Learning to draw parametric faces.

Humans' ability to draw faces accurately from memory is extremely rare. One source of difficulty is the drawing process itself, which requires converting a complex, three-dimensional mental representation to a two-dimensional drawing. To simplify the drawing process and more directly assess people's recall of faces, we used the Parameterized Face Drawing (PFD) model (Day & Davidenko, Visual Cognition, 26(2), 89-99, 2018; Day & Davidenko, Journal of Vision, 19(11):7, 1-12, 2019) to generate simplified face stimuli that non-artists could draw. In Experiment 1, participants (N = 37) completed a sequential drawing-by-copying task in which they were given 60 s to draw each of 18 target faces by copying them using a stylus on a touchscreen. Following each drawing, participants were prompted to label a set of 20 key points on their drawing based on a reference face, which were used to compute the drawing's accuracy. In Experiment 2, participants (N = 22) observed each target face for 15 s and were then given 60 s to draw it from memory. In Experiment 1, the accuracy of drawings improved slightly over the course of the 18 trials, although most of the improvement occurred during the first few trials. In Experiment 2 (drawing-from-memory), there was no evidence of improvement, although the null results are tentative given the small sample size. Despite weak evidence of learning, participants' drawings captured the likeness of the target faces significantly better than chance. We discuss implications of these findings for the use of drawing as a method of face recall.

Subjective control of polystable illusory apparent motion: Is control possible when the stimulus affords countless motion possibilities?

We investigate whether a new polystable illusion, illusory apparent motion (IAM), is susceptible to subjective perceptual control as has been shown in other polystable stimuli (e.g., the Necker cube, apparent motion quartets). Previous research has demonstrated that, although IAM shares some properties in common with other polystable stimuli, it also has some unique ones that make it unclear whether it should have similar susceptibility to subjective control. For example, IAM can be perceived in a countless number of directions and motion patterns (e.g., up-down, left-left, contracting-expanding, shear, diagonal). To explore perceptual control of IAM, in experiment 1 (n = 99) we used a motion persistence paradigm where participants are primed with different motion patterns and are instructed to control (change or hold) the initial motion pattern and indicate when the motion pattern changes. Building on experiment 1, experiment 2 (n = 76) brings the method more in line with previous subjective control research, testing whether participants can control their perception of IAM in a context without priming and while dynamically reporting their percepts throughout the trial. Findings from the two experiments demonstrate that participants were able to control their perception of IAM across paradigms. We explore the implications of these findings, strategies reported, and open questions for future research.

Visual priming of two-step motion sequences.

Perception of an ambiguous apparent motion is influenced by the immediately preceding motion. In positive priming, when an observer is primed with a slow-pace (1-3 Hz) sequence of motion frames depicting unidirectional drift (e.g., Right-Right-Right-Right), subsequent sequences of ambiguous frames are often perceived to continue moving in the primed direction (illusory Right-Right …). Furthermore, priming an observer with a slow-pace sequence of rebounding apparent motion frames that alternate between opponently coded motion directions (e.g., Right-Left-Right-Left) leads to an illusory continuation of the two-step rebounding sequence in subsequent random frames. Here, we show that even more arbitrary two-step motion sequences can be primed; in particular, two-step motion sequences that alternate between non-opponently coded directions (e.g., Up-Right-Up-Right; staircase motion) can be primed to be illusorily perceived in subsequent random frames. We found that staircase sequences, but not drifting or rebounding sequences, were primed more effectively with four priming frames compared with two priming frames, suggesting the importance of repeating the sequence element for priming arbitrary two-step motion sequences. Moreover, we compared the effectiveness of motion primes to that of symbolic primes (arrows) and found that motion primes were significantly more effective at producing prime-consistent responses. Although it has been proposed that excitatory and rivalry-like mechanisms account for drifting and rebounding motion priming, current motion processing models cannot account for our observed priming of staircase motion. We argue that higher order processes involving the recruitment and interaction of both attention and visual working memory are required to account for the type of two-step motion priming reported here.

Combined Neural Tuning in Human Ventral Temporal Cortex Resolves the Perceptual Ambiguity of Morphed 2D Images.

