Spared ability to recognise fear from static and moving whole-body cues following bilateral amygdala damage

Bilateral amygdala lesions impair the ability to identify certain emotions, especially fear, from facial expressions, and neuroimaging studies have demonstrated differential amygdala activation as a function of the emotional expression of faces, even under conditions of subliminal presentation, and again especially for fear. Yet the amygdala's role in processing emotion from other classes of stimuli remains poorly understood. On the basis of its known connectivity as well as prior studies in humans and animals, we hypothesised that the amygdala would be important also for the recognition of fear from body expressions. To test this hypothesis, we assessed a patient (S.M.) with complete bilateral amygdala lesions who is known to be severely impaired at recognising fear from faces. S.M. completed a battery of tasks involving forced-choice labelling and rating of the emotions in two sets of dynamic body movement stimuli, as well as in a set of static body postures. Unexpectedly, S.M.'s performance was completely normal. We replicated the finding in a second rare subject with bilateral lesions entirely confined to the amygdala. Compared to healthy comparison subjects, neither of the amygdala lesion subjects was impaired in identifying fear from any of these displays. Thus, whatever the role of the amygdala in processing whole-body fear cues, it is apparently not necessary for the normal recognition of fear from either static or dynamic body expressions.     

Brief Report: Imitation of Meaningless Gestures in Individuals with Asperger Syndrome and High-functioning Autism

Nineteen people with Asperger syndrome (AS)/High-Functioning Autism (HFA) (ages 7–15) were tested on imitation of two types of meaningless gesture: hand postures and finger positions. The individuals with AS/HFA achieved lower scores in the imitation of both hand and finger positions relative to a matched neurotypical group. The between-group difference was primarily accounted for by performance on a test of visual motor integration, together with a hand imitation deficit which was specifically due to errors in body part orientation. Our findings implicate both visuomotor processes (Damasio and Maurer, 1978) and self-other mapping (Rogers and Pennington, 1991) in ASD imitation deficits. Following Goldenberg (1999), we propose that difficulties with body part orientation may underlie problems in meaningless gesture imitation.     

Limb apraxia in corticobasal syndrome

Corticobasal syndrome (CBS) is a progressive neurodegenerative disorder with asymmetric presentation and course characterized by degeneration of basal ganglia and cortical structures. Limb apraxia is a commonly observed deficit in CBS. Few studies have examined comprehensively the nature of deficits in limb apraxia. The goal of our study was to investigate the severity of deficits in various conceptual and gesture production task modalities. CBS patients were divided in two groups based on the side of brain that was initially affected by the disease. Ten patients with right hemisphere presentation (RHP) and seven with left hemisphere presentation (LHP) were included. The results showed that while selective conceptual tasks deficits were present in both groups, the overall picture suggests preserved conceptual representations of tools and actions in CBS patients with either LHP or RHP. Both groups were impaired relative to controls on gesture production tasks. Performance on transitive gestures was more severely affected in both groups than intransitive gestures. Imitation was more severely affected than pantomime, suggesting deficits in visuomotor transformations. The addition of verbal cuing during concurrent imitation affected only the LHP patients, rendering them more impaired relative to controls in their imitation with verbal cuing as opposed to their imitation only performance. Imitation of non-representational gestures was least accurate and intransitive gestures were most accurate. Patients were more severely impaired relative to controls when holding the object and when they were shown pictures of tools to pantomime.     

