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Decision-making is in the service of action regardless of whether the decision concerns perceptual information, goods or memories. Compared to recent advances in the neurobiology of perceptual or value-based decisions, however, the neural bases supporting the sampling of evidence in long-term memory, and the transformation of memory-based decisions into appropriate actions, are still poorly understood. In the present fMRI study, we used multivariate pattern analysis to investigate the temporal dynamics of choice- and action-predictive signals during an item recognition task that manipulated the association between memory choices (old/new) and motor responses (eye/hand) across subjects. Choice-predictive activity was mainly observed in striatal, lateral prefrontal and lateral parietal regions, was sensitive to the amount of decision evidence and showed a rapid increase after stimulus onset, followed by a fast decay. Action-predictive signals were found in primary sensory motor, premotor and occipito–parietal regions, were generally observed at the end of the decision phase and were not modulated by decision evidence. These findings suggest that a memory decision variable, potentially represented in a fronto–striato–parietal network, is not directly transformed into an action plan as often observed in perceptual decisions. Regions exhibiting choice predictive activity, and especially the striatum, however, also showed a second peak of decision-related activity that, unlike pure choice- or action-predictive signals, depended on the particular choice–response association. This second peak of activity in the striatum might represent the neural signature of the transformation of a memory decision into an appropriate motor response based on the specific choice–response association. Electronic supplementary material The online version of this article (10.1007/s00429-020-02124-4) contains supplementary material, which is available to authorized users.

Motor awareness is the acknowledgment of (i) one's motor state while executing a movement or remaining still and (ii) one's motor abilities. The integrated contribution of different networks involving the parietal cortex, medial and lateral frontal regions, and subcortical structures gives rise to motor awareness. The damage to these structures or their disconnection results in a number of motor awareness disorders, such as the well-known Anosognosia for hemiplegia and apraxia, and the Anarchic Hand Syndrome. The deficit of motor awareness may also be present in other disorders such as Parkinson's and Huntington's diseases, Tics, and Tourette's Syndrome.

Introduction Evidence about altered bimanual coordination has been reported in Parkinson's Disease. However, no previous study has explored such an alteration quantifying the interference effect that the trajectory of each hand might impose on the other one. Thus, in the present research, we applied the traditional Circles-Lines Coupling Task, which allowed assessing the motor coordination of the two hands, in the context of Parkinson's Disease. Methods Thirty-six individuals affected by Parkinson's Disease were consecutively recruited and assigned to two groups according to their symptoms' lateralization. Moreover, eighteen age-matched healthy controls participated in the study. We capitalized on the Circles-Lines Coupling Task, in which the performance during incongruent movements (drawing lines with one hand and circles with the other hand) was compared with the performance during congruent movements (drawing lines with both hands). A bimanual coupling index was computed to compare the interference effect of each hand on the other one. Results In healthy controls, the bimanual coupling index did not differ between the two hands. Crucially, in both groups of individuals affected by Parkinson's Disease, the less affected hand showed a significantly higher bimanual coupling index, due to the abnormal interference exerted by the most affected one, than vice versa. Conclusions Our results highlighted an altered spatial bimanual coupling in Parkinson's disease, depending on the symptoms' lateralization. We offered different explanations of our results according to the theoretical frameworks about the mechanisms subserving bimanual coordination.

Right brain damaged patients sometimes deny that their left arm is paralysed or even claim to have just moved it. This condition is known as anosognosia for hemiplegia (AHP). Here, we used fMRI to study patients with and without AHP during the execution of a motor task. We found that the delusional belief of having moved was preceded by brain activation of the cortical regions that are implicated in motor control in the left intact hemisphere and in the spared motor regions of the right hemisphere; patients without anosognosia did not present with the same degree of activation. We conclude that the false belief of movement is associated with a combination of strategically placed brain lesions and the preceding residual neural activity of the fronto-parietal motor network. These findings provide evidence that the activity of motor cortices contributes to our beliefs about the state of our motor system.

