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Although behavioral evidence has shown that postural changes influence the ability to localize or detect tactile stimuli, little is known regarding the brain areas that modulate these effects. This 7T functional magnetic resonance imaging (fMRI) study explores the effects of touch of the hand as a function of hand location (right or left side of the body) and hand configuration (open or closed). We predicted that changes in hand configuration would be represented in contralateral primary somatosensory cortex (S1) and the anterior intraparietal area (aIPS), whereas change in position of the hand would be associated with alterations in activation in the superior parietal lobule. Multivoxel pattern analysis and a region of interest approach partially supported our predictions. Decoding accuracy for hand location was above chance level in superior parietal lobule (SPL) and in the anterior intraparietal (aIPS) area; above chance classification of hand configuration was observed in SPL and S1. This evidence confirmed the role of the parietal cortex in postural effects on touch and the possible role of S1 in coding the body form representation of the hand., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Using a mirror box, the concurrent stroking of the lateral side of the fifth finger behind the mirror along with stroking the empty space next to the mirror-reflected hand's fifth finger results in a strong sense of having a sixth finger-the Anne Boleyn illusion. We used this illusion to understand what constraints illusory embodiment. In Experiment 1, we manipulated the anatomical constraints, posture, and stroking of the sixth finger, along with other variants. Given evidence from other body illusions, we predicted no illusory embodiment in conditions in which the sixth finger was created in a manner incompatible with a typical hand, when the mirror and viewed hands were in different posture, and when stroking differed. Surprisingly, the illusion was persistent in most variants, including those with curved fingers, elongated fingers, and even with mismatches between the posture of the viewed and hidden hand. In Experiment 2, we manipulated the orientation, shape, and length of the illusory sixth finger, presenting more extreme versions of the illusion. The illusion was significantly diminished only when the sixth finger was far from the hand, or in a very implausible posture. This evidence suggests that body representations are extremely flexible and allow for embodiment of empty space in conditions not seen in other body illusions. We suggest that bottom-up information from concurrent visuotactile input, combined with reduced constraints provided by the "blank canvas" of empty space, results in a particularly robust illusion. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Magnified vision of one's body part has been shown to improve tactile discrimination. We used an anesthetic cream (AC) to determine if somesthetic stimulation that alters the perception of the size of one's body would also improve two point-discrimination (2PD). In Experiment 1, application of AC caused an increase in perceived lip size and an improvement in a 2PD. As perceived lip size increased, subjects became more accurate in identifying that they had been touched in two locations. Experiment 2 confirmed this effect in a larger sample and introduced a control condition (no AC) that demonstrated that the change in performance was not attributable to practice or familiarity with the task. In Experiment 3, we showed that both AC and moisturizing cream improved subjects' ability to indicate that they had been touched in 2 locations, but the improvement was modulated by perceived lip size only for AC. These results support the idea that changes in the body representation influence 2PD., (© 2023. The Author(s).)

Peripersonal space (PPS), the space closely surrounding the body, is typically characterised by enhanced multisensory integration. Neurophysiological and behavioural studies have consistently shown stronger visuo-tactile integration when a visual stimulus is presented close to the tactually stimulate body part in near space (within PPS) than in far space. However, in the majority of these studies, tactile stimuli were delivered to the upper limbs, torso and face. Therefore, it is not known whether the space surrounding the lower limbs is characterised by similar multisensory properties. To address this question, we asked participants to complete two versions of the classic visuo-tactile crossmodal congruency task in which they had to perform speeded elevation judgements of tactile stimuli presented to the dorsum of the hand and foot while a simultaneous visual distractor was presented at spatially congruent or incongruent locations either in near or far space. In line with existing evidence, when the tactile target was presented to the hand, the size of the crossmodal congruency effect (CCE) decreased in far as compared to near space, suggesting stronger visuo-tactile multisensory integration within PPS. In contrast, when the tactile target was presented to the foot, the CCE decreased for visual distractors in near than far space. These findings show systematic differences between the representation of PPS around upper and lower limbs, suggesting that the multisensory properties of the different body part-centred representations of PPS are likely to depend on the potential actions performed by the different body parts., (© 2022. The Author(s).)

