Visual Field Bias Research Articles

Valproic acid exposure affects social visual lateralization and asymmetric gene expression in zebrafish larvae

Cerebral asymmetry is critical for typical brain function and development; at the same time, altered brain lateralization seems to be associated with neuropsychiatric disorders. Zebrafish are increasingly emerging as model species to study brain lateralization, using asymmetric development of the habenula, a phylogenetically old brain structure associated with social and emotional processing, to investigate the relationship between brain asymmetry and social behavior. We exposed 5-h post-fertilization zebrafish embryos to valproic acid (VPA), a compound used to model the core signs of ASD in many vertebrate species, and assessed social interaction, visual lateralization and gene expression in the thalamus and the telencephalon. VPA-exposed zebrafish exhibit social deficits and a deconstruction of social visual laterality to the mirror. We also observe changes in the asymmetric expression of the epithalamic marker leftover and in the size of the dorsolateral part of the habenula in adult zebrafish. Our data indicate that VPA exposure neutralizes the animals’ visual field bias, with a complete loss of the left-eye use bias in front of their own mirror image, and alters brain asymmetric gene expression and morphology, opening new perspectives to investigate brain lateralization and its link to atypical social cognitive development.

Machine learning for distinguishing saudi children with and without autism via eye-tracking data

BackgroundDespite the prevalence of Autism Spectrum Disorder (ASD) globally, there’s a knowledge gap pertaining to autism in Arabic nations. Recognizing the need for validated biomarkers for ASD, our study leverages eye-tracking technology to understand gaze patterns associated with ASD, focusing on joint attention (JA) and atypical gaze patterns during face perception. While previous studies typically evaluate a single eye-tracking metric, our research combines multiple metrics to capture the multidimensional nature of autism, focusing on dwell times on eyes, left facial side, and joint attention.MethodsWe recorded data from 104 participants (41 neurotypical, mean age: 8.21 ± 4.12 years; 63 with ASD, mean age 8 ± 3.89 years). The data collection consisted of a series of visual stimuli of cartoon faces of humans and animals, presented to the participants in a controlled environment. During each stimulus, the eye movements of the participants were recorded and analyzed, extracting metrics such as time to first fixation and dwell time. We then used these data to train a number of machine learning classification algorithms, to determine if these biomarkers can be used to diagnose ASD.ResultsWe found no significant difference in eye-dwell time between autistic and control groups on human or animal eyes. However, autistic individuals focused less on the left side of both human and animal faces, indicating reduced left visual field (LVF) bias. They also showed slower response times and shorter dwell times on congruent objects during joint attention (JA) tasks, indicating diminished reflexive joint attention. No significant difference was found in time spent on incongruent objects during JA tasks. These results suggest potential eye-tracking biomarkers for autism. The best-performing algorithm was the random forest one, which achieved accuracy = 0.76 ± 0.08, precision = 0.78 ± 0.13, recall = 0.84 ± 0.07, and F1 = 0.80 ± 0.09.ConclusionsAlthough the autism group displayed notable differences in reflexive joint attention and left visual field bias, the dwell time on eyes was not significantly different. Nevertheless, the machine algorithm model trained on these data proved effective at diagnosing ASD, showing the potential of these biomarkers. Our study shows promising results and opens up potential for further exploration in this under-researched geographical context.

Self-reported eye contact sensitivity and face processing in chromosome 22q11.2 deletion syndrome

ABSTRACT Introduction 22q11.2 deletion syndrome (22qDS) has been associated with varying levels of social impairments, and with atypical visual scanning of faces. The present study explored whether self-reported sensitivity to eye contact might be related to these phenomena. Method Individuals with confirmed 22qDS were interviewed about their experience and possible discomfort with eye contact. In cases where individuals expresesed discomfort, they were subsequently asked about coping mechanisms used to deal with this discomfort. In addition to self-reported eye contact discomfort, gaze to emotional faces was examined using eye tracking. Results In the subgroup of individuals who reported discomfort during eye contact, eye tracking results revealed a lower amount of gaze in the eyes of neutral faces, as well as the absence of the typical left visual field (LVF) bias, indicative of alterations in hemispheric lateralization. This subgroup also scored lower on a measure of everyday functioning. Conclusions Our results show that, by simply asking individuals with this social and communicative disorder about eye gaze discomfort, we may better understand the specific challenges that they experience. Moreover, information gained from such first-person reports together with eye-tracking measures further informs about the integrity of their face processing system, as well as about the nature and degree of impairment in this population.