In anosognosia for hemiplegia, patients may claim having performed willed actions with the paralyzed limb despite unambiguous evidence to the contrary. Does this false belief of having moved reflect the functioning of the same mechanisms that govern normal motor performance? Here, we examined whether anosognosics show the same temporal constraints known to exist during bimanual movements in healthy subjects. In these paradigms, when participants simultaneously reach for two targets of different difficulties, the motor programs of one hand affect the execution of the other. In detail, the movement time of the hand going to an easy target (i.e., near and large), while the other is going to a difficult target (i.e., far and small), is slowed with respect to unimanual movements (temporal coupling effect). One right-brain-damaged patient with left hemiplegia and anosognosia, six right-brain-damaged patients with left hemiplegia without anosognosia, and twenty healthy subjects were administered such a bimanual task. We recorded the movement times for easy and difficult targets, both in unimanual (one target) and bimanual (two targets) conditions. We found that, as healthy subjects, the anosognosic patient showed coupling effect. In bimanual asymmetric conditions (when one hand went to the easy target and the other went to the difficult target), the movement time of the non-paralyzed hand going to the easy target was slowed by the ‘pretended’ movement of the paralyzed hand going to the difficult target. This effect was not present in patients without anosognosia. We concluded that in anosognosic patients, the illusory movements of the paralyzed hand impose to the non-paralyzed hand the same motor constraints that emerge during the actual movements. Our data also support the view that coupling relies on central operations (i.e., activation of intention/programming system), rather than on online information from the periphery.

Fresh empirical evidence supports the notion that fear of movement-related pain can be acquired through associative learning. In the context of these findings, 2 ideas are appealing, yet uninvestigated. The first is that merely the intention to perform a painful movement acts as a covert conditioned stimulus (CS) inducing defensive fear responses (ie, gaining excitatory properties following Pavlovian acquisition). The second idea is that after extinction, fear of movement-related pain can easily be reinstated after unexpected painful stimuli (ie, reinstatement). In a voluntary differential conditioning movement paradigm with movements as CSs and a painful electrocutaneous stimulus as the unconditioned stimulus (pain-US), 2 groups were included (Experimental/Control). One movement (CS+) was followed by the pain-US and another movement (CS) was not during acquisition, while the CS+ was no longer reinforced during extinction. Next, the Experimental group received 2 reinstating pain-USs, whereas the Control group did not. The CS+ but not the CS evoked fear of movement-related pain in self-reports and eye-blink startles. Intriguingly, the mere intention to perform the painful movement produced higher eye-blink startle responses than the intention to perform the nonpainful movement. We also demonstrated nondifferential reinstatement in the verbal fear ratings in the Experimental group only. Perspective: This study demonstrates that the mere intention to perform a painful movement prior to the actual painful movement itself can come to elicit conditioned fear responses. These results suggest that actual movement may not be necessary to elicit pain-related fear responses, maintaining chronic pain-related fear, avoidance, and disability. (C) 2013 by the American Pain Society

To optimise speed and accuracy of motor behaviour, we can prepare not only the type of movement to be made but also the time at which it will be executed. Previous cued reaction-time paradigms have shown that anticipating the moment in time at which this response will be made (“temporal orienting”) or selectively preparing the motor effector with which an imminent response will be made (motor intention or “motor orienting”) recruits similar regions of left intraparietal sulcus (IPS), raising the possibility that these two preparatory processes are inextricably co-activated. We used a factorial design to independently cue motor and temporal components of response preparation within the same experimental paradigm. By differentially cueing either ocular or manual response systems, rather than spatially lateralised responses within just one of these systems, potential spatial confounds were removed. We demonstrated that temporal and motor orienting were behaviourally dissociable, each capable of improving performance alone. Crucially, fMRI data revealed that temporal orienting activated the left IPS even if the motor effector that would be used to execute the response was unpredictable. Moreover, temporal orienting activated left IPS whether the target required a saccadic or manual response, and whether this response was left- or right-sided, thus confirming the ubiquity of left IPS activation for temporal orienting. Finally, a small region of left IPS was also activated by motor orienting for manual, though not saccadic, responses. Despite their functional independence therefore, temporal orienting and manual motor orienting nevertheless engage partially overlapping regions of left IPS, possibly reflecting their shared ontogenetic roots., Research Highlights ►Anticipating when and how to respond can be functionally and neurally dissociated. ►Temporal orienting (when) engages left IPS for both oculomotor and manual responses. ►Motor orienting (how) engages left IPS only for manual, not oculomotor, responses. ►Manual action circuits may be functionally recycled for anticipating when to respond.