Recent evidence has identified the N140cc lateralized component of event-related potentials as a reliable index of the deployment of attention to task-relevant items in touch. However, existing ERP studies have presented the tactile search array to participants' limbs, most often to the hands. Here, we investigated distractor interference effects when the tactile search array was presented to a portion of the body that is less lateralized and peripheral compared to the hands. Participants were asked to localize a tactile target presented among distractors in a circular arrangement to their back. The N140cc was elicited contralateral to the target when the singleton distractor was absent. Its amplitude was reduced when the singleton distractor was present and contralateral to the target, suggesting that attention was directed at least in part to the distractor when the singletons are on opposite sides. However, similar N140cc were observed when the singleton distractor was ipsilateral to the target compared to distractor absent trials. We suggest that when target and singleton distractor are ipsilateral, the exact localization of the target requires the attentional processing of all items on the same side of the array, similar to distractor absent trials. Together, these observations replicate the distractor interference effects previously observed for the hands, suggesting that analogous mechanisms guide attentional selectivity across different body parts., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Gherri, White and Ambron.)

How does the brain localize touch under conditions of uncertainty caused by brain damage? By testing single cases, previous work found mislocalization of touch toward the center of the hand. We investigated whether such central bias changes as a function of uncertainty in somatosensory system. Fifty-one brain-damaged individuals were presented with a tactile detection task to establish their tactile threshold, and a tactile localization task in which they localized suprathreshold stimuli presented at different locations on the hand. We predicted that with increased somatosensory uncertainty, indexed by higher detection thresholds, participants would more likely to localize the stimuli toward the center of the hand. Consistent with this prediction, participants' localization errors were biased towards the center of the hand and, importantly, this bias increased as detection threshold increased. These findings provide evidence that instead of showing random errors, uncertainty leads to systematic localization errors toward the center of the hand or the center of the stimulus distribution, which overlapped in the present study. We discuss these findings under different frameworks as potential mechanisms to explain biases in tactile localization subsequent to brain damage., (Copyright © 2021. Published by Elsevier Ltd.)

Background: Phantom limb pain (PLP) is a common and in some cases debilitating consequence of upper- or lower-limb amputation for which current treatments are inadequate., Objective: This small clinical trial tested whether game-like interactions with immersive VR activities can reduce PLP in subjects with transtibial lower-limb amputation., Methods: Seven participants attended 5-7 sessions in which they engaged in a visually immersive virtual reality experience that did not require leg movements (Cool! TM ), followed by 10-12 sessions of targeted lower-limb VR treatment consisting of custom games requiring leg movement. In the latter condition, they controlled an avatar with 2 intact legs viewed in a head-mounted display (HTC Vive TM ). A motion-tracking system mounted on the intact and residual limbs controlled the movements of both virtual extremities independently., Results: All participants except one experienced a reduction of pain immediately after VR sessions, and their pre session pain levels also decreased over the course of the study. At a group level, PLP decreased by 28% after the treatment that did not include leg movements and 39.6% after the games requiring leg motions. Both treatments were successful in reducing PLP., Conclusions: This VR intervention appears to be an efficacious treatment for PLP in subjects with lower-limb amputation.

Evidence suggests that the N140cc component of event-related potentials (ERP) observed in tactile search tasks reflects the attentional selection of the target. Here, we investigated whether the target selection processes are affected by the separation between the target and an ipsilateral singleton distractor (singletons delivered to contiguous or non-contiguous fingers of the same hand). In addition, the external distance between search items was varied through posture (splayed or touching fingers). Accuracy improved when target and distractor were delivered to contiguous fingers that were also touching. Regardless of target-distractor separation, the N140cc was larger when the external distance between search-array stimuli decreased (touching fingers). Importantly, a smaller N140cc was observed at reduced target-distractor separations, suggesting a narrower attentional focus for contiguous singletons. These findings reveal that the mechanisms responsible for tactile target selection in the presence of an ipsilateral singleton distractor are fundamentally different from those emerged in vision., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The rubber hand illusion (RHI) demonstrates that under some circumstances a fake hand can be regarded as part of one's body; the RHI and related phenomena have been used to explore the flexibility of the body schema. Recent work has shown that a sense of embodiment may be generated by virtual reality (VR). In a series of experiments, we used VR to assess the effects of the displacement of the virtual image of subjects' hands on action. Specifically, we tested whether spatial and temporal parameters of action change when participants perform a reaching movement towards the location of their virtual hand, the position of which was distorted on some trials. In different experiments, participants were sometimes provided with incorrect visual feedback regarding the position of the to-be-touched hand (Experiment 1), were deprived of visual feedback regarding the position of the reaching hand when acting (Experiment 2) or reached with the hand, the apparent position of which had been manipulated (Experiment 3). The effect was greatest when participants reached towards (Experiment 1) or with (Experiment 3) the displaced hand when the hand was visible during the reaching, but not when the vision of the hand was removed during the action (Experiment 2). Taken together, these data suggest that visual images of one's hand presented in VR influence the body schema and action performance.

