From Pictures to the People in Them: Averaging Within-Person Variability Leads to Face Familiarization.

Familiar faces can be confidently recognized despite sometimes radical changes in their appearance. Exposure to within-person variability-differences in facial characteristics over successive encounters-contributes to face familiarization. Research also suggests that viewers create mental averages of the different views of faces they encounter while learning them. Averaging over within-person variability is thus a promising mechanism for face familiarization. In Experiment 1, 153 Canadian undergraduates (88 female; age: M = 21 years, SD = 5.24) learned six target identities from eight different photos of each target interspersed among 32 distractor identities. Face-matching accuracy improved similarly irrespective of awareness of the target's identity, confirming that target faces presented among distractors can be learned incidentally. In Experiment 2, 170 Canadian undergraduates (125 female; age: M = 22.6 years, SD = 6.02) were tested using a novel indirect measure of learning. The results show that viewers update a mental average of a person's face as it becomes learned. Our findings are the first to show how averaging within-person variability over time leads to face familiarization.

Within-person variability contributes to more durable learning of faces.

Exposure to the natural, unsystematic within-person variability present across different encounters with a face (e.g., differences in emotion, makeup, and hairstyle) increases the likelihood the face will be recognized despite changes in appearance. In most studies, participants' memories are tested with a matching task administered shortly after exposure to a set of training images. In the real world, however, the time between when a face is first encountered and when it needs to be identified can be much longer. We hypothesized that in addition to facilitating acquisition of a representation of a face, unsystematic variability might also lead to better retention. To test this, in two experiments participants were randomly assigned to one of three training conditions: (a) no variability (still image), (b) systematic variability (changes in camera angle and pose in an otherwise constant setting), and (c) unsystematic variability (changes in hairstyle, makeup, clothing, and setting). Participants completed a sorting task 15 min and 5 days after viewing the target identity. Unsystematic variability led to better recognition than systematic variability, and this benefit was not reduced after a 5-day delay. Although participants expected their memory to be worse with a 5-day delay than with a 15-min delay, both overall accuracy and the advantage for training with unsystematic variability were virtually unaffected. The results suggest that exposure to unsystematic variability influences not only the initial acquisition of faces but also contributes to establishing a durable, flexible representation of faces in memory. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Can change detection succeed when change localization fails?

Statistical summary representations (SSRs) are thought to be computed by the visual system to provide a rapid summary of the properties of sets of similar objects. Recently, it has been suggested that a change in the statistical properties of a set can be identified even when changes to the individual items comprising the set cannot. Haberman and Whitney (2011) showed that subjects were correctly able to report which of 2 consecutively presented sets of faces was, on average, happier, even when participants were unable to localize any of the items contributing to this change. In this article, we revisit this conclusion and suggest that the results supporting it may be an artifact of the paradigm used. In 4 experiments, we find little evidence to suggest that subjects can reliably detect a change in the average size or emotion of an array of faces when they are unable to localize changes to individual items. The results are well accounted for by assuming that observers are selectively attending to individual items and then inferring the direction of the overall change based on the behavior of the attended items. We suggest that this occurs because change localization requires focused attention to individual items, impeding calculation of SSRs, which requires global attention to the entire set. We conclude that there is currently little evidence that SSRs can facilitate change detection when individual change localization fails. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

The single lineup paradigm: A new way to manipulate target presence in eyewitness identification experiments.

The suspect in eyewitness lineups may be guilty or innocent. These possibilities are traditionally simulated in eyewitness identification studies using a dual-lineup paradigm: All witnesses observe the same perpetrator and then receive one of two lineups. In this paradigm, the suspect's guilt is manipulated by including the perpetrator in one lineup and an innocent suspect in the other. The lineup is then filled with people matched to either the suspect (resulting in different fillers in perpetrator-present and perpetrator-absent lineups) or to the perpetrator (resulting in the same fillers in each lineup). An inescapable feature of the dual-lineup paradigm is that the perpetrator-present and perpetrator-absent lineups differ not only in the suspect's guilt, but also in their composition. Here, we describe a single-lineup paradigm: Subjects observe one of two perpetrators and then all subjects receive the same lineup containing one of the perpetrators. This alternative paradigm allows manipulation of the suspect's guilt without changing the lineup's composition. In three experiments, we applied the single-lineup paradigm to explore suspect-filler similarity and consistently found that increasing similarity reduced perpetrator identifications but did little to prevent innocent suspect misidentifications. Conversely, when fillers were matched to the perpetrator using a dual-lineup paradigm, increasing similarity reduced identification of perpetrators and innocent suspects. This finding suggests that the effect of filler similarity may depend on the person to whom the fillers are matched. We suggest that the single-lineup paradigm is a more ecologically valid and better controlled approach to creating suspect-matched lineups in laboratory investigations of eyewitness memory than existing procedures. (PsycINFO Database Record