Left visual field bias during face perception aligns with individual differences in reading skills and is absent in dyslexia.

When looking at faces, we tend to attend more to the left visual field (corresponding to the right side of the person's face). This phenomenon is called the left visual field bias (LVF) and is presumed to reflect the brain's right-sided dominance for face processing. Whether alterations in hemispheric dominance are present in dyslexia, and are linked with individual differences in word reading development more generally, is still unclear, and no prior research has utilized gaze-based LVF bias to explore these topics. The aim of the study was to examine whether the LVF bias differs in dyslexia and to examine the association with word-reading skills assessed dimensionally. Forty-six 9-13 year-old children with dyslexia and community control children, matched on age and listening comprehension. Participants were presented with a recorded face on a screen while their gaze patterns were collected with an eye tracker. Fixations to the left versus the right side of the face stimuli were compared. Results showed a clear LVF bias in community controls, while no such bias was seen in the dyslexic group. Moreover, the strength of the LVF bias was correlated with better word reading in the controls. Our results suggest a link between weakened hemispheric dominance for face processing in dyslexia and in poor word reading, at least to the extent that the LVF bias actually mirrors underlying physiology. We discuss the implications of these novel findings, highlighting the need for future research to determine the specificity and developmental sources of LVF bias alterations.

Top-down control of the left visual field bias in cued visual spatial attention.

A left visual field (LVF) bias in perceptual judgments, response speed, and discrimination accuracy has been reported in humans. Cognitive factors, such as visual spatial attention, are known to modulate or even eliminate this bias. We investigated this problem by recording pupillometry together with functional magnetic resonance imaging (fMRI) in a cued visual spatial attention task. We observed that (i) the pupil was significantly more dilated following attend-right than attend-left cues, (ii) the task performance (e.g. reaction time [RT]) did not differ between attend-left and attend-right trials, and (iii) the difference in cue-related pupil dilation between attend-left and attend-right trials was inversely related to the corresponding difference in RT. Neuroscientically, correlating the difference in cue-related pupil dilation with the corresponding cue-related fMRI difference yielded activations primarily in the right hemisphere, including the right intraparietal sulcus and the right ventrolateral prefrontal cortex. These results suggest that (i) there is an asymmetry in visual spatial attention control, with the rightward attention control being more effortful than the leftward attention control, (ii) this asymmetry underlies the reduction or the elimination of the LVF bias, and (iii) the components of the attentional control networks in the right hemisphere are likely part of the neural substrate of the observed asymmetry in attentional control.

Clutter Substantially Reduces Selectivity for Peripheral Faces in the Macaque Brain.

According to a prominent view in neuroscience, visual stimuli are coded by discrete cortical networks that respond preferentially to specific categories, such as faces or objects. However, it remains unclear how these category-selective networks respond when viewing conditions are cluttered, i.e., when there is more than one stimulus in the visual field. Here, we asked three questions: (1) Does clutter reduce the response and selectivity for faces as a function of retinal location? (2) Is the preferential response to faces uniform across the visual field? And (3) Does the ventral visual pathway encode information about the location of cluttered faces? We used fMRI to measure the response of the face-selective network in awake, fixating macaques (two female, five male). Across a series of four experiments, we manipulated the presence and absence of clutter, as well as the location of the faces relative to the fovea. We found that clutter reduces the response to peripheral faces. When presented in isolation, without clutter, the selectivity for faces is fairly uniform across the visual field, but, when clutter is present, there is a marked decrease in the selectivity for peripheral faces. We also found no evidence of a contralateral visual field bias when faces were presented in clutter. Nonetheless, multivariate analyses revealed that the location of cluttered faces could be decoded from the multivoxel response of the face-selective network. Collectively, these findings demonstrate that clutter blunts the selectivity of the face-selective network to peripheral faces, although information about their retinal location is retained.SIGNIFICANCE STATEMENT Numerous studies that have measured brain activity in macaques have found visual regions that respond preferentially to faces. Although these regions are thought to be essential for social behavior, their responses have typically been measured while faces were presented in isolation, a situation atypical of the real world. How do these regions respond when faces are presented with other stimuli? We report that, when clutter is present, the preferential response to foveated faces is spared but preferential response to peripheral faces is reduced. Our results indicate that the presence of clutter changes the response of the face-selective network.

