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Timing and communication of parietal cortex for visuomotor control
No full textIn both monkeys and humans, motor cognition emerges from a parietal-frontal network containing discrete dominant domains of visual, eye and hand signals, where neurons are responsible for goal and effector selection. Within these domains, the combination of different inputs shape the tuning properties of neurons, while local and long cortico-cortical connections outline the architecture of the distributed network and determine the conduction time underlying eye-hand coordination, necessary for visually guided operations in the action space. The analysis of the communication timing between parietal and frontal nodes of the network helps understanding the sensorimotor cortical delays associated to different functions, such as online control of movement and eye-hand coordination, and opens a new perspective to the study of the parieto-frontal interactions
NS.2.4 - SOCIAL ISOLATION EPISODES DURING PERI-ADOLESCENCE INDUCE DEPRESSION-LIKE PHENOTYPE AND EPIGENETIC MODIFICATIONS COMMON TO BRAIN AND BLOOD IN ADULT MICE
No full textPosterior parietal cortex encoding of dynamic hand force underlying hand–object interaction
Full text linkMajor achievements of primate evolution are skilled hand-object interaction and tool use, both in part dependent on parietal cortex expansion. We recorded spiking activity from macaque inferior parietal cortex during directional manipulation of an isometric tool, which required the application of hand forces to control a cursor's motion on a screen. In areas PFG/PF, the activity of ∼70% neurons was modulated by the hand force necessary to implement the desired target motion, reflecting an inverse model, rather than by the intended motion of the visual cursor (forward model). The population vector matched the direction and amplitude of the instantaneous force increments over time. When exposed to a new force condition, that obliged the monkey to change the force output to successfully bring the cursor to the final target, the activity of a consistent subpopulation of neurons changed in an orderly fashion and, at the end of a "Wash-out" session, retained memory of the new learned association, at the service of predictive control of force. Our findings suggest that areas PFG/PF represent a crucial node of the distributed control of hand force, by encoding instantaneous force variations and serving as a memory reservoir of hand dynamics required for object manipulation and tool use. This is coherent with previous studies in humans showing the following: (1) impaired adaptation to a new force field under TMS parietal perturbation; (2) defective control of direction of hand force after parietal lesion; and (3) fMRI activation of parietal cortex during object manipulation requiring control of fine hand forces
Impairment of Online Control of Hand and Eye Movements in a Monkey Model of Optic Ataxia
No full textThe parietal mechanisms for online control of hand trajectory were studied by combining single-cell recording and reversible inactivation of superior parietal area 5 (PE/PEc; SPL) of monkeys while these made reaches and saccades to visual targets, when the target position changed unexpectedly. Neural activity was modulated by hand position, speed, and movement direction, and by pre- and/or postsaccadic signals. After bilateral muscimol injection, an increase in the hand reaction- and movement-time toward both the first and second targets was observed. This caused an increase in the time necessary for the trajectory correction, and therefore an elongation of the hand-path toward the first target location. Furthermore, hand trajectories were different in shape than control ones. An elongation of the eye reaction time to both first and second targets was also observed, which could partially explain the deficit of planning and correction of hand movement. These results identify the superior parietal lobule as a crucial node in the online control of hand and eye movement and highlight the role of the eye impairment in the emergence of the reaching disorder so far regarded as the hallmark of optic ataxia
Computational architecture of the parieto-frontal network underlying cognitive-motor control in monkeys
Full text linkThe statistical structure of intrinsic parietal and parieto-frontal connectivity in monkeys was studied through hierarchical cluster analysis. Based on their inputs, parietal and frontal areas were grouped into different clusters, including a variable number of areas that in most instances occupied contiguous architectonic fields. Connectivity tended to be stronger locally: that is, within areas of the same cluster. Distant frontal and parietal areas were targeted through connections that in most instances were reciprocal and often of different strength. These connections linked parietal and frontal clusters formed by areas sharing basic functional properties. This led to five different medio-laterally oriented pillar domains spanning the entire extent of the parieto-frontal system, in the posterior parietal, anterior parietal, cingulate, frontal, and prefrontal cortex. Different information processing streams could be identified thanks to inter-domain connectivity. These streams encode fast hand reaching and its control, complex visuomotor action spaces, hand grasping, action/intention recognition, oculomotor intention and visual attention, behavioral goals and strategies, and reward and decision value outcome. Most of these streams converge on the cingulate domain, the main hub of the system. All of them are embedded within a larger eye-hand coordination network, from which they can be selectively set in motion by task demands
S.8.2 - EXPOSURE TO AGGRESSIVE ENVIRONMENT DURING THE PERIADOLESCENT PERIOD INDUCES VULNERABILITY TO DRUG-ADDICTION BEHAVIOR IN ADULT MICE
No full textDo non-human primates cooperate? Evidences of motor coordination during a joint action task in macaque monkeys
No full textHumans are intensively social primates, therefore many of their actions are dedicated to communication and interaction with other individuals. Despite the progress in understanding the cognitive and neural processes that allow humans to perform cooperative actions, in non-human primates only few studies have investigated the ability to interact with a partner in order to reach a common goal. These studies have shown that in naturalistic conditions animals engage in various types of social behavior that involve forms of mutual coordination and cooperation. However, little is known on the capacity of non-human primates to actively cooperate in a controlled experimental setting, which allows full characterization of the motor parameters underlying individual action and their change during motor cooperation. To this aim, we analyzed the behavior of three pairs of macaque monkeys trained to perform solo and joint-actions by exerting a force on an isometric joystick, as to move an individual or a common cursor toward visual targets on a screen. We found that during cooperation monkeys reciprocally adapt their behavior by changing the parameters that define the spatial and temporal aspects of their action, as to fine tune their joint effort, and maximize their common performance. Furthermore the results suggest that when acting together the movement parameters that specify each actor's behavior are not only modulated during execution, but also during planning. These findings provide the first quantitative description of action coordination in non-human primates during the performance of a joint action task
Depression in the Mirror: Depression Severity and Its Link to Negative Judgments of Symptoms
No full textBackground and Objectives: Depressive states represent a normal and physiological response to the experience of loss. However, it is possible to identify some elements that allow distinguishing physiological depressive states from pathological ones. Over the years, research has confirmed that a stable tendency to negative self-evaluation is a transdiagnostic factor that triggers and amplifies dysfunctional emotional reactivity, thus contributing to the shift from normal to pathological reaction. In this sense, the secondary problem, or meta-emotional problem, referring to the negative evaluation of one's depressive state and the consequent dysfunctional attempts to solve it, seems to play an important role. The aim of the present study is to investigate how dysfunctional beliefs and the evaluations of depressive symptoms (meta-emotional problems) are related to depression severity.
