Evaluating Seasonal Variations in Human Contact Patterns and Their Impact on the Transmission of Respiratory Infectious Diseases.

BACKGROUND: Human contact patterns are a key determinant driving the spread of respiratory infectious diseases. However, the relationship between contact patterns and seasonality as well as their possible association with the seasonality of respiratory diseases is yet to be clarified. METHODS: We investigated the association between temperature and human contact patterns using data collected through a cross-sectional diary-based contact survey in Shanghai, China, between December 24, 2017, and May 30, 2018. We then developed a compartmental model of influenza transmission informed by the derived seasonal trends in the number of contacts and validated it against A(H1N1)pdm09 influenza data collected in Shanghai during the same period. RESULTS: We identified a significant inverse relationship between the number of contacts and the seasonal temperature trend defined as a spline interpolation of temperature data (p = 0.003). We estimated an average of 16.4 (95% PrI: 15.1-17.5) contacts per day in December 2017 that increased to an average of 17.6 contacts (95% PrI: 16.5-19.3) in January 2018 and then declined to an average of 10.3 (95% PrI: 9.4-10.8) in May 2018. Estimates of influenza incidence obtained by the compartmental model comply with the observed epidemiological data. The reproduction number was estimated to increase from 1.24 (95% CI: 1.21-1.27) in December to a peak of 1.34 (95% CI: 1.31-1.37) in January. The estimated median infection attack rate at the end of the season was 27.4% (95% CI: 23.7-30.5%). CONCLUSIONS: Our findings support a relationship between temperature and contact patterns, which can contribute to deepen the understanding of the relationship between social interactions and the epidemiology of respiratory infectious diseases.

From Perugino to Picasso revisited: Electrophysiological responses to faces in paintings from different art styles.

Behavioral research (Ventura, et al., 2023) suggested that pictorial representations of faces varying along a realism-distortion spectrum elicit holistic processing as natural faces. Whether holistic face neural responses are engaged similarly remains, however, underexplored. In the present study, we evaluated the neural correlates of naturalist and artistic face processing, by exploring electrophysiological responses to faces in photographs versus in four major painting styles. The N170 response to faces in photographs was indistinguishable from that elicited by faces in the renaissance art style (depicting the most realistic faces), whilst both categories elicited larger N170 than faces in other art styles (post-impressionism, expressionism, and cubism), with a gradation in brain activity. The present evidence suggest that visual processing may become finer grained the more the realistic nature of the face. Despite behavioral equivalence, the neural mechanisms for holistic processing of natural faces and faces in diverse art styles are not equivalent.

Change detection versus change localization for faces, houses, and words.

Holistic processing aids in the discrimination of visually similar objects, but it may also come with a cost. Indeed holistic processing may improve the ability to detect changes to a face while impairing the ability to locate where the changes occur. We investigated the capacity to detect the occurrence of a change versus the capacity to detect the localization of a change for faces, houses, and words. Change detection was better than change localization for faces. Change localization outperformed change detection for houses. For words, there was no difference between detection and localization. We know from previous studies that words are processed holistically. However, being an object of visual expertise processed holistically, visual words are also a linguistic entity. Previously, the word composite effect was found for phonologically consistent words but not for phonologically inconsistent words. Being an object of visual expertise for which linguistic information is important, letter position information, is also crucial. Thus, the importance of localization of letters and features may augment the capacity to localize a change in words making the detection of a change and the detection of localization of a change equivalent.

The mechanisms supporting holistic perception of words and faces are not independent.

The question of whether word and face recognition rely on overlapping or dissociable neural and cognitive mechanisms received considerable attention in the literature. In the present work, we presented words (aligned or misaligned) superimposed on faces (aligned or misaligned) and tested the interference from the unattended stimulus category on holistic processing of the attended category. In Experiment 1, we found that holistic face processing is reduced when a face was overlaid with an unattended, aligned word (processed holistically). In Experiment 2, we found a similar reduction of holistic processing for words when a word was superimposed on an unattended, aligned face (processed holistically). This reciprocal interference effect indicates a trade-off in holistic processing of the two stimuli, consistent with the idea that word and face recognition may rely on non-independent, overlapping mechanisms.

