Sensorimotor Level Research Articles

Body ownership and kinaesthetic illusions: Dissociated bodily experiences for distinct levels of body consciousness?

Seeing an embodied humanoid avatar move its arms can induce in the observer the illusion that its own (static) arms are moving accordingly, the kinematic signals emanating from this avatar thus being considered like those from the biological body. Here, we investigated the causal relationship between these kinaesthetic illusions and the illusion of body ownership, manipulated through visuomotor synchronisation. The results of two experiments revealed that the sense of body ownership over an avatar seen from a first-person perspective was intimately linked to visuomotor synchrony. This was not the case for kinaesthetic illusions indicating that when superimposed on the biological body, the avatar is inevitably treated at the sensorimotor level as one’s own body, whether consciously considered as such or not. The question of whether these two bodily experiences (body ownership and kinaesthetic illusion) are underpinned by distinct representations, the body image, and the body schema, is discussed.

Multilevel development of cognitive abilities in an artificial neural network

Several neuronal mechanisms have been proposed to account for the formation of cognitive abilities through postnatal interactions with the physical and sociocultural environment. Here, we introduce a three-level computational model of information processing and acquisition of cognitive abilities. We propose minimal architectural requirements to build these levels, and how the parameters affect their performance and relationships. The first sensorimotor level handles local nonconscious processing, here during a visual classification task. The second level or cognitive level globally integrates the information from multiple local processors via long-ranged connections and synthesizes it in a global, but still nonconscious, manner. The third and cognitively highest level handles the information globally and consciously. It is based on the global neuronal workspace (GNW) theory and is referred to as the conscious level. We use the trace and delay conditioning tasks to, respectively, challenge the second and third levels. Results first highlight the necessity of epigenesis through the selection and stabilization of synapses at both local and global scales to allow the network to solve the first two tasks. At the global scale, dopamine appears necessary to properly provide credit assignment despite the temporal delay between perception and reward. At the third level, the presence of interneurons becomes necessary to maintain a self-sustained representation within the GNW in the absence of sensory input. Finally, while balanced spontaneous intrinsic activity facilitates epigenesis at both local and global scales, the balanced excitatory/inhibitory ratio increases performance. We discuss the plausibility of the model in both neurodevelopmental and artificial intelligence terms.

Goal Oriented Behavior With a Habit-Based Adaptive Sensorimotor Map Network.

We present a description of an ASM-network, a new habit-based robot controller model consisting of a network of adaptive sensorimotor maps. This model draws upon recent theoretical developments in enactive cognition concerning habit and agency at the sensorimotor level. It aims to provide a platform for experimental investigation into the relationship between networked organizations of habits and cognitive behavior. It does this by combining (1) a basic mechanism of generating continuous motor activity as a function of historical sensorimotor trajectories with (2) an evaluative mechanism which reinforces or weakens those historical trajectories as a function of their support of a higher-order structure of higher-order sensorimotor coordinations. After describing the model, we then present the results of applying this model in the context of a well-known minimal cognition task involving object discrimination. In our version of this experiment, an individual robot is able to learn the task through a combination of exploration through random movements and repetition of historic trajectories which support the structure of a pre-given network of sensorimotor coordinations. The experimental results illustrate how, utilizing enactive principles, a robot can display recognizable learning behavior without explicit representational mechanisms or extraneous fitness variables. Instead, our model's behavior adapts according to the internal requirements of the action-generating mechanism itself.

Adaptive Whisking in Mice.

Rodents generate rhythmic whisking movements to explore their environment. Whisking trajectories, for one, appear as a fixed pattern of whisk cycles at 5–10 Hz driven by a brain stem central pattern generator. In contrast, whisking behavior is thought to be versatile and adaptable to behavioral goals. To begin to systematically investigate such behavioral adaptation, we established a whisking task, in which mice altered the trajectories of whisking in a goal-oriented fashion to gain rewards. Mice were trained to set the whisker to a defined starting position and generate a protraction movement across a virtual target (no touch-related tactile feedback). By ramping up target distance based on reward history, we observed that mice are able to generate highly specific whisking patterns suited to keep reward probability constant. On a sensorimotor level, the behavioral adaptation was realized by adjusting whisker kinematics: more distant locations were targeted using higher velocities (i.e., pointing to longer force generation), rather than by generating higher acceleration (i.e., pointing to stronger forces). We tested the suitability of the paradigm of tracking subtle alteration in whisking motor commands using small lesions in the rhythmic whisking subfield (RW) of the whisking-related primary motor cortex. Small contralateral RW lesions generated the deterioration of whisking kinematics with a latency of 12 days post-lesion, a change that was readily discriminated from changes in the behavioral adaptation by the paradigm.