Methods: We asked to a community sample to focus on the depressive symptoms they regard as most distressful and evaluate them through specific questionnaires. One-hundred and eighty nine participants were asked to complete a set of questionnaires: (1) the Meta-Emotional Problem Questionnaire; (2) the Center for Epidemiologic Studies Depression Scale; (3) the Beck Depression Inventory; (4) the Dysfunctional Attitude Scale-24 in order to investigate the relation between dysfunctional beliefs, meta-emotional problems, and depressive symptoms severity.
Results: Our results show that higher levels of depression are associated both to more pervasive dysfunctional attitudes and increased evaluation of meta-emotional problem. In addition, we conduct a regression analysis to disentangle the impact of the two different measures of depressive symptoms (i.e., BDI-II and CES-D) with two explanatory variables (dysfunctional attitudes and meta-emotional problem). Results show that meta-emotional problem remains a significant and robust predictor of the severity of depressive symptomatology, while dysfunctional beliefs has a rather weak and non-significant relation with the criterion. In other words, meta-emotional problem consistently explains the higher variance of depressive symptoms than dysfunctional beliefs. In conclusion, our study shows a clear link between meta-emotional problem and depression severity. This is relevant for clinical practice, as it highlights the importance of specifically targeting beliefs about the depressive condition in cognitive-behavioral treatment of depression, since they represent crucial factors maintaining depressive symptomatologies
Development of motor coordination during joint action in mid-childhood
No full textThe ability to act jointly with others is a hallmark of primate evolution and is fundamental for human development. In recent years, the study of coordination strategies between individuals performing joint actions has received growing attention. However, when, in the course of post-natal development, this cognitive-motor function emerges is still unknown. Here, we studied dyads of peers aged 6-9 years, as well as adult subjects, while they performed a task where the same action, namely, exerting hand force on an isometric joystick to move a visual cursor from a central toward a peripheral target, was performed in a "solo" and in a social "cooperative" context. The results revealed that during joint action planning, an attempt to synchronize one's own action with that of a partner emerges at 7 years of age, together with a reduction in the duration and variability of the reaction times. A critical time is 8 years, when "solo" performance reaches a high level of accuracy. From this age, another coordination strategy, based on the online monitoring of the peer's behavior, seems to be implemented during the execution of joint action. The motor and cognitive development occurring during childhood are discussed as possible mechanisms mediating, respectively, the capability and the propensity to take into account the peer's behavior for implementing a common action plan
Understanding Trauma in IPV: Distinguishing Complex PTSD, PTSD, and BPD in Victims and Offenders
Full text linkThis work aims to shed light on the differential diagnosis of complex post-traumatic stress disorder (cPTSD), post-traumatic stress disorder (PTSD), and borderline personality disorder (BPD) within the context of intimate partner violence (IPV), which represents a highly innovative field of clinical research. To this end, a critical review of the literature was conducted to identify and compare the clinical patterns and symptomatic overlaps among cPTSD, PTSD, and BPD, with an emphasis on their manifestation in both IPV victims and offenders. The results show that despite some symptomatic similarities, cPTSD, PTSD, and BPD have distinct clinical patterns of interpersonal violence. Specifically, disturbances in self-organization (DSO) are more commonly found in offenders, while the diagnosis of cPTSD seems more aligned with the psychological functioning of victims. In addition, cPTSD and specific characteristics of BPD, such as fear of rejection and instability of identity, constitute risk factors for IPV victimization. cPTSD is shown as a predisposing factor not only for IPV victims but also for offenders, while PTSD emerges as a consequential factor. The specific pathways linking PTSD, cPTSD, and BPD with IPV have significant implications for clinical practice. Further research is needed to understand these profiles and the mechanisms linking trauma-related features to IPV, which is crucial for implementing effective violence prevention programs
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