Domain Specificity vs. Domain Generality: The Case of Faces and Words.

Faces and words are ever-present stimuli in social environments that require fine-grained, efficient discrimination of their constituents in order to acquire meaning. Provided that these stimuli share multiple characteristics, while simultaneously being different visual object categories in important ways, a debate has ensued pertaining to whether their processing can be reduced to a common mechanism or whether each category mobilizes exclusive resources. We thus first present briefly domain-specific and domain-general accounts, as opposing perspectives that highlight the absence and presence of commonalities in face and word processing, respectively. We then focus on how faces and words are processed. While faces are usually associated with holistic processing of facial features, to create a perceptual whole, there is no such consensus pertaining to word processing. Words have been argued to rely on either letter-by-letter processing or in a way closer to that of faces, since they are also objects of expertise. Lastly, we advance the debate by providing an overview of our latest research findings. These findings provide a more direct comparison of face and word processing, by incorporating both stimuli in one task concurrently.

Evaluation of FluSight influenza forecasting in the 2021-22 and 2022-23 seasons with a new target laboratory-confirmed influenza hospitalizations.

Accurate forecasts can enable more effective public health responses during seasonal influenza epidemics. Forecasting teams were asked to provide national and jurisdiction-specific probabilistic predictions of weekly confirmed influenza hospital admissions for one through four weeks ahead for the 2021-22 and 2022-23 influenza seasons. Across both seasons, 26 teams submitted forecasts, with the submitting teams varying between seasons. Forecast skill was evaluated using the Weighted Interval Score (WIS), relative WIS, and coverage. Six out of 23 models outperformed the baseline model across forecast weeks and locations in 2021-22 and 12 out of 18 models in 2022-23. Averaging across all forecast targets, the FluSight ensemble was the 2nd most accurate model measured by WIS in 2021-22 and the 5th most accurate in the 2022-23 season. Forecast skill and 95% coverage for the FluSight ensemble and most component models degraded over longer forecast horizons and during periods of rapid change. Current influenza forecasting efforts help inform situational awareness, but research is needed to address limitations, including decreased performance during periods of changing epidemic dynamics.

The relation between holistic processing as measured by three composite tasks and face processing: A latent variable modeling approach.

We investigated the relationship between holistic processing and face processing using a latent variables approach. Three versions of the composite paradigm were used to measure holistic processing: Vanderbilt Holistic Face Processing Test, a sequential composite matching task, and a simultaneous composite matching task. Three tasks were used to measure face perception and face memory abilities respectively. We had three pairs of tasks such that within each pair (of memory and perception task), the stimuli involved, the requirement for matching across viewpoints, etc., are the same, such that the only difference is whether perception or memory is taxed. There were no significant correlations between the different versions of the composite task. We discovered no evidence to support a distinction between face perception and face memory, suggesting the existence of a general face processing factor. Finally, there was no evidence that holistic processing (as captured by either of the three composite tasks) is predictive of better face processing per se, casting doubts on the role of holistic processing in differentiating different levels of efficiency in face processing.

Partial overlap between holistic processing of words and Gestalt line stimuli at an early perceptual stage.

A dual-route account of holistic processing has been proposed, which includes a stimulus-based and experience-based approach to holistic processing. The bottom-up route was suggested by the observation of holistic processing for novel Gestalt line patterns in the absence of expertise. For words, there is mainly evidence for a late, lexical, experience-based locus of holistic processing with scarce evidence for an early, stimulus-based locus. However, salient early Gestalt information (i.e., connectedness, closure, and continuity between parts) are important for letter and word identification. Thus, there might be an overlap at an early, perceptual processing stage, between Gestalt stimulus-based holistic processing and word holistic processing. In the task we used, words and Gestalt line patterns were superimposed, and we evaluated whether one class of stimuli was processed less holistically when an aligned other class pattern (processed holistically) was superimposed. There was some evidence supporting an early locus for the influence of word processing on Gestalt line patterns, but the interaction between the two stimuli was not reciprocal, which needs further clarification. When an aligned word (processed holistically) was overlaid on a line pattern, the line pattern was processed less holistically. However, when an aligned line pattern (processed holistically) was overlaid on a word, the word was not processed less holistically. This pattern might result from the higher cohesiveness of words and their automaticity and feedback from the lexicon.