Background: Increasing perceived hand size with magnifying lenses improves tactile discrimination and induces changes in action performance. We previously demonstrated that motor skills (tested with grip force, finger tapping, and a reach to grasp tasks) improved when actions were performed with magnified compared to normal vision; twenty-eight percent of 25 participants with stroke exhibited significant improvement on a composite measure of motor performance with magnification as compared to a session without magnification., Methods: To investigate the potential implications of magnification of vision for motor rehabilitation, we recruited individuals with stroke from the original cohort who exhibited an improvement of at least 10% in grip force and/or finger tapping for a home training protocol. Six individuals with stroke completed a two-week home-based training program in which they performed a range of activities while looking at their hand magnified. Motor skills were measured before, immediately after, and two weeks after the training., Results: Five of the six participants showed an improvement on motor tasks when tested after the training. In two participants the improvement was evident immediately after the training and persisted in time, while it occurred at two-weeks post-training in the other participants. These results suggest that the magnification of vision is a potential tool for the rehabilitation of post-stroke motor deficits., Competing Interests: The authors declare there are no competing interests.

Bodily states are fundamental to emotions' emergence and are believed to constitute the first step in the chain of events that culminate in emotional awareness. Recent works have shown that distinct topographical maps can be derived to describe how basic and more complex emotions are represented in the body. However, it is still unclear whether these bodily maps can also extend to emotions experienced specifically within social interactions and how these representations relate to basic emotions. To address this issue, we used the emBODY tool to obtain high-resolution bodily maps that describe the body activation and deactivation experienced by healthy participants when presented with social scenarios depicting establishment or loss of social bonds. We observed patterns of activation/deactivation for each single social scenario depending on the valence, but also a common activation of head, chest and deactivation of limbs for positive and negative social scenarios, respectively. Furthermore, we show that these maps are comparable to those obtained when taking the perspective of a third person, suggesting the existence of common body representation of social emotions for the self and other person evaluation. Finally, we showed that maps related to complex social scenarios are strongly correlated with bodily states experienced in basic emotions, suggesting that the patterns of body activation/deactivation observed for social scenarios might arise from a complex interaction of the basic emotions that these experiences elicit., Competing Interests: The authors have declared that no competing interests exist.

Objective: This study investigates closing-in behavior (CIB), a phenomenon observed in graphic copying tasks when responses encroach upon or overlap the model. The behavior is most common amongst individuals with dementia and amongst pre-school children. We explored the relationship between CIB and the 'distractor effect' in reaching, whereby salient visual stimuli can influence the spatial trajectory of the reach., Method: A group of individuals with overlap-CIB (n = 9), without CIB (n = 9) and healthy controls (HC; n = 6) underwent a task-irrelevant and a task-relevant distractors and the deviation of the movement trajectory towards the distractor location was measured in both tasks., Results: Individuals with graphic CIB showed more distractor-directed veering during reaching than did individuals without CIB or HC, provided that the distractor was relevant for the reaching task., Conclusions: These results strengthen the relationship between CIB and the distractor effect and reinforce the hypothesis that CIB represents a disinhibited tendency to act towards the focus of attention.

