Fast saccades to faces during the feedforward sweep.

Saccadic choice tasks use eye movements as a response method, typically in a task where observers are asked to saccade as quickly as possible to an image of a prespecified target category. Using this approach, face-selective saccades have been observed within 100 ms poststimulus. When taking into account oculomotor processing, this suggests that faces can be detected in as little as 70 to 80 ms. It has therefore been suggested that face detection must occur during the initial feedforward sweep, since this latency leaves little time for feedback processing. In the current experiment, we tested this hypothesis using backward masking-a technique shown to primarily disrupt feedback processing while leaving feedforward activation relatively intact. Based on minimum saccadic reaction time, we found that face detection benefited from ultra-fast, accurate saccades within 110 to 160 ms and that these eye movements are obtainable even under extreme masking conditions that limit perceptual awareness. However, masking did significantly increase the median SRT for faces. In the manual responses, we found remarkable detection accuracy for faces and houses, even when participants indicated having no visual experience of the test images. These results provide evidence for the view that the saccadic bias to faces is initiated by coarse information used to categorize faces in the feedforward sweep but that, in most cases, additional processing is required to quickly reach the threshold for saccade initiation.

Multi-omics prediction of oat agronomic and seed nutritional traits across environments and in distantly related populations.

KEY MESSAGE: Integration of multi-omics data improved prediction accuracies of oat agronomic and seed nutritional traits in multi-environment trials and distantly related populations in addition to the single-environment prediction. Multi-omics prediction has been shown to be superior to genomic prediction with genome-wide DNA-based genetic markers (G) for predicting phenotypes. However, most of the existing studies were based on historical datasets from one environment; therefore, they were unable to evaluate the efficiency of multi-omics prediction in multi-environment trials and distantly related populations. To fill those gaps, we designed a systematic experiment to collect omics data and evaluate 17 traits in two oat breeding populations planted in single and multiple environments. In the single-environment trial, transcriptomic BLUP (T), metabolomic BLUP (M), G + T, G + M, and G + T + M models showed greater prediction accuracy than GBLUP for 5, 10, 11, 17, and 17 traits, respectively, and metabolites generally performed better than transcripts when combined with SNPs. In the multi-environment trial, multi-trait models with omics data outperformed both counterpart multi-trait GBLUP models and single-environment omics models, and the highest prediction accuracy was achieved when modeling genetic covariance as an unstructured covariance model. We also demonstrated that omics data can be used to prioritize loci from one population with omics data to improve genomic prediction in a distantly related population using a two-kernel linear model that accommodated both likely casual loci with large-effect and loci that explain little or no phenotypic variance. We propose that the two-kernel linear model is superior to most genomic prediction models that assume each variant is equally likely to affect the trait and can be used to improve prediction accuracy for any trait with prior knowledge of genetic architecture.

Bird expertise does not increase motion sensitivity to bird flight motion.

While motion information is important for the early stages of vision, it also contributes to later stages of object recognition. For example, human observers can detect the presence of a human, judge its actions, and judge its gender and identity simply based on motion cues conveyed in a point-light display. Here we examined whether object expertise enhances the observer's sensitivity to its characteristic movement. Bird experts and novices were shown point-light displays of upright and inverted birds in flight, or upright and inverted human walkers, and asked to discriminate them from spatially scrambled point-light displays of the same stimuli. While the spatially scrambled stimuli retained the local motion of each dot of the moving objects, it disrupted the global percept of the object in motion. To estimate a detection threshold in each object domain, we systematically varied the number of noise dots in which the stimuli were embedded using an adaptive staircase approach. Contrary to our predictions, the experts did not show disproportionately higher sensitivity to bird motion, and both groups showed no inversion cost. However, consistent with previous work showing a robust inversion effect for human motion, both groups were more sensitive to upright human walkers than their inverted counterparts. Thus, the result suggests that real-world experience in the bird domain has little to no influence on the sensitivity to bird motion and that birds do not show the typical inversion effect seen with humans and other terrestrial movement.

Emotional gist: the rapid perception of facial expressions.