Gesture comprehension,knowledge and production in Alzheimer’s disease

Background and purpose: Although apraxia is a typical consequence of Alzheimer’s disease (AD), the profile of apraxic impairments is still subject to debate. Here, we analysed apraxia components in patients with AD with mild‐to‐moderate or moderately severe dementia. Methods: Thirty‐one patients were included. We first evaluated simple gestures, that is, the imitation of finger and hand configurations, symbolic gestures (recognition, production on verbal command and imitation), pantomimes (recognition, production on verbal command, imitation and production with the object), general knowledge and complex gestures (tool–object association, function–tool association, production of complex actions and knowledge about action sequences). Tests for dementia (Mini Mental State Examination and the Dementia Rating Scale), language disorders, visual agnosia and executive function were also administered. Results: Compared with controls, patients showed significant difficulties (P ≤ 0.01) in subtests relating to simple gestures (except for the recognition and imitation of symbolic gestures). General knowledge about tools, objects and action sequences was less severely impaired. Performance was frequently correlated with the severity of dementia. Multiple‐case analyses revealed that (i) the frequency of apraxia depended on the definition used, (ii) ideomotor apraxia was more frequent than ideational apraxia, (iii) conceptual difficulties were slightly more frequent than production difficulties in the early stage of AD and (iv) difficulties in gesture recognition were frequent (especially for pantomimes). Conclusion: Patients with AD can clearly show gesture apraxia from the mild–moderate stage of dementia onwards. Recognition and imitation disorders are relatively frequent (especially for pantomimes). We did not find conceptual difficulties to be the main problem in early‐stage AD.     

Who is a better teacher for children with autism? Comparison of learning outcomes between robot-based and human-based interventions in gestural production and recognition

BackgroundIndividuals with autism spectrum disorder (ASD) tend to show deficits in engaging with humans. Previous findings have shown that robot-based training improves the gestural recognition and production of children with ASD. It is not known whether social robots perform better than human therapists in teaching children with ASD.AimsThe present study aims to compare the learning outcomes in children with ASD and intellectual disabilities from robot-based intervention on gestural use to those from human-based intervention.Methods and proceduresChildren aged six to 12 with low-functioning autism were randomly assigned to the robot group (N = 12) and human group (N = 11). In both groups, human experimenters or social robots engaged in daily life conversations and demonstrated to children 14 intransitive gestures in a highly-structured and standardized intervention protocol.Outcomes and resultsChildren with ASD in the human group were as likely to recognize gestures and produce them accurately as those in the robot group in both training and new conversations. Their learning outcomes maintained for at least two weeks.Conclusions and implicationsThe social cues found in the human-based intervention might not influence gestural learning. It does not matter who serves as teaching agents when the lessons are highly structured.     

Early communicative skills of children with Klinefelter syndrome

Many studies reported the presence of language impairments in children and adolescents with Klinefelter syndrome (KS). However, the first stage of their language development has been scarcely studied. The present study aimed to describe the spontaneous communicative production of 18-month-old children with KS, in comparison with that of typically developing (TD) male peers, aiming to verify the existence of different early communicative skills in both vocal and gestural modality and to identify the presence of possible associations with their later vocabulary size.

Children with KS showed a lower competence in both lexical skills and emergent syntactic abilities than TD peers. No significant differences were found in gesture production. Considering the possibility of identifying an association between early communicative skills and later vocabulary size, the vocal production of TD children appeared to be significantly related to their later lexical skills; whereas, the number of gestures produced by children with KS appeared to be related to their later lexical abilities. The early detection of language risk factors will allow early intervention and careful monitoring of these children’s communicative development.     

Repetitive transcranial magnetic stimulation reveals a role for the left inferior parietal lobule in matching observed kinematics during imitation

Apraxia (a disorder of complex movement) suggests that the left inferior parietal lobule (IPL) plays a role in kinematic or spatial aspects of imitation, which may be particularly important for meaningless (i.e. unfamiliar intransitive) actions. Mirror neuron theories indicate that the IPL is part of a frontoparietal system that can support imitation by linking observed and stored actions through visuomotor matching, and have less to say about different subregions of the left IPL, or how different types of action (i.e. meaningful or meaningless) are processed for imitation. We used repetitive transcranial magnetic stimulation (rTMS) to bridge this gap and better understand the roles of the left supramarginal gyrus (SMG) and left angular gyrus (AG) in imitation. We also examined whether these areas are differentially involved in meaningful and meaningless action imitation. We applied rTMS over the left SMG, over the left AG or during a no‐rTMS baseline condition, and then asked participants to imitate a confederate's actions whilst the arm and hand movements of both individuals were motion‐tracked. rTMS over both the left SMG and the left AG reduced the velocity of participants’ finger movements relative to the actor during imitation of finger gestures, regardless of action meaning. Our results support recent claims in apraxia and confirm a role for the left IPL in kinematic processing during gesture imitation, regardless of action meaning.     

