Meaningless Actions Research Articles

FNIRS-Based Differences in Cortical Activation during Tool Use, Pantomimed Actions, and Meaningless Actions between Children with and without Autism Spectrum Disorder (ASD)

Children with autism spectrum disorder (ASD) have difficulties with tool use and pantomime actions. The current study utilized functional near-infrared spectroscopy (fNIRS) to examine the neural mechanisms underlying these gestural difficulties. Thirty-one children with and without ASD (age (mean ± SE) = 11.0 ± 0.6) completed a naturalistic peg-hammering task using an actual hammer (hammer condition), pantomiming hammering actions (pantomime condition), and performing meaningless actions with similar joint motions (meaningless condition). Children with ASD exhibited poor praxis performance (praxis error: TD = 17.9 ± 1.7; ASD = 27.0 ± 2.6, p < 0.01), which was significantly correlated with their cortical activation (R = 0.257 to 0.543). Both groups showed left-lateralized activation, but children with ASD demonstrated more bilateral activation during all gestural conditions. Compared to typically developing children, children with ASD showed hyperactivation of the inferior parietal lobe and hypoactivation of the middle/inferior frontal and middle/superior temporal regions. Our findings indicate intact technical reasoning (typical left-IPL activation) but atypical visuospatial and proprioceptive processing (hyperactivation of the right IPL) during tool use in children with ASD. These results have important implications for clinicians and researchers, who should focus on facilitating/reducing the burden of visuospatial and proprioceptive processing in children with ASD. Additionally, fNIRS-related biomarkers could be used for early identification through early object play/tool use and to examine neural effects following gesture-based interventions.

Neuropsychological Evidence for a Motor Working Memory Subsystem Related to Apraxia.

Recent evidence in healthy participants suggests that a motor subcomponent of working memory (mWM) may exist. We investigated whether this mWM is impaired in patients with a motor-dominant left hemisphere (LH) stroke and apraxia. Furthermore, we hypothesized that a deficient mWM contributes to deficits in motor cognition, that is, apraxia, in LH stroke. The study included 52 patients with LH stroke and 25 age-matched controls. Patients were classified into LH stroke patients with and without apraxia based on deficits in gesture imitation and object use. All participants were examined using the block span test (visuospatial WM), the digit span test (verbal WM), and a novel mWM task. In the latter, participants were presented with static pictures depicting three different actions: actions with objects, meaningless actions, and meaningful actions. In the mWM task, LH stroke patients with apraxia performed worse than age-matched controls. Notably, LH stroke patients with apraxia showed more pronounced mWM deficits than those without apraxia. These results remained significant even after controlling for visuospatial and verbal WM deficits. Regression analyses revealed that LH stroke patients' mWM deficits predicted deficits in imitation. Data provide neuropsychological evidence for a motor subsystem of WM and suggest that deficits in mWM contribute to the severity of apraxia in LH stroke patients.

Технология идентификации ключевых особенностей в последовательностях API-вызовов вредоносных программ

Today, almost everyone is faced with computer security problems in one or another way. Antivirus programs are used to control threats to the security of malicious software. Conventional methods for detecting malware are no longer effective enough; nowadays, neural networks and behavioral analysis technology have begun to be used for these purposes. Analyzing the behavior of programs is a difficult task, since there is no clear sequence of actions to accurately identify a program as malicious. In addition, such programs use measures to resist such detection, for example, noise masking the sequence of their work with meaningless actions. There is also the problem of uniquely identifying the class of malware due to the fact that malware can use similar methods, while being assigned to different classes. In this paper, it is proposed to use NLP methods, such as word embedding, and LDA in relation to the problems of analyzing malware API calls sequences in order to reveal the presence of semantic dependencies and assess the effectiveness of the application of these methods. The results obtained indicate the possibility of identifying the key features of malware behavior, which in the future will significantly improve the technology for detecting and identifying such programs.

