Visual Array Research Articles

Visual search attentional bias modification reduced the attentional bias in socially anxious individuals

AbstractRecent years have raised questions about the effectiveness of attentional bias modification (ABM) in individuals with social anxiety. In the current study, we employed a novel training method—ABM‐positive‐search training—to modify attentional bias in socially anxious individuals. The attentional bias was measured using the dot‐probe task, and brain electrical activity was recorded. The ABM‐positive‐search group was instructed to search for a happy face in a 3 × 3 visual array. The placebo control group was asked to find out whether the only male from the female or the only female from the male. In terms of behavioral indicators, the results showed a significant reduction in the variability of trial level‐bias score (TL‐BS) in the ABM‐positive‐search group post‐training. However, there was no significant change observed in the placebo control group. The electrophysiological results were consistent with the behavioral findings. To be specific, both groups displayed the N2pc effect in response to threatening faces before the training. After training, the N2pc effect disappeared in the ABM‐positive search group, while it remained in the placebo control group. In conclusion, ABM‐positive‐search training can effectively modify the attentional bias of socially anxious individuals, and cognitive control plays an important role in this process.

Visual Working Memory in Adolescents with Autism Spectrum Disorder.

Previous research suggests that individuals with autism spectrum disorder (ASD) may experience working memory (WM) problems, but the nature of the underlying disruption remains unknown. A recent study (Bodner et al. 2019) found that young adults with ASD experienced intact WM capacity but disruptions in their ability to efficiently filter and allocate attention. The goal of the present study was to extend this work and evaluate potential disruptions in WM capacity and attentional allocation ability in adolescents with ASD. A sample of 38 adolescents with ASD and 39 adolescents without ASD aged 11-15 years completed a computerized WM task. In brief, participants were shown visual arrays consisting of four or six colored stimuli (circles and squares). After a short delay, memory for one of the stimuli was probed. Importantly, participants were informed beforehand that one of the shapes (e.g., circles) was more likely to be probed compared to the other shape (e.g., squares) - thus making it strategically beneficial to focus primarily on the high frequency shapes. The ASD group demonstrated overall lower WM capacity compared to the non-ASD group. However, no group differences were seen in attentional allocation. There was also no evidence of sex-related differences in WM performance in adolescents with ASD. Taken together with previous findings, the current results suggest that adolescents with ASD show disruptions in WM capacity that are resolved by adulthood. Future longitudinal research is needed to further disentangle the component processes of WM and the developmental trajectories of these components.

Visual Sensor Array for Multiple Aromatic Amines via Specific Ascorbic Acid Oxidase Mimic Triggered Schiff-Base Chemistry.

Redox nanozymes have exhibited various applications in recognizing environmental pollutants but not aromatic amines (a type of typical pollutant). Herein, with Cu2+ as a node and tryptophan (Trp) as a linker, Cu-Trp as a specific ascorbic acid oxidase mimic was synthesized, which could catalyze ascorbic acid (AA) oxidation to dehydroascorbic acid (DHAA). Alternatively, with other natural amino acids as linkers to synthesize Cu-based nanozymes, such catalytic performances are also observed. The as-produced DHAA could react with o-phenylenediamine (OPD) and its derivatives (2,3-naphthalene diamine (NDA), 4-nitro-o-phenylenediamine (4-NO2-OPD), 4-fluoro-o-phenylenediamine (4-F-OPD), 4-chloro-o-phenylenediamine(4-Cl-OPD), and 4-bromo-o-phenylenediamine(4-Br-OPD)) to form a Schiff base and emit fluorescence. Based on the results, with Cu-Trp + AA and Cu-Arg (with arginine (Arg) as a linker) + AA as two sensing channels and extracted red, green, and blue (RGB) values from emitted fluorescence as read-out signals, a visual sensor array was constructed to efficiently distinguish OPD, NDA, 4-NO2-OPD, 4-F-OPD, 4-Cl-OPD, and 4-Br-OPD as low as 10 μM. Such detecting performance was further confirmed through discriminating binary, ternary, quinary, and senary mixtures with various concentration ratios, recognizing 18 unknown samples, and even quantitatively analyzing single aromatic amine. Finally, the discriminating ability was further validated in environmental waters, providing an efficient assay for large-scale scanning levels of multiple aromatic amines.

Crossmodal semantic congruence guides spontaneous orienting in real-life scenes.