Increasing perceived hand size using magnifying lenses improves tactile discrimination and motor performance in neurologically-intact individuals. We tested whether magnification of the hand can improve motor function in individuals with chronic stroke. Twenty-five individuals with a history of stroke more than 6 months prior to testing underwent a series of tasks exploring different aspects of motor performance (grip force, finger tapping, reaching and grasping, and finger matching) under two visual conditions: magnified or normal vision. Performance was also assessed shortly after visual manipulation to test if these effects persisted. Twenty-eight percent of individuals showed an immediate significant improvement averaged across all tasks with magnification; similar beneficial responses were also observed in 32% of individuals after a short delay. These results suggest that magnification of the image of the hand may be of utility in rehabilitation of individuals with stroke., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Closing-in behavior (CIB) is observed in copying tasks (graphic or gestural) when the copy is performed near or on the top of the model. This symptom has been classically considered to be a manifestation of constructional apraxia and is often associated with a visuospatial impairment. More recent work emphasizes the attentional and/or executive nature of the behavior and its association with frontal lobe dysfunction. We describe three patients in whom CIB was associated with posterior parietal deficits of different etiologies (stroke in Patient 1 and dementia in Patients 2 and 3). In copying figures, Patient 1 produced the shape with high accuracy but the rendering overlapped the model, while for Patients 2 and 3 the copies were distorted but overlapping or in close proximity to the target. In gesture imitation, Patient 2 performed the gestures toward the examiner's space, while Patient 1 showed a peculiar form of CIB: when he was asked to place the ipsilesional arm in a position that mirrored the contralesional hand, Patient 1 moved his hand toward his contralesional hand. Patient 3 did not present gestural CIB. While CIB in Patient 1 was associated with selective deficits in executive functions and attention, additional visuospatial deficits were observed in Patients 2 and 3. The latter two patients showed a general visuoconstructional deficit. These case studies support a primary attentional account of CIB but also suggest that visuoconstructional impairments may contribute to the emergence of CIB, in some subjects. This evidence argues for different types of CIB with different cognitive and neural underpinnings. Furthermore, the data support the hypothesis of a differential involvement of fronto-parietal network in CIB.

This study investigated whether the N140cc ERP component, described as a possible electrophysiological marker of target selection in touch, was modulated by body posture. Participants performed a tactile search task in which they had to localize a tactile target, presented to the left or right hand, while a simultaneous distractor was delivered to the opposite hand. Importantly, the distance between target and distractor (hands separation) was manipulated in different experimental conditions (near vs. far hands). Results showed reduced errors and enhanced amplitudes of the late N140cc when the hands were far apart than in close proximity. This suggests that the competition between target and distractor is stronger when the hands are close together in the near condition, resulting in a degraded selection process. These findings confirm that the N140cc reflects target selection during the simultaneous presentation of competing stimuli and demonstrate for the first time that the attentional mechanisms indexed by this ERP component are based at least in part on postural representations of the body., (© 2018 Society for Psychophysiological Research.)

Changes in the perceived size of a body part using magnifying lenses influence tactile perception and pain. We investigated whether the visual magnification of one's hand also influences the motor system, as indexed by transcranial magnetic stimulation (TMS)-induced motor evoked potentials (MEPs). In Experiment 1, MEPs were measured while participants gazed at their hand with and without magnification of the hand. MEPs were significantly larger when participants gazed at a magnified image of their hand. In Experiment 2, we demonstrated that this effect is specific to the hand that is visually magnified. TMS of the left motor cortex did not induce an increase of MEPs when participants looked at their magnified left hand. Experiment 3 was performed to determine if magnification altered the topography of the cortical representation of the hand. To that end, a 3 × 5 grid centered on the cortical hot spot (cortical location at which a motor threshold is obtained with the lowest level of stimulation) was overlaid on the participant's MRI image, and all 15 sites in the grid were stimulated with and without magnification of the hand. We confirmed the increase in the MEPs at the hot spot with magnification and demonstrated that MEPs significantly increased with magnification at sites up to 16.5 mm from the cortical hot spot. In Experiment 4, we used paired-pulse TMS to measure short-interval intracortical inhibition and intracortical facilitation. Magnification was associated with an increase in short-interval intracortical inhibition. These experiments demonstrate that the visual magnification of one's hand induces changes in motor cortex excitability and generates a rapid remapping of the cortical representation of the hand that may, at least in part, be mediated by changes in short-interval intracortical inhibition.