Online attention modification for social anxiety disorder: replication of a randomized controlled trial.

Social anxiety disorder (SAD) models posit vigilance for external social threat cues and exacerbated self-focused attention as key in disorder development and maintenance. Evidence indicates a modified dot-probe protocol may reduce symptoms of SAD; however, the efficacy when compared to a standard protocol and long-term maintenance of treatment gains remains unclear. Furthermore, the efficacy of such protocols on SAD-related constructs remains relatively unknown. The current investigation clarified these associations using a randomized control trial replicating and extending previous research. Participants with SAD (n = 113; 71% women) were randomized to complete a standard (i.e. control) or modified (i.e. active) dot-probe protocol consisting of 15-min sessions twice weekly for four weeks. Self-reported symptoms were measured at baseline, post-treatment, and 4-month and 8-month follow-ups. Hierarchical linear modeling indicated significant self-reported reductions in symptoms of social anxiety, fear of negative evaluation, trait anxiety, and depression, but no such reductions in fear of positive evaluation. Symptom changes did not differ based on condition and were maintained at 8-month follow-up. Attentional biases during the dot-probe task were not related to symptom change. Overall, our results replicate support for the efficacy of both protocols in reducing symptoms of SAD and specific related constructs, and suggest a role of exposure, expectancy, or practice effects, rather than attention modification, in effecting such reductions. The current results also support distinct relationships between fears of negative and positive evaluation and social anxiety. Further research focused on identifying the mechanisms of change in attention modification protocols appears warranted.

Attention capture without awareness in a non-spatial selection task.

Distractors presented prior to a critical target in a rapid sequence of visually-presented items induce a lag-dependent deficit in target identification, particularly when the distractor shares a task-relevant feature of the target. Presumably, such capture of central attention is important for bringing a target into awareness. The results of the present investigation suggest that greater capture of attention by a distractor is not accompanied by greater awareness of it. Moreover, awareness tends to be limited to superficial characteristics of the target such as colour. The findings are interpreted within the context of a model that assumes sudden increases in arousal trigger selection of information for consolidation in working memory. In this conceptualization, prolonged analysis of distractor items sharing task-relevant features leads to larger target identification deficits (i.e., greater capture) but no increase in awareness.

Incidental statistical summary representation over time.

Information taken in by the human visual system allows individuals to form statistical representations of sets of items. One's knowledge of natural categories includes statistical information, such as average size of category members and the upper and lower boundaries of the set. Previous research suggests that when subjects attend to a particular dimension of a set of items presented over an extended duration, they quickly learn about the central tendency of the set. However, it is unclear whether such learning can occur incidentally, when subjects are not attending to the relevant dimension of the set. The present study explored whether subjects could reproduce global statistical properties of a set presented over an extended duration when oriented to task-irrelevant properties of the set. Subjects were tested for their memory of its mean, its smallest and largest exemplars, the direction of its skew, and the relative distribution of the items. Subjects were able to accurately recall the average size circle, as well as the upper and lower boundaries of a set of 4,200 circles displayed over an extended period. This suggests that even without intending to do so, they were encoding and updating a statistical summary representation of a task-irrelevant attribute of the circles over time. Such incidental encoding of statistical properties of sets is thus a plausible mechanism for establishing a representation of typicality in category membership.

A randomized controlled trial of attention modification for social anxiety disorder.