We have an amazing ability to categorize objects in the world around us. Nevertheless, how cortical regions in human ventral temporal cortex (VTC), which is critical for categorization, support this behavioral ability, is largely unknown. Here, we examined the relationship between neural responses and behavioral performance during the categorization of morphed silhouettes of faces and hands, which are animate categories processed in cortically adjacent regions in VTC. Our results reveal that the combination of neural responses from VTC face- and body-selective regions more accurately explains behavioral categorization than neural responses from either region alone. Furthermore, we built a model that predicts a person's behavioral performance using estimated parameters of brain-behavior relationships from a different group of people. Moreover, we show that this brain-behavior model generalizes to adjacent face- and body-selective regions in lateral occipitotemporal cortex. Thus, while face- and body-selective regions are located within functionally distinct domain-specific networks, cortically adjacent regions from both networks likely integrate neural responses to resolve competing and perceptually ambiguous information from both categories.

The Upper Eye Bias: Rotated Faces Draw Fixations to the Upper Eye.

There is a consistent left-gaze bias when observers fixate upright faces, but it is unknown how this bias manifests in rotated faces, where the two eyes appear at different heights on the face. In two eye-tracking experiments, we measured participants' first and second fixations, while they judged the expressions of upright and rotated faces. We hypothesized that rotated faces might elicit a bias to fixate the upper eye. Our results strongly confirmed this hypothesis, with the upper eye bias completely dominating the left-gaze bias in ±45° faces in Experiment 1, and across a range of face orientations (±11.25°, ±22.5°, ±33.75°, ±45°, and ±90°) in Experiment 2. In addition, rotated faces elicited more overall eye-directed fixations than upright faces. We consider potential mechanisms of the upper eye bias in rotated faces and discuss some implications for research in social cognition.

Parametric face drawings: A demographically diverse and customizable face space model.

We introduce a novel face space model-parametric face drawings (or PFDs)-to generate schematic, though realistic, parameterized line drawings of faces based on the statistical distribution of human facial features. A review of existing face space models (including FaceGen Modeller, Synthetic Faces, MPI, and active appearance model) indicates that current models are constrained by their reliance on ethnically homogeneous face databases. This constraint has led to negative consequences for underrepresented populations, such as impairments in automatized identity recognition of certain demographic groups. Our model is based on a demographically diverse sample of 400 faces (200 female, 200 male; 100 East Asian/Pacific Islander, 100 Latinx/Hispanic, 100 black/African-American, and 100 white/Caucasian) compiled from several face databases (including FERET face recognition technology and the Chicago Face Database). Each front-view face image is manually coded with 85 landmark points that are then normalized and rendered with MATLAB (MathWorks, Natick, MA) tools to produce a smooth, parameterized face line drawing. We present data from two behavioral experiments to validate our model and demonstrate its applicability. In Experiment 1 we show that PFDs produce a reliable "inversion effect" in short-term recognition, a hallmark of holistic processing. In Experiment 2, we conduct a celebrity recognition task, comparing performance on PFDs to performance on untextured renderings from FaceGen Modeller. Participants successfully recognized approximately 50% of celebrity faces based on the PFD models, comparable to performance based on FaceGen Modeler (also 50% correct). We highlight a range of potential applications of our model, list some limitations, and provide MATLAB resources for researchers to utilize our face space, including the ability to customize the demographic makeup of the face space, add new faces, and produce morphs and caricatures.

The influence of visual and vestibular orientation cues in a clock reading task.

We investigated how performance in the real-life perceptual task of analog clock reading is influenced by the clock's orientation with respect to egocentric, gravitational, and visual-environmental reference frames. In Experiment 1, we designed a simple clock-reading task and found that observers' reaction time to correctly tell the time depends systematically on the clock's orientation. In Experiment 2, we dissociated egocentric from environmental reference frames by having participants sit upright or lie sideways while performing the task. We found that both reference frames substantially contribute to response times in this task. In Experiment 3, we placed upright or rotated participants in an upright or rotated immersive virtual environment, which allowed us to further dissociate vestibular from visual cues to the environmental reference frame. We found evidence of environmental reference frame effects only when visual and vestibular cues were aligned. We discuss the implications for the design of remote and head-mounted displays.

Dissociating Higher and Lower Order Visual Motion Systems by Priming Illusory Apparent Motion.

Motion processing is thought of as a hierarchical system composed of higher and lower order components. Past research has shown that these components can be dissociated using motion priming paradigms in which the lower order system produces negative priming while the higher order system produces positive priming. By manipulating various stimulus parameters, researchers have probed these two systems using bistable test stimuli that permit only two motion interpretations. Here we employ maximally ambiguous test stimuli composed of randomly refreshing pixels in a task that allows observers to report more than just two types of motion percepts. We show that even with such stimuli, motion priming can constrain the unstructured random pixel patterns into coherent percepts of positive or negative apparent motion. Moreover, we find that the higher order system is uniquely susceptible to cognitive influences, as evidenced by a significant suppression of positive priming in the presence of alternative response options.