The relationships between reading fluency and different measures of holistic word processing.

Recently, paradigms in the face recognition literature have been adopted to reveal holistic processing in word recognition. It is unknown, however, whether different measures of holistic word processing share similar underlying mechanisms, and whether fluent word reading relies on holistic word processing. We measured holistic processing effects in three paradigms (composite, configural sensitivity, part-whole) as well as in reading fluency (3DM task: reading aloud high- and low-frequency words and pseudowords). Bin scores were used to combine accuracy and response time variables in the quest for a more comprehensive, reliable, and valid measure of holistic processing. Weak correlations were found between the different holistic processing measures, with only a significant correlation between the configural sensitivity effect and part-whole effect (r = .32) and a trend of a positive correlation between the word composite effect and configural sensitivity effect (r = .21). Of the three holistic processing measures, only one (part-whole effect) correlated with a lexical access measure of 3DM (r = .23). We also performed a principal component analysis (PCA) of performance in the three lists of 3DM, with the second most probably reflecting lexical access processes. There was a tendency for a positive correlation between part-whole bin measure and Component 2 of PCA. We also found a positive correlation between composite aligned in accuracy and Component 2 of PCA.Our results show that different measures of holistic word processing reflect predominantly different mechanisms, and that differences among normal readers in word reading do not seem to depend highly on holistic processing.

Modeling the effects of social distancing on the large-scale spreading of diseases.

To contain the propagation of emerging diseases that are transmissible from human to human, non-pharmaceutical interventions (NPIs) aimed at reducing the interactions between humans are usually implemented. One example of the latter kind of measures is social distancing, which can be either policy-driven or can arise endogenously in the population as a consequence of the fear of infection. However, if NPIs are lifted before the population reaches herd immunity, further re-introductions of the pathogen would lead to secondary infections. Here we study the effects of different social distancing schemes on the large scale spreading of diseases. Specifically, we generalize metapopulation models to include social distancing mechanisms at the subpopulation level and model short- and long-term strategies that are fed with local or global information about the epidemics. We show that different model ingredients might lead to very diverse outcomes in different subpopulations. Our results suggest that there is not a unique answer to the question of whether contention measures are more efficient if implemented and managed locally or globally and that model outcomes depends on how the full complexity of human interactions is taken into account.

Change detection vs. change localization for own-race and other-race faces.

The other-race effect (ORE) is a well-known phenomenon in which people discriminate and recognize faces from their ethnic group more accurately than faces from other ethnic groups. Holistic processing, or the mandatory tendency to process all parts of an object together, has been proposed as an explanation for the ORE. According to the holistic perspective of the ORE, other-race faces might be subject to weaker holistic processing than own-race faces. However, evidence for this hypothesis is inconsistent. Although it is generally assumed that holistic processing helps the individuation of objects, holistic processing may also come at a cost. Specifically, holistic processing may reduce the capacity to localize changes in the constituent parts of an object, but not in detecting changes to an object as a whole. In the present study, we examined change detection and change localization accuracy for Caucasian and African faces, and houses. Performance was better for change detection than change localization for Caucasian faces. While clear costs of holistic processing for Caucasian faces were thus found, the difference between change localization and change detection was not obvious for African faces. However, childhood exposure to other-race people correlated with change detection for African faces, but not with change localization for African faces. Our results thus show that holistic processing of other-race faces may depend on early contact with other-race people.

Children process faces holistically with the same efficiency as adults.