Measuring the response to visually presented faces in the human lateral prefrontal cortex.

Neuroimaging studies identify multiple face-selective areas in the human brain. In the current study, we compared the functional response of the face area in the lateral prefrontal cortex to that of other face-selective areas. In Experiment 1, participants (n = 32) were scanned viewing videos containing faces, bodies, scenes, objects, and scrambled objects. We identified a face-selective area in the right inferior frontal gyrus (rIFG). In Experiment 2, participants (n = 24) viewed the same videos or static images. Results showed that the rIFG, right posterior superior temporal sulcus (rpSTS), and right occipital face area (rOFA) exhibited a greater response to moving than static faces. In Experiment 3, participants (n = 18) viewed face videos in the contralateral and ipsilateral visual fields. Results showed that the rIFG and rpSTS showed no visual field bias, while the rOFA and right fusiform face area (rFFA) showed a contralateral bias. These experiments suggest two conclusions; firstly, in all three experiments, the face area in the IFG was not as reliably identified as face areas in the occipitotemporal cortex. Secondly, the similarity of the response profiles in the IFG and pSTS suggests the areas may perform similar cognitive functions, a conclusion consistent with prior neuroanatomical and functional connectivity evidence.

Development of upper visual field bias for faces in infants.

The spatial location of the face and body seen in daily life influences human perception and recognition. This contextual effect of spatial locations suggests that daily experience affects how humans visually process the face and body. However, it remains unclear whether this effect is caused by experience, or innate neural pathways. To address this issue, we examined the development of visual field asymmetry for face processing, in which faces in the upper visual field were processed preferentially compared to the lower visual field. We found that a developmental change occurred between 6 and 7 months. Older infants aged 7-8 months showed bias toward faces in the upper visual field, similar to adults, but younger infants of 5-6 months showed no such visual field bias. Furthermore, older infants preferentially memorized faces in the upper visual field, rather than in the lower visual field. These results suggest that visual field asymmetry is acquired through development, and might be caused by the learning of spatial location in daily experience.

Social gaze in preterm infants may act as an early indicator of atypical lateralization.

Visual field biases have been identified as markers of atypical lateralization in children with developmental conditions, but this is the first investigation to consider early lateralized gaze behaviors for social stimuli in preterm infants. Eye‐tracking methods with 51 preterm (33 male, 92.1% White) and 61 term‐born (31 male, 90.1% White) infants aged 8–10 months from Edinburgh, UK, captured the development of visual field biases, comparing gaze behavior to social and non‐social stimuli on the left versus right of the screen. Preterm infants showed a significantly reduced interest to social stimuli on the left versus right compared to term children (d = .58). Preterm children exhibit early differential orienting preferences that may be an early indicator of atypical lateralized function.

Data-driven analysis of gaze patterns in face perception: Methodological and clinical contributions

Gaze patterns during face perception have been shown to relate to psychiatric symptoms. Standard analysis of gaze behavior includes calculating fixations within arbitrarily predetermined areas of interest. In contrast to this approach, we present an objective, data-driven method for the analysis of gaze patterns and their relation to diagnostic test scores. This method was applied to data acquired in an adult sample (N = 111) of psychiatry outpatients while they freely looked at images of human faces. Dimensional symptom scores of autism, attention deficit, and depression were collected. A linear regression model based on Principal Component Analysis coefficients computed for each participant was used to model symptom scores. We found that specific components of gaze patterns predicted autistic traits as well as depression symptoms. Gaze patterns shifted away from the eyes with increasing autism traits, a well-known effect. Additionally, the model revealed a lateralization component, with a reduction of the left visual field bias increasing with both autistic traits and depression symptoms independently. Taken together, our model provides a data-driven alternative for gaze data analysis, which can be applied to dimensionally-, rather than categorically-defined clinical subgroups within a variety of contexts. Methodological and clinical contribution of this approach are discussed.