In real-world scenes, the different objects and events are often interconnected within a rich web of semantic relationships. These semantic links help parse information efficiently and make sense of the sensory environment. It has been shown that, during goal-directed search, hearing the characteristic sound of an everyday life object helps finding the affiliate objects in artificial visual search arrays as well as in naturalistic, real-life videoclips. However, whether crossmodal semantic congruence also triggers orienting during spontaneous, not goal-directed observation is unknown. Here, we investigated this question addressing whether crossmodal semantic congruence can attract spontaneous, overt visual attention when viewing naturalistic, dynamic scenes. We used eye-tracking whilst participants (N = 45) watched video clips presented alongside sounds of varying semantic relatedness with objects present within the scene. We found that characteristic sounds increased the probability of looking at, the number of fixations to, and the total dwell time on semantically corresponding visual objects, in comparison to when the same scenes were presented with semantically neutral sounds or just with background noise only. Interestingly, hearing object sounds not met with an object in the scene led to increased visual exploration. These results suggest that crossmodal semantic information has an impact on spontaneous gaze on realistic scenes, and therefore on how information is sampled. Our findings extend beyond known effects of object-based crossmodal interactions with simple stimuli arrays and shed new light on the role that audio-visual semantic relationships out in the perception of everyday life scenarios.

Eye and head movements in visual search in the extended field of view

In natural environments, head movements are required to search for objects outside the field of view (FoV). Here we investigate the power of a salient target in an extended visual search array to facilitate faster detection once this item comes into the FoV by a head movement. We conducted two virtual reality experiments using spatially clustered sets of stimuli to observe target detection and head and eye movements during visual search. Participants completed search tasks with three conditions: (1) target in the initial FoV, (2) head movement needed to bring the target into the FoV, (3) same as condition 2 but the periphery was initially hidden and appeared after the head movement had brought the location of the target set into the FoV. We measured search time until participants found a more salient (O) or less salient (T) target among distractors (L). On average O’s were found faster than T’s. Gaze analysis showed that saliency facilitation occurred due to the target guiding the search only if it was within the initial FoV. When targets required a head movement to enter the FoV, participants followed the same search strategy as in trials without a visible target in the periphery. Moreover, faster search times for salient targets were only caused by the time required to find the target once the target set was reached. This suggests that the effect of stimulus saliency differs between visual search on fixed displays and when we are actively searching through an extended visual field.

Bio-inspired “Self-denoising” capability of 2D materials incorporated optoelectronic synaptic array

In in-sensor image preprocessing, the sensed image undergoes low level processing like denoising at the sensor end, similar to the retina of human eye. Optoelectronic synapse devices are potential contenders for this purpose, and subsequent applications in artificial neural networks (ANNs). The optoelectronic synapses can offer image pre-processing functionalities at the pixel itself—termed as in-pixel computing. Denoising is an important problem in image preprocessing and several approaches have been used to denoise the input images. While most of those approaches require external circuitry, others are efficient only when the noisy pixels have significantly lower intensity compared to the actual pattern pixels. In this work, we present the innate ability of an optoelectronic synapse array to perform denoising at the pixel itself once it is trained to memorize an image. The synapses consist of phototransistors with bilayer MoS2 channel and p-Si/PtTe2 buried gate electrode. Our 7 × 7 array shows excellent robustness to noise due to the interplay between long-term potentiation and short-term potentiation. This bio-inspired strategy enables denoising of noise with higher intensity than the memorized pattern, without the use of any external circuitry. Specifically, due to the ability of these synapses to respond distinctively to wavelengths from 300 nm in ultraviolet to 2 µm in infrared, the pixel array also denoises mixed-color interferences. The “self-denoising” capability of such an artificial visual array has the capacity to eliminate the need for raw data transmission and thus, reduce subsequent image processing steps for supervised learning.

Expectancy and attention bias to spiders: Dissecting anticipation and allocation processes using ERPs.

The current registered report focused on the temporal dynamics of the relationship between expectancy and attention toward threat, to better understand the mechanisms underlying the prioritization of threat detection over expectancy. In the current event-related potentials experiment, a-priori expectancy was manipulated, and attention bias was measured, using a well-validated paradigm. A visual search array was presented, with one of two targets: spiders (threatening) or birds (neutral). A verbal cue stating the likelihood of encountering a target preceded the array, creating congruent and incongruent trials. Following cue presentation, preparatory processes were examined using the contingent negative variation (CNV) component. Following target presentation, two components were measured: early posterior negativity (EPN) and late positive potential (LPP), reflecting early and late stages of natural selective attention toward emotional stimuli, respectively. Behaviorally, spiders were found faster than birds, and congruency effects emerged for both targets. For the CNV, a non-significant trend of more negative amplitudes following spider cues emerged. As expected, EPN and LPP amplitudes were larger for spider targets compared to bird targets. Data-driven, exploratory, topographical analyses revealed different patterns of activation for bird cues compared to spider cues. Furthermore, 400-500 ms post-target, a congruency effect was revealed only for bird targets. Together, these results demonstrate that while expectancy for spider appearance is evident in differential neural preparation, the actual appearance of spider target overrides this expectancy effect and only in later stages of processing does the cueing effect come again into play.

