Newborns discriminate schematic faces from scrambled faces.

Newborn attention to, and discrimination of, facelike patterns was examined in three experiments employing 35 one- to three-day-old infants. Differential eye tracking and head turning to three moving stimuli (a schematic face, a scrambled face, and a luminance-matched blank) were measured in two of the three experiments. The newborns turned their eyes and heads farther to follow patterned stimuli, containing facelike features, than to a luminance-matched blank, but they did not turn farther to a stimulus with the features arranged in a facelike manner compared to features scrambled. A third experiment tested newborns' ability to discriminate between the facelike and scrambled face patterns. Using an infant-controlled procedure, infants showed similar initial fixation times and similar numbers of trials to reach a 60% response decrement criterion to both patterned stimuli. Following habituation, novelty responding indicated that infants discriminated between the schematic face and the scrambled face patterns. Although infants did not show a preference for a facelike stimulus compared to a features-scrambled pattern in the present experiments, they could discriminate the two patterns based on the internal arrangement of the facial features.     

Searching for faces in crowd chokepoint videos

Investigations of face identification have typically focussed on matching faces to photographic IDs. Few researchers have considered the task of searching for a face in a crowd. In Experiment 1, we created the Chokepoint Search Test to simulate real-time search for a target. Performance on this test was poor (39% accuracy) and showed moderate associations with tests of face matching and memory. In addition, trial-level confidence predicted accuracy, and for those participants who were previously familiar with one or more targets, higher familiarity was associated with increased accuracy. In Experiment 2, we found improvements in performance on the test when three recent images of the target, but not three social media images, were displayed during searches. Taken together, our results highlight the difficulties inherent in real-time searching for faces, with important implications for those security personnel who carry out this task on a daily basis.     

A comparative study of face processing using scrambled faces

It is a widespread assumption that all primate species process faces in the same way because the species are closely related and they engage in similar social interactions. However, this approach ignores potentially interesting and informative differences that may exist between species. This paper describes a comparative study of holistic face processing. Twelve subjects (six chimpanzees Pan troglodytes and six rhesus monkeys Macaca mulatta) were trained to discriminate whole faces (faces with features in their canonical position) and feature-scrambled faces in two separate conditions. We found that both species tended to match the global configuration of features over local features, providing strong evidence of global precedence. In addition, we show that both species were better able to generalize from a learned configuration to an entirely novel configuration when they were first trained to match feature-scrambled faces compared to when they were trained with whole faces. This result implies that the subjects were able to access local information easier when facial features were presented in a scrambled configuration and is consistent with a holistic processing hypothesis. Interestingly, these data also suggest that, while holistic processing in chimpanzees is tuned to own-species faces, monkeys have a more general approach towards all faces. Thus, while these data confirm that both chimpanzees and rhesus monkeys process faces holistically, they also indicate that there are differences between the species that warrant further investigation.     

Infants rapidly detect human faces in complex naturalistic visual scenes

Infants respond preferentially to faces and face‐like stimuli from birth, but past research has typically presented faces in isolation or amongst an artificial array of competing objects. In the current study infants aged 3‐ to 12‐months viewed a series of complex visual scenes; half of the scenes contained a person, the other half did not. Infants rapidly detected and oriented to faces in scenes even when they were not visually salient. Although a clear developmental improvement was observed in face detection and interest, all infants displayed sensitivity to the presence of a person in a scene, by displaying eye movements that differed quantifiably across a range of measures when viewing scenes that either did or did not contain a person. We argue that infant's face detection capabilities are ostensibly “better” with naturalistic stimuli and artificial array presentations used in previous studies have underestimated performance.     