While it has been established that expression perception is rapid, it is unclear whether early appraisal mechanisms invoke holistic perception. In the current study, we defined gist perception as the appraisal of a stimulus within a single glance (<125 ms). We employed the expression composite task used previously by Tanaka and colleagues in a 2012 study, with several critical modifications: (i) we developed stimuli that eliminated contrast artifacts, (ii) we employed a masking technique to abolish low-level cues, and (iii) all the face stimuli were composite stimuli compared to mix of natural and composite stimuli previously used. Participants were shown a congruent (e.g. top: angry/ bottom: angry) or incongruent (e.g. top: angry/ bottom: happy) expression for 17, 50 or 250 ms and instructed to selectively attend to the cued expression depicted in the top (or bottom) half of the composite face and ignore the uncued portion. Compared to the isolated condition, a facilitation effect was found for congruent angry expressions, as well as an interference effect for incongruent happy and angry expressions at the shortest exposure duration of 17. Together these results provide evidence that the holistic gist perception of expression cannot be overridden by selective attention.

Neural and behavioral effects of subordinate-level training of novel objects across manipulations of color and spatial frequency.

Perceptual expertise is marked by subordinate-level recognition of objects in the expert domain. In this study, participants learned one family of full-color, artificial objects at the subordinate (species) level and another family at the basic (family) level. Discrimination of trained and untrained exemplars was tested before and after training across several image manipulations [full-color, grayscale, low spatial frequency (LSF) and high spatial frequency (HSF)] while event-related potentials (ERPs) were recorded. Regardless of image manipulation, discrimination (indexed by d') of trained and of untrained exemplars was enhanced after subordinate-level training, but not after basic-level training. Enhanced discrimination after subordinate-level training generalized to untrained exemplars and to grayscale images and images in which LSF or HSF information was removed. After training, the N170 and N250, recorded over occipital and occipitotemporal brain regions, were both more enhanced after subordinate-level training than after basic-level training. However, the topographic distribution of enhanced responses differed across components. The N170 latency predicted reaction time after both basic-level training and subordinate-level training, highlighting an association between behavioral and neural responses. These findings further elucidate the role of the N170 and N250 as ERP indices of subordinate-level expert object processing and demonstrate how low-level manipulations of color and spatial frequency impact behavior and the N170 and N250 components independent of training or expertise.

Inversion Impairs Expert Budgerigar Identity Recognition: A Face-Like Effect for a Nonface Object of Expertise.

The face-inversion effect is the finding that picture-plane inversion disproportionately impairs face recognition compared to object recognition and is now attributed to greater orientation-sensitivity of holistic processing for faces but not common objects. Yet, expert dog judges have showed similar recognition deficits for inverted dogs and inverted faces, suggesting that holistic processing is not specific to faces but to the expert recognition of perceptually similar objects. Although processing changes in expert object recognition have since been extensively documented, no other studies have observed the distinct recognition deficits for inverted objects-of-expertise that people as face experts show for faces. However, few studies have examined experts who recognize individual objects similar to how people recognize individual faces. Here we tested experts who recognize individual budgerigar birds. The effect of inversion on viewpoint-invariant budgerigar and face recognition was compared for experts and novices. Consistent with the face-inversion effect, novices showed recognition deficits for inverted faces but not for inverted budgerigars. By contrast, experts showed equal recognition deficits for inverted faces and budgerigars. The results are consistent with the hypothesis that processes underlying the face-inversion effect are specific to the expert individuation of perceptually similar objects.

Individual Differences in Face Identity Processing with Fast Periodic Visual Stimulation.

A growing body of literature suggests that human individuals differ in their ability to process face identity. These findings mainly stem from explicit behavioral tasks, such as the Cambridge Face Memory Test (CFMT). However, it remains an open question whether such individual differences can be found in the absence of an explicit face identity task and when faces have to be individualized at a single glance. In the current study, we tested 49 participants with a recently developed fast periodic visual stimulation (FPVS) paradigm [Liu-Shuang, J., Norcia, A. M., & Rossion, B. An objective index of individual face discrimination in the right occipitotemporal cortex by means of fast periodic oddball stimulation. Neuropsychologia, 52, 57-72, 2014] in EEG to rapidly, objectively, and implicitly quantify face identity processing. In the FPVS paradigm, one face identity (A) was presented at the frequency of 6 Hz, allowing only one gaze fixation, with different face identities (B, C, D) presented every fifth face (1.2 Hz; i.e., AAAABAAAACAAAAD…). Results showed a face individuation response at 1.2 Hz and its harmonics, peaking over occipitotemporal locations. The magnitude of this response showed high reliability across different recording sequences and was significant in all but two participants, with the magnitude and lateralization differing widely across participants. There was a modest but significant correlation between the individuation response amplitude and the performance of the behavioral CFMT task, despite the fact that CFMT and FPVS measured different aspects of face identity processing. Taken together, the current study highlights the FPVS approach as a promising means for studying individual differences in face identity processing.