Особенности развития семантической стороны речи младших школьников с умственной отсталостью

The article discusses the problem of education of children with disabilities, which is relevant today due to the objective difficulties of social functioning and the child's entry into society. It is known that the basis of a person's speech organization is vocabulary, the shortcomings of which significantly complicate the process of social adaptation. The features of the intellectual and speech development of students with mental retardation limit the ability of these children to understand the speech of others, to adequately express their own thoughts and lead to an inferiority of social and everyday orientation. Consequently, one of the urgent areas of work with children with mental retardation should be the formation and development of vocabulary, characterized by sufficiency and usefulness, in terms of the volume of vocabulary, semantics and syntagmatic characteristics. The solution of this practical problem will allow primary schoolchildren with intellectual disabilities to expand their vocabulary, to form their basic cognitive processes, in the structure of which speech occupies one of the basic positions. To study the level of formation of the semantic side of speech of children with intellectual underdevelopment at the present stage, we conducted a psychological and pedagogical study, in which 1376 schoolchildren from Kaluga and Obninsk, Kaluga region, took part. The diagnostic results made it possible to reveal the fact that with mental retardation, operations and levels of speech utterance generation (semantic, linguistic, sensorimotor levels) are impaired to varying degrees. The most underdeveloped are highly organized, complex levels (semantic, linguistic), requiring a high degree of formation of the operations of analysis, synthesis, generalization, the sensorimotor level of speech in these children suffers in different ways. The study showed that the symptomatology and mechanism of speech disorders in these children are determined not only by the presence of a general underdevelopment of the cerebral systems, which causes systemic speech impairment, but also local pathology on the part of systems directly related to speech, which further complicates the picture of speech impairments in mentally retarded children.

How preadolescents and adults remember and experience virtual reality: The role of avatar incarnation, emotion, and sense of presence

Incarnate bodies in the first-person view in virtual reality, especially with a head-mounted display, could impact cognitive processes relying on self-representation, such as memory, emotion, or sense of presence. The goal of this study is to investigate these effects by comparing adults’ and preadolescents’ behaviors. We manipulated incarnation by presenting the experience with or without an avatar (full-body avatar versus VR controllers), while manipulating emotion with presented stimuli. 40 adults and 32 preadolescents were both divided into two experimental groups (avatar versus no-avatar). Valence, arousal, and presence were self-evaluated, and a free recall task was performed. Physiological measurements were carried out to add objective support for our findings. We showed an emotional enhancement of memory in both age groups. Importantly, embodying an avatar permitted preadolescents to have the same memory performance than adults. Memory was predicted by valence and head movements in adults, but no predictors were found for preadolescents. Overall, preadolescents rated virtual environments as more arousing, more positive, and inducing more presence than adults. Surprisingly, avatar incarnation did not impact these measures, we propose that immersion at a sensorimotor level is a more crucial component than incarnation.

Modifying auditory perception with prisms? Aftereffects of prism adaptation on a wide auditory spectrum in musicians and nonmusicians

Prism adaptation consists of pointing to visual targets while wearing prisms that shift the visual field laterally. The aftereffects are not restricted to sensorimotor level but extend to spatial cognition. There is a link between spatial representation and auditory frequency, with an association of low frequencies on the left side and high frequencies on the right side of space. The present study aimed first at evaluating the representation of auditory frequencies on a wide range of frequencies in musicians and nonmusicians. We used the ‘auditory interval bisection judgment’ within three auditory intervals. The results showed a pseudoneglect behavior in pretest in musicians and nonmusicians for high frequency intervals, reflecting a perceptual bias of the subjective interval center toward lower frequencies. The second aim of the present study was to evaluate the aftereffects of prism adaptation on an expanded auditory spectrum. The results showed aftereffects of adaptation to a leftward optical deviation for high frequency intervals in musicians and nonmusicians. Adaptation to a leftward optical deviation affects the auditory perception on an extended auditory spectrum, by shifting the subjective interval center toward high frequencies. The present study provides innovative data about representation of auditory perception and its modulation by prism adaptation.