Social Anxiety Disorder (SAD) models implicate social threat cue vigilance (i.e., attentional biases) in symptom development and maintenance. A modified dot-probe protocol has been shown to reduce SAD symptoms, in some but not all studies, presumably by modifying an attentional bias. The current randomized controlled trial was designed to replicate and extend such research. Participants included treatment-seeking adults (n = 108; 58% women) who met diagnostic criteria for SAD. Participants were randomly assigned to a standard (i.e., control) or modified (i.e., active) dot-probe protocol condition and to participate in-lab or at home. The protocol involved twice-weekly 15-min sessions, for 4 weeks, with questionnaires completed at baseline, post-treatment, 4-month follow-up, and 8-month follow-up. Symptom reports were assessed with repeated measures mixed hierarchical modeling. There was a main effect of time from baseline to post-treatment wherein social anxiety symptoms declined significantly (p < .05) but depression and trait anxiety did not (p > .05). There were no significant interactions based on condition or participation location (ps > .05). Reductions were maintained at 8-month follow-up. Symptom reductions were not correlated with threat biases as indexed by the dot-probe task. The modified and standard protocol both produced significant sustained symptom reductions, whether administered in-lab or at home. There were no robust differences based on protocol type. As such, the mechanisms for benefits associated with modified dot-probe protocols warrant additional research.

Suspect filler similarity in eyewitness lineups: a literature review and a novel methodology.

Eyewitness lineups typically contain a suspect (guilty or innocent) and fillers (known innocents). The degree to which fillers should resemble the suspect is a complex issue that has yet to be resolved. Previously, researchers have voiced concern that eyewitnesses would be unable to identify their target from a lineup containing highly similar fillers; however, our literature review suggests highly similar fillers have only rarely been shown to have this effect. To further examine the effect of highly similar fillers on lineup responses, we used morphing software to create fillers of moderately high and very high similarity to the suspect. When the culprit was in the lineup, a higher correct identification rate was observed in moderately high similarity lineups than in very high similarity lineups. When the culprit was absent, similarity did not yield a significant effect on innocent suspect misidentification rates. However, the correct rejection rate in the moderately high similarity lineup was 20% higher than in the very high similarity lineup. When choosing rates were controlled by calculating identification probabilities for only those who made a selection from the lineup, culprit identification rates as well as innocent suspect misidentification rates were significantly higher in the moderately high similarity lineup than in the very high similarity lineup. Thus, very high similarity fillers yielded costs and benefits. Although our research suggests that selecting the most similar fillers available may adversely affect correct identification rates, we recommend additional research using fillers obtained from police databases to corroborate our findings.

Flexible cue combination in the guidance of attention in visual search.

Hodsoll and Humphreys (2001) have assessed the relative contributions of stimulus-driven and user-driven knowledge on linearly- and nonlinearly separable searches. However, the target feature used to determine linear separability in their task (i.e., target size) was required to locate the target. In the present work, we investigated the contributions of stimulus-driven and user-driven knowledge when a linearly- or a nonlinearly-separable feature is available but not required for target identification. We asked observers to complete a series of standard color×orientation conjunction searches in which target size was either linearly- or nonlinearly separable from the size of the distractors. When guidance by color×orientation and guidance by size information are both available, observers rely on whichever information results in the best search efficiency. This is the case irrespective of whether we provide target foreknowledge by blocking stimulus conditions, suggesting that feature information is used in both a stimulus-driven and a user-driven fashion.

Intentionally forgetting other-race faces: costs and benefits?

Eyewitnesses to events with multiple actors might be aware that during a subsequent investigation some actors will need to be remembered and others can be forgotten. Research on the directed-forgetting procedure suggests that when some information is cued to be forgotten, retention of other information is enhanced. In three experiments, directed-forgetting conditions were compared with control conditions to assess potential costs and benefits of forgetting other-race faces. In Experiment 1, undergraduate students (N = 148; mostly Caucasian) viewed all Black faces or all Asian faces followed by overt remember or forget cues. Participants in the directed-forgetting conditions of Experiments 2 and 3 received more covert cues instructing them to remember the faces of one race and to forget the faces of another race. In Experiment 2, undergraduate students (N = 116; all Caucasian) viewed Black and Asian faces within the context of a criminal storyline. In Experiment 3, undergraduate students (N = 94; all Caucasian) again viewed Black and Asian faces; however, the remember and forget cues were embedded in a noncriminal narrative. Although faces generally were forgotten on cue, forgetting some faces did not enhance memory for other faces. Furthermore, recognition of remember-cued faces was impaired by exposure to forget-cued faces. These findings indicate that faces can be forgotten on cue, but that doing so confers no benefit for remembering other faces. Eyewitnesses are advised that exposure to irrelevant faces reduces the likelihood that relevant faces will be remembered, even when effort is allocated to forgetting the irrelevant faces.