Threatening scenes but not threatening faces shorten time-to-contact estimates

We previously reported that time-to-contact (TTC) judgments of threatening scene pictures (e.g., frontal attacks) resulted in shortened estimations and were mediated by cognitive processes, and that judgments of threatening (e.g., angry) face pictures resulted in a smaller effect and did not seem cognitively mediated. In the present study, the effects of threatening scenes and faces were compared in two different tasks. An effect of threatening scene pictures occurred in a prediction-motion task, which putatively requires cognitive motion extrapolation, but not in a relative TTC judgment task, which was designed to be less reliant on cognitive processes. An effect of threatening face pictures did not occur in either task. We propose that an object’s explicit potential of threat per se, and not only emotional valence, underlies the effect of threatening scenes on TTC judgments and that such an effect occurs only when the task allows sufficient cognitive processing. Results are consistent with distinctions between predator and social fear systems and different underlying physiological mechanisms. Not all threatening information elicits the same responses, and whether an effect occurs at all may depend on the task and the degree to which the task involves cognitive processes.     

Searching in the dark: Cognitive relevance drives attention in real-world scenes

We investigated whether the deployment of attention in scenes is better explained by visual salience or by cognitive relevance. In two experiments, participants searched for target objects in scene photographs. The objects appeared in semantically appropriate locations but were not visually salient within their scenes. Search was fast and efficient, with participants much more likely to look to the targets than to the salient regions. This difference was apparent from the first fixation and held regardless of whether participants were familiar with the visual form of the search targets. In the majority of trials, salient regions were not fixated. The critical effects were observed for all 24 participants across the two experiments. We outline a cognitive relevance framework to account for the control of attention and fixation in scenes.     

Usage of spatial scales for the categorization of faces, objects, and scenes

The role of spatial scales (or spatial frequencies) in the processing of faces, objects, and scenes has recently seen a surge of research activity. In this review, we will critically examine two main theories of scale usage. The fixed theory proposes that spatial scales are used in a fixed, perceptually determined order (coarse to fine). The flexible theory suggests instead that usage of spatial scales is flexible, depending on the requirements of visual information for the categorization task at hand. The implications of the theories are examined for face, object, and scene categorization, attention, perception, and representation.     

Summarizing scrambled stories

Subjects read stories 1,400 words long and wrote 60- to 80-word summaries of these stores. Reading time was either unrestricted or limited, and the stories were either presented in natural order or with their paragraphs scrambled. Reading times were longer for the scrambled stories, but the same kind of summaries were produced whether stories were presented in natural or scrambled order. When a well-structured story was used, judges were unable to distinguish the two types of summaries and rated the adequacy of summaries based upon the scrambled version about as high as that of summaries based upon normal stories. For a less well-structured story, judges could differentiate between the summaries from natural and scrambled stories. These results demonstrate the effectiveness of the story schema which permits subjects to comprehend scrambled stories by reorganizing them.     

Independent effects of local and global binocular disparity on the perceived convexity of stereoscopically presented faces in scenes

Evidence suggests that experiencing the hollow-face illusion involves perceptual reversal of the binocular disparities associated with the face even though the rest of the scene appears unchanged. This suggests stereoscopic processing of object shape may be independent of scene-based processing of the layout of objects in depth. We investigated the effects of global scene-based and local object-based disparity on the compellingness of the perceived convexity of the face. We took stereoscopic photographs of people in scenes, and independently reversed the binocular disparities associated with the head and scene. Participants rated perceived convexity of a natural disparity ("convex") or reversed disparity ("concave") face shown either in its original context with reversed or natural disparities or against a black background. Faces with natural disparity were rated as more convincingly convex independent of the background, showing that the local disparities can affect perceived convexity independent of disparities across the rest of the image. However, the apparent convexity of the faces was also greater in natural disparity scenes compared to either a reversed disparity scene or a zero disparity black background. This independent effect of natural scene disparity suggests that the 'solidity' associated with natural scene disparities spread to enhance the perceived convexity of the face itself. Together, these findings suggest that global and local disparity exert independent and additive effects upon the perceived convexity of the face.     

