Category: Uncategorised

The Laboratoire de Perception Visuelle et Sociale is pleased to announce that a number of its students distinguished themselves by receiving grants for their graduate studies from various selections at the provincial and national levels.

At the masters level, Kim Calvé, Michaël Massicotte and Francis Gingras have received Canada’s Graduate Scholarships (CGS M) from the Natural Sciences and Engineering Research Council (NSERC) of the Government of Canada.

At the doctoral level, Joël Guérette has been awarded a doctoral scholarship (B2) given by the Fonds de Recherche Québecois en Société et Culture (FRQSC). Isabelle Charbonneau has also received the prestigious Joseph Armand Bombardier scholarship, given by the Social Sciences and Humanities Research Council (SSHRC) of the Government of Canada.

The LPVS team extends its heartfelt congratulations for all these students, and wish them the best of luck in their graduate studies.

The team at LPVS is proud to announce that Dr. Justin Duncan is officially the first student of the lab to obtain a Ph.D. His thesis, translated as «Visual Information Orientation and its Role in Face Perception», studies the relevance of horizontal spatial information in face perception. Dr. Duncan created, and then used the orientations bubbles method, consisting of isolating orientations to evaluate their role in facial perception, to reach his conclusions. In the following year, he will begin post-doctoral studies in Switzerland with Roberto Caldara, a researcher specialized in visual cognition and social and cultural differences.

Here is a summary of his thesis:

“In the last 10 years, researchers have shown that many aspects of facial perception rely on horizontal spatial information. In this thesis, I answer the following questions: I) What is their role in in facial expression recognition? II) How are they related to treatment of different facial regions? III) Do they explain individual differences in facial recognition ability? IV) Does the cerebral activity asymmetry observed during face perception concord with hemispheric differences in the treatment of these orientations? In order to answer these questions, I developed the orientations bubbles method, allowing me to individually assess each orientation’s contribution in face perception. My first study examines experimental data that shows i) that facial recognition is dependent on the treatment of horizontal information and ii) that the ability to treat horizontal information is predicted by the treatment of the eyes region. In a second study, I show that without a doubt that individuals with higher performance in facial recognition show better use of horizontal facial information. Finally, experimental data collected in the last study shows that the left visual field superiority (faces presented in the left visual field are treated more efficiently than in the right visual field) is associated with a better use of horizontal information in the right hemisphere, better in face perception. Taken together, these studies add weight to the hypothesis according to which the visual system’s capacity to selectively treat facial information contained in horizontal spatial orientations play a crucial role in numerous aspects in the treatment of faces and point toward a psychophysical mechanism from which could emerge the visual expertise found in face perception.” -Justin Duncan, Ph. D.

The LPVS gives its heartfelt congratulations to Justin; We wish you the best during your post-doc over in Switzerland.

We thank you for the amazing years you have spent alongside us!

-The team at LPVS

The LPVS was present during the 87th annual congress of the French association for knowledge (ACFAS), which took place at UQO this year. This congress is a meeting for french research scientists and its purpose is to promote the diffusion of knowledge in french. Some members of our laboratory presented either an oral communication or a poster about one of their research projects. Here is an overlook of the research work presented by the LPVS at the congress:

Oral communications

Seminar: Non verbal communication: Research, issues and interdisciplinary dialogues

Caroline Blais – La reconnaissance des expressions faciales : des mécanismes visuels fondamentaux aux influences socioculturelles

La capacité à reconnaitre l’expression faciale d’un individu est cruciale pour l’humain, tant au niveau de sa survie qu’au niveau de son adaptation sociale. D’ailleurs, Darwin suggérait déjà, en 1872, que les mouvements faciaux effectués durant l’expression de certaines émotions (p.ex., la peur, la colère, le dégoût) ont évolué pour maximiser les chances de survie de l’humain. Encore aujourd’hui, cette proposition est d’actualité (Susskind et al., 2008), bien qu’elle soit aussi remise en question par plusieurs (Russel, 1994; Jack et al., 2012). Alors qu’une majeure partie des études dans le domaine de l’expression faciale a porté sur la caractérisation du signal émotionnel transmis par celles-ci, il importe aussi d’investiguer les stratégies développées par le système visuel pour arriver à décoder ce signal. Cette présentation explorera cette question sous différents angles. Nous verrons que les mouvements faciaux représentant le cœur d’une expression faciale n’ont pas tous la même importance pour le système visuel. Nous verrons aussi comment l’ajout de propriétés rendant une expression plus naturelle (p.ex. expressions dynamiques vs. statiques, expressions spontanées vs. posées) influence l’information utilisée par le système visuel. Finalement, nous discuterons de la façon dont les expressions faciales d’émotion de même que les stratégies de décodage du système visuel peuvent être influencées par l’environnement socioculturel dans lequel un individu se développe.

Seminar: Neurosciences, mental health and toxicomania

Isabelle Charbonneau – Impact de l’anxiété sociale sur les représentations visuelles d’expressions faciales

Des études montrent que les personnes souffrant d’anxiété sociale ont des difficultés à reconnaître les expressions faciales. Afin de mieux comprendre ce déficit, nous avons comparé les représentations visuelles (RVs) du dégoût et de la colère de personnes anxieuses avec celles de participants contrôles. Les RVs de ces deux expressions ont été révélées chez 40 participants (20 par groupe) grâce à la corrélation inverse (Mangini & Biederman, 2004). À chaque essai, les participants devaient choisir lequel de 2 stimuli semblait le plus colérique ou le plus dégoûté. Les deux stimuli étaient générés à partir du même visage auquel était ajoutée une plage de bruit aléatoire. Une image de classification a été générée pour chaque groupe et chaque expression en moyennant les plages de bruit sélectionnées à chaque essai. Les résultats ne révèlent aucune différence entre les deux groupes quant aux régions faciales représentées en mémoire pour les deux expressions faciales. Des analyses subséquentes montrent toutefois que les RVs des participants anxieux sont jugées comme plus tristes par des participants naïfs, et ce, pour les deux expressions évaluées (colère=[X²(1)=24.14, p<0.001], dégoût=[X²(1)=28, p<0.001]), ce qui est consistant avec l’observation d’un niveau de dépression plus élevé chez nos participants anxieux [t(38)=2.57, p=0.02]. Ces résultats suggèrent que la présence de dépression chez les anxieux sociaux altère les RVs en les rendant plus tristes.

Justin Duncan – Sélectivité de l’hémisphère cérébral droit pour l’information horizontale durant le traitement facial

Le traitement des visages est plus efficace lorsqu’ils sont présentés dans le champ visuel gauche (CVG). Cette supériorité du CVG est attribuée à la dominance de l’hémisphère droit pour les visages, mais peu d’explications fonctionnelles ont été proposées (p.ex., traitement global/local). Des travaux récents ont révélé l’importance des orientations spatiales horizontales dans le traitement facial (ex., Goffaux & Dakin, 2010). Nous avons donc vérifié si leur traitement diffère entre les hémisphères. Trente participants ont complété deux tâches dans lesquelles des visages étaient filtrés avec des bulles d’orientation (Duncan et al., 2017). La première, une tâche d’identification, visait à établir un profil de référence. Dans la seconde tâche, un paradigme pareil/différent, une sonde était présentée au CVG ou CVD pendant que l’autre côté voyait un visage moyen. Une cible était ensuite présentée bilatéralement et les participants devaient indiquer si la sonde et la cible étaient la même personne. Des images de classification ont permis d’extraire les orientations utiles (Zcrit=2,101, p<0,05; Chauvin et al., 2005). Tel qu’attendu, l’information horizontale constitue le meilleur prédicteur de performance dans la tâche de référence, Z=3,38. Cela était aussi vrai pour le CVG (Z=3,45), mais pas le CVD (Z=–1,92). La supériorité de l’hémisphère droit serait donc liée à un meilleur traitement des orientations horizontales, mécanisme qui n’avait jamais été exploré jusqu’à maintenant.