Size averaging of irrelevant stimuli cannot be prevented.

Research suggests that subjects can compute the mean size of two sets of interspersed objects concurrently, but that doing so incurs a cost of dividing attention across the two sets. Alternatively, costs may arise from failing to exclude irrelevant items from the calculation of mean size. Here, we examined whether attention can be selectively deployed to prevent the inclusion of items from an irrelevant, concurrently displayed set in the computation of the relevant set's mean size. The results suggest that mean size is computed prior to the deployment of attention, failing to exclude processing of items that are irrelevant to the task. The influence of the irrelevant items is evident both with brief exposures of the set (200ms) and in a simultaneous judgment task with unlimited viewing time, suggesting that attention cannot be effectively deployed to facilitate selective averaging of the size of the relevant set. Size averaging appears to precede the deployment of selective attention, suggesting that it may be carried out automatically, without intention.

Size and emotion averaging: costs of dividing attention after all.

Perceptual averaging is a process by which sets of similar items are represented by summary statistics such as their average size, luminance, or orientation. Researchers have argued that this process is automatic, able to be carried out without interference from concurrent processing. Here, we challenge this conclusion and demonstrate a reliable cost of computing the mean size of circles distinguished by colour (Experiments 1 and 2) and the mean emotionality of faces distinguished by sex (Experiment 3). We also test the viability of two strategies that could have allowed observers to guess the correct response without computing the average size or emotionality of both sets concurrently. We conclude that although two means can be computed concurrently, doing so incurs a cost of dividing attention.

The relationship between collisions and pseudoneglect: is it right?

When walking through narrow doorways people collide more frequently on the right side than on the left. This rightward collision bias has been attributed to pseudoneglect. Originally pseudoneglect was defined as leftward errors on a line bisection task; however, the term is used more broadly now to refer to the slight tendency to neglect the right side of space and attend more towards the left. Thus, rightward collisions are said to occur because the right side is neglected. In the present experiments, we examined this pseudoneglect hypothesis by assessing the influence of three factors (age, cuing, and motor activity) known to affect performance on traditional measures of pseudoneglect, such as line bisection tasks. Navigation and line bisection tasks were completed by younger and older adults performing a concurrent motor task (Experiment 1) and by younger adults performing no concurrent motor task (Experiment 2). In both experiments, attention was cued to the left, right, or both sides of space, or was uncued. In contrast to previous reports, in both experiments we found a leftward collision bias on the navigation task; this bias was relatively unaffected by age or cuing manipulations, and was attenuated by concurrent motor activity. In addition, we found no relation between performance on the navigation and line-bisection tasks, indicating that the leftward bias on the navigation task cannot be attributed to pseudoneglect. We provide alternative hypotheses that may explain differences between our results and those observed in others' studies.

Change detection inflates confidence on a subsequent recognition task.

A face viewed under good encoding conditions is more likely to be remembered than a face viewed under poor encoding conditions. In four experiments we investigated how encoding conditions affected confidence in recognising faces from line-ups. Participants performed a change detection task followed by a recognition task and then rated how confident they were in their recognition accuracy. In the first two experiments the same faces were repeated across trials. In the final two experiments novel faces were used on each trial. Target-present and target-absent line-ups were utilised. In each experiment participants had greater recognition confidence after change detection than after change blindness. The finding that change detection inflates confidence, even for inaccurate recognitions, indicates recognition certainty can be a product of perceived encoding conditions rather than authentic memory strength.

The whole is indeed more than the sum of its parts: perceptual averaging in the absence of individual item representation.