Narrowing in categorical responding to other-race face classes by infants.

Infants can form object categories based on perceptual cues, but their ability to form categories based on differential experience is less clear. Here we examined whether infants filter through perceptual differences among faces from different other-race classes and represent them as a single other-race class different only from own-race faces. We used a familiarization/novelty-preference procedure to investigate category formation for two other-race face classes (Black vs. Asian) by White 6- and 9-month-olds. The data indicated that while White 6-month-olds categorically represented the distinction between Black and Asian faces, White 9-month-olds formed a broad other-race category inclusive of Black and Asian faces, but exclusive of own-race White faces. The findings provide evidence that narrowing can occur for mental processes other than discrimination: category formation is also affected. The results suggest that frequency of experience with own-race versus other-race classes of faces may propel infants to contrast own-race faces with other-race faces, but not different classes of other-race faces with each other.

Individuation training with other-race faces reduces preschoolers' implicit racial bias: a link between perceptual and social representation of faces in children.

The present study examined whether perceptual individuation training with other-race faces could reduce preschool children's implicit racial bias. We used an 'angry = outgroup' paradigm to measure Chinese children's implicit racial bias against African individuals before and after training. In Experiment 1, children between 4 and 6 years were presented with angry or happy racially ambiguous faces that were morphed between Chinese and African faces. Initially, Chinese children demonstrated implicit racial bias: they categorized happy racially ambiguous faces as own-race (Chinese) and angry racially ambiguous faces as other-race (African). Then, the children participated in a training session where they learned to individuate African faces. Children's implicit racial bias was significantly reduced after training relative to that before training. Experiment 2 used the same procedure as Experiment 1, except that Chinese children were trained with own-race Chinese faces. These children did not display a significant reduction in implicit racial bias. Our results demonstrate that early implicit racial bias can be reduced by presenting children with other-race face individuation training, and support a linkage between perceptual and social representations of face information in children.

Fine mapping of a preharvest sprouting QTL interval on chromosome 2B in white wheat.

KEY MESSAGE: Fine mapping by recombinant backcross populations revealed that a preharvest sprouting QTL on 2B contained two QTLs linked in coupling with different effects on the phenotype. Wheat preharvest sprouting (PHS) occurs when grain germinates on the plant before harvest, resulting in reduced grain quality. Previous mapping of quantitative trait locus (QTL) revealed a major PHS QTL, QPhs.cnl-2B.1, located on chromosome 2B significant in 16 environments that explained from 5 to 31 % of the phenotypic variation. The objective of this project was to fine map the QPhs.cnl-2B.1 interval. Fine mapping was carried out in recombinant backcross populations (BC1F4 and BC1F5) that were developed by backcrossing selected doubled haploids to a recurrent parent and self-pollinating the BC1F4 and BC1F5 generations. In each generation, three markers in the QPhs.cnl-2B.1 interval were used to screen for recombinants. Fine mapping revealed that the QPhs.cnl-2B.1 interval contained two PHS QTLs linked in coupling. The distal PHS QTL, located between Wmc453c and Barc55, contributed 8 % of the phenotypic variation and also co-located with a major seed dormancy QTL determined by germination index. The proximal PHS QTL, between Wmc474 and CNL415-rCDPK, contributed 16 % of the variation. Several candidate genes including Mg-chelatase H subunit family protein, GTP-binding protein and calmodulin/Ca(2+)-dependent protein kinase were linked to the PHS QTL. Although many recombinant lines were identified, the lack of polymorphism for markers in the QTL interval prevented the localization of the recombination breakpoints and identification of the gene underlying the phenotype.

Developmental plateau in visual object processing from adolescence to adulthood in autism.