Predictive sensorimotor control in autism.

Autism spectrum disorder has been characterized by atypicalities in how predictions and sensory information are processed in the brain. To shed light on this relationship in the context of sensorimotor control, we assessed prediction-related measures of cognition, perception, gaze and motor functioning in a large general population (n = 92; Experiment 1) and in clinically diagnosed autistic participants (n = 29; Experiment 2). In both experiments perception and action were strongly driven by prior expectations of object weight, with large items typically predicted to weigh more than equally-weighted smaller ones. Interestingly, these predictive action models were used comparably at a sensorimotor level in both autistic and neurotypical individuals with varying levels of autistic-like traits. Specifically, initial fingertip force profiles and resulting action kinematics were both scaled according to participants' pre-lift heaviness estimates, and generic visual sampling behaviours were notably consistent across groups. These results suggest that the weighting of prior information is not chronically underweighted in autism, as proposed by simple Bayesian accounts of the disorder. Instead, our results cautiously implicate context-sensitive processing mechanisms, such as precision modulation and hierarchical volatility inference. Together, these findings present novel implications for both future scientific investigations and the autism community.

Altered Proprioceptive Feedback Influences Movement Kinematics in a Lifting Task.

Movement control process can be considered to take place on at least two different levels: a high, more cognitive level and a low, sensorimotor level. On a high level processing a motor command is planned accordingly to the desired goal and the sensory afference, mainly proprioception, is used to determine the necessary adjustments in order to minimize any discrepancy between predicted and executed action. On a lower level processing, the proprioceptive feedback later employed in high level regulations, is generated by Ia sensory fibers positioned in muscle main proprioceptors: muscle spindles. By entraining the activity of these spindle fibers through 80Hz vibration of triceps distal tendon, we show the intriguing possibility of inducing kinematics adjustments due to negative feedback corrections, during a lifting task.

M58. EVALUATING WEIGHTINGS OF PREDICTIVE AND POSTDICTIVE PROCESSES IN ABERRANT SENSE OF AGENCY IN SCHIZOPHRENIA

BackgroundSense of agency (SoA) refers to the subjective feeling that one is the agent who causes and controls one’s own actions and those effects on the external world. It’s widely known that patients with schizophrenia show aberrant SoA, but its cognitive and neural mechanisms remain unclear. Previous studies suggest that abnormal SoA is probably due to impaired predictive processes, such as predicting sensory feedbacks according to one’s own motor intention or motor commands. However, dysfunction of the prediction process alone cannot explain various symptoms of schizophrenia. The impairment in postdictive processes in patients with schizophrenia is also considered to be important to explain their symptoms. However, how the predictive and postdictive processes actually contribute to the judgment of agency in patients with schizophrenia remains unknown. In the present study, we focus on the functional contribution of the two processes at sensorimotor level to the judgment of agency at the cognitive level, rather than the performance of these functions. Our approach allows us to evaluate the weightings of each contribution quantitatively, and to associate such weightings to symptoms for each individual. The results of our study point to potential useful diagnosis, and can provide important knowledge for treatment in future research.MethodsWe use two sensorimotor tasks (i.e. the reaching task and the control detection task) and one explicit agency judgment task in this study. In all tasks, participants move one or several dots on a screen by moving a mouse. The speed of the dots’ motion always corresponds to participants’ mouse movement, but the direction of the dots’ motion is combined with both participants’ motion and prerecorded motion, and is applied with a certain angular bias. In the reaching task, participants move the dot to touch a destination on screen as quickly as possible. This task is designed to measure the extent of prediction errors at the sensorimotor level, which is considered as an important signal for the predictive process underlying agency judgment. In the control detection task, participants move three dots simultaneously, and identified one dot that can be partially controlled by their mouse movement, while the other two dots move in pre-recorded directions. This task does not require explicit judgment of agency. It measures the postdictive process that to detect the regularity between the visual feedbacks and one’s own movements at the sensorimotor level. At last, in the explicit agency judgment task, participants made binary judgment (i.e. yes or no) regarding whether they feel that they controlled the moving direction of the dot or not in each condition. In summary, the two sensorimotor tasks measure the output of predictive and postdictive processes at the sensorimotor level, respectively, and the explicit agency judgment task measures agency judgment at the cognitive level. We designed six experimental conditions, in which the actual angular error and regularity were systematically manipulate. Such manipulation creates variability in the performance of each task, and allows us to use structure equation modelling to analyze the contributions of the performance in the two sensorimotor tasks to the explicit agency judgment task, and to compare the results with healthy controls. We focus on the functional structure of the sensorimotor sub-component and the cognitive judgment of SoA.ResultsThe data collection is currently in progress. We plan to finish it by February.DiscussionWe predict weakened contributions from the two sub-components to SoA in patients, compared to healthy control. We plan to link the quantitatively estimated weightings to individual symptoms including both positive and negative symptoms.

