Facial comparison behaviour of forensic facial examiners

Facial examiners make visual comparisons of face images to establish the identities of persons in police investigations. This study utilised eye-tracking and an individual differences approach to investigate whether these experts exhibit specialist viewing behaviours during identification, by comparing facial examiners with forensic fingerprint analysts and untrained novices across three tasks. These comprised of face matching under unlimited (Experiment 1) and time-restricted viewing (Experiment 2), and with a feature-comparison protocol derived from examiner casework procedures (Experiment 3). Facial examiners exhibited individual differences in facial comparison accuracy and did not consistently outperform fingerprint analysts and novices. Their behaviour was also marked by similarities to the comparison groups in terms of how faces were viewed, as evidenced from eye movements, and how faces were perceived, based on the made feature judgements and identification decisions. These findings further understanding of how facial comparisons are performed and clarify the nature of examiner expertise.     

The Role of Emotional Content and Perceptual Saliency During the Programming of Saccades Toward Faces

Previous studies have shown that the human visual system can detect a face and elicit a saccadic eye movement toward it very efficiently compared to other categories of visual stimuli. In the first experiment, we tested the influence of facial expressions on fast face detection using a saccadic choice task. Face-vehicle pairs were simultaneously presented and participants were asked to saccade toward the target (the face or the vehicle). We observed that saccades toward faces were initiated faster, and more often in the correct direction, than saccades toward vehicles, regardless of the facial expressions (happy, fearful, or neutral). We also observed that saccade endpoints on face images were lower when the face was happy and higher when it was neutral. In the second experiment, we explicitly tested the detection of facial expressions. We used a saccadic choice task with emotional-neutral pairs of faces and participants were asked to saccade toward the emotional (happy or fearful) or the neutral face. Participants were faster when they were asked to saccade toward the emotional face. They also made fewer errors, especially when the emotional face was happy. Using computational modeling, we showed that this happy face advantage can, at least partly, be explained by perceptual factors. Also, saccade endpoints were lower when the target was happy than when it was fearful. Overall, we suggest that there is no automatic prioritization of emotional faces, at least for saccades with short latencies, but that salient local face features can automatically attract attention.     

Horizontal eye movements foster approach to negative pictures but do not change emotional valence: A dopaminergic regulation hypothesis

A new dopaminergic regulation hypothesis is proposed based on two experiments exploring eye-movement effects. In the Eye Movement Desensitization and Reprocessing (EMDR) and Saccade-Induced Retrieval Enhancement (SIRE) domains, eye-movement mechanisms are mainly studied with explicit measures. Here implicit and explicit measures of emotion and memory for positive and negative pictures were investigated after eye movements or fixation in extreme right-handers. Eye movements enhanced explicit recognition predominantly for negative pictures. The absence of implicit repetition priming in both experiments supported a dissociation between implicit and explicit memory. Motivational eye-movement effects emerged but implicit and explicit affect remained unchanged. Experiment 2 revealed, after initial freezing to negative pictures, an acceleration, particularly of approach responses. Eye movements are postulated to foster approach towards negative memories, and promote, though dopaminergic pathways from the Superior Colliculus, enhanced explicit memory and active emotion regulation, primarily in persons with a collateralization of eye and dopamine dominance.     

Automatic gaze to the nose region cannot be inhibited during observation of facial expression in Eastern observers

Humans can extract a great deal of information about others very quickly. This is partly because the face automatically captures observers’ attention. Specifically, the eyes can attract overt attention. Although it has been reported that not only the eyes but also the nose can capture initial oculomotor movement in Eastern observers, its generalizability remains unknown. In this study, we applied the “don’t look” paradigm wherein participants are asked not to fixate on a specific facial region (i.e., eyes, nose, and mouth) during an emotion recognition task with upright (Experiment 1) and inverted (Experiment 2) faces. In both experiments, we found that participants were less able to inhibit the initial part of their fixations to the nose, which can be interpreted as the nose automatically capturing attention. Along with previous studies, our overt attention tends to be attracted by a part of the face, which is the nose region in Easterner observers.     