Francis Gingras – Différences culturelles dans la représentation mentale de la douleur exprimée par des visages d’une autre ethnie que celle de l’observateur

Une reconnaissance efficace de l’expression faciale de douleur est cruciale afin de réagir correctement face aux personnes souffrantes. La présente étude visait à révéler la représentation perceptive de l’expression faciale de douleur pour deux groupes ethniques. Des images de classification (ICs) ont été générées afin de visualiser les représentations de douleur de visages Blancs et Noirs chez 30 participants occidentaux grâce à la reverse correlation (Mangini & Biederman, 2004). Ces ICs ont ensuite été soumises à un Cluster test (Chauvin et al., 2005; t_crit=3.0, k=246, p<0.025). Les résultats révèlent que l’œil droit et la bouche sont représentés différemment pour les deux ethnies de visages. Puisque ces variations n’étaient pas corrélées aux préjugés ethniques (tous les p>0.5), sept participants africains ont été testés afin de tenter d’expliquer ces différences. On cherchait alors à déterminer si ces différences étaient attribuables à la morphologie des visages ou à l’importance accordée par l’observateur aux traits de douleur pour un visage provenant d’une autre ethnie. Pour les participants africains, la douleur pour les visages Blancs est davantage associée au plissement des sourcils comparativement à celle pour les visages Noirs (t_crit=3.0, k=246, p<0.025). Ces résultats suggèrent que l’importance accordée aux traits de douleur est modulée par l’ethnie du visage qui l’exprime.

Poster session

Seminar: Neurosciences, mental health and toxicomania

Gabrielle Dugas – Les orientations spatiales spécifiques à l’identification des visages

Plusieurs études ont révélé le rôle fondamental des orientations horizontales en identification de visages. Or, les tâches utilisées pour l’instant ne permettent pas discerner l’impact de l’information d’identité de celle de l’information physique de bas niveau. Afin de contourner ce problème, nous avons utilisé une méthode contrôlant précisément les différences physiques entre des stimuli qui peuvent être catégorisés comme provenant de la même identité ou non. À chaque essai, les participants (N = 10) voyaient une cible et deux choix de réponse dont l’information visuelle était échantillonnée avec des bulles d’orientation. L’un des choix, la bonne réponse, était identique à la cible. Les possibles choix alternatifs, créés par un logiciel de morphing, pouvaient soit partager l’identité de la cible ou provenir d’une identité différente. De façon importante, tous les choix alternatifs étaient identiques quant à leur distance physique avec la cible. Les orientations horizontales étaient significativement associées aux bonnes réponses (Zcrit=2.101; Zmax=4,25, p<0,05) mais uniquement quand les deux choix de réponse différaient sur l’identité. Par contre, aucune orientation n’a atteint le seuil lorsque les deux choix différaient uniquement sur l’information de bas niveau (Zmax=1,41, p>0,05). Une comparaison à l’aide d’un test-t apparié a révélé une spécificité du traitement des horizontales lorsque la tâche implique de reconnaitre l’identité d’un visage (t(9)=2,8, p<0,05).

Marie-Pier Plouffe-Demers – L’impact du genre sur la capacité à discriminer l’expression faciale de douleur

Des études ont démontré un avantage des femmes en reconnaissance des expressions de douleur (e.g. Hill and Craig, 2004), mais l’impact du genre sur les stratégies visuelles qui y sont sous-jacentes demeure inexploré. Nous avons mesuré les stratégies visuelles de 30 participants (15 hommes) avec la méthode Bubbles (Gosselin & Schyns, 2001), qui échantillonne aléatoirement des traits du visage dans 5 bandes de fréquences spatiales. Pour chacun des 1512 essais, deux avatars bullés (parmis 2 genres x 4 niveaux d’intensité de douleur) étaient présentés au participant qui devait identifier celui présentant le plus haut niveau de douleur. L’écart d’intensité entre les 2 visages variait entre 100% (facile), 66% (moyen) et 33% (difficile). Le nombre de bulles nécessaire au maintien d’une précision moyenne de 75% faisait office de mesure de performance (Royer et al., 2015). Les résultats indiquent la nécessité d’un plus grand nombre de bulles pour les hommes (M=77.6, SD=36.8) que les femmes (M=52.3, SD=24.5) dans la condition la plus difficile [t(28)=2.22, p=0.04], suggérant une performance supérieure des femmes. De plus, les résultats indiquent que les femmes utilisent davantage la bande de fréquence spatiale la plus basse comparativement aux hommes (Z_crit=2.7, p<0.05; 5.4-2.7 cycles par visage). Ces résultats suggèrent un impact du genre de l’observateur sur la performance et sur les stratégies visuelles sous-jacentes à la discrimination de l’expression faciale de la douleur.

 

Camille Saumure – Le niveau d’empathie a un impact sur les représentations mentales de l’expression faciale de douleur

L’expérience de douleur entraîne la contraction de muscles faciaux (Kunz et al., 2012) qui sont encodés dans la représentation mentale (RM) de l’observateur (Blais et al., en révision). L’exposition à la douleur entraînerait une réaction cérébrale empathique (Botvinick et al.,2005) qui varie en fonction du niveau d’empathie (Saarela et al. 2007). Dans la présente étude, les RMs de 54 participants (18 hommes) ont été mesurées avec la Reverse Correlation (Mangini & Biederman, 2004). Pour 500 essais, ceux-ci devaient choisir le visage qui semblait le plus en douleur entre deux stimuli. À chaque essai, les stimuli étaient générés à partir du même visage, auquel était ajouté ou soustrait du bruit visuel. Le niveau d’empathie a été mesuré avec le test du quotient émotionnel (Baron-Cohen et Wheelwright, 2004) et utilisé comme poids pour générer deux images de classification (IC) pour les niveaux d’empathie élevée et faible. Des sujets indépendants (N = 24) ont ensuite jugé l’IC de forte empathie comme étant significativement plus intense dans les régions associées à l’expression de douleur (sourcils x² = 24, nez/lèvre supérieure x² = 10.67, yeux x² = 6 [p<0.05]). Une IC de différence (forte–faible empathie), soumise à un Cluster test (Chauvin et al., 2005), a dévoilé une différence significative dans la région de la bouche (ZCrit = 2.7, K = 90, p<0.025). Ces résultats suggèrent que la RM de l’expression de douleur varie selon les différences individuelles d’empathie.