Effectiveness of folklore as a means of early speech therapy

The article deals with the issue of mastering verbal and non-verbal means of communication by young children with delayed speech development. Modern ideas about the developing capabilities of folklore, its structural and speech features are analyzed. The results of diagnostics of the level of development of speech, expressive-mimic and subject-effective means of communication, sensorimotor and motivational-need levels of speech development of young children with speech development delay are presented.

Особливості застосування метода заміщувального онтогенезу в роботі з дітьми з розладами аутистичного спектру

The article is devoted to the study of features of the application of the method of replacement ontogenesis in work with children with autism spectrum disorders. The article describes the content of the concepts «autism», «method of replacement ontogenesis», also analyzed the views of Ukrainian and foreign scientists about the problem of applying neuropsychological approach in working with children with autism spectrum disorders, considered the positive aspects of the method of replacement ontogenesis. The features of the three-level system of the method of replacement ontogenesis have been analyzed. Performance of tasks facing the method of replacement ontogenesis is possible when applying a complex of specially selected exercises, which are oriented to optimization of the operation of the basic sensorimotor level, which is the basis of human cognitive functions. Theoretical conclusions can be interesting for specialists in the field of correction pedagogy and special psychology.

Clinical spectrum of higher level gait disorders (HLGD) in a tertiary care movement disorder clinic - A prospective study

Gait disorders are classified into lower, middle, and higher sensorimotor levels (Nutt 1993). HLGD are common and disabling in the elderly. To study the burden, demographic profile and etiologic profile of HLGD in a tertiary care center in India. Patients presenting with Parkinsonism and predominant lower limb involvement in the form of gait difficulty (freezing, shuffling or slowness) and/or postural instability (imbalance or falls), not completely accounted for by visual, vestibular or proprioceptive deficits, were studied. Follow up was done for 3 months. 56 consecutive patients with HLGD, forming 3.38% of new referrals, were included. 23 patients (41%) fulfilled criteria for Progressive Supranuclear Palsy (PSP) (Höglinger 2017), 11 (20%) for vascular parkinsonism (VaP) (Winikates 1999), 9 (16%) for Normal pressure hydrocephalus (NPH) (Relkin 2013), and 2 (4%) had a multisensory gait disorder. 11 cases (20%) remained unclassified. Patients with PSP (Table 1) had REM Sleep behavior disorder (RBD), extraocular abnormalities (EOM), axial rigidity, masked facies, gait freezing, inability to arise from chair unsupported, severe postural instability on pull test, and midbrain atrophy on MRI brain. Patients with VaP had ≥2 vascular risk factors, pyramidal signs, broad-based asymmetric gait, and leukoaraiosis on MRI brain. NPH was a diagnosis of exclusion (Table 1) with ventriculomegaly on MRI, and improvement at lumbar tap test (LTT) which eventually predicted VP Shunt responsiveness. PSP is the commonest HLGD. VaP and NPH are other common HLGD. Reaching a diagnosis requires assessment of all features in unison. Clinical phenotype evolves with time on follow up.