Collective memories,emotions, and spatial tactics in social movements: The case of the Umbrella Movement in Hong Kong

Recent studies have increasingly acknowledged the dynamic relationship between emotions and space in social movements. They, however, have seldom tied emotions and space to time when discussing activists’ emotions and their tactical choices. This paper studies the 2014 Umbrella Movement in Hong Kong and explores how collective memory and generational experiences—two intertwined notions of time—shaped how activists felt and how they designed and deployed a spatial tactic. The Umbrella Movement was characterized by miscellaneous emotions and intense disputes among activists regarding how to best use spatial occupation to fight for democratization before and during the struggle. Using a qualitative dataset that contains textual and interview data, I argue that while emotions and the political-cultural characteristics of contentious space were two factors in informing tactical choices, collective memory and generational experiences were key to understanding the rise of the movement and its characteristics. Experiencing different political events in their years of early adulthood, young and veteran activists felt differently in the context of 2013–2014, which led them to embrace disjunctive views on the pace, sequence, and bodily action for the same tactic of spatial occupation and dissimilar emotional management strategies. This created ongoing internal clashes before and during the movement.     

Rank order in pairs of communally nursing female mice (Mus musculus domesticus) and Maternal Aggression Towards Conspecific Intruders of Differing Sex

This study examined social behavior between pairs of unfamiliar lactating females, with litters of the same age, at different periods after parturition (3, 7, and 17 days). Tests were generally followed by the formation of communal rearing nests, and subsequent maternal attack on intruders of differing sex was assessed. In all three intervals lactating females showed ritualized attack with formation of clear dominance-subordination relationships before combining litters into communal nests. The dominant females in 90% of cases started to retrieve alien pups into their nests. Agonistic behavior and communal nest formation were most rapid when pups were around 3 days old. Maternal attack on conspecific intruders was mainly displayed by the dominant lactating females. Male and female intruders were equally attacked (in terms of frequency and intensity of attack), but there was less such aggression when pups were around 17 days of age. Nevertheless the topography of biting attack employed against female and male conspecific intruders was different. Females were attacked using a strategy avoiding bites to the head and ventral surface (indicative of “offensive” behavior) whereas males were severely bitten on vulnerable body regions (indicative of “defensive” behavior).     

Effects of ritanserin on offense and defense in male mice

Effects of ritanserin on agonistic behavior of isolated mice exhibiting aggressive or nonaggressive behavioral strategies were studied in pair-wise encounters with group-housed opponents. An ethological approach to behavioral scoring is adopted, which allows for examination of the profiles of individual subjects. Although the data generally support the view that ritanser in has little effect on offense or defense in male mice, the stimulation of pre-aggressive behavior (threats, alerts, tail rattles) was detected in some nonaggressive mice. © 1995 Wiley-Liss, Inc.     

Defensive reactions of “wild-type” and “Domesticated” wild rats to approach and contact by a threat stimulus

Selective breeding of wild rats over many generations on the basis of low or high defensive threat and attack to human approach and contact has produced highly polarized “domesticated” and “wild-type” animals. Because the selection procedure selectively involves these two defense patterns, and these clearly differ in the two groups, it is of interest to determine if other, nonselected, defensive behaviors to threat stimuli also change. “Domesticated” and “wild-type” rats of the thirty-fifth generation were run in a fear defense test battery (F/DTB) to systematically evaluate defensive behaviors to a variety of present threat stimuli. “Domesticated” rats showed reduced avoidance and slower flight speed to an approaching experimenter, reduced jump/startle response to handelap and dorsal contact, less vocalization and boxing to vibrissae stimulation or to an anesthetized conspecific, and reduced defensiveness to an attempted pickup by the experimenter. These results indicate that selective bi-directional breeding for defensive threat and attack to human approach and contact produces group differences in a variety of defensive behaviors, and in defensiveness to stimuli other than those on which the selection was based. © 1994 Wiley-Liss, Inc.     

The ventromedial hypothalamus and aggressive behaviour in rats

Male rats were given bilateral lesions in either the anterior or posterior ventromedial hypothalamus (VMH). The intermale aggressive behaviour of these animals within their own territory was observed before and after the surgical procedure and compared with the behaviour of sham-operated animals. The effects of anterior VMH lesions include an increased tendency to respond with frontal threatening upon approach of a conspecific male. This behaviour closely resembles the aggressive responses described in “shock-induced aggression” tests. Posterior VMH lesions facilitate territorial aggressive behaviour characterized by approaching the opponent followed by lateral threatening and fighting. It is suggested that 2 distinct neural substrates exist, which serve to inhibit defensive (anterior-VMH) and offensive (posterior-VMH) intermale aggression, respectively.