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While it is well documented that the motor system is more than a mere implementer of motor actions, the possible applications of its cognitive side are still under-exploited, often remaining as poorly organized evidence. Here, we will collect evidence showing the value of action observation treatment (AOT) in the recovery of impaired motor abilities for a vast number of clinical conditions, spanning from traumatological patients to brain injuries and neurodegenerative diseases. Alongside, we will discuss the use of AOT in the maintenance of appropriate motor behavior in subjects at risk for events with dramatic physical consequences, like fall prevention in elderly people or injury prevention in sports. Finally, we will report that AOT can help to tune existing motor competencies in fields requiring precise motor control. We will connect all these diverse dots into the neurophysiological scenario offered by decades of research on the human mirror mechanism, discussing the potentialities for individualization. Empowered by modern technologies, AOT can impact individuals' safety and quality of life across the whole lifespan., (Copyright © 2021. Published by Elsevier Ltd.)

The aim of the present review is to discuss the localization of circuits that allow recognition of emotional facial expressions in blindsight patients. Because recognition of facial expressions is function of different centers, and their localization is not always clear, we decided to discuss here three emotional facial expression - smiling, disgust, and fear - whose anatomical localization in the pregenual sector of the anterior cingulate cortex (pACC), anterior insula (AI), and amygdala, respectively, is well established. We examined, then, the possible pathways that may convey affective visual information to these centers following lesions of V1. We concluded that the pathway leading to pACC, AI, and amygdala involves the deep layers of the superior colliculus, the medial pulvinar, and the superior temporal sulcus region. We suggest that this visual pathway provides an image of the observed affective faces, which, although deteriorated, is sufficient to determine some overt behavior, but not to provide conscious experience of the presented stimuli., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The internal state of others can be understood observing their actions or listening to their voice. While the neural bases of action style (vitality forms) have been investigated, there is no information on how we recognize others' internal state by listening to their speech. Here, using fMRI technique, we investigated the neural correlates of auditory vitality forms while participants listened to action verbs in three different conditions: human voice pronouncing the verbs in a rude and gentle way, robot voice pronouncing the same verbs without vitality forms, and a scrambled version of the same verbs pronounced by human voice. In agreement with previous studies on vitality forms encoding, we found specific activation of the central part of insula during listening to human voice conveying specific vitality forms. In addition, when listening both to human and robot voices there was an activation of the posterior part of the left inferior frontal gyrus and of the parieto-premotor circuit typically described to be activated during observation and execution of arm actions. Finally, the superior temporal gyrus was activated bilaterally in all three conditions. We conclude that, the central part of insula is a key region for vitality forms processing allowing the understanding of the vitality forms regardless of the modality by which they are conveyed., (Copyright © 2016. Published by Elsevier Ltd.)

Through his whole life Marc Jeannerod was fascinated by Freud's thinking. His interest in Freud is witnessed by several of his writings in which he expresses interest in building a bridge between psychoanalysis and cognitive neuroscience. Following Jeannerod's ideas we discuss here a fundamental point of Freud's construction, the concept of ego, from a neurophysiological point of view. We maintain that, in order both to act coherently and to have a basic, first person, understanding of the behavior of others, it is necessary to posit the existence of a neurophysiological "motor" ego similar to the "rider" of the Freudian metaphor. We review then a series of neurophysiological findings showing that the systems underlying the organization of action and conscious perception are both mediated by a cortical motor network formed by parieto-frontal circuits. In conclusion, we show that the activity of this network has strong similarities to that postulated by Freud for the conscious part of ego. We also propose that the default-mode network might represent that part of ego that is mostly involved in unconscious processes., (© 2013 Published by Elsevier Ltd.)

Along with the understanding of the goal of an action ("what" is done) and the intention underlying it ("why" it is done), social interactions largely depend on the appraisal of the action from the dynamics of the movement: "how" it is performed (its "vitality form"). Do individuals with autism, especially children, possess this capacity? Here we show that, unlike typically developing individuals, individuals with autism reveal severe deficits in recognizing vitality forms, and their capacity to appraise them does not improve with age. Deficit in vitality form recognition appears, therefore, to be a newly recognized trait marker of autism., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

