David Framorando

Naso-temporal asymmetries: suppression of emotional faces in the temporal visual hemifield

An ongoing debate exists regarding the possible existence of a retino-tectal visual pathway projecting to the amygdala, which would rapidly process information involving threatening or behaviorally-relevant stimuli. It has been suggested that this route might be responsible for the involuntary capture of attention by potentially dangerous stimuli. In separate studies, anatomical evidence has suggested that the retino-tectal pathway relies essentially on projections from the nasal hemiretina (temporal visual field). In this study, we chose to take advantage of this anatomical difference to further investigate whether emotional facial expressions are indeed processed through a subcortical pathway. Using EEG, participants performed a monocular spatial attention paradigm in which lateralized, task-irrelevant distractors were presented, followed by a target. The distractors were fearful faces that appeared either in nasal or temporal visual hemifield (by virtue of their monocular presentations), while the neutral face was presented simultaneously on the opposite side. Participants were asked to identify a target letter that appeared subsequently in the nasal or temporal visual hemifield. Event-related potentials (ERPs) results revealed that fearful faces appearing in the temporal visual hemifield produced a strong inhibitory response, while a negative deflection reflecting attentional capture followed presentations of fear in the nasal hemifield. These effects can be explained by a greater sensitivity of the subcortical pathway for emotional stimuli. Fearful faces conveyed through this route are processed more effectively, consequently necessitating more vigorous suppression in order for targets to be dealt with adequately.

Straight gaze facilitates face processing but does not cause involuntary attentional capture

ABSTRACT This study aimed to investigate the conditions under which eyes with a straight gaze capture attention more than eyes with an averted gaze, a phenomenon called the stare-in-the-crowd effect. In Experiment 1, we measured attentional capture by distractor faces with either straight or averted gaze that were shown among faces with closed eyes. Gaze direction of the distractor face was irrelevant because participants searched for a tilted face and indicated its gender. The presence of the distractor face with open eyes resulted in slower reaction times, but gaze direction had no effect, suggesting that straight gaze does not result in more involuntary attentional capture than averted gaze. In three further experiments with the same stimuli, the gaze direction of the target, and not the distractor, was varied. Better performance with straight than averted gaze of the target face was observed when the gaze direction or gender of the target face had to be discriminated. However, no difference between straight and averted was observed when only the presence of a face with open eyes had to be detected. Thus, the stare-in-the crowd effect is only observed when eye gaze is selected as part of the target and only when features of the face have to be discriminated. Our findings suggest that preference for straight gaze bears on target-related processes rather than on attentional capture per se.

What are the barriers to access to mental healthcare and the primary needs of asylum seekers? A survey of mental health caregivers and primary care workers

BackgroundWe aimed to assess the opinion of primary care workers, social workers, translators and mental health caregivers who work with asylum seekers about the latter’s unmet needs and barriers to access to mental healthcare.MethodsWe used a Likert scale to assess the opinion of 135 primary care workers (general practitioners, nurses, social workers and translators) and mental health caregivers about the proportion of asylum seekers with psychiatric disorders, their priority needs and their main barriers to mental health services.ResultsInsufficient access to adequate financial resources, poor housing and security conditions, access to employment, professional training and legal aid were considered as priority needs, as were access to dental and mental healthcare. The main barriers to access to mental healthcare for asylum seekers included a negative representation of psychiatry, fear of being stigmatized by their own community and poor information about existing psychiatric services.ConclusionsWe found a good correlation between the needs reported by healthcare providers and those expressed by the asylum-seeking population in different studies. We discuss the need for greater mobility and accessibility to psychiatric services among this population.

ERP responses greater for faces in the temporal compared to the nasal visual field

The distribution of retino-tectal projections is dissimilar depending on whether the receptors are situated in the nasal and temporal visual hemiretinas. Indeed, it has been claimed that the superior colliculus receives a greater proportion of its input from the temporal visual hemifield (nasal hemi-retina) relative to the nasal hemifield (temporal hemi-retina). In order to investigate whether these subcortical projections influence face processing, we investigated the early cortical ERP responses to faces and houses presented in the temporal and nasal retinas using monocular viewing. Neutral or fearful faces were presented concurrently with houses on either side of a central fixation cross, while participants were asked to discriminate changes in luminance at the center. Results showed that the lateralized N170, computed as the contralateral-ipsilateral electrode difference, was greater for faces appearing in the nasal relative to the temporal visual hemifield. This was due to a greater ipsilateral N170 for temporal relative to nasal presentations. By contrast, no difference was found across emotional expressions. The enhanced ERP response to faces appearing in the temporal visual field, suggests that the retinotectal pathway modulates cortical processing, most likely through activation of a colliculo-pulvino-amygdalar pathway, with subsequent back-projections from the amygdala to visual cortical regions. However, unattended facial expressions do not seem to modulate the response, at least at these angles of eccentricity.