Motion perception is a fundamental feature of the human visual system. As part of our daily life we often have to determine the direction of motion, even in ambiguous situations. These situations force us to rely on exogenous cues, such as other environmental motion, endogenous cues, such as our own actions, or previously learned experiences. In three experiments, we asked participants to report the direction of an ambiguous motion display, manipulating exogenous and endogenous sources of information. Specifically, in all three experments the exogenous information was represented by another motion cue while the endogenous cue was represented respectively by movement execution, movement planning, or a learned association about the motion display. Participants were consistently biased by stable motion cues in the environment when reporting the ambiguous target direction. In the absence of stable exogenous motion information, participants were biased by their motor movements and even the planning of such movements. However, when participants learned a specific association about the target motion, this acquired endogenous knowledge countered exogenous motion cues in biasing participants’ perception. Taken together, our findings demonstrate that we disambiguate ambiguous motion using different sources of exogenous and endogenous cues, and that learned associations may be particularly salient in countering the biasing effects of environmental cues.

When given a choice between actions that yield the same reward, we tend to prefer the one that requires the least effort. Recent studies have shown that humans are remarkably accurate at evaluating the effort of potential reaching actions and can predict the subtle energetic demand caused by the nonisotropic biomechanical properties of the arm. In the present study, we investigated the time course over which such information is computed and comes to influence decisions. Two independent approaches were used. First, subjects performed a reach decision task in which the time interval for deciding between two candidate reaching actions was varied from 200 to 800 ms. Second, we measured motor-evoked potential (MEPs) to single-pulse transcranial magnetic stimulation (TMS) over the primary motor cortex (M1) to probe the evolving decision at different times after stimulus presentation. Both studies yielded a consistent conclusion: that a prediction of the effort associated with candidate movements is computed very quickly and influences decisions within 200 ms after presentation of the candidate actions. Furthermore, whereas the MEPs measured 150 ms after stimulus presentation were well correlated with the choices that subjects ultimately made, later in the trial the MEP amplitudes were primarily related to the muscular requirements of the chosen movement. This suggests that corticospinal excitability (CSE) initially reflects a competition between candidate actions and later changes to reflect the processes of preparing to implement the winning action choice.

International audience; Tool-use representations have been suggested to be supported by the representation of hand actions and/or by the representation of tool actions. A major issue is to know which one of these two representations is preferentially activated when people intend to use a tool. To address this issue, we developed a paradigm in which, in 20% of trials, participants had to press a button and actually use pliers to move an object in response to a predefined target symbol. Importantly, two masks hiding the symbols performed “opening” or “closing” actions before symbols appeared. In Experiment 1, participants used normal pliers: Hand’s opening actions induced pliers’ opening actions and vice versa for hands’ closing actions. Results indicated a compatibility effect between masks’ actions and pliers’ actions. Participants were faster to press the button in response to the target symbol when opening and closing actions of the masks were congruent with the corresponding actions of the hand. In Experiment 2 participants used inverse pliers: Hand’s opening actions involved pliers’ closing actions and vice versa. In this situation, results showed that the congruency of masks’ actions occurred with pliers’ actions and not hand’s actions. Altogether, these findings demonstrate that intention of use is preferentially based on the representation of tool actions, and have important implications for the domain of neuropsychology of tool use and the theories of goal-directed behavior.

The neuropsychological disorder known as agnosia refers to the impairment of stimulus recognition in one modality in the absence of perceptual deficits, memory problems, and general intellectual impairment. This disorder is intriguing, both scientifically and clinically, and its study has contributed to shed light on how the normal visual system functions. Here, we focus specifically on the neuropsychological studies of agnosia and provide a broad overview of the wide range of impairments characterized by lack of knowledge, including visual agnosia, prosopagnosia, agnosia for words, tactile agnosia and color agnosia. A separate section is devoted to anosognosia, which is the denial of illness or of the symptoms of a particular disease usually associated with a specific brain damage.

In learning models of strategic game play, an agent constructs a valuation (action value) over possible future choices as a function of past actions and rewards. Choices are then stochastic functions of these action values. Our goal is to uncover a neural signal that correlates with the action value posited by behavioral learning models. We measured activity from neurons in the superior colliculus (SC), a midbrain region involved in planning saccadic eye movements, in monkeys while they performed two saccade tasks. In the strategic task, monkeys competed against a computer in a saccade version of the mixed-strategy game “matching-pennies”. In the instructed task, stochastic saccades were elicited through explicit instruction rather than free choices. In both tasks, neuronal activity and behavior were shaped by past actions and rewards with more recent events exerting a larger influence. Further, SC activity predicted upcoming choices during the strategic task and upcoming reaction times during the instructed task. Finally, we found that neuronal activity in both tasks correlated with an established learning model, the Experience Weighted Attraction model of action valuation (Ho, Camerer, and Chong, 2007). Collectively, our results provide evidence that action values hypothesized by learning models are represented in the motor planning regions of the brain in a manner that could be used to select strategic actions.