A hand grasping a cup or gesturing "thumbs-up", while both manual actions, have different purposes and effects. Grasping directly affects the cup, whereas gesturing "thumbs-up" has an effect through an implied verbal (symbolic) meaning. Because grasping and emblematic gestures ("emblems") are both goal-oriented hand actions, we pursued the hypothesis that observing each should evoke similar activity in neural regions implicated in processing goal-oriented hand actions. However, because emblems express symbolic meaning, observing them should also evoke activity in regions implicated in interpreting meaning, which is most commonly expressed in language. Using fMRI to test this hypothesis, we had participants watch videos of an actor performing emblems, speaking utterances matched in meaning to the emblems, and grasping objects. Our results show that lateral temporal and inferior frontal regions respond to symbolic meaning, even when it is expressed by a single hand action. In particular, we found that left inferior frontal and right lateral temporal regions are strongly engaged when people observe either emblems or speech. In contrast, we also replicate and extend previous work that implicates parietal and premotor responses in observing goal-oriented hand actions. For hand actions, we found that bilateral parietal and premotor regions are strongly engaged when people observe either emblems or grasping. These findings thus characterize converging brain responses to shared features (e.g., symbolic or manual), despite their encoding and presentation in different stimulus modalities., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Williams syndrome (WS) is a rare genetic disorder associated with unusually hyper-social demeanor and ease with strangers. These personality traits are accompanied by difficulties in social interactions, possibly related, at least in part, to a difficulty in understanding others' mental states. Studies on mentalizing capacities in individuals with WS have often led to contrasting results, some studies revealing specific impairments, others highlighting spared mentalizing capacities. So far, however, no study investigated the performance of individuals with WS in non-inferential understanding of others' motor intentions. In the present study we investigated this capacity by using a computer-based behavioral task using pictures of hand-object interactions. We asked individuals with WS first to describe what the other was doing (i.e. a task implying no kind of intention reading), and secondly, if successful in answering the first question, to describe the motor intention underlying the observed motor acts (i.e. why an act was being done, a task requiring non-inferential motor intention understanding). Results showed that individuals with WS made more errors in understanding what the other was doing (i.e. understanding a motor act) compared to both mental-age matched controls and chronological-age matched peers with typical development, while showing mental-age appropriate performance in understanding why an individual was acting (i.e. understanding a motor intention). These findings suggest novel perspectives for understanding impairments in social behavior in WS., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

The relations between stimuli triggering a hand grasping movement and the subsequent action were studied in normal human participants. Participants were instructed to prepare to grasp a bar, oriented either clockwise or counterclockwise, and to grasp it as fast as possible on presentation of a visual stimulus with their right hand. The visual stimuli were pictures of the right hand as seen in a mirror. In Experiment 1, they represented the mirror image of the hand final posture as achieved in grasping the bar oriented either clockwise or counterclockwise. In Experiment 2, in addition to the pictures of Experiment 1, another two pictures, obtained rotating the hands represented in the previous ones of 90 degrees, were also used. Both experiments showed that the reaction times were faster when there was a similarity between hand position as depicted in the triggering visual stimulus and the grasping hand final position, the fastest responses being those where this similarity was the closest. In addition, Experiment 2 showed that reaction times to not rotated stimuli were faster than reaction times to the rotated stimuli, thus excluding a simple stimulus-response compatibility explanation of the findings. The data are interpreted as behavioral evidence that there is a close link between specific visual stimuli and specific motor actions. A neurophysiological model for this visuo-motor link is presented.

The main aim of the present study was to clarify whether different types of grasping may affect the transport component of prehension movements. To this purpose two experiments were carried out. In the first experiment the kinematics of arm movements (transport and manipulation components) were studied in eight normal subjects instructed to reach and grasp different objects located either 20 or 30 cm from their hand. The objects employed required two different types of grip: prehension with the whole hand and prehension with the index finger and the thumb (precision grip). In the second experiment subjects were instructed to point to the same objects employed in the first experiment. This experiment served as a control for the precision requirements related to the object size. The results showed that, once the precision requirements were taken into account, the transport component remained unmodified with the different types of grip. The time course of the manipulation component and its temporal relations with the transport component changed with the type of grasping. The maximal hand aperture was reached earlier in the precision grip than in the whole hand prehension and the temporal coupling with the transport component was weaker in the former condition than in the latter. The data are interpreted as further evidence in favour of independence between the transport and the manipulation "channels".

Simple reaction times (RTs) to lateralized unstructured visual stimuli were measured in normal subjects while they were carrying out concomitant oculomotor tasks. Four tasks were used. In the first task, subjects had to find the correct path in a maze presented at the centre of a screen; in the second task, subjects had to follow a bright dot moved on a screen with variable direction, trajectory and velocity with their eyes; in the third task, the subjects had to follow a bright dot moved back and forth either horizontally or vertically along the same trajectory and at a constant velocity; in the fourth task, the subjects had to monitor the movement of a bright dot moved with variable direction, trajectory and velocity without moving the eyes. In all tasks, with the exception of the third, there was a selective lengthening of RTs mediated by the right hemisphere. It is concluded that the right hemisphere is dominant in programming eye movements.