Predicting domain-specific actions in expert table tennis players activates the semantic brain network

Motor expertise acquired during long-term training in sports enables top athletes to predict the outcomes of domain-specific actions better than nonexperts do. However, whether expert players encode actions, in addition to the concrete sensorimotor level, also at a more abstract, conceptual level, remains unclear. The present study manipulated the congruence between body kinematics and the subsequent ball trajectory in videos of an expert player performing table tennis serves. By using functional magnetic resonance imaging, the brain activity was evaluated in expert and nonexpert table tennis players during their predictions on the fate of the ball trajectory in congruent versus incongruent videos. Compared with novices, expert players showed greater activation in the sensorimotor areas (right precentral and postcentral gyri) in the comparison between incongruent vs. congruent videos. They also showed greater activation in areas related to semantic processing: the posterior inferior parietal lobe (angular gyrus), middle temporal gyrus, and ventromedial prefrontal cortex. These findings indicate that action anticipation in expert table tennis players engages both semantic and sensorimotor regions and suggests that skilled action observation in sports utilizes predictions both at motor-kinematic and conceptual levels.

Decisions are expedited through multiple neural adjustments spanning the sensorimotor hierarchy

When decisions are made under speed pressure, “urgency” signals elevate neural activity toward action-triggering thresholds independent of the sensory evidence, thus incurring a cost to choice accuracy. While urgency signals have been observed in brain circuits involved in preparing actions, their influence at other levels of the sensorimotor pathway remains unknown. We used a novel contrast-comparison paradigm to simultaneously trace the dynamics of sensory evidence encoding, evidence accumulation, motor preparation, and muscle activation in humans. Results indicate speed pressure impacts multiple sensorimotor levels but in crucially distinct ways. Evidence-independent urgency was applied to cortical action-preparation signals and downstream muscle activation, but not directly to upstream levels. Instead, differential sensory evidence encoding was enhanced in a way that partially countered the negative impact of motor-level urgency on accuracy, and these opposing sensory-boost and motor-urgency effects had knock-on effects on the buildup and pre-response amplitude of a motor-independent representation of cumulative evidence.

Force field adaptation does not alter space representation

Prism adaptation is a well-known model to study sensorimotor adaptive processes. It has been shown that following prism exposure, after-effects are not only restricted to the sensorimotor level but extend as well to spatial cognition. The main purpose of the present study was to investigate in healthy individuals whether expansion to spatial cognition is restricted to adaptive processes peculiar to prism adaptation or whether it occurs as well following other forms of adaptive process such as adaptation to a novel dynamic environment during pointing movements. Representational after-effects were assessed by the perceptual line bisection task before and after adaptation to a leftward or a rightward force field. The main results showed that adaptation developed at sensorimotor level but did not influence space representation. Our results have therefore a strong methodological impact for prospective investigations focusing on sensorimotor plasticity while sparing space cognition. These methodological considerations will be particulary relevant when addressing sensorimotor plasticity in patients with specific representational feature to preserve. The discussion highlights the differences between prism and dynamic adaptation that could explain the lack of after-effect on space representation following force field adaptation.

Teaching a Robot the Semantics of Assembly Tasks

We present a three-level cognitive system in a learning by demonstration context. The system allows for learning and transfer on the sensorimotor level as well as the planning level. The fundamentally different data structures associated with these two levels are connected by an efficient mid-level representation based on so-called “semantic event chains.” We describe details of the representations and quantify the effect of the associated learning procedures for each level under different amounts of noise. Moreover, we demonstrate the performance of the overall system by three demonstrations that have been performed at a project review. The described system has a technical readiness level (TRL) of 4, which in an ongoing follow-up project will be raised to TRL 6.