Previous studies had reported qualitatively identical holistic face processing (using the composite task) already in 6-year-olds. In the present study, we evaluated these processes quantitatively by evaluating whether children are less efficient in dealing with and encoding faces. Thus, in the present study we explored the time course of holistic processing in children and adults by manipulating stimulus presentation time. The study composite task was presented for 800 ms. The test composite face was presented either for 183 ms or 800 ms. Our youngest participants, 6-year-olds, process faces holistically with the same efficiency as typical adults.

Face and word composite effects are similarly affected by priming of local and global processing.

Holistic processing has been shown with both faces and words, but it is unclear how similar their underlying mechanisms are. In this study attention to global and local features was manipulated and the consequences for holistic word and face processing were examined. On each trial participants were presented two Navon figures and told to focus on either the global or the local level. Then they performed a composite task in which they indicated whether the target halves of two sequentially presented faces or words were the same or different, ignoring the irrelevant halves. Similar stronger global priming effects were found for faces and words, indicating that holistic processing for the two types of stimuli were susceptible to attention manipulations to similar degrees, which was confirmed with Bayesian analyses. The findings add to the investigation of the similarity and differences between holistic processing and help reveal those aspects of holistic processing that are domain general and those specific to individual categories.

Disease and information spreading at different speeds in multiplex networks.

Nowadays, one of the challenges we face when carrying out modeling of epidemic spreading is to develop methods to control disease transmission. In this article we study how the spreading of knowledge of a disease affects the propagation of that disease in a population of interacting individuals. For that, we analyze the interaction between two different processes on multiplex networks: the propagation of an epidemic using the susceptible-infected-susceptible dynamics and the dissemination of information about the disease-and its prevention methods-using the unaware-aware-unaware dynamics, so that informed individuals are less likely to be infected. Unlike previous related models where disease and information spread at the same time scale, we introduce here a parameter that controls the relative speed between the propagation of the two processes. We study the behavior of this model using a mean-field approach that gives results in good agreement with Monte Carlo simulations on homogeneous complex networks. We find that increasing the rate of information dissemination reduces the disease prevalence, as one may expect. However, increasing the speed of the information process as compared to that of the epidemic process has the counterintuitive effect of increasing the disease prevalence. This result opens an interesting discussion about the effects of information spreading on disease propagation.

Further evidence for a late locus of holistic word processing: Exploring vertex effect in the word composite task.

Previous studies have shown a rather late and lexical level for holistic word processing. In the present study, we evaluated whether there are early effects in holistic processing of words, taking into consideration the role of lower-level visual processes that are critical in the hierarchy of visual word recognition: the extraction of viewpoint-invariant line junctions/vertices. We used contour-deleted words in two conditions: preservation of the vertices versus preservation of midsegments and an all-contour condition. We found evidence of a composite effect that was equivalent for all materials. Thus, we found no evidence of an early contribution of holistic processing to word recognition, and confirmed that holistic word processing is related to late lexical orthographic representations.

Holistic word processing is correlated with efficiency in visual word recognition.

Holistic processing of visual words (i.e., obligatory encoding of/attending to all letters of a word) could be a marker of expert word recognition. In the present study, we thus examined for the first time whether there is a direct relation between the word-composite effect (i.e., all parts of a visual word are fully processed when observers perform a task on a word part) and fast access to the orthographic lexicon by visual word experts (i.e., fluent adult readers). We adopted an individual differences approach and used the word-frequency effect (i.e., faster recognition of high- than low-frequency words) in an independent lexical decision task as a proxy of fast access to lexical orthographic representations. Fluent readers with larger word-composite effect showed smaller word-frequency effect. This correlation was mainly driven by an association between a larger composite effect and faster lexical decision on low-frequency words, probably because these lexical representations are less stable and integrated/unitized, hence allowing differentiating among fluent readers. We thus showed that holistic processing of visual words is indeed related to higher efficiency in visual word recognition by skilled readers.

We see the orange not the lemon: typicality effects in ultra-rapid categorization in adults with and without autism spectrum disorder.