Upper visual field bias for face detection in infants

Upper visual field bias for face detection in infants

Self-motion cues in the natural habitats of zebrafish support lower visual field bias

Self-motion cues in the natural habitats of zebrafish support lower visual field bias

Does face-selective cortex show a left visual field bias for centrally-viewed faces?

The left half of a centrally-viewed face contributes more strongly to recognition performance than the right. This left visual field (LVF) advantage is typically attributed to an untested assumption that face-selective cortex in the right hemisphere (RH) exhibits a contralateral bias, even for centrally-viewed faces. We tested the validity of this assumption using a behavioral measure of the LVF advantage and an fMRI experiment that measured laterality of face-selective cortex and neural contralateral bias. In the behavioral experiment, participants performed a chimeric face-matching task (Harrison and Strother, 2019). In the fMRI experiment, participants viewed chimeric faces comprised of face halves that either repeated or changed simultaneously in both hemifields, or repeated in one hemifield and changed in the other. This enabled us to measure lateralization of fMRI face-repetition suppression and hemifield-specific half-face sensitivity in face-selective cortex. We found that LVF bias in the fusiform face area (FFA) and right-lateralization of the FFA for changing versus repeated faces were both positively correlated with a behavioral measure of the LVF advantage for upright (but not inverted) faces. Results from regression analyses showed that LVF bias in the right FFA and FFA laterality make separable contributions to the prediction of our behavioral measure of the LVF bias for upright faces. Our results confirm a ubiquitous but previously untested assumption that RH superiority combined with contralateral bias in face-selective cortex explains the LVF advantage in face recognition. Specifically, our results show that neural LVF bias in the right FFA is sufficient to explain the relationship between FFA laterality and the perceptual LVF bias for centrally-viewed faces.

Reduced left visual field bias for faces in adolescents with social anxiety disorder

ABSTRACT Introduction: Individuals tend to explore the left side of a face first and for a longer time in comparison to the right side. This left visual field (LVF) bias is suggested to reflect right hemispheric dominance for face processing. Social anxiety disorder (SAD) is associated with maladaptive interpretations of facial expressions, but it is not known whether this is linked to an atypical LVF bias. Previous studies have reported a reduced LVF bias in autism, a condition overlapping with SAD. This pre-registered study examined the LVF bias in adolescents with SAD. Methods: Eye-tracking was used to investigate the ratio of first fixations to the left on upright and inverted face stimuli in 26 adolescents (13-17 years) with SAD and 23 healthy controls primed to look either between the eyes or at the mouth. Results: The SAD group showed a smaller LVF bias and an atypical face inversion effect when primed to look at the eyes. Autistic traits predicted a smaller LVF bias, independently of social anxiety level. Conclusions: Results suggest that SAD is associated with impaired processing of faces at an early stage of visual scanning. The findings contribute to a better understanding of SAD and its overlap with autism.

Motor resonance in monkey parietal and premotor cortex during action observation: Influence of viewing perspective and effector identity

Observing others performing motor acts like grasping has been shown to elicit neural responses in the observer`s parieto-frontal motor network, which typically becomes active when the observer would perform these actions him/herself. While some human studies suggested strongest motor resonance during observation of first person or egocentric perspectives compared to third person or allocentric perspectives, other research either report the opposite or did not find any viewpoint-related preferences in parieto-premotor cortices. Furthermore, it has been suggested that these motor resonance effects are lateralized in the parietal cortex depending on the viewpoint and identity of the observed effector (left vs right hand). Other studies, however, do not find such straightforward hand identity dependent motor resonance effects. In addition to these conflicting findings in human studies, to date, little is known about the modulatory role of viewing perspective and effector identity (left or right hand) on motor resonance effects in monkey parieto-premotor cortices. Here, we investigated the extent to which different viewpoints of observed conspecific hand actions yield motor resonance in rhesus monkeys using fMRI. Observing first person, lateral and third person viewpoints of conspecific hand actions yielded significant activations throughout the so-called action observation network, including STS, parietal and frontal cortices. Although region-of-interest analysis of parietal and premotor motor/mirror neuron regions AIP, PFG and F5, showed robust responses in these regions during action observation in general, a clear preference for egocentric or allocentric perspectives was not evident. Moreover, except for lateralized effects due to visual field biases, motor resonance in the monkey brain during grasping observation did not reflect hand identity dependent coding.