Simple reaction times to lateralized unstructured visual stimuli were measured in normal subjects while they were carrying out concomitant left hemisphere tasks. Three tasks were used. In the first task the subjects had to pay attention to strings of digits, acoustically presented, and detect letters randomly interspersed among the digits; in the second task the subjects had to memorize strings of acoustically presented digits; in the third task they had to repeat each digit of a string as soon as they heard it. In spite of the greater difficulty of the first two tasks with respect to the third one, only this last task, the only one requiring a verbo-motor response, produced a significant disadvantage for the left hemisphere responses to light. It is argued that in RT experiments a specific left hemisphere interference takes place when the secondary task requires the organization of a motor response

Six experiments were conducted to examine the effect of various attentional manipulations on reaction time to visual stimuli. The first three experiments compared the responses to stimuli presented in the depth (Experiment 1), along the horizontal (Experiment 2), and vertical (Experiment 3) meridians in a valid condition (stimulus presented in the cued position), an invalid condition (stimulus presented in the alternative position to the cued position) and a neutral condition (no information on stimulus position). The most interesting result was the demonstration that attention can be moved along the sagittal plane in the absence of vergence eye movements and that when attention is focused on a certain point, unattended points between this point and the observer (i.e. near points) are responded faster than unattended points beyond it (i.e. far points). In the frontal plane no asymmetry was found between the responses to unattended points above or below the fixation, whereas a certain, albeit non-constant, advantage was present for unattended stimuli on the right of the fixation point in respect to those on the left of it. The second series of experiments was similar to the first one, except that a new situation was introduced in which the fixation point was cued and stimuli could appear either in correspondence to it or in a peripheral position (invalid condition with attention at the fixation point). The results showed that in this new situation the responses to unattended stimuli are much longer than they are under neutral conditions, and as long as they are under conventional invalid condition. It is suggested that the so called neutral condition is a condition of diffuse attention and an attempt is made to explain it in terms of a premotor theory of attention.

Two experiments are described in which simple reaction times (RTs) to lateralized visual stimuli were measured in normal subjects during negative affect and during recollection of everyday life scenes. In both experiments the mental activity produced a remarkable increase of RTs with respect to a control situation without interfering activity. During production of the negative affect there was a selective lengthening of RTs mediated by the right hemisphere. The role of the right hemisphere in producing emotions is discussed.

Stimuli presented in a non-attended location are responded to much slower than stimuli presented in an attended one. The hypotheses proposed to explain this effect make reference to covert movement of attention, hemifield inhibition, or attentional gradients. The experiment reported here was aimed at discriminating among these hypotheses. Subjects were cued to attend to one of four possible stimulus locations, which were arranged either horizontally or vertically, above, below, to the right or left of a fixation point. The instructions were to respond manually as fast as possible to the occurrence of a visual stimulus, regardless of whether it occurred in a cued or in a non-cued location. In 70% of the cued trials the stimulus was presented in the cued location and in 30% in one of the non-cued locations. In addition there were trials in which a non-directional cue instructed the subject to pay attention to all four locations. The results showed that the correct orienting of attention yielded a small but significant benefit; the incorrect orienting of attention yielded a large and significant cost; the cost tended to increase as a function of the distance between the attended location and the location that was actually stimulated; and an additional cost was incurred when the stimulated and attended locations were on opposite sides of the vertical or horizontal meridian. We concluded that neither the hypothesis postulating hemifield inhibition nor that postulating movement of attention with a constant time can explain the data. The hypothesis of an attention gradient and that of attention movements with a constant speed are tenable in principle, but they fail to account for the effect of crossing the horizontal and vertical meridians. A hypothesis is proposed that postulates a strict link between covert orienting of attention and programming explicit ocular movements. Attention is oriented to a given point when the oculomotor programme for moving the eyes to this point is ready to be executed. Attentional cost is the time required to erase one ocular program and prepare the next one.

The study was aimed at testing various models that can explain visual lateral asymmetries due to hemispheric specialization. In Experiments 1-3 the subjects had to perform a lateralized "go-no go" discrimination of words (primary task) either alone or in association with secondary tasks that interfered with the processing of the left hemisphere (ordered tapping) or the right hemisphere (finger flexion). In Experiment 4 the primary task was one of lateralized "go-no go" discrimination of faces while the secondary tasks were again those of ordered tapping and finger flexion. The results showed that in the case of word discrimination the advantage in speed of response in favour of the right visual field/left hemisphere (RVF/LH), which was observed for the primary task alone, did not change when the secondary task was added. This held true irrespective of whether the secondary task loaded the left or right hemisphere. The advantage for the left visual field/right hemisphere (LVF/RH) observed for face discrimination alone, disappeared when the secondary task interfered with the processing of the right hemisphere and did not change when the secondary task concerned the left hemisphere. It was concluded that each hemisphere is able to elaborate in parallel the incoming information, but, in normal conditions, interhemispheric transmission is responsible for the lateral asymmetries in perception (conditional interhemispheric transmission model).