A taxonomy for scenes

Tomkins [Tomkins, S. (1979). Script theory: Differential magnification of affects. In: C. Keasey (Ed.), Nebraska Symposium on Motivation, Vol. 26 (pp. 201–236). Lincoln: University of Nebraska Press; Tomkins, S. (1987). Script theory. In: J. Aronoff, A. Rabin, & R. Zucker (Eds.), The Emergence of Personality (pp. 147–216). New York: Springer] proposed that personality is built from the experience of scenes, which minimally consist of an emotion and an event evoking that emotion. This study sought to identify a taxonomy of emotion-eliciting events. Examples of specific events eliciting love, joy, sadness, anger, and fear were collected from 200 participants, another 120 participants independently sorted these examples for similarity, and a hierarchical cluster analysis was run on these similarity sorts. The resulting tree diagram displayed categories of events at varying levels of abstraction. Individual differences were found in the types of events offered for each of the five emotions.     

Incidental visual memory for objects in scenes

Three experiments were conducted to investigate the existence of incidentally acquired, long-term, detailed visual memory for objects embedded in previously viewed scenes. Participants performed intentional memorization and incidental visual search learning tasks while viewing photographs of real-world scenes. A visual memory test for previously viewed objects from these scenes then followed. Participants were not aware that they would be tested on the scenes following incidental learning in the visual search task. In two types of memory tests for visually specific object information (token discrimination and mirror-image discrimination), performance following both the memorization and visual search conditions was reliably above chance. These results indicate that recent demonstrations of good visual memory during scene viewing are not due to intentional scene memorization. Instead, long-term visual representations are incidentally generated as a natural product of scene perception.     

Visual memory for moving scenes

In the present study, memory for picture boundaries was measured with scenes that simulated self-motion along the depth axis. The results indicated that boundary extension (a distortion in memory for picture boundaries) occurred with moving scenes in the same manner as that reported previously for static scenes. Furthermore, motion affected memory for the boundaries but this effect of motion was not consistent with representational momentum of the self (memory being further forward in a motion trajectory than actually shown). We also found that memory for the final position of the depicted self in a moving scene was influenced by properties of the optical expansion pattern. The results are consistent with a conceptual framework in which the mechanisms that underlie boundary extension and representational momentum (a) process different information and (b) both contribute to the integration of successive views of a scene while the scene is changing.     

Memory for temporally dynamic scenes

Recognition memory was investigated for individual frames extracted from temporally continuous, visually rich film segments of 5–15 min. Participants viewed a short clip from a film in either a coherent or a jumbled order, followed by a recognition test of studied frames. Foils came either from an earlier or a later part of the film (Experiment 1) or from deleted segments selected from random cuts of varying duration (0.5 to 30?s) within the film itself (Experiment 2). When the foils came from an earlier or later part of the film (Experiment 1), recognition was excellent, with the hit rate far exceeding the false-alarm rate (.78 vs. 18). In Experiment 2, recognition was far worse, with the hit rate (.76) exceeding the false-alarm rate only for foils drawn from the longest cuts (15 and 30?s) and matching the false-alarm rate for the 5?s segments. When the foils were drawn from the briefest cuts (0.5 and 1.0 s), the false-alarm rate exceeded the hit rate. Unexpectedly, jumbling had no effect on recognition in either experiment. These results are consistent with the view that memory for complex visually temporal events is excellent, with the integrity unperturbed by disruption of the global structure of the visual stream. Disruption of memory was observed only when foils were drawn from embedded segments of duration less than 5?s, an outcome consistent with the view that memory at these shortest durations are consolidated with expectations drawn from the previous stream.     

Memory for object position in natural scenes

Memory for the positions of objects in natural scenes was investigated. Participants viewed an image of a real-world scene (preview scene), followed by a target object in isolation (target probe), followed by a blank screen with a mouse cursor. Participants estimated the position of the target using the mouse. Three conditions were compared. In the target present preview condition, the target object was present in the scene preview. In the target absent preview condition, the target object not present in the scene preview. In the no preview condition, no preview scene was displayed. Localization accuracy in the target present preview condition was reliably higher than that in the target absent preview condition, which was reliably higher than localization accuracy in the no preview condition. These data demonstrate that participants can remember both the spatial context of a scene and the specific positions of local objects.     