A lack of typical age-related improvement from adolescence to adulthood contributes to face recognition deficits in adults with autism on the Cambridge Face Memory Test (CFMT). The current studies examine if this atypical developmental trajectory generalizes to other tasks and objects, including parts of the face. The CFMT tests recognition of whole faces, often with a substantial delay. The current studies used the immediate memory (IM) task and the parts-whole face task from the Let's Face It! battery, which examines whole faces, face parts, and cars, without a delay between memorization and test trials. In the IM task, participants memorize a face or car. Immediately after the target disappears, participants identify the target from two similar distractors. In the part-whole task, participants memorize a whole face. Immediately after the face disappears, participants identify the target from a distractor with different eyes or mouth, either as a face part or a whole face. Results indicate that recognition deficits in autism become more robust by adulthood, consistent with previous work, and also become more general, including cars. In the IM task, deficits in autism were specific to faces in childhood, but included cars by adulthood. In the part-whole task, deficits in autism became more robust by adulthood, including both eyes and mouths as parts and in whole faces. Across tasks, the deficit in autism increased between adolescence and adulthood, reflecting a lack of typical improvement, leading to deficits with non-face stimuli and on a task without a memory delay. These results suggest that brain maturation continues to be affected into adulthood in autism, and that the transition from adolescence to adulthood is a vulnerable stage for those with autism.

The effects of information type (features vs. configuration) and location (eyes vs. mouth) on the development of face perception.

The goal of the current study was to investigate the development of face processing strategies in a perceptual discrimination task. Children (7-12 years of age) and young adults were administered the Face Dimensions Task. In the Face Dimensions Task, participants were asked to judge whether two simultaneously presented faces were the "same" or "different". For the "same" trials, the two faces were identical. For the "different" trials, the faces differed in either the spacing between the eyes, the spacing between the nose and the mouth, the size of the eyes, or the size of the mouth. The main finding was that 7- to 10-year-old children showed no difference in their ability to discriminate differences in eye size and eye spacing but showed a poor ability to discriminate differences in nose and mouth spacing and, to a lesser extent, mouth size. The developmental lag between nose-mouth discriminations and the other featural and configural discriminations was reduced in older children and eliminated by young adulthood. These results indicate that the type of face information (i.e., configural vs. featural) and its location (i.e., eye vs. mouth) jointly contribute to the development of face perception abilities.

The role of color in expert object recognition.

In the current study, we examined how color knowledge in a domain of expertise influences the accuracy and speed of object recognition. In Experiment 1, expert bird-watchers and novice participants categorized common birds (e.g., robin, sparrow, cardinal) at the family level of abstraction. The bird images were shown in their natural congruent color, nonnatural incongruent color, and gray scale. The main finding was that color affected the performance of bird experts and bird novices, albeit in different ways. Although both experts and novices relied on color to recognize birds at the family level, analysis of the response time distribution revealed that color facilitated expert performance in the fastest and slowest trials whereas color only helped the novices in the slower trials. In Experiment 2, expert bird-watchers were asked to categorize congruent color, incongruent color, and gray scale images of birds at the more subordinate, species level (e.g., Nashville warbler, Wilson's warbler). The performance of experts was better with congruent color images than with incongruent color and gray scale images. As in Experiment 1, analysis of the response time distribution showed that the color effect was present in the fastest trials and was sustained through the slowest trials. Collectively, the findings show that experts have ready access to color knowledge that facilitates their fast and accurate identification at the family and species level of recognition.

The moving window technique: a window into developmental changes in attention during facial emotion recognition.

The strategies children employ to selectively attend to different parts of the face may reflect important developmental changes in facial emotion recognition. Using the Moving Window Technique (MWT), children aged 5-12 years and adults (N = 129) explored faces with a mouse-controlled window in an emotion recognition task. An age-related increase in attention to the left eye emerged at age 11-12 years and reached significance in adulthood. This left-eye bias is consistent with previous eye tracking research and findings of a perceptual bias for the left side of faces. These results suggest that a strategic attentional bias to the left eye begins to emerge at age 11-12 years and is likely established sometime in adolescence.

Does face inversion qualitatively change face processing: an eye movement study using a face change detection task.