Seminar: Development and operational running of people and communities, and social life

Joël Guérette – L’influence du statut suite à l’éjection d’un joueur ou d’un entraîneur dans la Ligue de baseball majeur

Les joueurs et entraîneurs de baseball critiquent le travail des officiels, entre autres afin d’influencer leurs décisions. Nous avons récemment montré que de critiquer une décision de l’arbitre au marbre modifie la surface de la zone de prises, offrant un avantage à l’équipe ayant exprimé son désaccord. La critique étant inacceptable au baseball, cet avantage est accompagné de l’éjection de la personne fautive. L’éjection d’un joueur a des conséquences négatives plus importantes pour une équipe que celle d’un entraîneur. L’objectif de la présente étude est de comparer l’impact de l’éjection d’un joueur et d’un entraîneur sur la surface de la zone de prises. Pour ce faire, nous avons comparé la taille de la zone de prises des officiels de la Ligue de baseball majeur (MLB) selon le type d’éjection. Les surfaces de zones de prises ont été mesurées avant et après les expulsions à partir du positionnement spatial des lancers (72258) recueillis dans la base de données de la MLB pour les saisons 2008 à 2015. Une analyse par bootstrap à l’aide du modèle additif généralisé a révélé une diminution significativement plus grande de la zone de prises, t(389)=-3.66, p<0.001, suite à l’éjection d’un joueur par rapport à celle d’un entraîneur. Ces résultats suggèrent que suite à l’éjection d’une personne par l’arbitre, la perception et la prise de décision de ce dernier lors des lancers subséquents changent de façon à compenser les conséquences négatives engendrées par l’expulsion.

Congratulations everyone!!!

Congratulations everyone!!!

The LPVS presented many research projects during last Vision Science Society‘s annual congress, which took place on the week of May 17^th to May 22^nd, 2019, at St. Pete Beach in Florida. This international congress consists of a meet-up between researchers studying vision and its components. Researchers from many fields, such as visual and perceptive psychology, neurosciences, computational vision and cognitive psychology, presented their new findings linked with this subject during the congress. The poster sessions were divided by themes depending on the subject of the posters presented. Here is an overlook of the posters presented by our laboratory during the congress:

Poster session – Faces: Wholes, parts, features

 

Right hemisphere horizontal tuning during face processing

Justin Duncan^1,2, Guillaume Lalonde-Beaudoin¹, Caroline Blais¹, Daniel Fiset¹;

1 Université du Québec en Outaouais, 2 Université du Québec à Montréal

 

SEE POSTER

 

Left visual field (LVF) superiority refers to greater face processing accuracy and speed, compared to faces presented in the right VF (e.g., Sergent & Bindra, 1981). It is generally attributed to right hemisphere dominance (e.g., Kanwisher et al., 1997), but few mechanisms have been proposed for this phenomenon (e.g., global/local or low/high spatial frequency processing differences). Recent forays in the face processing literature have however revealed a critical role for horizontal spatial orientations (e.g., Goffaux & Dakin, 2010; Pachai et al., 2013). In line with these results, we verified whether orientation tuning might differ across hemispheres. Thirty participants completed two tasks measuring tuning profiles with orientation bubbles (Duncan et al., 2017). The first task was a 10 AFC identification, to generate a reference profile. The second task introduced lateralized presentations. In this task, a filtered probe face half (one of ten familiar individuals) was presented to either the LVF or RVF, while the other side viewed an average face half (randomized across trials). A target was then presented bilaterally, and participants indicated whether the probe and target were the same person. Central fixation was enforced with eye tracking (M = 97.7%, SD = 3.1% compliant trials) during the probe presentation (60 ms). Classification images were generated to extract diagnostic orientations. The statistical threshold (Zcrit = 2.101, p < 0.05) was established with the Stat4CI toolbox (Chauvin et al., 2005). As expected, horizontals predicted the best accuracy in the reference task (Z = 3.38). This relationship was also observed for the LVF (Z = 3.45), but not for the RVF (Z = –1.92). These results provide novel evidence for right hemisphere horizontal tuning for faces.

Identity specific orientation tuning for faces revealed by morphing Angelina into Jessica

Gabrielle Dugas¹, Justin Duncan^1,2, Caroline Blais¹ , Daniel Fiset¹;

1 Université du Québec en Outaouais, 2 Université du Québec à Montréal

 

SEE POSTER

 

Many recent studies have revealed that face recognition heavily relies on the processing of horizontal spatial orientations. However, most of those studies used tasks where it is difficult to dissociate the impact of physical face information from that of identity-specific information. To investigate this issue, we used a method designed to precisely control the physical difference between stimuli, and verified the horizontal tuning for faces of identical distances with regard to low-level properties but of different perceptual distance with regard to identity. Ten participants each completed 2,880 trials in a 2-ABX match-to-sample task. On each trial, the participants saw a target and two response alternatives, both sampled with the same orientation bubbles (Duncan et al., 2017). One response choice was visually identical to the sample (i.e. the correct response) whereas the other was either on the same side (within-identity [WI]) or on the other side (between-identity [BI]) of the categorical barrier. Thus, the physical distance between the target and the different (WI or BI) alternative was always the same, but the perceptual distance was not. As expected, WI trials were more difficult than BI trials for all participants, as indicated by the higher number of bubbles needed for the former (WI: M=101.66, SD=83.50) than the latter (BI: M=15.85, SD=14.94). Orientation tuning in the BI and WI conditions was revealed by computing a weighted sum of the orientation filters across trials, using participant accuracies as weights. In the BI condition, horizontal orientations between 62 and 101degres were significantly associated with accuracy (Zcrit=2.101; Zmax=4.25, p<0.05, peak at 84 degres); whereas no orientation reached the threshold in the WI condition (Zmax=1.41, p>0.05). Comparing horizontal tuning between the two conditions using a paired sample t test reveals an identity-specific horizontal tuning for faces, t(6) = 2.8, p < 0.05.

Poster session – Faces: Expressions, speech

 

Discrimination of facial expressions and pain through different viewing distances

Isabelle Charbonneau¹, Joël Guérette^{1 2}, Caroline Blais¹, Stéphanie Cormier¹, Fraser Smith, Daniel Fiset¹;

1 Université du Québec en Outaouais, 2 Université du Québec à Montréal

 

SEE POSTER

 

Due to its important communicative function, a growing body of research has focused on the effective recognition of the facial expression of pain. Here, we investigated how pain along with the basic emotions are recognized at different viewing distances. Sixteen participants took part in an 8-expression categorization task (2400 trials per participant). We used the Laplacian Pyramid toolbox (Burt & Adelson, 1983) to create six reduced-size images simulating increasing viewing distances (i.e. 3.26, 1.63, 0.815, 0.41, 0.20, 0.10 degree of visual angle). Unbiased hit rates (Wagner, 1993) were calculated to quantify the participants’ performance at each viewing distance. A 6 x 8 (Distance x Emotion) repeated measures ANOVA revealed a significant interaction F(8.54, 128.22) = 15.97, p < .001 (η2=0.516). Separate repeated measure ANOVAs looking at the effect of Emotion for each Distance were conducted and follow-up paired sample t-tests (corrected p = 0.05/28) revealed significant differences between expressions. At the most proximal distance, we found a significant effect of Emotion F(7,105)=21.41, p<.001 (η2=0.588) where happiness and angry were the two best-recognized emotions (all p’s<.005) followed by disgust, pain, fear, surprise and sadness. Interestingly, we found surprise and happiness to be the best-recognized expressions at further distances (all p’s<.05) which is consistent with previous findings (Smith & Schyns, 2009). Most importantly, recognition of pain decreased with increasing viewing distances and was not well recognized at the furthest distance. Taking into account that changes in viewing distance modulate the spatial frequency content available to an observer by progressively peeling off high SFs as the stimulus moves further away, these results are consistent with recent findings suggesting that pain categorization and discrimination rely mostly on mid-SFs (Guérette et al., VSS 2017).