Persistent illusory apparent motion in sequences of uncorrelated random dots.

We report a novel phenomenon in which long sequences of random dot arrays refreshing at 2.5 Hz lead to persistent illusory percepts of coherent apparent motion. We term this effect illusory apparent motion (IAM). To quantify this illusion, we devised a persistence task in which observers are primed with a particular motion pattern and must indicate when the motion pattern ends. In Experiment 1 (N = 119), we induced translational apparent motion patterns and show that both drifting motion (e.g., up-up-up-up) and rebounding motion (e.g., up-down-up-down) persists throughout many frames of uncorrelated random dots, although rebounding motion tends to persist for longer (a rebounding bias). In Experiment 2 (N = 60), we induced rotational IAM on an annulus-shaped display, and show that the topology of the display (whether the annulus is complete or has a gap) determines whether or not the rebounding bias is present. Based on our findings, we argue that IAM provides a powerful tool to study the mechanisms, constraints, and individual differences in the perception of illusory motion.

Silhouette estimation.

Silhouettes arise in a variety of imaging scenarios. Pristine silhouettes are often degraded via blurring, detector sampling, and detector noise. We present a maximum a posteriori estimator for the restoration of parameterized facial silhouettes. Extreme dealiasing and dramatic superresolution, well beyond the diffraction limit, are demonstrated through the use of strong prior knowledge.

Absolute pitch in involuntary musical imagery.

Memory for isolated absolute pitches is extremely rare in Western, English-speaking populations. However, past research has found that people can voluntarily reproduce well-known songs in the original key much more often than chance. It is unknown whether this requires deliberate effort or if it manifests in involuntary musical imagery (INMI, or earworms). Participants (N = 30, convenience sample) were surveyed at random times over a week and asked to produce a sung recording of any music they were experiencing in their heads. We measured the "pitch error" of each recording to the nearest semitone by comparing participants' recordings to the original song. We found that 44.7% of recordings had a pitch error of 0 semitones, and 68.9% of recordings were within ± 1 semitone of the original song. Our results provide novel evidence that a large proportion of the population has access to absolute pitch, as revealed in their INMI.

Face-likeness and image variability drive responses in human face-selective ventral regions.

The human ventral visual stream contains regions that respond selectively to faces over objects. However, it is unknown whether responses in these regions correlate with how face-like stimuli appear. Here, we use parameterized face silhouettes to manipulate the perceived face-likeness of stimuli and measure responses in face- and object-selective ventral regions with high-resolution fMRI. We first use "concentric hyper-sphere" (CH) sampling to define face silhouettes at different distances from the prototype face. Observers rate the stimuli as progressively more face-like the closer they are to the prototype face. Paradoxically, responses in both face- and object-selective regions decrease as face-likeness ratings increase. Because CH sampling produces blocks of stimuli whose variability is negatively correlated with face-likeness, this effect may be driven by more adaptation during high face-likeness (low-variability) blocks than during low face-likeness (high-variability) blocks. We tested this hypothesis by measuring responses to matched-variability (MV) blocks of stimuli with similar face-likeness ratings as with CH sampling. Critically, under MV sampling, we find a face-specific effect: responses in face-selective regions gradually increase with perceived face-likeness, but responses in object-selective regions are unchanged. Our studies provide novel evidence that face-selective responses correlate with the perceived face-likeness of stimuli, but this effect is revealed only when image variability is controlled across conditions. Finally, our data show that variability is a powerful factor that drives responses across the ventral stream. This indicates that controlling variability across conditions should be a critical tool in future neuroimaging studies of face and object representation.

Development and Evaluation of a Sound-Swapped Video Database for Misophonia.