Waist-to-hip ratio affects female body attractiveness and modulates early brain responses

This investigation examined the electrophysiological response underlying the visual processing of waist‐to‐hip ratio (WHR) in female bodies, a characteristic known to affect perceived attractiveness. WHRs of female bodies were artificially adjusted to values of 0.6, 0.7, 0.8 or 0.9. Behavioural ratings of attractiveness of the bodies revealed a preference for WHRs of 0.7 in the overall group of participants, which included both male and female heterosexual individuals. Event‐related potentials (ERPs) were then recorded while participants performed a selective attention task involving photographs of female models and scrambled images. Results showed that the P1 (80–120 ms) and N1 (130–170 ms) components situated over posterior brain regions were the earliest components to be modulated by attention and bodies. Interestingly, the vertex‐positive potential, occurring between 120–180 ms, produced a greater positivity for WHRs of 0.7 compared to the other ratios. However, this increase was only observed when the body stimuli were attended, while no effect was observed for unattended bodies. These findings provide evidence of an early brain sensitivity to visual attributes that constitute secondary sexual characteristics. Although they are relatively discrete from the point of view of their physical quality, these signs possess strong behavioural significance, producing greater reported attractiveness, likely by conveying the biological meaning that signals good health and greater reproductive success. Our results therefore reveal that attributes associated with sexual attractiveness in female bodies are processed rapidly in the stream of visual processing.

Early and late cortical responses to directly gazing faces are task dependent

Gender categorisation of human faces is facilitated when gaze is directed toward the observer (i.e., a direct gaze), compared with situations where gaze is averted or the eyes are closed (Macrae, Hood, Milne, Rowe, & Mason, Psychological Science, 13(5), 460–464, 2002). However, the temporal dynamics underlying this phenomenon remain to some extent unknown. Here, we used electroencephalography (EEG) to assess the neural correlates of this effect, focusing on the event-related potential (ERP) components known to be sensitive to gaze perception (i.e., P1, N170, and P3b). We first replicated the seminal findings of Macrae et al. (2002, Experiment 1) regarding facilitated gender discrimination, and subsequently measured the underlying neural responses. Our data revealed an early preferential processing of direct gaze as compared with averted gaze and closed eyes at the P1, which reverberated at the P3b (Experiment 2). Critically, using the same material, we failed to reproduce these effects when gender categorisation was not required (Experiment 3). Taken together, our data confirm that direct gaze enhances the early P1, as well as later cortical responses to face processing, although the effect appears to be task dependent.

Face processing is enhanced in the left and upper visual hemi-fields

ABSTRACT We tested whether two known hemi-field asymmetries would affect visual search with face stimuli. Holistic processing of spatial configurations is better in the left hemi-field, reflecting a right hemisphere specialization, and object recognition is better in the upper visual field, reflecting stronger projections into the ventral stream. Faces tap into holistic processing and object recognition at the same time, which predicts better performance in the left and upper hemi-field, respectively. In the first experiment, participants had to detect a face with a gaze direction different from the remaining faces. Participants were faster to respond when targets were presented in the left and upper hemi-field. The same pattern of results was observed when only the eye region was presented. In the second experiment, we turned the faces upside-down, which eliminated the typical spatial configuration of faces. The left hemi-field advantage disappeared, showing that it is related to holistic processing of faces, whereas the upper hemi-field advantage related to object recognition persisted. Finally, we made the search task easier by asking observers to search for a face with open among closed eyes or vice versa. The easy search task eliminated the need for complex object recognition and, accordingly, the advantage of the upper visual field disappeared. Similarly, the left hemi-field advantage was attenuated. In sum, our findings show that both horizontal and vertical asymmetries affect the search for faces and can be selectively suppressed by changing characteristics of the stimuli.

Determinants of Suicidality and of Treatment Modalities in a Community Psychiatry Sample of Asylum Seekers

Abstract A high prevalence of mental illness has been reported in asylum seekers. The present cross-sectional study examined suicidal thoughts, treatment modalities (outpatient crisis intervention, inpatient care), and their determinants in asylum seekers (n = 119) and permanent residents (n = 120) attending the same outpatient clinic in Geneva, Switzerland. The most frequent diagnoses were depressive disorders (64.7%) and posttraumatic stress disorder (34.5%) in asylum seekers and psychotic (55.0%) and depressive disorders (33.3%) in permanent residents. The frequency of suicidal thoughts was similar in both groups (>30%). Asylum seekers benefited from outpatient crisis intervention more frequently than residents did (26.9% vs. 5.8%), whereas inpatient care was less frequent (25.2% vs. 44.2%). In asylum seekers, acute suicidal thoughts were associated with increased frequency of outpatient crisis interventions, and, suicidal thoughts, psychosis, or personality disorders were associated with higher rates of hospitalization. Documenting clinical characteristics and service utilization of asylum seekers is a prerequisite to organizing targeted interventions.