 

Spatial frequencies underlying the detection of basic emotions and pain

Joël Guérette^{1 2} , Isabelle Charbonneau¹, Stéphanie Cormier¹, Caroline Blais¹, Daniel Fiset¹;

1 Université du Québec en Outaouais, 2 Université du Québec à Montréal

 

SEE POSTER

 

Many studies have examined the role of spatial frequencies (SFs) in facial expression perception. However, although their detection and recognition have been proposed to rely on different perceptual mechanisms (Sweeny et al., 2013; Smith & Rossit, 2018), the SFs underlying these two tasks have never been compared. Thus, the present study aimed to compare the SFs underlying the detection and recognition of facial expressions of basic emotions and pain. Here, we asked 10 participants (1400 trials per participant) to decide if a stimulus randomly sampled with SF Bubbles (Willenbockel et al., 2010) corresponded to an emotion or a neutral face. Classification vectors for each emotion were computed using a weighted sum of SFs sampled on each trial, with accuracies transformed in z-scores as weights. We then compared the SFs used in this task to those obtained in a previous study using the same stimuli and method but during a recognition task (Charbonneau et al., 2018). Overall, accurate detection of emotions was significantly associated with the use of low-SFs (ranging from 3.33 to 6 cycles per face (cpf); Zcrit=3.45, p< 0.05). Happiness was the only emotion relying on similar low-SFs for both tasks. Other emotions were associated with the use of higher SFs in the recognition task. Interestingly, the detection of fear (ranging from 1.67 to 7 cpf, peaking at 4 cpf) and surprise (ranging from 1.33 and 6.33 cpf, peaking at 3.33 cpf) was associated with the lowest SF information. These results are consistent with the idea that low-SF represent potent information for the detection of emotions, especially those with a survival value such as fear. However, the contribution of higher SFs is needed to discriminate between emotions for their accurate recognition.

Poster session – Faces: Gaze

 

Link between initial fixation location and spatial fre- quency utilization in face recognition

Amanda Estéphan^1,2, Carine Charbonneau¹ , Virginie Leblanc¹, Daniel Fiset¹, Caroline Blais¹; 1 Université du Québec en Outaouais, 2 Université du Québec à Montréal

 

SEE POSTER

 

Recent face perception studies have explored cultural and individual differences with regard to visual processing strategies. Two main strategies, associated with distinct eye movement patterns, have been highlighted: global (or holistic) face processing involves fixations near the center of the face to facilitate simultaneous peripheral processing of key facial features (i.e. eyes and mouth); local (or analytic) face processing involves fixations directed to those facial features (Chuk et al, 2014; Miellet et al, 2011). Interestingly, some studies have also found cultural and individual differences in the spatial frequencies (SFs) used for face identification, which seem to fit the eye movement data. For instance, East Asians use a more global fixation pattern (Blais et al, 2008), and lower SFs (Tardif et al, 2017), compared to Western Caucasians; myopes tend to use a more local fixation pattern, and higher SFs, compared to emmetropes (Estephan et al, 2018). However, whether a common underlying link between eye movements and SF use exists is still unknown. In order to investigate this question, the eye movements of 24 Canadian participants were monitored while they completed an Old/New face recognition task, and the SF Bubbles method (Willenbockel et al., 2010) was used to measure the same participants’ SF utilization during a face identification task. Fixation duration maps were computed for each participant using the iMap4 toolbox (Lao et al., 2017), and participants’ individual SF tuning peaks, obtained with SF Bubbles, were calculated. Group analyses based on participants’ initial fixation location were performed on SF tuning; correlations between initial fixation location and SF tuning peaks were also calculated. In sum, our data failed to reveal a clear link between eye movement patterns and SF utilization. However, these results are preliminary and more participants will be tested to increase statistical power. Nonetheless, our results highlight that the underlying relation between eye movements and SF use that could possibly drive the previously observed contingencies between these two measures is potentially of a more complex nature.

Poster session – Faces: Social and Cultural Factors

Evaluating Trustworthiness: Differences in Visual Rep- resentations as a Function of Face Ethnicity

Francis Gingras¹, Karolann Robinson¹, Daniel Fiset¹, Caroline Blais¹;

1 Université du Québec en Outaouais

 

SEE POSTER

 

Trustworthiness is rapidly and automatically assessed based on facial appearance, and it is one of the main dimensions of face evaluation (Oosterhof & Todorov, 2008). Few studies have investigated how we evaluate trustworthiness in faces of other ethnicities. The present study aimed at comparing how individuals imagine a trustworthy White or Black face. More specifically, the mental representations of a trustworthy White and Black face were measured in 30 participants using a Reverse Correlation task (Mangini & Biederman, 2004). On each trial (N=500 per participant), two stimuli, created by adding sinusoidal white noise to an identical base face (White or Black, depending on the experimental condition), were presented side-by-side. The participant’s task was to decide which of the two looked most trustworthy. The noise patches corresponding to the chosen stimuli were summed to produce a classification image, representing the luminance variations associated with a percept of trustworthiness. A statistical threshold was found using the Stat4CI’s cluster test (Chauvin et al., 2005), a method that corrects for the multiple comparisons across all pixels while taking into account the spatial dependence inherent to coherent images (t_crit=3.0, k=246, p<0.025). Results show that for a White face, perception of trustworthiness is associated with a lighter eye region; for a Black face, perception of trustworthiness is associated with a darker right eye and a lighter mouth. Statistically comparing both classification images (t_crit=3.0, k=246, p<0.025) revealed that the eye region was more important in judging trustworthiness of White faces, while the mouth region was more important for Black faces. The present study shows that facial traits used to form the mental representation of trustworthiness differ with face ethnicity. More research will be needed to verify if this finding generalizes across populations of different ethnicities.

Variation of empathy in viewers impacts facial features encoded in their mental representation of pain expression.

Marie-Pier Plouffe-Demers^{1 2} , Camille Saumure¹, Daniel Fiset¹ , Stéphanie Cormier¹ ,  Miriam Kunz³ , Caroline Blais¹;
1 Université du Québec en Outaouais, 2 Université du Québec à Montréal, 3 University of Groningen

 

SEE POSTER

 

The impact of gender on visual strategies underlying the discrimination of facial expressions of pain

Camille Saumure¹, Marie-Pier Plouffe-Demers^{1 2}, Daniel Fiset¹ , Stéphanie Cormier¹ ,  Miriam Kunz³ , Caroline Blais¹;
1 Université du Québec en Outaouais, 2 Université du Québec à Montréal, 3 University of Groningen

 

SEE POSTER

 

