration of these processes, we created a large database of confidence studies spanning a broad set of paradigms, participant populations and fields of study. The data from each study are structured in a common, easy-to-use format that can be easily imported and analysed using multiple software packages. Each dataset is accompanied by an explanation regarding the nature of the collected data. At the time of publication, the Confidence Database (which is available at https://osf.io/s46pr/) contained 145 datasets with data from more than 8,700 participants and almost 4 million trials. The database will remain open for new submissions indefinitely and is expected to continue to grow. Here we show the usefulness of this large collection of datasets in four different analyses that provide precise estimations of several foundational confidence-related effects.

The language of accurate recognition memory.

The natural language accompanying recognition judgments is a largely untapped though potentially rich source of information about the kinds of processing that may support recognition memory. The current report illustrates a series of methods using machine learning and receiver operating characteristics (ROCs) to examine whether the language participants use to justify their 'old' and 'new' recognition decisions (viz., memory justifications) predicts accuracy. The findings demonstrate that the natural language of observers conveys the accuracy of 'old' (hits versus false alarms) but not 'new' (misses versus correct rejections) decisions. The classifier trained on this language was considerably more predictive of accuracy than the initial speed of the decisions, generalized to the justification language of two independent experiments using different procedures, and appeared sensitive to the presence versus absence of recollective experiences in the observer's reports. We conclude by considering extensions of the approach to several basic and applied areas, and, more broadly, to identifying the explicit bases (if any) of classification decisions in general.

Mere exposure effect(s) in the context of explicit memory search.

Prior stimulus exposure often increases later ratings of positive affect (e.g., pleasantness ratings). This phenomenon - the mere exposure effect (MEE) - appears robust following subliminal and incidental exposures. However, its expression in the context of explicit memory judgment remains unclear. In four studies, memory and pleasantness ratings were combined to investigate how memory conclusions (e.g., "studied" or "unstudied") might moderate exposure effects. Experiment 1 examined basic recognition, Experiment 2 manipulated incentives for recognition decisions, and Experiments 3 and 4 examined source memory and paired-associate recall respectively. In general, items endorsed as recognized, attributed to the queried source, or accompanied by successful recall of a paired associate (i.e., confirmations) were rated as more pleasant than baseline norms. As important, items endorsed as unstudied, rejected as originating from a queried source, or failing to yield successful recall of a paired associated were rated as less pleasant than baseline norms. This suggests that it is the outcome of memory search that alters pleasantness ratings in the context of retrieval demands, and we discuss how this confirmation of search (COS) hypothesis accounts for current and prior findings.

Partitioning the sources of recognition confidence: The role of individual differences.

Confidence ratings during old-new recognition memory tasks are thought to index the strength of memory evidence elicited by test probes. However, various subject-specific factors may also influence reported confidence, including perceived self-efficacy and idiosyncratic interpretation of the confidence scale. To measure the contribution of subject-specific variables to confidence ratings, we performed regression analyses on extant data from three recognition experiments encompassing procedural variations in encoding and stimuli, testing the degree to which the person making the judgment (the "subject" factor), versus whether or not the judgment is accurate, influences reported confidence. Overall, confidence was less linked to changes in accuracy, for "new" than for "old" judgments. Critically, the subject factor was at least as predictive of rated confidence as accuracy for "old" judgments, whereas for "new" judgments the subject factor was substantially more predictive of confidence than accuracy. These results suggest that measured confidence is largely a function of who is making the rating, especially when items are identified as "new." This suggests that the utility of confidence in predicting memory accuracy will be limited when stable estimates of subject contributions are unavailable, such as when each subject provides one or a few responses.

The importance of decision bias for predicting eyewitness lineup choices: toward a Lineup Skills Test.