Absurd Elements in Anthony Neilson’s Realism and The Wonderful World of Dissocia Plays

After World War II, British theatre generally dealt with people’s meaningless actions and aimless lives. During the 1950s theatre reflecting the changing society opposed to the traditional theatre in terms of pattern and plot. The period in 1950s was named as Absurd Theatre by Martin Esslin and it has affected many writers until today. In 1990s theatre which reveals the untold explicitly and throws the violence in them to their face was coined by Alex Sierz. In Realism (2006), Anthony Neilson, one of In-yer-face playwrights, presents us with the melancholy protagonist Stuart, who is distant from the outside world, and who is lost amidst both his own sense of disinterest as well as life. The Wonderful World of Dissocia (2004), takes a look at the protagonist Lisa’s watch- which is consistently one hour behind- being fixed, as well as at the absurd events unfolding within Lisa’s imagination. The aim of this paper is to analyze the theme of absurdity in Anthony Neilson’s Realism and The Wonderful World of Dissocia through the lens of Esslin.

Repetitive Transcranial Magnetic Stimulation Over the Left Posterior Middle Temporal Gyrus Reduces Wrist Velocity During Emblematic Hand Gesture Imitation

Results from neuropsychological studies, and neuroimaging and behavioural experiments with healthy individuals, suggest that the imitation of meaningful and meaningless actions may be reliant on different processing routes. The left posterior middle temporal gyrus (pMTG) is one area that might be important for the recognition and imitation of meaningful actions. We studied the role of the left pMTG in imitation using repetitive transcranial magnetic stimulation (rTMS) and two-person motion-tracking. Participants imitated meaningless and emblematic meaningful hand and finger gestures performed by a confederate actor whilst both individuals were motion-tracked. rTMS was applied during action observation (before imitation) over the left pMTG or a vertex control site. Since meaningless action imitation has been previously associated with a greater wrist velocity and longer correction period at the end of the movement, we hypothesised that stimulation over the left pMTG would increase wrist velocity and extend the correction period of meaningful actions (i.e., due to interference with action recognition). We also hypothesised that imitator accuracy (actor-imitator correspondence) would be reduced following stimulation over the left pMTG. Contrary to our hypothesis, we found that stimulation over the pMTG, but not the vertex, during action observation reduced wrist velocity when participants later imitated meaningful, but not meaningless, hand gestures. These results provide causal evidence for a role of the left pMTG in the imitation of meaningful gestures, and may also be in keeping with proposals that left posterior temporal regions play a role in the production of postural components of gesture.

Correction to: 'The left ventral premotor cortex is involved in hand shaping for intransitive gestures: evidence from a two-person imitation experiment'.

[This corrects the article DOI: 10.1098/rsos.181356.].

The left ventral premotor cortex is involved in hand shaping for intransitive gestures: evidence from a two-person imitation experiment.

The ventral premotor cortex (PMv) is involved in grasping and object manipulation, while the dorsal premotor cortex (PMd) has been suggested to play a role in reaching and action selection. These areas have also been associated with action imitation, but their relative roles in different types of action imitation are unclear. We examined the role of the left PMv and PMd in meaningful and meaningless action imitation by using repetitive transcranial magnetic stimulation (rTMS). Participants imitated meaningful and meaningless actions performed by a confederate actor while both individuals were motion-tracked. rTMS was applied over the left PMv, left PMd or a vertex control site during action observation or imitation. Digit velocity was significantly greater following stimulation over the PMv during imitation compared with stimulation over the PMv during observation, regardless of action meaning. Similar effects were not observed over the PMd or vertex. In addition, stimulation over the PMv increased finger movement speed in a (non-imitative) finger–thumb opposition task. We suggest that claims regarding the role of the PMv in object-directed hand shaping may stem from the prevalence of object-directed designs in motor control research. Our results indicate that the PMv may have a broader role in ‘target-directed’ hand shaping, whereby different areas of the hand are considered targets to act upon during intransitive gesturing.