Linking cognitive control to language comprehension: proportion congruency effects in syntactic ambiguity resolution

ABSTRACT Two experiments investigated the effect of sustained cognitive control engagement on syntactic ambiguity resolution. Participants heard (Experiment 1) or read (Experiment 2) garden path sentences like “Put the kiwi on the rectangle on the circle”, in which “on the rectangle” could temporarily reflect either a destination of “Put” or modifier of “kiwi”, and they viewed visual arrays with a kiwi on a rectangle and an empty rectangle and circle. Cognitive control was manipulated experimentally by interleaving sentence trials among either mostly incongruent or mostly congruent Stroop trials. Across both experiments, garden path mouse cursor movements to incorrect destinations were reduced when sentence trials were interleaved among mostly incongruent Stroop trials, and in Experiment 2, garden path reading time effects were also reduced in this condition. These results suggest that a high proportion of incongruent trials supports the sustained engagement of cognitive control and causally improves sentence comprehension across (i.e. spoken and written) modalities.

Hybrid visual and memory search for scenes and objects with variable viewpoints.

In hybrid search, observers search visual arrays for any of several target types held in memory. The key finding in hybrid search is that response times (RTs) increase as a linear function of the number of items in a display (visual set size), but RTs increase linearly with the log of the memory set size. Previous experiments have shown this result for specific targets (find exactly this picture of a boot on a blank background) and for broad categorical targets (find any animal). Arguably, these are rather unnatural situations. In the real world, objects are parts of scenes and are seen from multiple viewpoints. The present experiments generalize the hybrid search findings to scenes (Experiment 1) and multiple viewpoints (Experiment 2). The results replicated the basic pattern of hybrid search results: RTs increased logarithmically with the number of scene photos/categories held in memory. Experiment 3 controls the experiment for which viewpoints were seen in an initial learning phase. The results replicate the findings of Experiment 2. Experiment 4 compares hybrid search for specific viewpoints, variable viewpoints, and categorical targets. Search difficulty increases from specific viewpoints to variable viewpoints and then to categorical targets. The results of the four experiments show the generality of logarithmic search through memory in hybrid search.

Modelling Working Memory Capacity: Is the Magical Number Four, Seven, or Does it Depend on What You Are Counting?

Limited attentional capacity is essential to working memory. How its limit should be assessed is a debated issue. Five experiments compare Cowan's 4-units and Pascual-Leone's 7-units models of limited working memory capacity, with presentation time and attention to operative schemes as potential explanations of this discrepancy. Experiments 1a-1c used the Compound Stimuli Visual Information (CSVI) task, with long versus brief presentation. Capacity was estimated with the Bose-Einstein model, assuming a different number of attending acts in each condition. Participants' k estimates in both conditions were highly correlated and the means were not different, indicating that the same capacity is assessed in both conditions. Experiments 2 and 3 used the 5000-msec CSVI, and the Visual Array Task (VAT) in two conditions (5000- vs. 120-msec presentation). Capacity in the VAT was estimated with Morey's Bayesian method. Participants' k estimates in both VAT conditions were correlated, but the mean was higher with long presentation, suggesting that the long condition benefits from recoding or chunking. The k estimate in the CSVI correlated with the short VAT and (to a lesser degree in Exp.2) with the long VAT. The mean estimate of k in the CSVI was one unit more than in the short VAT. We conclude that the CSVI and the short VAT tap the same capacity, one unit of which in the short VAT is allocated to an operative scheme; we discuss how Cowan's and Pascual-Leone's views on limited capacity can be reconciled.

The Electrophysiological Markers of Statistically Learned Attentional Enhancement: Evidence for a Saliency-based Mechanism.