Aortic valve bypass surgery in severe aortic valve stenosis: Insights from cardiac and brain magnetic resonance imaging

ObjectiveTo investigate and describe the distribution of aortic and cerebral blood flow (CBF) in patients with severe valvular aortic stenosis (AS) before and after aortic valve bypass (AVB) surgery. MethodsWe enrolled 10 consecutive patients who underwent AVB surgery for severe AS. Cardiovascular magnetic resonance imaging (CMR) and brain magnetic resonance imaging were performed as baseline before surgery and twice after surgery. Quantitative flow measurements were obtained using 1.5-T magnetic resonance imaging (MRI) scanner phase-contrast images of the ascending aorta, descending thoracic aorta (3 cm proximally and distally from the conduit-to-aorta anastomosis), and ventricular outflow portion of the conduit. The evaluation of CBF was performed using 3.0-T MRI scanner arterial spin labeling (ASL) through sequences acquired at the gray matter, dorsal default-mode network, and sensorimotor levels. ResultsConduit flow, expressed as the percentage of total antegrade flow through the conduit, was 63.5 ± 8% and 67.8 ± 7% on early and mid-term postoperative CMR, respectively (P < .05). Retrograde perfusion from the level of the conduit insertion in the descending thoracic aorta toward the aortic arch accounted for 6.9% of total cardiac output and 11% of total conduit flow. We did not observe any significant reduction in left ventricular stroke volume at postoperative evaluation compared with preoperative evaluation (P = .435). No differences were observed between preoperative and postoperative CBF at the gray matter, dorsal default-mode network, and sensorimotor levels (P = .394). ConclusionsAfter AVB surgery in patients with severe AS, cardiac output is split between the native left ventricular outflow tract and the apico-aortic bypass, with two-thirds of the total antegrade flow passing through the latter and one-third passing through the former. In our experience, CBF assessment confirms that the flow redistribution does not jeopardize cerebral blood supply.

Assessing Self-Awareness through Gaze Agency.

We define gaze agency as the awareness of the causal effect of one’s own eye movements in gaze-contingent environments, which might soon become a widespread reality with the diffusion of gaze-operated devices. Here we propose a method for measuring gaze agency based on self-monitoring propensity and sensitivity. In one task, naïf observers watched bouncing balls on a computer monitor with the goal of discovering the cause of concurrently presented beeps, which were generated in real-time by their saccades or by other events (Discovery Task). We manipulated observers’ self-awareness by pre-exposing them to a condition in which beeps depended on gaze direction or by focusing their attention to their own eyes. These manipulations increased propensity to agency discovery. In a second task, which served to monitor agency sensitivity at the sensori-motor level, observers were explicitly asked to detect gaze agency (Detection Task). Both tasks turned out to be well suited to measure both increases and decreases of gaze agency. We did not find evident oculomotor correlates of agency discovery or detection. A strength of our approach is that it probes self-monitoring propensity–difficult to evaluate with traditional tasks based on bodily agency. In addition to putting a lens on this novel cognitive function, measuring gaze agency could reveal subtle self-awareness deficits in pathological conditions and during development.

The emergence of phonetic–phonological features in a biologically inspired model of speech processing

Because speech acquisition begins with sensorimotor activity (i.e. babbling and imitation of speech items in order to learn articulatory–acoustic relations) as well as with semantic cognitive processing (i.e. linking phonetic items with concepts), distinctiveness as well as phonetic–phonological features emerge early in speech acquisition. Based on a biologically inspired model of speech processing, using interconnected growing self-organizing maps (I-GSOMs), the phonetic–phonological interface is described here in terms of a numerical computer-implemented model. By simulating early phases of speech acquisition, it can be shown that vocalic features like low–high as well as consonantal features describing the manner of articulation (like plosive, fricative, nasal, lateral, etc.) already arise at sensorimotor levels. This is reflected in our model by an ordering of syllables with respect to phonetic–phonological features at the level of an auditory based neural map. Other features like consonantal place of articulation (labial, apical, dorsal) as well as voiced–voiceless emerge at higher levels within our model, i.e. at the level of neural associations between a phonetic and a semantic neural map. It can be hypothesized from these findings that the phonetic–phonological interface does not appear as a clean cut within the speech processing system but as a broader zone within that system located between sensorimotor and semantic processing.