Investigating face and house discrimination at foveal to parafoveal locations reveals category-specific characteristics

Since perceptual and neural face sensitivity is associated with a foveal bias, and neural place sensitivity is associated with a peripheral bias (integration over space), we hypothesized that face perception ability will decline more with eccentricity than place perception ability. We also wanted to examine whether face perception ability would show a left visual field (LeVF) bias due to earlier reports suggesting right hemisphere dominance for faces, or would show an upper or lower visual field bias. Participants performed foveal and parafoveal face and house discrimination tasks for upright or inverted stimuli (≤4°) while their eye movements were monitored. Low-level visual tasks were also measured. The eccentricity-related accuracy reductions were evident for all categories. Through detailed analyses we found (i) a robust face inversion effect across the parafovea, while for houses an opposite effect was found, (ii) higher eccentricity-related sensitivity for face performance than for house performance (via inverted vs. upright within-category eccentricity-driven reductions), (iii) within-category but not across-category performance associations across eccentricities, and (iv) no hemifield biases. Our central to parafoveal investigations suggest that high-level vision processing may be reflected in behavioural performance.

Lateralization of facial emotion processing and facial paresis in Vestibular Schwannoma patients.

ObjectiveThis study investigates whether there exist differences in lateralization of facial emotion processing in patients suffering from Vestibular Schwannoma (VS) based on the presence of a facial paresis and their degree of facial functioning as measured by the House Brackmann Grading scale (HBG).MethodsForty‐four VS patients, half of them with a facial paresis and half of them without a facial paresis, rated how emotive they considered images of faces showing emotion in the left versus right visual field. Stimuli consisted of faces with a neutral half and an emotional (happy or angry) half. The study had a mixed design with emotional expression (happy vs. angry) and emotional half (left vs. right visual field) of the faces as repeated measures, and facial paresis (present vs. absent) and HBG as between subjects’ factors. The visual field bias was the main dependent variable.ResultsIn line with typical findings in the normal population, a left visual field bias showed in the current sample: patients judged emotional expressions shown in the left visual field as more emotive than those shown in the right visual field. No differences in visual field bias showed based on the presence of a facial paresis nor based on patients’ HBG.ConclusionVS patients show a left visual field bias when processing facial emotion. No differences in lateralization showed based on the presence of a facial paresis or on patients’ HBG. Based on this study, facial paresis thus does not affect the lateralization of facial emotion processing in patients with VS.

Parallel Channels for Motion Feature Extraction in the Pretectum and Tectum of Larval Zebrafish

Non-cortical visual areas in vertebrate brains extract relevant stimulus features, such as motion, object size, and location, to support diverse behavioral tasks. The optic tectum and pretectum, two primary visual areas in zebrafish, are involved in motion processing, and yet their differential neural representation of behaviorally relevant visual features is unclear. Here, we characterize receptive fields (RFs) of motion-sensitive neurons in the diencephalon and midbrain. We show that RFs of many pretectal neurons are large and sample the lower visual field, whereas RFs of tectal neurons are mostly small-size selective and sample the upper nasal visual field more densely. Furthermore, optomotor swimming can reliably be evoked by presenting forward motion in the lower temporal visual field alone, matching the lower visual field bias of the pretectum. Thus, tectum and pretectum extract different visual features from distinct regions of visual space, which is likely a result of their adaptations to hunting and optomotor behavior, respectively.

Lateralization of facial emotion processing and facial mimicry

ABSTRACT The two halves of the brain are believed to play different roles in emotional processing. In studies involving chimeric faces, emotional expressions in the left visual field are more strongly perceived as emotional than those in the right visual field. Notably, the role of facial mimicry has not been studied in relation to hemispheric lateralization. In the current study, which used a novel stimulus set of chimeric faces, we proposed and found that emotional intensity judgments replicate the left visual field bias for facial expressions of emotions. While a general facial mimicry effect to the chimeric faces occurred for the corrugator muscle, these mimicry effects were not related to the visual field bias. The results suggest that encoding the emotionality of another person’s facial expression might occur independent from the mere mimicry of the facial expression itself.

Cue-evoked pupillary response reveals a left visual field bias in covert spatial visual attention

Cue-evoked pupillary response reveals a left visual field bias in covert spatial visual attention