Understanding the Face Inversion Effect is important for the study of face processing. Some researchers believe that the processing of inverted faces is qualitatively different from the processing of upright faces because inversion leads to a disproportionate performance decrement on the processing of different kinds of face information. Other researchers believe that the difference is quantitative because the processing of all kinds of facial information is less efficient due to the change in orientation and thus, the performance decrement is not disproportionate. To address the Qualitative and Quantitative debate, the current study employed a response-contingent, change detection paradigm to study eye movement during the processing of upright and inverted faces. In this study, configural and featural information were parametrically and independently manipulated in the eye and mouth region of the face. The manipulations for configural information involved changing the interocular distance between the eyes or the distance between the mouth and the nose. The manipulations for featural information involved changing the size of the eyes or the size of the mouth. The main results showed that change detection was more difficult in inverted than upright faces. Specifically, performance declined when the manipulated change occurred in the mouth region, despite the greater efforts allocated to the mouth region. Moreover, compared to upright faces where fixations were concentrated on the eyes and nose regions, inversion produced a higher concentration of fixations on the nose and mouth regions. Finally, change detection performance was better when the last fixation prior to response was located on the region of change, and the relationship between last fixation location and accuracy was stronger for inverted than upright faces. These findings reinforce the connection between eye movements and face processing strategies, and suggest that face inversion produces a qualitative disruption of looking behavior in the mouth region.

Development of Recognition of Face Parts from Unfamiliar Faces.

The present study examined developmental changes in the ability to recognize face parts. In Experiment 1, participants were familiarized with whole faces and given a recognition test with old and new eyes, noses, mouths, inner faces, outer faces, or whole faces. Adults were above chance in their recognition of the eye and mouth regions. However, children did not naturally encode and recognize face parts independently of the entire face. In addition, all age groups showed comparable inner and outer face recognition, except for 8- to 9-year-olds who showed a recognition advantage for outer faces. In Experiment 2, when participants were familiarized with eyes, noses, or mouths and tested with eyes, noses, or mouths, respectively, all ages showed above-chance recognition of eyes and mouths. Thirteen- to 14-year-olds were adult-like in their recognition of the eye region, but mouth recognition continued to develop beyond 14 years of age. Nose recognition was above chance among 13- to 14-year-olds, but recognition scores remained low even in adulthood. The present findings reveal unique developmental trajectories in the use of isolated facial regions in face recognition and suggest that featural cues (as a class) have a different ontogenetic course relative to holistic and configural cues.

The culture of perceptual expertise and the other-race effect.

In our commentary, we propose that the ORE can be viewed as a form of perceptual expertise. Like experts, we recognize own-race faces at the subordinate level as individuals and novices when recognize other-race faces at the basic level of race. Applying a perceptual expertise account, we explain the ORE in terms of its cognitive, neural, and motivational factors. We suggest that by creating a culture of "other-race" expertise, improvements in other-race face recognition can be achieved.

A perceptual field test in object experts using gaze-contingent eye tracking.

A hallmark of expert object recognition is rapid and accurate subordinate-category recognition of visually homogenous objects. However, the perceptual strategies by which expert recognition is achieved is less known. The current study investigated whether visual expertise changes observers' perceptual field (e.g., their ability to use information away from fixation for recognition) for objects in their domain of expertise, using a gaze-contingent eye-tracking paradigm. In the current study, bird experts and novices were presented with two bird images sequentially, and their task was to determine whether the two images were of the same species (e.g., two different song sparrows) or different species (e.g., song sparrow and chipping sparrow). The first study bird image was presented in full view. The second test bird image was presented fully visible (full-view), restricted to a circular window centered on gaze position (central-view), or restricted to image regions beyond a circular mask centered on gaze position (peripheral-view). While experts and novices did not differ in their eye-movement behavior, experts' performance on the discrimination task for the fastest responses was less impaired than novices in the peripheral-view condition. Thus, the experts used peripheral information to a greater extent than novices, indicating that the experts have a wider perceptual field to support their speeded subordinate recognition.

Investigating the Influence of Autism Spectrum Traits on Face Processing Mechanisms in Developmental Prosopagnosia.

Autism traits are common exclusionary criteria in developmental prosopagnosia (DP) studies. We investigated whether autism traits produce qualitatively different face processing in 43 DPs with high vs. low autism quotient (AQ) scores. Compared to controls (n = 27), face memory and perception were similarly deficient in the high- and low-AQ DPs, with the high-AQ DP group additionally showing deficient face emotion recognition. Task-based fMRI revealed reduced occipito-temporal face selectivity in both groups, with high-AQ DPs additionally demonstrating decreased posterior superior temporal sulcus selectivity. Resting-state fMRI showed similar reduced face-selective network connectivity in both DP groups compared with controls. Together, this demonstrates that high- and low-AQ DP groups have very similar face processing deficits, with additional facial emotion deficits in high-AQ DPs.