It is well established that attention can be sharpened through the process of statistical learning (e.g., visual search becomes faster when targets appear at high-relative-to-low probability locations). Although this process of statistically learned attentional enhancement differs behaviorally from the well-studied top-down and bottom-up forms of attention, relatively little work has been done to characterize the electrophysiological correlates of statistically learned attentional enhancement. It thus remains unclear whether statistically learned enhancement recruits any of the same cognitive mechanisms as top-down or bottom-up attention. In the current study, EEG data were collected from while participants searched for an ambiguous unique shape in a visual array (the additional singleton task). Unbeknown to the participants, targets appeared more frequently in one location in space (probability cuing). Encephalographic data were then analyzed in two phases: an anticipatory phase and a reactive phase. In the anticipatory phase preceding search stimuli onset, alpha lateralization as well as the Anterior Directing Attention Negativity and Late Directing Attention Positivity components-signs of preparatory attention known to characterize top-down enhancement-were tested. In the reactive phase, the N2pc component-a well-studied marker of target processing-was examined following stimuli onset. Our results showed that statistically learned attentional enhancement is not characterized by any of the well-known anticipatory markers of top-down attention; yet targets at high probability locations did reliably evoke larger N2pc amplitudes, a finding that is associated with bottom-up attention and saliency. Overall, our findings are consistent with the notion that statistically learned attentional enhancement increases the perceptual salience of items appearing at high-probability locations relative to low-probability locations.

Electrophysiological correlates of objective memory impairments in community‐dwelling older adults at risk of dementia

AbstractBackgroundThe electrophysiological correlates of Short‐Term Memory Binding (STMB) have been previously investigated in older adults at risk of dementia (i.e., Mild Cognitive Impairment ‐MCI). Pietto et al. (2016) reported reduced early electrophysiological activity (100‐250 ms) over fronto‐central (FC) and parieto‐occipital (PO) regions in MCI patients recruited from clinic. We investigated if such an electrophysiological pattern is also observed in a larger sample of community‐dwelling older adults with MCI who had not sought medical advice.MethodsA sample of 215 community‐dwelling older adults were recruited into the study. They were assessed with a battery of cognitive tests including CERAD (Aguirre‐Acevedo et al., 2016), the Addenbrooke’s Cognitive Examination (ACE‐R), the STMB Task, clinical, and functional scales. The STMB task assesses the ability to detect changes between two consecutive visual arrays of coloured shapes. Changes consisted of shapes swapping colours (the binding condition). Time‐locked EEG signals were collected while participants performed the STMB task. Monte Carlo tests and non‐parametric bootstrapping running 1000 permutations revealed electrodes and time windows of relevance.ResultsA group of 108 participants met classical criteria for MCI (Petersen, 2004; Winblad et al., 2004). They showed impaired STMB abilities. ERP analyses revealed significant Group x Time Windows interactions (p<0.01). Early ERP showed reduced neural recruitment (MCI<HC) on the left PO and right centro‐parietal (CP) (300‐500ms) regions during shape‐colour encoding, and on PO bilaterally and left FC during retrieval (150‐450ms). Late ERP showed increased neural recruitment (MCI>HC) on right fronto‐central (FC) regions (900‐1200ms) during shape‐colour encoding, and on left FC and PO regions (872‐1200ms) during retrieval.ConclusionAltered spatio‐temporal dynamics underpinning STMB deficits in MCI patients followed a pattern similar to that described by Pietto et al. (2016). Of note, we observed hyper‐recruitment for late ERP linked to encoding and retrieval over anterior and posterior regions of the STMB network. Such hyper‐recruitment may reflect compensatory changes in the early stages of MCI. These results confirm the usefulness of EEG‐based cognitive biomarkers to screen community‐dwelling older adults at risk of dementia.Aguirre‐Acevedo et al. (2016). Int. Psychogeriatr, 28(3), 503‐510.Pietto et al. (2016). Journal of Alzheimer’s Disease, 53(4), 1325‐1340.

Creating ad hoc graphical representations of number

The ability to communicate about exact number is critical to many modern human practices spanning science, industry, and politics. Although some early numeral systems used 1-to-1 correspondence (e.g., ‘IIII' to represent 4), most systems provide compact representations via more arbitrary conventions (e.g., ‘7’ and ‘VII'). When people are unable to rely on conventional numerals, however, what strategies do they initially use to communicate number? Across three experiments, participants used pictures to communicate about visual arrays of objects containing 1–16 items, either by producing freehand drawings or combining sets of visual tokens. We analyzed how the pictures they produced varied as a function of communicative need (Experiment 1), spatial regularities in the arrays (Experiment 2), and visual properties of tokens (Experiment 3). In Experiment 1, we found that participants often expressed number in the form of 1-to-1 representations, but sometimes also exploited the configuration of sets. In Experiment 2, this strategy of using configural cues was exaggerated when sets were especially large, and when the cues were predictably correlated with number. Finally, in Experiment 3, participants readily adopted salient numerical features of objects (e.g., four-leaf clover) and generally combined them in a cumulative-additive manner. Taken together, these findings corroborate historical evidence that humans exploit correlates of number in the external environment – such as shape, configural cues, or 1-to-1 correspondence – as the basis for innovating more abstract number representations.