Misophonia has been characterized as intense negative reactions to specific trigger sounds (often orofacial sounds like chewing, sniffling, or slurping). However, recent research suggests high-level, contextual, and multisensory factors are also involved. We recently demonstrated that neurotypicals' negative reactions to aversive sounds (e.g., nails scratching a chalkboard) are attenuated when the sounds are synced with positive attributable video sources (PAVS; e.g., tearing a piece of paper). To assess whether this effect generalizes to misophonic triggers, we developed a Sound-Swapped Video (SSV) database for use in misophonia research. In Study 1, we created a set of 39 video clips depicting common trigger sounds (original video sources, OVS) and a corresponding set of 39 PAVS temporally synchronized with the OVS videos. In Study 2, participants (N = 34) rated the 39 PAVS videos for their audiovisual match and pleasantness. We selected the 20 PAVS videos with best match scores for use in Study 3. In Study 3, a new group of participants (n = 102) observed the 20 selected PAVS and 20 corresponding OVS and judged the pleasantness or unpleasantness of each sound in the two contexts accompanying each video. Afterward, participants completed the Misophonia Questionnaire (MQ). The results of Study 3 show a robust attenuating effect of PAVS videos on the reported unpleasantness of trigger sounds: trigger sounds were rated as significantly less unpleasant when paired with PAVS with than OVS. Moreover, this attenuating effect was present in nearly every participant (99 out of 102) regardless of their score on the MQ. In fact, we found a moderate positive correlation between the PAVS-OVS difference and misophonia severity scores. Overall our results provide validation that the SSV database is a useful stimulus database to study how misophonic responses can be modulated by visual contexts. Here, we release the SSV database with the best 18 PAVS and 18 OVS videos used in Study 3 along with aggregate ratings of audio-video match and pleasantness (https://osf.io/3ysfh/). We also provide detailed instructions on how to produce these videos, with the hope that this database grows and improves through collaborations with the community of misophonia researchers.

Cross-Sensory Stimuli Modulate Reactions to Aversive Sounds.

We propose that cross-sensory stimuli presenting a positive attributable source of an aversive sound can modulate negative reactions to the sound. In Experiment 1, participants rated original video sources (OVS) of eight aversive sounds (e.g., nails scratching a chalkboard) as more aversive than eight positive attributable video sources (PAVS) of those same sounds (e.g., someone playing a flute) when these videos were presented silently. In Experiment 2, new participants were presented with those eight aversive sounds in three blocks. In Blocks 1 and 3, the sounds were presented alone; in Block 2, four of the sounds were randomly presented concurrently with their corresponding OVS videos, and the other four with their corresponding PAVS videos. Participants rated each sound, presented with or without video, on three scales: discomfort, unpleasantness, and bodily sensations. We found the concurrent presentation of videos robustly modulates participants' reactions to the sounds: compared to the sounds alone (Block 1), concurrent presentation of PAVS videos significantly reduced negative reactions to the sounds, and the concurrent presentation of OVS videos significantly increased negative reactions, across all three scales. These effects, however, did not linger into Block 3 when the sounds were presented alone again. Our results provide novel evidence that negative reactions to aversive sounds can be modulated through cross-sensory temporal syncing with a positive attributable video source. Although this research was conducted with a neurotypical population, we argue that our findings have implications for the treatment of misophonia.

Reading sideways: Effects of egocentric and environmental orientation in a lexical decision task.

Many image-level factors affect reading speed and comprehension, including the in-plane orientation of text. As words' angular deviation from upright increases, so do response times. Here we investigated whether these orientation effects in reading are based purely on an egocentric (retinal) reference frame, or whether there is also a contribution of the environmental reference frame. Participants completed a lexical decision task with six-letter, two-syllable words and nonwords presented at a wide range of angles, in increments of 22.5°. A control group of participants (N = 66) completed the task while sitting upright, and an experimental group (N = 43) completed the task while lying sideways on their right side. The function relating the egocentric orientation of strings to response times was symmetric for upright observers, but skewed for observers who lay sideways, with an advantage for responding to environmentally upright text. Our results suggest that sideways readers may use an oblique reference frame (similar to the perceptual upright) for mentally rotating text. We discuss implications for designing optimal text orientations in head mounted displays.

Primed and unprimed rebounding illusory apparent motion.

Although sequences of uncorrelated random dots can yield a wide range of illusorily coherent motion percepts (including translation, rotation, contraction, expansion, shear, and rebounding motion), past priming studies have relied on two-alternative forced choice tasks that only measure unidirectional (positive or negative) priming effects. In Experiment 1 we showed that when participants are primed with unidirectional motion and given an additional option to report bidirectional (rebounding) motion, they do so frequently, suggesting that unidirectional motion can "default" to a rebounding percept. Furthermore, rebounding percepts are more prevalent during trials with long frame durations, suggesting a role for attention in forming and maintaining these illusory percepts. In Experiment 2 we compared rebounding percepts that followed unidirectional, drifting primes with rebounding percepts that followed bidirectional, rebounding primes, and found that these two types of illusory rebounding motion percepts differ systematically in their temporal structures. We argue that rebounding percepts following drifting primes can be understood as a breakdown of positive priming into an underlying oscillatory state, whereas rebounding percepts following rebounding primes may be understood either as (1) the initialization of the same oscillatory process, or (2) the entrainment of a two-step motion pattern by a higher-order mechanism.