Visual phonetic processing localized using speech and nonspeech face gestures in video and point‐light displays

The talking face affords multiple types of information. To isolate cortical sites with responsibility for integrating linguistically relevant visual speech cues, speech and nonspeech face gestures were presented in natural video and point‐light displays during fMRI scanning at 3.0T. Participants with normal hearing viewed the stimuli and also viewed localizers for the fusiform face area (FFA), the lateral occipital complex (LOC), and the visual motion (V5/MT) regions of interest (ROIs). The FFA, the LOC, and V5/MT were significantly less activated for speech relative to nonspeech and control stimuli. Distinct activation of the posterior superior temporal sulcus and the adjacent middle temporal gyrus to speech, independent of media, was obtained in group analyses. Individual analyses showed that speech and nonspeech stimuli were associated with adjacent but different activations, with the speech activations more anterior. We suggest that the speech activation area is the temporal visual speech area (TVSA), and that it can be localized with the combination of stimuli used in this study. Hum Brain Mapp, 2010. © 2010 Wiley‐Liss, Inc.     

Symptoms after sport-related concussions alter gestural functions

ObjectivesSymptoms after sport-related concussions (SRC) are common. Because post-concussion symptoms are often not clearly visible, speech-accompanying gestures may help clinicians to gain additional information about the patient’s history and symptoms during medical consultation. We hypothesized that athletes with SRC and who suffered from persisting symptoms would display more gestures during concussion assessment protocols when compared to non-concussed athletes because of the athletes’ previous motor-sensory experiences made during the concussive event.DesignA retrospective cross-sectional study.MethodsThree matched groups of 40 (active) athletes were investigated in the context of concussion assessment (/and baseline) protocols: 14 symptomatic and 14 asymptomatic athletes with a SRC, and 12 non-concussed athletes. Certified raters using a standard analysis system for nonverbal behaviour analysed videotaped hand movements and gestures during a standardized concussion assessment protocol.ResultsSymptomatic athletes spent significantly more time with in space hand movements, i.e., movements that act in the body-external free space without touching anything and specifically, motion quality presentation gestures than non-concussed athletes.ConclusionsIncreased in space movements, which are functionally gestures, and specifically, motion quality presentation gestures in symptomatic athletes indicate that the more vivid sensory motor experience of the head trauma is reflected in more gestural expressions. Thus, hand movements and gestures differentiate athletes who suffer from post-concussion symptoms from non-concussed athletes indicating the athletes’ motor-sensory experiences of the event and its aftereffects. The present study highlights the fact that gestures can be employed as behavioural markers of symptoms after sport-related concussions.     

On the utility of 3D hand cursors to explore medical volume datasets with a touchless interface

Analyzing medical volume datasets requires interactive visualization so that users can extract anatomo-physiological information in real-time. Conventional volume rendering systems rely on 2D input devices, such as mice and keyboards, which are known to hamper 3D analysis as users often struggle to obtain the desired orientation that is only achieved after several attempts. In this paper, we address which 3D analysis tools are better performed with 3D hand cursors operating on a touchless interface comparatively to a 2D input devices running on a conventional WIMP interface. The main goals of this paper are to explore the capabilities of (simple) hand gestures to facilitate sterile manipulation of 3D medical data on a touchless interface, without resorting on wearables, and to evaluate the surgical feasibility of the proposed interface next to senior surgeons (N = 5) and interns (N = 2). To this end, we developed a touchless interface controlled via hand gestures and body postures to rapidly rotate and position medical volume images in three-dimensions, where each hand acts as an interactive 3D cursor. User studies were conducted with laypeople, while informal evaluation sessions were carried with senior surgeons, radiologists and professional biomedical engineers. Results demonstrate its usability as the proposed touchless interface improves spatial awareness and a more fluent interaction with the 3D volume than with traditional 2D input devices, as it requires lesser number of attempts to achieve the desired orientation by avoiding the composition of several cumulative rotations, which is typically necessary in WIMP interfaces. However, tasks requiring precision such as clipping plane visualization and tagging are best performed with mouse-based systems due to noise, incorrect gestures detection and problems in skeleton tracking that need to be addressed before tests in real medical environments might be performed.