A kinematic examination of dual-route processing for action imitation

The dual-route model of imitation suggests that meaningful and meaningless actions are processed through either an indirect or a direct route, respectively. Evidence indicates that the direct route is more cognitively demanding since it relies on mapping visuospatial properties of the observed action on to a performed one. These cognitive demands might negatively influence reaction time and accuracy for actions performed following a meaningless action under time constraints. However, how meaningful and meaningless action imitation processing is reflected in movement kinematics is not yet clear. We wanted to confirm whether meaningless action performance incurs a reaction time cost, whether the cost is reflected in kinematics, and, more generally, to examine kinematic markers of emblematic meaningful and meaningless action imitation. We examined participants’ reaction time and wrist movements when they imitated emblematic meaningful or matched meaningless gestures in either blocks of the same action type or mixed blocks. Meaningless actions were associated with a greater correction period at the end of the movement, possibly reflecting a strategy designed to ensure accurate completion for less familiar actions under time constraints. Furthermore, in mixed blocks, trials following meaningless actions had a significantly increased reaction time, supporting previous claims that route selection for action imitation may be stimulus-driven. However, there was only convincing evidence for this effect with an interval of ~2,948ms, but not ~3,573ms or ~2,553ms, between movements. Future work motion-tracking the entire hand to assess imitation accuracy, and more closely examining the influence of duration between movements, may help to explain these effects.

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.

How is defensive medicine understood and experienced in a primary care setting? A qualitative focus group study among Danish general practitioners

ObjectivesRecent years have witnessed a progressive increase in defensive medicine (DM) in several Western welfare countries. In Danish primary and secondary care, documentation on the extent of DM is lacking....

Evidence for a sex effect during overimitation: boys copy irrelevant modelled actions more than girls across cultures.

Children are skilful at acquiring tool-using skills by faithfully copying relevant and irrelevant actions performed by others, but poor at innovating tools to solve problems. Five- to twelve-year-old urban French and rural Serbian children (N = 208) were exposed to a Hook task; a jar containing a reward in a bucket and a pipe cleaner as potential recovering tool material. In both countries, few children under the age of 10 made a hook from the pipe cleaner to retrieve the reward on their own. However, from five onward, the majority of unsuccessful children succeeded after seeing an adult model manufacturing a hook without completing the task. Additionally, a third of the children who observed a similar demonstration including an irrelevant action performed with a second object, a string, replicated this meaningless action. Children's difficulty with innovation and early capacity for overimitation thus do not depend on socio-economic background. Strikingly, we document a sex difference in overimitation across cultures, with boys engaging more in overimitation than girls, a finding that may result from differences regarding explorative tool-related behaviour. This male-biased sex effect sheds new light on our understanding of overimitation, and more generally, on how human tool culture evolved.

Group Membership Influences More Social Identification Than Social Learning or Overimitation in Children.

Group membership is a strong driver of everyday life in humans, influencing similarity judgments, trust choices, and learning processes. However, its ontogenetic development remains to be understood. This study investigated how group membership, age, sex, and identification with a team influenced 39- to 60-month-old children (N=94) in a series of similarity, trust, and learning tasks. Group membership had the most influence on similarity and trust tasks, strongly biasing choices toward in-groups. In contrast, prior experience and identification with the team were the most important factors in the learning tasks. Finally, overimitation occurred most when the children's team, but not the opposite, displayed meaningless actions. Future work must investigate how these cognitive abilities combine during development to facilitate cultural processes.