Previous studies have found a female advantage in the recognition/detection (Hill and Craig, 2004; Prkachin et al., 2004) of pain expressions, although this effect is not systematic (Simon et al., 2008; Riva et al., 2011). However, the impact of gender on pain expression recognition visual strategies remains unexplored. In this experiment, 30 participants (15 males) were tested using the Bubbles method (Gosselin & Schyns, 2001), which randomly sampled facial features across five spatial frequency (SF) bands to infer what visual information was successfully used. On each of the 1,512 trial, two bubblized faces, sampled from 8 avatars (2 genders; 4 levels of pain intensity), were presented to participants who identified the one expressing the highest pain level. Three difficulty levels, determined by the percentage of pain difference between the two stimuli (i.e 100%, 66% or 33%) were included. Number of bubbles needed to maintain an average accuracy of 75% was used as a performance measure (Royer et al., 2015). Results indicated a trend towards a higher number of bubbles needed by male (M=57.7, SD=30.4) in comparison to female (M=40.2, SD=23.2), [t(28)=2.02, p=0.05]. Moreover, this difference was significant with the highest level of difficulty [t(28)=2.22, p=0.04], suggesting that pain discrimination was more difficult for male (M=77.6, SD=36.8) than female (M=52.3, SD=24.5). Classification images, generated by calculating a weighted sum of the bubbles position (where accuracies transformed in z-scores were used as weights), revealed that female made a significantly higher use of the lowest band of SF (Zcrit = 2.7, p<0.05; 5.4-2.7 cycles per face). These results suggest that gender impacts the performance and the visual strategies underlying pain expression recognition.

We are proud to announce that Camille Saumure, one of the laboratory’s clinical neuropsychology grad student, received the prestigious Seed Grant for Female Junior Scientists from Women in Cognitive Science Canada 2019.

Congratulations Camille, you deserved it!

We are happy to announce that the Social and Visual Perception Laboratory (LPVS) recently obtained a research fund of a value of 249 978$ from the Canada Foundation for Innovation (CFI) and its collaborators, which includes the Government of Quebec. This fund will be used to develop three different platforms in the laboratory. These platforms are psychophysics, eye movements and electroencephalography. A lot of new projects are coming soon at the laboratory!

The LPVS was also well represented at the annual congress of the Société québécoise pour la recherche en psychologie (SQRP), which took place in Mont-Tremblant on March 22nd, 23rd and 24th. Our directors and our students were part of two symposiums and made, in total, eleven presentations and two posters. Furthermore, Isabelle Charbonneau, Marie-Pier Plouffe-Demers and Gabrielle Dugas, three of our students, were members of the committee organizing the congress. They helped a lot to make this weekend well organized and unforgettable.

Ashley Nixon Photography. Left to right: Gabrielle Dugas, Isabelle Charbonneau, Amanda Estéphan, Camille Saumure, Caroline Blais, Daniel Fiset, Justine Goulet, Joël Guérette, Justin Duncan and Francis Gingras. (Missing: Adrianne Pauzé)

We also want to congratulate Amanda Estéphan, Ph.D student, for winning the Guy Bégin award at the SQRP congress. She won the award following the publishing of her article entitled “Time course of cultural differences in spatial frequency use for face identification (2018)”. She had the chance to present her article at the congress. Her study postulates that culture affects the visual systems’ preferences. Its impact on face processing occurs early on in the process.

All of our congratulations to Amanda!

Ashley Nixon Photography. Amanda Estéphan.

Finally, we are thrilled to announce that Joël Guérette, Ph.D student, won for the second time in a row the award for the best student oral communication in the social/organization axis following his presentation entitled “Makeup calls in baseball : Major League Baseball players’s level of performance effects on umpire decisions”. In his oral communication, he postulated that when a succesful baseball player screams at the referee, it helps him to make his team win.

Congratulations Joël!

Ashley Nixon Photography. Left to right: Isabelle Charbonneau, Joël Guérette and Denis Cousineau.

LPVS-UQO has been awarded a research grant as part of the Pilot Grants Competition of the Center for Research in Cognitive Neuroscience at the Université du Québec à Montréal (NeuroQAM).

As part of this competition, Dr. Fiset and Dr. Blais in collaboration with Dr Saint-Amour of UQAM set up a project entitled “The Impact of Amblyopia on Face Treatment: A Psychophysical and Electrophysiological Study”. Thus, this project aims to better understand the consequences of amblyopia on face perception at the behavioral and neurophysiological levels.

We are very happy with this news and enthusiastic as we embark on this exciting project!

Samedi dernier a été marqué par la cérémonie de la collation des grades organisée pas l’Université du Québec en Outaouais, lors de laquelle les étudiants du LPVS se sont démarqués.

Félicitation à nos doctorantes:

Jessica Royer

Essai doctoral intitulé : Différences individuelles dans les habiletés d’identification et l’utilisation de l’information visuelle des visages

L’identification d’un visage requiert l’extraction fine et précise des informations contenues dans le stimulus; or, tous les individus ne sont pas aussi habiles pour accomplir cette tâche. Nos travaux ont permis de démontrer que la stratégie d’extraction de l’information visuelle lors d’une tâche d’identification de visages, particulièrement l’utilisation de la région des yeux, est liée au niveau d’habileté individuel à reconnaître les visages.

Cette essai était dirigé par docteur Daniel Fiset et codirigée par docteure Caroline Blais.

Youna Dion-Marcoux

Essai doctoral intitulé : Impact du vieillissement sur les stratégies perceptives utilisées en reconnaissance d’expressions faciales d’émotion

Les données de la littérature scientifique suggèrent la présence d’une diminution des habiletés de reconnaissances des expressions faciales lors du vieillissement normal. Cette thèse visait en premier lieu à évaluer les performances en reconnaissance des expressions faciales chez les personnes âgées avec des stimuli appartenant aux deux groupes d’âge. Elle avait comme second objectif de vérifier l’impact de l’âge sur les stratégies perceptives utilisées lors du traitement des expressions faciales par nos deux groupes de participants.

Cet essai était dirigé par docteure Caroline Blais. et codirigé par docteursDaniel Fiset et Hélène Forget.

Marie-Josée Roy

Essai doctoral intitulé : L’impact de l’anxiété sociale sur les stratégies perceptives sous-jacentes au traitement des expressions faciales d’émotion

La capacité à développer et à maintenir des liens sociaux et plus spécifiquement à comprendre les émotions semble déficitaire dans plusieurs pathologies psychiatriques. Dans l’anxiété sociale, des performances mitigées au niveau de la reconnaissance des expressions faciales d’émotion ont été observées, ce qui pourrait s’expliquer par une sur-activation de l’amygdale pour certaines expressions faciales. Puisque l’amygdale modulerait les stratégies perceptives utilisées en reconnaissance d’expressions faciales, il est possible que les stratégies perceptives utilisées par les anxieux sociaux diffèrent de celles des participants contrôles. Cet essai doctoral visait ainsi à mieux comprendre les stratégies perceptives sous-jacentes à la reconnaissance des expressions faciales d’émotion chez un échantillon d’adultes d’hommes et de femmes rapportant
vivre de l’anxiété sociale. Plus précisément, cet essai visait à vérifier si les participants anxieux sociaux différaient des participants contrôles sur leur utilisation des stratégies perceptives en reconnaissance des six expressions faciales de base : le dégoût, la colère, la peur, la joie, la surprise et la tristesse.

Cet essai était dirigé par docteur Daniel Fiset.

Félicitation à nos Bacheliers: Isabelle Charbonneau, Joël Guérette et Marie-Pier Plouffe-Demers.

Une mention toute spéciale à Isabelle pour l’obtention de la prestigieuse médaille d’argent de la Gouverneure générale du Canada qui lui a été décernée au nom de son Excellence, la très honorable Julie Payette, pour avoir  terminé son baccalauréat en psychologie avec une moyenne cumulative de 4,26/4,30.