Visual memory for moving scenes

In the present study, memory for picture boundaries was measured with scenes that simulated self-motion along the depth axis. The results indicated that boundary extension (a distortion in memory for picture boundaries) occurred with moving scenes in the same manner as that reported previously for static scenes. Furthermore, motion affected memory for the boundaries but this effect of motion was not consistent with representational momentum of the self (memory being further forward in a motion trajectory than actually shown). We also found that memory for the final position of the depicted self in a moving scene was influenced by properties of the optical expansion pattern. The results are consistent with a conceptual framework in which the mechanisms that underlie boundary extension and representational momentum (a) process different information and (b) both contribute to the integration of successive views of a scene while the scene is changing.     

Global context effect in normal and scrambled musical sequences

The processing of chords is facilitated when they are harmonically related to the context in which they appear. The purpose of this study was to assess whether this harmonic priming effect depends on the version (normal vs. scrambled) of the context chord sequences. Normal sequences were scrambled by permuting chords two-by-two (Experiment 1) or four-by-four (Experiments 2 and 3). Normal chord sequences were judged less coherent than scrambled sequences. However, normal chord sequences showed facilitation for harmonically related rather than for unrelated targets, and this effect of relatedness did not diminish for scrambled sequences (Experiments 1-3). The data of musicians and nonmusicians were interpreted with Bharucha's (1987) spreading activation framework. Simulations suggested that harmonic priming results from activation that spreads via schematic knowledge of Western harmony and accumulates in short-term memory over the course of the chord sequence.     

Emotional scenes elicit more pronounced self-reported emotional experience and greater EPN and LPP modulation when compared to emotional faces

Emotional faces and scenes carry a wealth of overlapping and distinct perceptual information. Despite widespread use in the investigation of emotional perception, expressive face and evocative scene stimuli are rarely assessed in the same experiment. Here, we evaluated self-reports of arousal and pleasantness, as well as early and late event-related potentials (e.g., N170, early posterior negativity [EPN], late positive potential [LPP]) as subjects viewed neutral and emotional faces and scenes, including contents representing anger, fear, and joy. Results demonstrate that emotional scenes were rated as more evocative than emotional faces, as only scenes produced elevated self-reports of arousal. In addition, viewing scenes resulted in more extreme ratings of pleasantness (and unpleasantness) than did faces. EEG results indicate that both expressive faces and emotional scenes evoke enhanced negativity in the N170 component, while the EPN and LPP components show significantly enhanced modulation only by scene, relative to face stimuli. These data suggest that viewing emotional scenes results in a more pronounced emotional experience that is associated with reliable modulation of visual event-related potentials that are implicated in emotional circuits in the brain.     

Visual search for arbitrary objects in real scenes

How efficient is visual search in real scenes? In searches for targets among arrays of randomly placed distractors, efficiency is often indexed by the slope of the reaction time (RT) × Set Size function. However, it may be impossible to define set size for real scenes. As an approximation, we hand-labeled 100 indoor scenes and used the number of labeled regions as a surrogate for set size. In Experiment 1, observers searched for named objects (a chair, bowl, etc.). With set size defined as the number of labeled regions, search was very efficient (~5 ms/item). When we controlled for a possible guessing strategy in Experiment 2, slopes increased somewhat (~15 ms/item), but they were much shallower than search for a random object among other distinctive objects outside of a scene setting (Exp. 3: ~40 ms/item). In Experiments 4–6, observers searched repeatedly through the same scene for different objects. Increased familiarity with scenes had modest effects on RTs, while repetition of target items had large effects (>500 ms). We propose that visual search in scenes is efficient because scene-specific forms of attentional guidance can eliminate most regions from the “functional set size” of items that could possibly be the target.