모션 히스토리 영상 및 기울기 방향성 히스토그램과 적출 모델을 사용한 깊이 정보 기반의 연속적인 사람 행동 인식 시스템

본 논문은 깊이 정보를 기반으로 모션 히스토리 영상 및 기울기 방향성 히스토그램과 적출 모델을 사용하여 연속적인 사람 행동들을 인식하는 시스템을 설명하고 연속적인 행동 인식 시스템에서 인식 성능을 개선하기 위해 행동 적출을 수행하는 적출 모델을 제안한다. 본 시스템의 구성은 전처리 과정, 사람 행동 및 적출 모델링 그리고 연속적인 사람 행동 인식으로 이루어져 있다. 전처리 과정에서는 영상 분할과 시공간 템플릿 기반의 특징을 추출하기 위하여 Depth-MHI-HOG 방법을 사용하였으며, 추출된 특징들은 사람 행동 및 적출 모델링 과정을 통해 시퀀스들로 생성된다. 이 생성된 시퀀스들과 은닉 마르코프 모델을 사용하여 정의된 각각의 행동에 적합한 사람 행동 모델과 제안된 적출 모델을 생성한다. 연속적인 사람 행동 인식은 연속적인 행동 시퀀스에서 적출 모델에 의해 의미 있는 행동과 의미 없는 행동을 분할하는 행동 적출과 의미 있는 행동 시퀀스에 대한 모델의 확률 값들을 비교하여 연속적으로 사람 행동들을 인식한다. 실험 결과를 통해 제안된 모델이 연속적인 행동 인식 시스템에서 인식 성능을 효과적으로 개선하는 것을 검증한다. In this paper, recognition system for continuous human action is explained by using motion history image and histogram of oriented gradient with spotter model based on depth information, and the spotter model which performs action spotting is proposed to improve recognition performance in the recognition system. The steps of this system are composed of pre-processing, human action and spotter modeling and continuous human action recognition. In pre-processing process, Depth-MHI-HOG is used to extract space-time template-based features after image segmentation, and human action and spotter modeling generates sequence by using the extracted feature. Human action models which are appropriate for each of defined action and a proposed spotter model are created by using these generated sequences and the hidden markov model. Continuous human action recognition performs action spotting to segment meaningful action and meaningless action by the spotter model in continuous action sequence, and continuously recognizes human action comparing probability values of model for meaningful action sequence. Experimental results demonstrate that the proposed model efficiently improves recognition performance in continuous action recognition system.

Continuous human action recognition using depth-MHI-HOG and a spotter model.

In this paper, we propose a new method for spotting and recognizing continuous human actions using a vision sensor. The method is comprised of depth-MHI-HOG (DMH), action modeling, action spotting, and recognition. First, to effectively separate the foreground from background, we propose a method called DMH. It includes a standard structure for segmenting images and extracting features by using depth information, MHI, and HOG. Second, action modeling is performed to model various actions using extracted features. The modeling of actions is performed by creating sequences of actions through k-means clustering; these sequences constitute HMM input. Third, a method of action spotting is proposed to filter meaningless actions from continuous actions and to identify precise start and end points of actions. By employing the spotter model, the proposed method improves action recognition performance. Finally, the proposed method recognizes actions based on start and end points. We evaluate recognition performance by employing the proposed method to obtain and compare probabilities by applying input sequences in action models and the spotter model. Through various experiments, we demonstrate that the proposed method is efficient for recognizing continuous human actions in real environments.

Relation entre dyspraxie gestuelle et dyslexie chez des enfants avec troubles des apprentissages