Optimizing and interpreting the latent space of the conditional text-to-image GANs

Text-to-image generation intends to automatically produce a photo-realistic image, conditioned on a textual description. To facilitate the real-world applications of text-to-image synthesis, we focus on studying the following three issues: (1) How to ensure that generated samples are believable, realistic or natural? (2) How to exploit the latent space of the generator to edit a synthesized image? (3) How to improve the explainability of a text-to-image generation framework? We introduce two new data sets for benchmarking, i.e., the Good & Bad, bird and face, data sets consisting of successful as well as unsuccessful generated samples. This data set can be used to effectively and efficiently acquire high-quality images by increasing the probability of generating Good latent codes with a separate, new classifier. Additionally, we present a novel algorithm which identifies semantically understandable directions in the latent space of a conditional text-to-image GAN architecture by performing independent component analysis on the pre-trained weight values of the generator. Furthermore, we develop a background-flattening loss (BFL), to improve the background appearance in the generated images. Subsequently, we introduce linear-interpolation analysis between pairs of text keywords. This is extended into a similar triangular ‘linguistic’ interpolation. The visual array of interpolation results gives users a deep look into what the text-to-image synthesis model has learned within the linguistic embeddings. Experimental results on the recent DiverGAN generator, pre-trained on three common benchmark data sets demonstrate that our classifier achieves a better than 98% accuracy in predicting Good/Bad classes for synthetic samples and our proposed approach is able to derive various interpretable semantic properties for the text-to-image GAN model.

Authenticity identification of high – Temperature Daqu Baijiu through multi-channel visual array sensor of organic dyes combined with smart phone App

High - temperature Daqu Baijiu faces a challenge from illegal adulteration of high-grade Baijiu bottles with low-grade Baijiu, affecting its quality and value. This study developed a rapid identification method for high temperature Daqu Baijiu with the same aroma type using a four-channel visual array sensor and detection of color changes caused by competition coordination with Zn2+ and color-changing organic dyes. The array sensor demonstrated high stability and repeatability in targeting flavor components and achieved 97.78 % or more accuracy combined with DD-SIMCA model in detecting adulteration across the Baijiu with same aroma type. The results of GC–MS and Quantum Chemical Calculation showed that esters, acids, and pyrazines played a crucial role. The smart phone App could quickly identify the authenticity of Baijiu with accuracy achieved 93 %. This research provides a foundation for rapid and reliable assessment of Baijiu quality and authenticity, enabling the industry to combat fraudulent practices effectively.

Machine learning-assisted visual sensor array for identifying the origin of Lilium bulbs

In this work, we constructed a machine learning-assisted dual-channel visual sensor array for identifying the origin of Lilium bulbs (BH). Nanogold clusters (AuNCs) and quantum dots (QDs) were selected and combined into sensor arrays. The amino acids existed in lilium bulbs could induce aggregation-induced fluorescence enhancement effect (AIEE) of AuNCs through hydrogen bonding. The hydrogen protons released from the amino acids and phenolic acids could interact with the COO- group of QDs, resulting in aggregation-caused quenching (ACQ) of QDs. Due to the different contents of amino acids and phenolic acids in BH from different origins, the sensor array can produce distinct and different fluorescent colors, such as red, blue, green and purple. In conjunction with pattern recognition by the RF model, the sensor array clearly identifies the origin of BH with 94.4% prediction accuracy. The visual sensor array constructed in this work exhibited the advantages of simplicity, speed, accuracy and portability, showing potential application prospects in identifying the origin of food and traditional Chinese medicine.