Semantic meaning can be extracted from pictures presented very briefly, in the order of tens of milliseconds. This ultra-rapid categorization processing appears to respect a coarse-to-fine path where lower level representations of concepts, or more detailed information, need additional time. We question whether variations in the levels of typicality of the target-item would implicate additional processing for correct classification, both in neurotypical (NT) individuals and with autism spectrum disorder (ASD). Previous research in ASD points out that atypical exemplars of a category might be abnormally processed (e.g., longer times in identifying a penguin as a bird), an observation that we further tested with a rapid serial visual presentation (RSVP) task. In this study, we applied a RSVP task, with four different presentation times (13, 27, 50, and 80 ms) and with typical and atypical exemplars to a group of NT individuals and a sample of individuals with ASD. We found, overall, a strong effect of typicality with a higher detection rate for typical items. In addition, we observed a group × typicality × duration interaction. We interpret these findings in the light of the competences of the feedforward sweep of information through our visual system.

Is holistic processing of written words modulated by phonology?

Holistic processing, a hallmark of face processing, has been shown for written words, signaled by the word composite effect. Fluent readers find it harder to focus on one half of a written word (e.g., the first syllable of a CV.CV word) while ignoring the other half (e.g., the second syllable), especially when the two halves are aligned rather than misaligned. Given the linguistic nature of written words, in the present study, we examined whether the word composite effect is modulated by phonology. In Experiment 1, participants saw two sequentially presented CV.CV words and had to decide if the left half (first syllable) was the same or not, regardless of the right half. The word pairs were either phonologically consistent (univocal orthography to phonology mapping; e.g., TI is always /ti/ in Portuguese) or inconsistent (orthography can map into different phonological representations; e.g., CA can correspond to /ka/ or /kɐ/). The word composite effect was found for phonologically consistent words but not for phonologically inconsistent words. In Experiment 2, timing of trial events was reduced to test whether the influence of phonology was fast and automatic. Similar to what was found in Experiment 1, the word composite effect was found only for phonologically consistent words. The faster trial events in Experiment 2 rendered it less likely that the influence of phonology in word composite effect is merely a result of strategic processing. These findings suggest that holistic processing of visual words is modulated by fast and automatic activation of lexical phonological representations.

Holistic word context does not influence holistic processing of artificial objects in an interleaved composite task.

Holistic processing, a hallmark of expert processing, has been shown for written words, signaled by the word composite effect, similar to the face composite effect: fluent readers find it difficult to focus on just one half of a written word while ignoring the other half, especially when the two word halves are aligned rather than misaligned. This effect is signaled by a significant interaction between alignment and congruency of the two word parts. Face and visual word recognition, however, involve different neural mechanisms with an opposite hemispheric lateralization. It is then possible that faces and words can both involve holistic processing in their own separate face and word processing systems, but by using different mechanisms. In the present study, we replicated with words a previous study done with faces (Richler, Bukach, & Gauthier, 2009, Experiment 3). In a first experiment we showed that in a composite task with aligned artificial objects, no congruency effects are found. In a second experiment, using an interleaved task, a congruency effect for Ziggerins was induced in trials in which a word was first encoded, but more strongly when it was aligned. However, in a stricter test, we found no differences between the congruency effect for Ziggerins induced by aligned words versus pseudowords. Our results demonstrate that different mechanisms can underlie holistic processing in different expertise domains.

Hemispheric asymmetry in holistic processing of words.

Holistic processing has been regarded as a hallmark of face perception, indicating the automatic and obligatory tendency of the visual system to process all face parts as a perceptual unit rather than in isolation. Studies involving lateralized stimulus presentation suggest that the right hemisphere dominates holistic face processing. Holistic processing can also be shown with other categories such as words and thus it is not specific to faces or face-like expertize. Here, we used divided visual field presentation to investigate the possibly different contributions of the two hemispheres for holistic word processing. Observers performed same/different judgment on the cued parts of two sequentially presented words in the complete composite paradigm. Our data indicate a right hemisphere specialization for holistic word processing. Thus, these markers of expert object recognition are domain general.