Gestures and language are thought as two cognitive functions that are closely linked. From an evolutionary point of view, recent theories suggest that language evolved from manual gestures, rather than from animal vocal call. Moreover, in developmental psychology, several studies have revealed the role of gestures in the development of language abilities. In neuropsychology, the recent cognitive models of praxis processing have been mapped onto the cognitive models of written language processing, further suggesting an analogy between the way gestures and higher language abilities are processed. If gestures have a role in language development, a deficit in processing gestures should affect reading abilities. We report the case of five children (three with visuo-constructive disorders, two with dyslexia and one with both visuo-constructive disorder and dyslexia) who were tested using a series of tasks targetting reading and praxis abilities. Tasks assessing recognition, comprehension and production of gestures and language were included to evaluate the integrity of the lexical routes. Tasks to evaluate imitation of meaningless gestures and the ability to read pseudo-words were also included to investigate the sub-lexical routes. Results showed that children having visuo-constructive disorders were also affected by limb dyspraxia and dyslexia and that the language and praxis profiles based on the cognitive models were similar. In particular, the two children with visuo-constructive disorders showed a deficit at the lexical and sub-lexical routes for both gestures and language; the child with both dyslexia and visuo-constructive disorders had difficulties in the production of meaningful gestures and in meaningless actions imitation, as well as in reading words and pseudo-words. This pattern of results was compatible with a deficit at the level of the buffers as proposed by the two cognitive models. The two dyslexic children did not show any sign of limb dyspraxia, and their dyslexia was mainly attributed to a deficit to the lexical and sub-lexical route in one case; and to the sub-lexical route in the other case. Overall, results showed that those children with deficits in gesture processing also had difficulties in reading, but that children presenting only dyslexia did not show any sign of praxis impairments. Taken together, these findings are in line with the idea that gesture might play a role in the development of language abilities.

The effects of visual half-field priming on the categorization of familiar intransitive gestures, tool use pantomimes, and meaningless hand movements.

Although the control of meaningful gestures is one of the most left-lateralized functions, the relative contribution of the two hemispheres to their processing is still debated. We tested the effects of primes appearing in the left or right visual field in the form of pictures (Experiment 1), and words (Experiment 2) on categorization of movies showing intransitive (“communicative”) gestures, tool use (transitive) pantomimes, and meaningless movements. Fifteen participants (eight women) watched 36 movies (12 from each category) primed for 150 ms with either a congruent or incongruent stimulus followed by a 50-ms mask. On congruent trials, a picture or word was directly related to the presented gesture, including nonsense pictures or non-words for meaningless actions. On incongruent trials, a picture or word belonged to a different category. In Experiment 1, intransitive gestures were categorized significantly faster than the other two types of hand movements. Moreover, whereas the categorization of transitive gestures was significantly facilitated by congruent pictures on the right, the effect was weaker for intransitive, and reversed for meaningless movements. In Experiment 2, intransitive gestures were again categorized significantly faster, but transitive significantly slower than the other two gesture categories. Yet, there was now a significant facilitation of intransitive, and inhibition of transitive gesture categorization following congruent prime words in the right visual field, and significantly faster categorization of intransitive gestures following incongruent words in the left visual field. These outcomes lend support to the complexity account of differences in left-hemisphere representations of meaningful gestures reported in the neuropsychological, behavioral, and neuroimaging literature. Nevertheless, they also indicate that the representations of intransitive gestures show some differential, and sometimes counterintuitive sensitivity to right hemisphere processing.

Lateral occipitotemporal cortex and action representation

Representation of body and body movements is essential for identifying others intentions or actions or for learning from them. Over the last 10 years, a large collection of research has demonstrated that body representations are distributed across a widely distributed brain network. In this functional magnetic resonance imaging study, we focus on lateral occipitotemporal cortex (LOTC), a recently identified brain region that could represent the body in a multisensory and dynamic manner. We addressed the question of LOTC involvement in visual processing of others׳ actions through a factorial analysis that manipulated the meaning of an observed action, completed by a psychophysiological interaction analysis. The results show that only left LOTC was significantly activated in relation to others׳ actions meaning. In addition, only left LOTC was activated during both action observation and action production but it was more dorsal than the activation related to the meaning of observed actions. Furthermore, the psychophysiological interaction analysis showed that when watching meaningless actions, the more dorsal part of the LOTC (the area active during both action production and action observation) had higher functional connectivity with primary visual areas while the more ventral part (that responded to action meaning) had higher correlation with anterior cingulate and medioprefrontal cortices. Taken together these results plead in favour of a strong implication of left LOTC in action observation and understanding, with a possible functional specialisation between the more ventral and the more dorsal parts of LOTC.