Nous sommes très très fiers de vous et vous souhaitons encore bien des découvertes et réussites pour les années à venir.

Here’s an overview of the projects presented by the LPVS at the annual conference of Vision Science Society who brings together in one forum scientists from the broad range of disciplines that contribute to vision science, including visual psychophysics, neuroscience, computational vision and cognitive psychology. The scientific content of the meetings reflects the breadth of topics in modern vision science, from visual coding to perception, recognition and the visual control of action, as well as the recent development of new methodologies from cognitive psychology, computer vision and neuroimaging.

Poster session – Faces: Neural mechanisms

N170 sensitivity to the horizontal information of facial expressions

Justin Duncan^1,2, Frédéric Gosselin³ , Caroline Blais¹ , Daniel Fiset¹
1 Université du Québec en Outaouais, 2 Université du Québec à Montréal, 3 Université de Montréal

 

SEE POSTER

 

The N170 event-related potential, which is preferentially tuned to faces (see for review Rossion, 2014), has been linked with processing of the eyes (Rousselet, Ince, van Rijsbergen & Schyns, 2014), of diagnostic facial features of emotions (Schyns, Petro & Smith, 2007), and of horizontal facial information (Jacques, Schiltz & Goffaux, 2014). Recent findings have shown that horizontal information is highly diagnostic of the basic facial expressions, and this link is best predicted by utilization of the eyes (Duncan et al., 2017). Given these findings, we were interested in how N170 amplitude relates with spatial orientations in a facial expressions categorization task. Five subjects each completed 7,000 trials (1,000 per expression) while EEG activity was measured at a 256 Hz sampling rate. Faces were randomly filtered with orientation bubbles (Duncan et al., 2017) and presented on screen for 150ms. Performance was maintained at 57.14%, using QUEST (Watson & Pelli, 1983) to modulate stimulus contrast. The signal was referenced to the mastoid electrodes and bandpass filtered (1-30 Hz). It was epoched between -300 and 700 ms relative to stimulus onset, and eye movements were removed using ICA. Single-trial spherical spline current source density (CSD) was computed using the CSD toolbox (Kayser & Tenke, 2006; Tenke & Kayser, 2012). Our main analysis consisted in conducting a multiple linear regression of singletrial orientation filters on PO8 voltages at each time point. The statistical threshold (Zcrit= 3.6, p< .05, two-tailed) was established with the Stat4CI toolbox (Chauvin et al., 2005). We found a negative correlation between horizontal information availability and voltage (Zmin= -5.43, p< .05) in the 50ms leading up to the N170’s peak. Consistent with the proposition that the N170 component reflects the integration of diagnostic information (Schyns, Petro & Smith, 2007), the association between horizontal information and amplitude was strongest 25 ms before the peak, and completely disappeared at peak.

Acknowledgement: Natural Sciences and Engineering Research Council of Canada

Cortical activation of fearful faces requires central resources: multitasking processing deficits revealed by event-related potentials

Amélie Roberge¹ , Justin Duncan^2-3, Ulysse Fortier-Gauthier¹ , Daniel Fiset² , Benoit Brisson¹
1 Département de psychologie, Université du Québec à Trois-Rivières, 2 Département de Psychoéducation et de Psychologie, Université du Québec en Outaouais, 3 Département de Psychologie, Université du Québec à Montréal

To investigate if emotional face processing requires central attention, a psychological refractory period paradigm was combined with the event-related potential (ERP) technique. Participants were asked to categorize tones as high (900 Hz or 2000 Hz) or low (200 Hz or 426 Hz) as quickly and accurately as possible and then to indicate if a face expressed fear or a neutral expression. Stimulus onset asynchrony (SOA) between the presentation of the tone and the face was manipulated (SOA: 300, 650 or 1000ms) to vary the amount of central attention available to perform the face expression task (less central attention available at short than long SOAs). The amplitude of frontally distributed ERP components associated to emotional face processing (computed as the difference between fear and neutral conditions: Eimer & Holmes, 2007) were measured at all SOAs. The first component (175-225 ms post-visual stimulus onset), which is thought to reflect rapid initial detection of the emotion, was not affected by SOA, F(2,50) = 2.24, p = .12. However, a significant effect of SOA was observed on a later sustained frontal positivity (300-400 ms post-visual stimulus onset), that is thought to reflect the conscious evaluation of emotional content, F(2,50) = 5.33, p = .01. For both components, no effect of SOA was observed in a subsequent control experiment in which both stimuli were presented but only a response to the expression of the face was required, F(2,32) = 2.80, p = .10 and F(2,32) = 1.26, p = .30. These results suggest that the rapid perceptual detection of the facial expression is independent of central attention. In contrast, the subsequent cognitive stage of conscious evaluation of emotional content does require central attention to proceed.

Acknowledgement: Conseil de recherches en sciences naturelles et en génie du Canada (CRSNG), Fonds québécois de la recherche sur la nature et les technologies (FRQNT)

Poster session – Faces: Emotions

Spatial frequencies for accurate categorization and discrimination of facial expressions

Isabelle Charbonneau¹, Stéphanie Cormier ¹ , Joël Guérette¹ , Marie-Pier Plouffe-Demers¹ , Caroline Blais¹ , Daniel Fiset¹ 1 Université du Québec en Outaouais

 

SEE POSTER

 

studies have examined the role of spatial frequencies (SFs) in facial expression perception. However, most of these studies used arbitrary cut-off to isolate the impact of low and high SFs (De Cesarei & Codispoti, 2012) thus removing possible contribution of mid-SFs. This present study aims to reveal the diagnostic SFs for each basic emotion as well as neutral using SFs Bubbles (Willenbockel et al., 2010). Forty participants were tested (20 in a categorization task, 20 in a discrimination task; 4200 trials per participant). In the categorization task, subjects were asked to identify the perceived emotion among all the alternatives. In the discrimination task, subjects were asked, in a block-design setting (block order was counterbalanced across participants), to discriminate between a target emotion (e.g fear) and all other emotions. Mean accuracy was maintained halfway between chance (i.e. 12.5% and 50% correct for each task, respectively) and perfect accuracy. In both tasks, accuracy for happiness and surprise is associated with low-SFs (peaking at around 5 cycles per face (cpf); Zcrit=3.45, p< 0.05 for all analysis) whereas accuracy for sadness and neutrality is associated with mid-SFs (peaking between 11.5 and 15 cpf for both tasks). Interestingly, the facial expressions of fear and anger reveal significantly different patterns of use across task. Whereas their correct categorization is correlated with the presence of mid-to-high SFs (peaking at 14 and 20 cpf for angry and fear, respectively) their accurate discrimination is correlated with the utilization of lower SFs (peaking at 4 and 3.7 cpf). These results suggest that the visual system is able to use low-SF information to detect and discriminate social threatening cues. However, higher-SFs are probably necessary in a multiple-choices categorization task to allow fine-grained discrimination.