ᅟ: We report on research on individual-difference measures that could be used to assess the validity of eyewitness identification decisions. BACKGROUND: The predictive utility of face recognition tasks for eyewitness identification has received some attention from psychologists, but the previous research focused primarily on witnesses' likelihood of correctly choosing the culprit when present in a lineup. Far less discussed has been individual differences in witnesses' proclivity to choose from a lineup that does not contain the culprit. We designed a two-alternative non-forced-choice face recognition task (consisting of mini-lineup test pairs, half old/new and half new/new) to predict witnesses' proclivity to choose for a set of culprit-absent lineups associated with earlier-viewed crime videos. RESULTS: In two studies involving a total of 402 participants, proclivity to choose on new/new pairs predicted mistaken identifications on culprit-absent lineups, with r values averaging .43. The likelihood of choosing correctly on old/new pairs (a measure of face recognition skill) was only weakly predictive of correct identifications in culprit-present lineups (mean r of .22). CONCLUSIONS: Our findings could be the basis for further research aimed at developing a standardized measure of proclivity to choose that could be used, along with other measures, to weigh eyewitnesses' lineup identification decisions.

Confidence carryover during interleaved memory and perception judgments.

Recognition memory tests typically consist of randomly intermixed studied and nonstudied items that subjects classify as old or new, often while indicating their confidence in these classifications. Under most decision theories, confidence ratings index an item's memory strength-the extent to which it elicits evidence of prior occurrence. Because the test probes are randomly ordered, these theories predict that confidence judgments should be sequentially independent: confidence on trial n should not predict confidence on n + 1. However, analysis of two extant data sets demonstrated reliable serial correlations in recognition memory confidence (confidence carryover). In a new experiment, we examined the domain specificity of confidence carryover by serially interleaving recognition and perceptual classification judgments. Analysis revealed domain-general and domain-specific confidence carryover effects: The confidence of a current recognition judgment was shown to reflect both the confidence of an immediately preceding perceptual gender judgment (domain-general carryover at Lag 1) and also the confidence of the recognition judgment prior to that (domain-specific carryover at Lag 2). Moreover, the domain-specific effect was sensitive to response consistency: Confidence carryover was highest when old-new classifications repeated across trials. Whereas the domain-general effect may reflect metacognitive monitoring of internal factors such as alertness, the domain-specific effect was easily simulated by assuming that evidence within domains is "sticky," such that current memory or perceptual evidence is pulled toward prior evidence representations.

Cross-task and cross-manipulation stability in shifting the decision criterion.

In recognition memory experiments participants must discriminate between old and new items, a judgment influenced by response bias. Research has shown substantial individual differences in the extent to which people will strategically adjust their response bias to diagnostic cues such as the prior probability of an old item. Despite this significant between subject variability, shifts in bias have been found to be relatively predictive within individuals across memory tests. Experiment 1 sought to determine whether this predictability extends beyond memory. Results revealed that the amount a subject shifted response bias in a recognition memory task was significantly predictive of shifting in a visual perception task, suggesting that shifting can generalise outside of a specific testing domain. Experiment 2 sought to determine how predictive shifting would be across two manipulations well known to induce shifts in bias: a probability manipulation and a response payoff manipulation. A modest positive relationship between these two methods was observed, suggesting that shifting behaviour is relatively predictive across different manipulations of shifting. Overall, results from both experiments suggest that response bias shifting, like response bias setting, is a relatively stable behaviour within individuals despite changes in test domain and test manipulation.

Dubious decision evidence and criterion flexibility in recognition memory.

When old-new recognition judgments must be based on ambiguous memory evidence, a proper criterion for responding "old" can substantially improve accuracy, but participants are typically suboptimal in their placement of decision criteria. Various accounts of suboptimal criterion placement have been proposed. The most parsimonious, however, is that subjects simply over-rely on memory evidence - however faulty - as a basis for decisions. We tested this account with a novel recognition paradigm in which old-new discrimination was minimal and critical errors were avoided by adopting highly liberal or conservative biases. In Experiment 1, criterion shifts were necessary to adapt to changing target probabilities or, in a "security patrol" scenario, to avoid either letting dangerous people go free (misses) or harming innocent people (false alarms). Experiment 2 added a condition in which financial incentives drove criterion shifts. Critical errors were frequent, similar across sources of motivation, and only moderately reduced by feedback. In Experiment 3, critical errors were only modestly reduced in a version of the security patrol with no study phase. These findings indicate that participants use even transparently non-probative information as an alternative to heavy reliance on a decision rule, a strategy that precludes optimal criterion placement.

Category exemplars normed in Canada.