Although it is well established that parietal cortex is important in processing sensorimotor transformations, less is known about the neuronal dynamics of this process in humans. Using magnetoencephalography, we investigated the dynamics of parietal oscillatory activity during saccade planning in terms of sensory and motor goal processing. In the experiments, a peripheral stimulus was flashed in either the left or right hemifield, followed by a 1.5 s delay period, after which the subject executed a saccade toward (prosaccade) or away from (antisaccade) the stimulus. In response to stimulus presentation, we observed an initial increase in gamma-band power (40–120 Hz) in a region in the posterior parietal cortex contralateral to the direction of the stimulus. This lateralized power enhancement, which was sustained in a more narrow frequency band (85–105 Hz) during the delay period of prosaccades, mapped to the hemisphere contralateral to the direction of the saccade goal during the delay period of antisaccades. These results suggest that neuronal gamma-band synchronization in parietal cortex represents the planned direction of the saccade, not the memorized stimulus location. In the lower-frequency bands, we observed sustained contralateral alpha (7–13 Hz) power suppression after stimulus presentation in parieto-occipital regions. The dynamics of the alpha band was strongly related to the processing of the stimulus and showed only modest selectivity for the goal of the saccade. We conclude that parietal gamma-band synchronization reflects a mechanism to encode the motor goals in the visuomotor processing for saccades.

Experiments in monkeys demonstrated that many parietal and premotor neurons coding a specific motor act (e.g., grasping) show a markedly different activation when this act is part of actions that have different goals (e.g., grasping for eating vs. grasping for placing). Many of these “action-constrained” neurons have mirror properties firing selectively to the observation of the initial motor act of the actions to which they belong motorically. By activating a specific action chain from its very outset, this mechanism allows the observers to have an internal copy of the whole action before its execution, thus enabling them to understand directly the agent's intention. Using electromyographic recordings, we show that a similar chained organization exists in typically developing children, whereas it is impaired in children with autism. We propose that, as a consequence of this functional impairment, high-functioning autistic children may understand the intentions of others cognitively but lack the mechanism for understanding them experientially.

International audience; Recent advances in the cognitive neuroscience of action have considerably enlarged our understanding of human motor cognition. In particular, the activity of the mirror system, first discovered in the brain of non-human primates, provides an observer with the understanding of a perceived action by means of the motor simulation of the agent's observed movements. This discovery has raised the prospects of a motor theory of social cognition. In humans, social cognition includes the ability to mindread, and many motor theorists of social cognition try to bridge the gap between motor cognition and mindreading by endorsing a simulation account of mindreading. Here, we question the motor theory of social cognition and give reasons for our skepticism.

In everyday life, we constantly act and interact with objects and with others’ people through our body. To properly perform actions, the representations of the dimension of body-parts (metric body representation, BR) and of the space surrounding the body (peripersonal space, PPS) need to be constantly updated. Previous evidence has shown that BR and PPS representation are highly flexible, being modulated by sensorimotor experiences, such as the active use of tools to reach objects in the far space. In this study, we investigate whether the observation of another person using a tool to interact with objects located in the far space is sufficient to influence the plasticity of BR and PPS representation in a similar way to active tool-use. With this aim, two groups of young healthy participants were asked to perform 20 min trainings based on the active use of a tool to retrieve far cubes (active tool-use) and on the first-person observation of an experimenter doing the same tool-use training (observational tool-use). Behavioural tasks adapted from literature were used to evaluate the effects of the active and observational tool-use on BR (body-landmarks localization task-group 1), and PPS (audio-tactile interaction task – group 2). Results show that after active tool-use, participants perceived the length of their arm as longer than at baseline, while no significant differences appear after observation. Similarly, significant modifications in PPS representation, with comparable multisensory facilitation on tactile responses due to near and far sounds, were seen only after active tool-use, while this did not occur after observation. Together these results suggest that a mere observational training could not be sufficient to significantly modulate BR or PPS. The dissociation found in the active and observational tool-use points out differences between action execution and action observation, by suggesting a fundamental role of the motor planning, the motor intention, and the related sensorimotor feedback in driving BR and PPS plasticity.