Acknowledgement: Natural Sciences and Engineering Research Council of Canada

Spatial frequencies for the visual processing of the facial expression of pain

Joël Guérette¹ , Stéphanie Cormier¹ , Isabelle Charbonneau¹ , Caroline Blais¹ , Daniel Fiset¹ ;
1 Département de psychoéducation et de psychologie, Université du Québec en Outaouais

 

SEE POSTER

 

Recent studies suggest that low spatial frequencies (SFs) are particularly important for the visual processing of the facial expression of pain (Wang et al., 2015; 2017). However, these studies used arbitrary cut-off to isolate the impact of low (under 8 cycles per faces (cpf)) and high (over 32 cpf) SFs, thus removing any contribution of the mid-SFs. Here we compared the utilization of SFs for pain and other basic emotions in three tasks (20 participants per task), that is 1) a facial expression recognition task with all basic emotions and pain, 2) a facial expression discrimination task where one target expression needed to be discriminated from the others and 3) a facial expression discrimination task with only two choices (i.e. fear vs. pain, pain vs. happy). SF Bubbles were used (Willenbockel et al., 2010), a method which randomly samples SFs on a trial-by-trial basis, enabling us to pinpoint the SFs that are correlated with accuracy. In the first task, accurate categorization of pain was correlated with the presence of a large band of SFs ranging from 4.3 to 52 cpf peaking at 14 cpf (Zcrit=3.45, p< 0.05 for all analysis). In the second task, the correct discrimination of pain was correlated with the presence of a band of SFs ranging from 5 to 20 cpf peaking at 11 cpf. In the third task, we computed the classification vectors for pain-happiness and pain-fear conditions and revealed the overlapping SFs. In this task, SFs ranging from 2.7 to 13 cpf peaking at 7.3 cpf are significantly correlated with pain discrimination. Our results highlight the importance of the mid-SFs in the visual processing of the facial expression of pain and suggest that any method removing these SFs offers an incomplete account of SFs diagnosticity.

Acknowledgement: Natural Sciences and Engineering Research Council of Canada

Poster session – Faces: Individual differences

Task-specific extraction of horizontal information in faces

Gabrielle Dugas¹ , Jessica Royer¹ , Justin Duncan^{1, 2}, Caroline Blais¹ , Daniel Fiset¹ ;
1 Université du Québec en Outaouais, 2 Université du Québec à Montréal

 

SEE POSTER

 

Horizontal information is crucial for accurate face processing (Goffaux & Dakin, 2010). Individual differences in horizontal tuning were shown to correlate with aptitude levels in both face identification (Pachai, Sekuler & Bennett, 2013) and facial expression categorization (Duncan et al., 2017).These results thus indicate that the same visual information correlates with abilities in two different face processing tasks. Here, we intended to verify if the ability to extract horizontal information generalizes from one task to the other at the individual level. To do this, we asked 28 participants to complete both a 10-AFC face identification task and a race categorization (Caucasian vs. African-American) task (600 trials per task). To find out which parts of the orientation spectrum were associated with accuracy, images were randomly filtered with orientation bubbles (Duncan et al., 2017). We then performed, for each subject, what amounts to a multiple linear regression of orientation sampling vectors (independent variable) on response accuracy scores (dependent variable). A group classification vector (CV) was created by first summing individually z-scored CVs across subjects, and then dividing the outcome by √n, where n is the sample size. These analyses, performed separately for each task, show that horizontal information is highly diagnostic for both face identification (Zmax = 24.8) and race categorization (Zmax = 22.9), all ps < .05 and Group CVs of both task were highly correlated, r= .96, p< .001, showing high similarity in visual strategies at the group level. At the individual level, however, horizontal tuning measures (as per Duncan et al., 2017) in the identification and race categorization tasks did not correlate, r = -0.02, ns. Our results thus show that, although horizontal information is diagnostic for both tasks, individual differences in the extraction of this information appears to be task dependent.

Acknowledgement: Natural Sciences and Engineering Research Council

Individual differences in face identification correlate with face detection ability

Virginie Burns¹, Guillaume Lalonde-Beaudoin¹ , Justin Duncan^1,2, Stéphanie Bouchard¹ , Caroline Blais¹ , Daniel Fiset¹
1 Département de Psychoéducation et de Psychologie, Université du Québec en Outaouais, 2 Département de Psychologie, Université du Québec à Montréal

 

SEE POSTER

 

Our brain is tuned to detect, identify and integrate social information conveyed by faces. Despite the crucial role of face detection, little is known about the visual processes underlying this endeavor and how it is related to face identification. Recently, Xu and Biederman (2014) presented a case of acquired prosopagnosia with a face-specific detection impairment. Compared with controls, MJH needs significantly more visual signal for face detection, but not for car detection. Thus, we hypothesized that there may exist a correlation between face identification and detection proficiency in normal adults. Forty-five participants (24 women) performed the Cambridge Face Memory Test (CFMT; Duchaine, & Nakayama, 2006), the Cambridge Face Perception Test (CFPT; Duchaine, Germine, & Nakayama, 2007), and the Glasgow Face Memory Test (GFMT; Burton, White, & McNeil, 2010). They also completed two detection tasks : a face detection task and a car detection task. The power spectra were equalized across face and car stimuli. Individual face identification abilities were calculated by computing a weighted average of CFMT, GFMT, and CFPT scores (the latter of which was negatively scored). Face and car detection abilities were reflected by their respective detection thresholds, defined as phase spectrum coherence (as per Xu and Biederman, 2014). We observed a negative correlation between face identification ability scores and face detection thresholds (r = -.47 p< .01), which remained significant when computing the Spearman correlation (rs = -.42, p< .01). The correlation also remained significant when controlling for car detection ability (r = -.371, p< .05). Our results suggest that face detection and face identification share some perceptual or cognitive resources. More research will be needed to better understand what exactly is shared between these two tasks.

Acknowledgement: Natural Sciences and Engineering Research Council of Canada

Poster session – Attention: Individual differences

 

Evidence for a broader allocation of attention in emmetropes over myopes during three visual processing tasks

Amanda Estéphan^1,2, Carine Charbonneau¹ , Hana Furumoto-Deshaies¹ , Marie-Pier PlouffeDemers¹ , Daniel Fiset¹ , Roberto Caldara³ , Caroline Blais¹ ;
1 Département de Psychoéducation et Psychologie, Université du Québec en Outaouais, 2 Département de Psychologie, Université du Québec à Montréal, 3 Department of Psychology, University of Fribourg

 

SEE POSTER

 

Last year (VSS, 2017), we explored the impact of myopia on visual attention as a possible explanation for the perceptual differences observed between Easterners and Westerners: namely, that Easterners have a larger global advantage than Westerners in a Navon Task (McKone et al., 2010); fixate less the eyes and mouth, and more the centre of the face during its processing (Blais et al., 2008); and tend to process faces in lower spatial frequencies (Tardif et al., 2017). Myopes and emmetropes were tested using Navon’s paradigm to measure their ability to detect global versus local target letters, and the Spatial Frequency (SF) Bubbles method (Willenbockel et al., 2010a) to measure their use of SFs during a face identification task: we initially found unexpected results suggesting that emmetropes were better than myopes at detecting global letters and that they used lower SFs than the latter group to correctly identity faces. Here, we delved deeper into this inquiry: a greater number of participants were tested with Navon’s paradigm (myopes = 18; emmetropes = 29) and with SF Bubbles (myopes = 15; emmetropes = 18). In addition, we measured participants eye-movements during another face recognition task (myopes = 11; emmetropes = 9). In support of our previous findings, our new results indicate that emmetropes have a higher global processing bias than myopes [t(45) = -3.269; p = 0.002], and make greater use of lower SFs, between 4.3 to 5.7 cycles per face [Stat4CI (Chauvin et al., 2005): Zcrit=-3.196, p< 0.025]. Finally, our eye-movement results suggest that emmetropes fixate the center of the face to a greater extent than myopes [analysis with iMap4 (Lao et al., in press)]. These findings offer a new avenue to explore how myopes and emmetropes process information contained in visual stimuli.