Normative data on category exemplar generation are widely used by psychologists but vary across cultures such that well-known norm sets developed in the United States might not be appropriate for use in Canada. To date, no published set of category exemplars has been normed with a Canadian undergraduate population. We describe the creation of such a set using the popular Battig and Montague (1969) categories and provide a link to the full set of norms.

Cross-situational consistency in recognition memory response bias.

Individuals taking an old-new recognition memory test differ widely in their bias to respond "old," ranging from strongly conservative to strongly liberal, even without any manipulation intended to affect bias. Kantner and Lindsay (2012) found stability of bias across study-test cycles, suggesting that bias is a cognitive trait. That consistency, however, could have arisen because participants perceived the two tests as being part of the same experiment in the same context. In the present study, we tested for stability across two recognition study-test procedures embedded in markedly different experiments, held weeks apart, that participants did not know were connected. Bias showed substantial cross-situational stability. Moreover, bias weakly predicted identifications on an eyewitness memory task and accuracy on a go-no-go task. Although we found little in the way of relationships between bias and five personality measures, these findings suggest that response bias is a stable and broadly influential characteristic of recognizers.

Top-down constraint on recognition memory.

Can recognition memory be constrained "at the front end," such that people are more likely to retrieve information about studying a recognition-test probe from a specified target source than they are to retrieve such information about a probe from a nontarget source? We adapted a procedure developed by Jacoby, Shimizu, Daniels, and Rhodes (Psychonomic bulletin & review 12:852-857, 2005) to address this question. Experiment 1 yielded evidence of source-constrained retrieval, but that pattern was not significant in Experiments 2, 3, and 4 (nor in several unpublished pilot experiments). In experiment 5, in which items from the two studied sources were perceptibly different, a pattern consistent with front-end constraint of recognition emerged, but this constraint was likely exercised via visual attention rather than memory. Experiment 6 replicated both the absence of a significant constrained-retrieval pattern when the sources did not differ perceptibly (as in exps. 2, 3 and 4) and the presence of that pattern when they did differ perceptibly (as in exp. 5). Our results suggest that people can easily constrain recognition when items from the to-be-recognized source differ perceptibly from items from other sources (presumably via visual attention), but that it is difficult to constrain retrieval solely on the basis of source memory.

Response bias in recognition memory as a cognitive trait.

According to signal detection theory, old-new recognition decisions can be affected by response bias, a general proclivity to respond either "old" or "new." In recognition experiments, response bias is usually analyzed at a group level, but substantial individual differences in bias can underlie group means. These differences suggest that, independent of any experimental manipulation, some people require more memory evidence than do others before they are willing to call an item "old." In four experiments, we investigated the possibility that recognition response bias is a partial function of a trait-like predisposition. Bias was highly correlated across two recognition study-test cycles separated by 10 min (Experiment 1). A nearly identical correlation was observed when the tasks were separated by one week (Experiment 2). Bias correlations remained significant even when the stimuli differed sharply between the first and second study-test cycles (Experiment 3). No relationship was detected between bias and response strategies in two general knowledge tests (Experiments 2 and 4), but bias did weakly predict frequency of false recall in the Deese/Roediger-McDermott (DRM) paradigm (Experiment 4). This evidence of trait-like stability suggests an entirely different aspect of response bias than that studied by examining its modulation by task variables, one for which complete theories of recognition memory may need to account.

Nonprobative photographs (or words) inflate truthiness.

When people evaluate claims, they often rely on what comedian Stephen Colbert calls "truthiness," or subjective feelings of truth. In four experiments, we examined the impact of nonprobative information on truthiness. In Experiments 1A and 1B, people saw familiar and unfamiliar celebrity names and, for each, quickly responded "true" or "false" to the (between-subjects) claim "This famous person is alive" or "This famous person is dead." Within subjects, some of the names appeared with a photo of the celebrity engaged in his or her profession, whereas other names appeared alone. For unfamiliar celebrity names, photos increased the likelihood that the subjects would judge the claim to be true. Moreover, the same photos inflated the subjective truth of both the "alive" and "dead" claims, suggesting that photos did not produce an "alive bias" but rather a "truth bias." Experiment 2 showed that photos and verbal information similarly inflated truthiness, suggesting that the effect is not peculiar to photographs per se. Experiment 3 demonstrated that nonprobative photos can also enhance the truthiness of general knowledge claims (e.g., Giraffes are the only mammals that cannot jump). These effects add to a growing literature on how nonprobative information can inflate subjective feelings of truth.

