Words Are More Than The Sum Of Their Parts: Evidence For Detrimental Effects Of Word-Level Information in Alexia

The effects of sequential letter presentation on reading were investigated with both normal readers and an alexic patient. Normal readers showed longer naming latencies when words were presented letter-by-letter than when all the letters were presented simultaneously. In contrast, naming latencies for the alexic reader were shorter when words were presented letter-by-letter (error rates did not differ for the patient and the controls). Further experiments provided evidence for the patient being abnormally affected by lateral masking between stimuli, though she could access phonology from subword functional spelling units. The experiments demonstrate that, for alexic and normal readers alike, words are more than the sum of their individual letters; however, for normal readers a supra-letter reading strategy is useful whereas it can be detrimental in alexia.     

Overcoming unintelligibility in aphasia: The impact of non‐verbal interactive strategies

As a follow‐up to previous research, this report focuses on the wide range of gestures employed by an individual with aphasia to overcome instances of unintelligibility and re‐establish intelligibility. The gestures observed are woven seamlessly into the fabric of the interactions and range from deictic to metaphorical or symbolic in nature. Specific examples are provided.     

Gesture production in school vs. clinical samples of children with Developmental Coordination Disorder (DCD) and typically developing children

Dyspraxia, a difficulty in executing an operationalised act, has been associated with Developmental Coordination Disorder (DCD). However, issues relating to the area such as comparisons across modalities, comparisons of school vs. clinical populations, and developmental delay vs. pathology have not been addressed in the same, comprehensive study. In the current study, therefore, familiar gesture production in DCD was addressed in a comprehensive manner to follow-up outstanding issues from previous studies: The production of familiar gestures and praxis imagery in a school (n = 26) vs. clinic sample (n = 19) of children with DCD was examined in relation to typically developing age matched (n = 24) all aged from 9 to 11 years, and two groups of younger children within the age ranges of 5-6 (n = 23) and 4-5 (n = 26) years. Overall, children with Developmental Coordination Disorder showed an impaired ability to produce familiar gestures compared to their typical peers, and this was dependant on the type of gesture and presentation modality. Differences were found between school and clinic samples of children with DCD, suggestive of the recruitment of different underlying mechanisms in the two samples. The results have a bearing on our understanding of the relationship of developmental dyspraxia to DCD, as well as of the issue of developmental delay vs. pathology.     

Familiarity modulates mirror neuron and mentalizing regions during intention understanding

Recent research suggests that the inference of others' intentions from their observed actions is supported by two neural systems that perform complementary roles. The human putative mirror neuron system (pMNS) is thought to support automatic motor simulations of observed actions, with increased activity for previously experienced actions, whereas the mentalizing system provides reflective, non-intuitive reasoning of others' perspectives, particularly in the absence of prior experience. In the current fMRI study, we show how motor familiarity with an action and perceptual familiarity with the race of an actor uniquely modulate these two systems. Chinese participants were asked to infer the intentions of actors performing symbolic gestures, an important form of non-verbal communication that has been shown to activate both mentalizing and mirror neuron regions. Stimuli were manipulated along two dimensions: (1) actor's race (Caucasian vs. Chinese actors) and (2) participants' level of experience with the gestures (familiar or unfamiliar). We found that observing all gestures compared to observing still images was associated with increased activity in key regions of both the pMNS and mentalizing systems. In addition, observations of one's same race generated greater activity in the posterior pMNS-related regions and the insula than observations of a different race. Surprisingly, however, familiar gestures more strongly activated regions associated with mentalizing, while unfamiliar gestures more strongly activated the posterior region of the pMNS, a finding that is contrary to prior literature and demonstrates the powerful modulatory effects of both motor and perceptual familiarity on pMNS and mentalizing regions when asked to infer the intentions of intransitive gestures.     

Multifocal intraparietal activation during discrimination of action intention in observed tool grasping

The way we grasp an object varies depending on how we want to use that object, and this knowledge can be used to predict the object-related behavior of others. In this study, we assessed the neural correlates that determine the action intention of another person based on observed prehensile movements. Fourteen right-handed volunteers watched video clips of a person performing right-handed transitive grasping gestures that were either aimed at displacing or using a tool-object. Clips showing the grasping and displacement of neutral shapes served as a control condition. By discrimination of the actor's intention, three roughly symmetrical foci were activated in the anterior, middle, and caudal segments of the intraparietal sulci, and in the fusiform gyri and parts of the lateral occipital complex. Anterior intraparietal activation has been associated with the representation of object goals (object specific), and the present findings extend its involvement to functional goals (use-specific). Activation in the middle intraparietal region during intention discrimination was very similar to the activation elicited in a saccadic localizer task, suggesting a relation with spatial attention and eye movements. The caudal intraparietal region has been related with visuospatial guidance of reaching, and its activation during action intention discrimination indicates that the visuospatial properties of the observed reaching movement contribute to understanding of actions. As these parietal regions are strongly linked with motor behavior, our results appear to support the motor simulation hypothesis for action understanding with the preferential recruitment of the mirror-neuron system. This could at least be the case when no contextual information other than the visual properties of the movement is provided to discriminate the intention of an observed hand action.     

The neural substrate of gesture recognition

Previous studies have linked action recognition with a particular pool of neurons located in the ventral premotor cortex, the posterior parietal cortex and the superior temporal sulcus (the mirror neuron system). However, it is still unclear if transitive and intransitive gestures share the same neural substrates during action-recognition processes. In the present study, we used event-related functional magnetic resonance imaging (fMRI) to assess the cortical areas active during recognition of pantomimed transitive actions, intransitive gestures, and meaningless control actions. Perception of all types of gestures engaged the right pre-supplementary motor area (pre-SMA), and bilaterally in the posterior superior temporal cortex, the posterior parietal cortex, occipitotemporal regions and visual cortices. Activation of the posterior superior temporal sulcus/superior temporal gyrus region was found in both hemispheres during recognition of transitive and intransitive gestures, and in the right hemisphere during the control condition; the middle temporal gyrus showed activation in the left hemisphere when subjects recognized transitive and intransitive gestures; activation of the left inferior parietal lobe and intraparietal sulcus (IPS) was mainly observed in the left hemisphere during recognition of the three conditions. The most striking finding was the greater activation of the left inferior frontal gyrus (IFG) during recognition of intransitive actions. Results show that a similar neural substrate, albeit, with a distinct engagement underlies the cognitive processing of transitive and intransitive gestures recognition. These findings suggest that selective disruptions in these circuits may lead to distinct clinical deficits.     

Study of hand signs in Judeo-Christian art

Hand gestures play a crucial role in religious art. An examination of Judeo-Christian art finds an ecclesiastical language that is concealed in metaphors and expressed by unique hand gestures. Many of these hand signs convey messages that are not familiar to most people admiring these paintings. Investigating the history and classifying some of the predominant hand signs found in Judeo-Christian art might serve to stimulate discussion concerning the many nuances of symbolic art. This presentation examines the meaning behind 8 common hand signs in Judeo-Christian art.     

孤独症谱系障碍儿童手势缺陷的研究进展

手势先于语言产生,促进语言的发展。孤独症谱系障碍(ASD)儿童手势的类型和功能存在非典型使用及发展,手势-语言轨迹发展缓慢,可以成为ASD儿童的一个关键早期行为标记。手势的发展与后期语言、认知、社交和ASD诊断显著相关,应对ASD儿童的早期手势功能进行评估和监测。针对手势特点进行个性化训练,增加儿童社会参与和学习潜能,以手势为中介促进语言、认知及社交发展,提高康复效果。