We tested Ariely's (2001) proposal that the visual system represents the overall statistical properties of sets of objects against alternative accounts of rapid averaging involving sub-sampling strategies. In four experiments, observers could rapidly extract the mean size of a set of circles presented in an RSVP sequence, but could not reliably identify individual members. Experiment 1 contrasted performance on a member identification task with performance on a mean judgment task, and showed that the tasks could be dissociated based on whether the test probe was presented before or after the sequence, suggesting that member identification and mean judgment are subserved by different mechanisms. In Experiment 2, we confirmed that when given a choice between a probe corresponding to the mean size of the set and a foil corresponding to the mean of the smallest and largest items only, the former is preferred to the latter, even when observers are explicitly instructed to average only the smallest and largest items. Experiment 3 showed that a test item corresponding to the mean size of the set could be reliably discriminated from a foil but the largest item in the set, differing by an equivalent amount, could not. In Experiment 4, observers rejected test items dissimilar to the mean size of the set in a member identification task, favoring test items that corresponded to the mean of the set over items that were actually shown. These findings suggest that mean representation is accomplished without explicitly encoding individual items.

Rapid averaging? Not so fast!

Previous research suggests that sets of similar items are represented using a rapid averaging mechanism that automatically extracts statistical properties within 50 ms. However, typically in these studies, displays are not masked, so it is possible that the sets are available for longer than this duration. In the present study, using masked displays, we (a) tested a newly proposed strategy for extracting the mean size of a set of circles, and (b) more precisely evaluated the time course of rapid averaging. The results indicate that when viewing conditions are poor, performance can be explained by assuming that observers rely on information from previous trials. In this study, observers required at least a 200-ms exposure time in order to derive the average size of a set of circles without relying on information from previously-viewed sets, suggesting that rapid averaging is not as fast as previously assumed and, therefore, that it may not be an automatic process.

Visual similarity in masking and priming: The critical role of task relevance.

Cognitive scientists use rapid image sequences to study both the emergence of conscious perception (visual masking) and the unconscious processes involved in response preparation (masked priming). The present study asked two questions: (1) Does image similarity influence masking and priming in the same way? (2) Are similarity effects in both tasks governed by the extent of feature overlap in the images or only by task-relevant features? Participants in Experiment 1 classified human faces using a single dimension even though the faces varied in three dimensions (emotion, race, sex). Abstract geometric shapes and colors were tested in the same way in Experiment 2. Results showed that similarity reduced the visibility of the target in the masking task and increased response speed in the priming task, pointing to a double-dissociation between the two tasks. Results also showed that only task-relevant (not objective) similarity influenced masking and priming, implying that both tasks are influenced from the beginning by intentions of the participant. These findings are interpreted within the framework of a reentrant theory of visual perception. They imply that intentions can influence object formation prior to the separation of vision for perception and vision for action.

A negative compatibility effect in priming of emotional faces.

The negative compatibility effect (NCE) is the surprising result that low-visibility prime arrows facilitate responses to opposite-direction target arrows. Here we compare the priming obtained with simple arrows to the priming of emotions when categorizing human faces, which represents a more naturalistic set of stimuli and for which there are no preexisting response biases. When inverted faces with neutral expressions were presented alongside emotional prime and target faces, only strong positive priming occurred. However, when the neutral faces were made to resemble the target faces in geometry (upright orientation), time (flashing briefly), and space (appearing in the same location), positive priming gradually weakened and became negative priming. Implications for theories of the NCE are discussed.

The cerebellum mediates conflict resolution.

Regions within the frontal and parietal cortex have been implicated as important neural correlates for cognitive control during conflict resolution. Despite the extensive reciprocal connectivity between the cerebellum and these putatively critical cortical areas, a role for the cerebellum in conflict resolution has never been identified. We used a task-switching paradigm that separates processes related to task-set switching and the management of response conflict independent of motor processing. Eleven patients with chronic, focal lesions to the cerebellum and 11 healthy controls were compared. Patients were slower and less accurate in conditions involving conflict resolution. In the absence of response conflict, however, tasks-witching abilities were not impaired in our patients. The cerebellum may play an important role in coordinating with other areas of cortex to modulate active response states. These results are the first demonstration of impaired conflict resolution following cerebellar lesions in the presence of an intact prefrontal cortex.