How category structure influences the perception of object similarity: the atypicality bias.

Why do some faces appear more similar than others? Beyond structural factors, we speculate that similarity is governed by the organization of faces located in a multi-dimensional face space. To test this hypothesis, we morphed a typical face with an atypical face. If similarity judgments are guided purely by their physical properties, the morph should be perceived to be equally similar to its typical parent as its atypical parent. However, contrary to the structural prediction, our results showed that the morph face was perceived to be more similar to the atypical face than the typical face. Our empirical studies show that the atypicality bias is not limited to faces, but extends to other object categories (birds) whose members share common shape properties. We also demonstrate atypicality bias is malleable and can change subject to category learning and experience. Collectively, the empirical evidence indicates that perceptions of face and object similarity are affected by the distribution of stimuli in a face or object space. In this framework, atypical stimuli are located in a sparser region of the space where there is less competition for recognition and therefore, these representations capture a broader range of inputs. In contrast, typical stimuli are located in a denser region of category space where there is increased competition for recognition and hence, these representation draw a more restricted range of face inputs. These results suggest that the perceived likeness of an object is influenced by the organization of surrounding exemplars in the category space.

Exploring the perceptual spaces of faces, cars and birds in children and adults.

While much developmental research has focused on the strategies that children employ to recognize faces, less is known about the principles governing the organization of face exemplars in perceptual memory. In this study, we tested a novel, child-friendly paradigm for investigating the organization of face, bird and car exemplars. Children ages 3-4, 5-6, 7-8, 9-10, 11-12 and adults were presented with 50/50 morphs of typical and atypical face, bird and car parent images. Participants were asked to judge whether the 50/50 morph more strongly resembled the typical or the atypical parent image. Young and older children and adults showed a systematic bias to the atypical faces and birds, but no bias toward the atypical cars. Collectively, these findings argue that by the age of 3, children encode and organize faces, birds and cars in a perceptual space that is strikingly similar to that of adults. Category organization for both children and adults follows Krumhansl's (1978) distance-density principle in which the similarity between two exemplars is jointly determined by their physical appearance and the density of neighboring exemplars in the perceptual space.

The intention interference effect.

Intentions have been shown to be more accessible (e.g., more quickly and accurately recalled) compared to other sorts of to-be-remembered information; a result termed an intention superiority effect (Goschke & Kuhl, 1993). In the current study, we demonstrate an intention interference effect (IIE) in which color-naming performance in a Stroop task was slower for words belonging to an intention that participants had to remember to carry out (Do-the-Task condition) versus an intention that did not have to be executed (Ignore-the-Task condition). In previous work (e.g., Cohen et al., 2005), having a prospective intention in mind was confounded with carrying a memory load. In Experiment 1, we added a digit-retention task to control for effects of cognitive load. In Experiment 2, we eliminated the memory confound in a new way, by comparing intention-related and control words within each trial. Results from both Experiments 1 and 2 revealed an IIE suggesting that interference is very specific to the intention, not just to a memory load.

Can corrective feedback improve recognition memory?

An understanding of the effects of corrective feedback on recognition memory can inform both recognition theory and memory training programs, but few published studies have investigated the issue. Although the evidence to date suggests that feedback does not improve recognition accuracy, few studies have directly examined its effect on sensitivity, and fewer have created conditions that facilitate a feedback advantage by encouraging controlled processing at test. In Experiment 1, null effects of feedback were observed following both deep and shallow encoding of categorized study lists. In Experiment 2, feedback robustly influenced response bias by allowing participants to discern highly uneven base rates of old and new items, but sensitivity remained unaffected. In Experiment 3, a false-memory procedure, feedback failed to attenuate false recognition of critical lures. In Experiment 4, participants were unable to use feedback to learn a simple category rule separating old items from new items, despite the fact that feedback was of substantial benefit in a nearly identical categorization task. The recognition system, despite a documented ability to utilize controlled strategic or inferential decision-making processes, appears largely impenetrable to a benefit of corrective feedback.