Acknowledgement: Natural Sciences and Engineering Research Council of Canada

Poster session Faces: Familiarity and other-race effects

Cultural differences in spatial frequency utilisation do not generalize across various object classes

Caroline Blais¹ , Amanda Estéphan^{1, 2}, Michael N’Guiamba N’Zie¹ , Marie-Pier Plouffe-Demers¹ , Ye Zhang^3,4, Dan Sun^3,4, Daniel Fiset¹ ;
1 Psychology department, University of Quebec in Outaouais, 2 Psychology department, University of Quebec in Montreal, 3 Institute of Psychological Sciences, Hangzhou Normal University, 4 Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments

 

SEE POSTER

 

Several studies have shown cultural differences in the fixation patterns observed during tasks of different nature, e.g. face identification (Blais et al., 2008; Kelly et al., 2011), race categorization (Blais et al., 2008), and recognition of visually homogeneous objects (Kelly et al., 2010). These differences suggest that Easterners deploy their attention more broadly and rely more on extrafoveal processing than Westerners (Miellet et al., 2013). This finding is in line with a dominant theory in the field suggesting that cultural differences in cognition, attention and perception may be related to social systems (Nisbett & Miyamoto, 2005). Specifically, Easterners, because they have evolved in a more collectivistic system, would deploy their attention more broadly than Westerners, who have evolved in a more individualistic system. However, studies revealing cultural differences in fixation patterns during face processing have been challenged by the findings that two fixations suffice for face recognition (Hsiao & Cottrell, 2008), and that early fixations are not modulated by culture (Or, Peterson & Eckstein, 2015). Since deploying attention over a broader area has been shown to modulate the spatial resolution, directly assessing the spatial frequency (SF) utilisation underlying stimulus recognition would help clarify the impact of culture on perceptual processing. Here, we present a set of four experiments in which the SF used by Easterners and Westerners were measured while they identified faces, discriminated familiar from unfamiliar faces, and categorized object and scenes. The results reveal that Easterners are tuned towards lower SF than Westerners when they identify faces and discriminate familiar from unfamiliar ones (Tardif et al., 2017), but use the same SF to categorize objects and scenes. Together, these results challenge the view that the exposition to different social systems leads to the development of different perceptual strategies generalizable to various object classes.

Acknowledgement: Natural Sciences and Engineering Research Council of Canada

The impact of culture on visual strategies underlying the judgment of facial expressions of pain.

Camille Saumure¹, Marie-Pier Plouffe-Demers¹ , Daniel Fiset¹ , Stéphanie Cormier¹ , Dan Sun^3,4, Zhang Ye^3,4, Miriam Kunz² , Caroline Blais¹ ;
1 Département de psychoéducation et de psychologie, Université du Québec en Outaouais, 2 Department of General Practice and Elderly Care Medicine, University of Groningen, 3 Institute of Psychological Sciences, Hangzhou Normal University, 4 Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments

 

SEE POSTER

 

Research has revealed that observers’ ability to recognize basic facial emotions expressed by individuals of another ethnic group is poor (Elfenbein, & Ambady, 2002), and that culture modulates the visual strategies underlying the recognition of basic facial expressions (Jack et al., 2009; Jack, Caldara, Schyns, 2012; Jack et al., 2012). Although it has been suggested that pain expression has evolved in order to be easily detected (Williams, 2002), the impact of culture on the visual strategies underlying the recognition of pain facial expressions remains underexplored. In this experiment, Canadians (N=28) and Chinese (N=30) participants were tested with the Bubbles method (Gosselin & Schyns, 2001) to compare the facial features used to discriminate between two pain intensities. Stimuli consisted of 16 face avatars (2 identities x 2 ethnicities x 4 levels of intensity difference) created with FACEGen and FACSGen. The amount of facial information needed to reach an accuracy rate of 75% was higher for Chinese (M=93.3, SD=25.04) than for Canadian participants (M=47.2, SD=48.02) [t(44.3)=-4.63, p< 0.001], suggesting that it was harder for Chinese to discriminate among two pain intensities. Classification images representing the facial features used by participants were generated separately for Asian and Caucasian faces. Statistical thresholds were found using the cluster test from Stat4CI (Chauvin et al, 2005; Zcrit=3.0; k=667; p< 0.05). Canadians used the eyes, the wrinkles between the eyebrows and the nose wrinkles/upper lip area with both face ethnicities. Chinese used the eye area with Asian faces, but no facial area reached significance with Caucasian faces. Compared with Chinese participants, Canadians relied more on the nose wrinkles area (Zcrit=3.0; k=824; p< 0.025). Together, these results suggest that culture impacts the visual decoding of pain facial expressions.

Acknowledgement: Social Sciences and Humanities Research Council

The impact of culture on the visual representation of pain facial expressions

Marie-Pier Plouffe Demers ¹, Camille Saumure¹ , Stéphanie Cormier¹ , Daniel Fiset¹ , Miriam Kunz² , Dan Sun^3,4, Zhang Ye^3,4, Caroline Blais¹ ;
1 Department of psychoeducation and psychology, Université du Québec en Outaouais, 2 Department of General Practice and Elderly Care Medicine, University of Groningen, 3 Institute of Psychological Sciences, Hangzhou Normal University, 4 Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments

 

SEE POSTER

 

Some studies suggest that communication of pain is connected to the evolution of human race and has evolved in a way to increase an individual’s chance of survival (Williams, 2002). However, even though facial expressions of emotions have long been considered culturally universal (Izard, 1994; Matsumoto & Willingham, 2009), some studies revealed cultural differences in the perceptual mechanisms underlying their recognition (e.g. Jack et al., 2009; Jack et al., 2012). The present study aims to verify the impact of culture on the facial features that are stored by individuals in their mental representation of pain facial expressions. In that respect, observer-specific mental representations of 60 participants (i.e. 30 Caucasians, 30 Chineses) have been measured using the Reverse Correlation method (Mangini & Biederman, 2004). In 500 trials, participants chose, from two stimuli, the face that looked the most in pain. For each trial, both stimuli would consist of the same base face (i.e. morph between average Asian and Caucasian avatars showing low pain level) with random noise superimposed, one with a random noise pattern added, and the other the same pattern subtracted. We generated a classification image (CI) for each group by averaging noise patterns chosen by participants. The cultural impact on mental representations was measured by subtracting the Caucasian CI from the Chinese CI, to which was applied a Stat4CI cluster test (Chauvin et al., 2005). Results indicate significant differences in the mouth and left eyebrow areas (ZCrit=3.09, K=167, p< 0.025), and suggest a mental representation of pain facial expression of greater intensity for Chinese participants. Given that mental representations reflect expectations about the world based on past experiences (Jack et al., 2012), the results suggest that Chinese participants may have previously been exposed to facial expressions displaying greater pain intensities.

Acknowledgement: Social Sciences and Humanities Research Council