Silhouetted face profiles: a new methodology for face perception research.

We present a new methodology for constructing face stimuli for psychological experiments based on silhouetted face profiles. Face silhouettes carry a number of theoretical and methodological advantages compared to more complex face stimuli and lend themselves to a simple yet powerful parameterization. In five behavioral studies, we show that face silhouettes are processed like regular face stimuli: They provide enough information for accurate gender judgments (Study 1), age estimations (Study 2), and reliable and cross-valid attractiveness ratings (Study 3). Furthermore, face silhouettes elicit an inversion effect (Study 4) and allow for remarkably accurate cross-identification with front-view photographs (Study 5). We then describe a shape-based parameterization that relies on a small set of landmark points and show that face silhouettes can be effectively represented in a 20-dimensional "silhouette face space" (Study 6). We show that in this physical space, distance from the center of the space corresponds to perceived distinctiveness (Study 7), confirming a key axiom in the formulation of the face space model. Finally, we discuss straightforward applications of the face silhouette methodology and address some limitations.

Attending to Race (or Gender) Does Not Increase Race (or Gender) Aftereffects.

Recent research has shown that attention can influence the strength of face aftereffects. For example, attending to changes in facial features increases the strength of identity and figural aftereffects relative to passive viewing (Rhodes et al., 2011). Here, we ask whether attending to a specific social dimension of a face (such as race or gender) influences the strength of face aftereffects along that dimension. Across three experiments, participants completed many single-shot face adaptation trials. In each trial, participants observed a computer-generated adapting face for 5 s while instructed to focus on either the race or gender of that adapting face. Adapting faces were either Asian and female or Caucasian and male. In Experiment 1, all trials included an intermediate question (IQ) following each adaptation period, soliciting a rating of the adapting face on the attended dimension (e.g., race). In Experiment 2, only half of the trials included this IQ, and in Experiment 3 only a quarter of the trials did. In all three experiments, participants were subsequently presented with a race- and gender-neutral face and asked to rate it on either the attended dimension (e.g., race, attention-congruent trials) or the unattended dimension (e.g., gender, attention-incongruent trials) using a seven-point scale. Overall, participants showed significant aftereffects in all conditions, manifesting as (i) higher Asian ratings of the neutral faces following Caucasian vs. Asian adapting faces and (ii) higher female ratings of neutral faces following male vs. female adapting faces. Intriguingly, although reaction times were shorter during attention-congruent vs. attention-incongruent trials, aftereffects were not stronger along attention-congruent than attention-incongruent dimensions. Our results suggest that attending to a facial dimension such as race or gender does not result in increased adaptation to that dimension.

Environmental inversion effects in face perception.

Visual processing is highly sensitive to stimulus orientation; for example, face perception is drastically worse when faces are oriented inverted vs. upright. However, stimulus orientation must be established in relation to a particular reference frame, and in most studies, several reference frames are conflated. Which reference frame(s) matter in the perception of faces? Here we describe a simple, novel method for dissociating effects of egocentric and environmental orientation on face processing. Participants performed one of two face-processing tasks (expression classification and recognition memory) as they lay horizontally, which served to disassociate the egocentric and environmental frames. We found large effects of egocentric orientation on performance and smaller but reliable effects of environmental orientation. In a follow-up control experiment, we ruled out the possibility that the latter could be explained by compensatory ocular counterroll. We argue that environmental orientation influences face processing, which is revealed when egocentric orientation is fixed.

Compensatory rationalizations and the resolution of everyday undeserved outcomes.

People prefer to perceive the world as just; however, the everyday experience of undeserved events challenges this perception.The authors suggest that one way people rationalize these daily experiences of unfairness is by means of a compensatory bias. People make undeserved events more palatable by endorsing the notion that outcomes naturally balance out in the end--good, yet undeserved, outcomes will balance out bad outcomes, and bad undeserved outcomes will balance out good outcomes.The authors propose that compensatory biases manifest in people's interpretive processes (Study 1) and memory (Study 2). Furthermore, they provide evidence that people have a natural tendency to anticipate compensatory outcomes in the future, which, ironically, might lead them to perceive a current situation as relatively more fair (Study 3).These studies highlight an understudied means of justifying unfairness and elucidate the justice motive's power to affect people's construal of their social world.