Neural correlates of transitive and intransitive action imitation: an investigation using voxel-based morphometry.

The ability to reproduce visually presented actions has been studied through neuropsychological observations of patients with ideomotor apraxia. These studies include attempts to understand the neural basis of action reproduction based on lesion–symptom mapping in different patient groups. While there is a convergence of evidence that areas in the parietal and frontal lobes within the left hemisphere are involved in the imitation of a variety of actions, questions remain about whether the results generalize beyond the imitation of tool use and whether the presence of a strong grasp component of the action is critical. Here we used voxel-based lesion–symptom mapping to assess the neural substrates of imitating meaningful (familiar, MF) and meaningless (unfamiliar, ML) tool-related (transitive) and non-tool related (intransitive) actions. The analysis showed that the left parietal cortex was involved in the imitation of transitive gestures, regardless of whether they were meaningful or not. In addition there was poor reproduction of meaningless actions (both transitive and intransitive) following damage of the right frontal cortex. These findings suggest a role of right frontal regions in processing of unfamiliar actions.

The role of the basal ganglia in action imitation: neuropsychological evidence from Parkinson’s disease patients

Though previous studies have suggested that the basal ganglia are necessarily involved in action imitation, their precise role is unclear. An important source of evidence concerns patients with Parkinson's disease (PD) who suffer basal ganglia impairments. Some studies report poor execution of observed meaningful (MF) transitive (tool-related) actions but normal performance with intransitive (non-tool-related) MF and meaningless (ML) actions (Leiguarda et al. in Brain 120:75-90, 1997; Leiguarda 2001 in Neuroimage 14:137-141). In other cases, though, patients with lesions involving the basal ganglia appear impaired in imitating ML as compared to meaningful MF transitive pantomimes. Here, we tested a group of PD patients in a full 2×2 design with MF transitive and intransitive pantomimes and matched ML movements. PD patients generated higher scores when imitating MF transitive actions than ML-matched actions. On the other hand, ML than MF intransitive actions did not differ significantly. The performance of the patients on imitating ML transitive actions also correlated with their performance on the Corsi block test of visuospatial memory and their scores at the test of verbal fluency for phonemic categories (FAS) while MF intransitive actions correlated with FAS and the neurological evaluation (UPDRS) The results are discussed in terms of the factors that load on visual memory for action reproduction, as well as the possible role of the basal ganglia in communicative actions (for MF intransitive actions).

Understanding and Imitating Unfamiliar Actions: Distinct Underlying Mechanisms

The human “mirror neuron system” has been proposed to be the neural substrate that underlies understanding and, possibly, imitating actions. However, since the brain activity with mirror properties seems insufficient to provide a good description for imitation of actions outside one’s own repertoire, the existence of supplementary processes has been proposed. Moreover, it is unclear whether action observation requires the same neural mechanisms as the explicit access to their meaning. The aim of this study was two-fold as we investigated whether action observation requires different processes depending on 1) whether the ultimate goal is to imitate or understand the presented actions and 2) whether the to-be-imitated actions are familiar or unfamiliar to the subject. Participants were presented with both meaningful familiar actions and meaningless unfamiliar actions that they had to either imitate or discriminate later. Event-related Potentials were used as differences in brain activity could have been masked by the use of other techniques with lower temporal resolution. In the imitation task, a sustained left frontal negativity was more pronounced for meaningless actions than for meaningful ones, starting from an early time-window. Conversely, observing unfamiliar versus familiar actions with the intention of discriminating them led to marked differences over right centro-posterior scalp regions, in both middle and latest time-windows. These findings suggest that action imitation and action understanding may be sustained by dissociable mechanisms: while imitation of unfamiliar actions activates left frontal processes, that are likely to be related to learning mechanisms, action understanding involves dedicated operations which probably require right posterior regions, consistent with their involvement in social interactions.