The flexibility and representational nature of phonological prediction in listening comprehension: evidence from the visual world paradigm

AbstractUsing the visual world paradigm with printed words, this study investigated the flexibility and representational nature of phonological prediction in real-time speech processing. Native speakers of Mandarin Chinese listened to spoken sentences containing highly predictable target words and viewed a visual array with a critical word and a distractor word on the screen. The critical word was manipulated in four ways: a highly predictable target word, a homophone competitor, a tonal competitor, or an unrelated word. Participants showed a preference for fixating on the homophone competitors before hearing the highly predictable target word. The predicted phonological information waned shortly but was re-activated later around the acoustic onset of the target word. Importantly, this homophone bias was observed only when participants were completing a ‘pronunciation judgement’ task, but not when they were completing a ‘word judgement’ task. No effect was found for the tonal competitors. The task modulation effect, combined with the temporal pattern of phonological pre-activation, indicates that phonological prediction can be flexibly generated by top-down mechanisms. The lack of tonal competitor effect suggests that phonological features such as lexical tone are not independently predicted for anticipatory speech processing.

Spider vs. guns: expectancy and attention biases to phylogenetic threat do not extend to ontogenetic threat.

Attention bias plays an important role in specific fears and phobias. Previous studies revealed that a-priori expectancies affect attention toward neutral stimuli but not threatening stimuli. The aim of the current study was to test whether this selective influence of expectancies on attention is specific to phylogenetic threat (i.e., spiders) or whether it can be generalized to ontogenetic threat (i.e., guns). Correspondingly, we directly compared expectancy effects on attentional allocation to phylogenetically vs. ontogenetically threatening stimuli. Expectancies were manipulated by presenting a cue indicating the likelihood of the appearance of a deviant picture in a visual search array. The array included eight distractors and one neutral (phone/bird) or threatening (gun/spider) deviant picture. In a comprehensive design, we examined the effects of stimulus type (phylogenetic/ontogenetic) and visual background (white and sterile/complex and ecological). Individual differences such as intolerance of uncertainty and spider fear were also measured. Results showed that attention bias toward spiders does not extend to threatening ontogenetic stimuli (i.e., guns). Our previous findings on attention bias toward spiders were replicated and a small to medium positive correlation was found between reaction time to bird targets and pre-existing fear of spider levels. Cues were used to detect threatening as well as neutral targets on both background types, except for spider targets on a complex background, replicating previous results. A small to medium positive correlation was also found between fear of spiders and intolerance of uncertainty. Together, these results suggest that expectancy and attentional processes may differ between ontogenetic and phylogenetic threat. Importantly, the effects of expectancy on attentional allocation depend on an interaction between the type of threat (ontogenetic/phylogenetic), visual factors, and individual differences.

Visual Sensor Arrays for Distinction of Phenolic Acids Based on Two Single-Atom Nanozymes.

Although great achievements have been made in the study of artificial enzymes, the design of nanozymes with high catalytic activities of natural enzymes and the further establishment of sensitive biosensors still remain challenging. Here, two nanozymes, i.e., ZnCoFe three-atom nanozyme (TAzyme) and Sn single-atom nanozyme (SAzyme)/Ti3C2Tx, are developed, which show peroxidase-like catalytic activities by catalyzing the reaction of hydrogen peroxide (H2O2), 4-aminoantipyrine (4-AAP), and phenolic acids to generate colorimetric reactions. The involvement of different phenolic acids leads to the generation of different color products. These subtle color-variation profiles between these phenolic acids prompt us to exploit an electronic tongue based on the two nanozymes to distinguish phenolic acids. Data interpretation by the pattern recognition method, such as linear discriminant analysis (LDA), displays good clustering separation of six different phenolic acids at concentrations of 0.1 μM to 1 mM, validating the effectiveness of the colorimetric nanozyme sensor array.

Understanding face detection with visual arrays and real-world scenes

ABSTRACT Face detection has been studied by presenting faces in blank displays, object arrays, and real-world scenes. This study investigated whether these display contexts differ in what they can reveal about detection, by comparing frontal-view faces with those shown in profile (Experiment 1), rotated by 90° (Experiment 2), or turned upside-down (Experiment 3). In blank displays, performance for all face conditions was equivalent, whereas upright frontal faces showed a consistent detection advantage in arrays and scenes. Experiment 4 examined which facial characteristics drive this detection advantage by rotating either the internal or external facial features by 90° while the other features remained upright. Faces with rotated internal features were detected as efficiently as their intact frontal counterparts, whereas detection was impaired when external features were rotated. Finally, Experiment 5 applied Voronoi transformations to scenes to confirm that complexity of stimulus displays modulates the detection advantage for upright faces. These experiments demonstrate that context influences what can be learned about the face detection process. In complex visual arrays and natural scenes, detection proceeds more effectively when external facial features are preserved in an upright orientation. These findings are consistent with a cognitive detection template that focuses on general face-shape information.