Impulsivity, conceptualized as impulsive personality trait, poor inhibitory control and enhanced reward sensitivity, has been strongly linked to obesity. In particular, a disequilibrium between cognitive control and reward sensitivity has been observed in obese individuals in both behavioural and imaging studies. While this issue has been widely investigated in children and adults, it has received little attention in older adults. Here, obese and non-obese participants aged between 40 and 70 years completed the Barratt Impulsiveness scale (assessing motor, non-planning and attentional impulsiveness), a Go/no-go task with foods and non-foods (assessing inhibitory control) and a reward sensitivity battery with high and low caloric foods (assessing liking, wanting, tastiness and frequency of consumption). We observed that participants with higher BMI reported increased wanting for high calorie foods, but did not show poorer inhibitory control. Interestingly, participants who scored lower on the MMSE reported to consume high calorie more than low calorie foods. Finally, those who presented low scores on non-planning and motor impulsiveness subscales reported higher tastiness ratings for low calorie foods. These results show that increased reward sensitivity but not reduced inhibitory control may characterize higher BMI during aging. Importantly, they also highlight new findings concerning food preferences among older adults., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objective: Closing-in behavior (CIB) defines the abnormal misplacement of the copy performance, positioned very closed to or on the top of the model. This symptom is observed in graphic copying by patients suffering from different neurological diseases, most commonly dementia. The cognitive origins of this behavior are still a matter of investigation, and research of the last 10 years has been focused on exploring 2 main accounts of CIB, the compensation and the attraction hypotheses, providing evidence in both directions. While the first account defines CIB as a compensatory strategy to overcome visuospatial and/or working memory deficits during copying tasks, the attraction hypothesis looks at CIB as primitive default behavior in which attention and action are closely coupled and movements are performed toward the focus of attention., Method: We explored these 2 hypotheses in a sample of patients with and without CIB, and controls in 5 experiments: Experiments 1 and 2 tested the attraction hypothesis and, respectively, the prediction that CIB can be elicited in a noncopying dual task condition loading upon attentional resources or by irrelevant attentional grabbing stimuli. The other experiments investigated the compensation hypothesis manipulating the distance between model and copying space (Experiment 3), the task demand (single or dual task loading on verbal working memory; Experiment 4), the task requirements (copying and tracing) and visual demand (visual copy and memory; Experiment 5)., Results: The results support the attraction hypothesis of CIB., Conclusions: CIB reflects an impairment of the attention and action system, rather than a compensatory strategy. (PsycINFO Database Record, ((c) 2018 APA, all rights reserved).)

Up to 90% of amputees experience sensations in their phantom limb, often including strong, persistent phantom limb pain (PLP). Standard treatments do not provide relief for the majority of people who experience PLP, but virtual reality (VR) has shown promise. This study provides additional evidence that game-like training with low-cost immersive VR activities can reduce PLP in lower-limb amputees. The user of our system views a real-time rendering of two intact legs in a head-mounted display while playing a set of custom games. The movements of both virtual extremities are controlled by measurements from inertial sensors mounted on the intact and residual limbs. Two individuals with unilateral transtibial amputation underwent multiple sessions of the VR treatment over several weeks. Both participants experienced a significant reduction of pain immediately after each VR session, and their pre-session pain levels also decreased greatly over the course of the study. Although preliminary, these data support the idea that VR interventions like ours may be an effective low-cost treatment of PLP in lower-limb amputees.

Reaching and grasping movements rely on visual information regarding the target characteristics (e.g. size) and the hand position during the action execution. Changes in the visual representation of the body (e.g. increase in the perceived size of the hand) can modify action performance, but it is still unclear how these modifications interact with changes in the external environment. We investigated this topic by manipulating the perceived size of both hand and target objects and the degree of visual feedback available during the movement execution. Ten young adults were asked to reach and grasp geometrical objects in four different conditions: (i) with normal vision with the light on, (ii) with normal vision in the dark, (iii) using magnifying lenses in the light and (iv) using magnifying lenses in the dark. In contrast with previous works, our results show that movement execution is longer in magnified vision compared to normal when the action is executed in the light, but the grasping component was not affected by changes in size in this condition. On the contrary, when the visual feedback of the hand was removed and participants performed the action in the dark, movements were faster and the distances across fingers larger in the magnified than normal vision. This pattern of data suggests that grasping movements adapt rapidly and compensate for changes in vision when this process depends on the degree of visual feedback and/or environmental cues available. In the debate regarding the dissociation between action and perception, our data suggest that action may overcome changes in perception when visual feedback is available, but perception may trick action in situations of reduced visual information., (Copyright © 2017 Elsevier B.V. All rights reserved.)

When performing complex actions, like graphic copying or imitation of gestures, some patients may perform these actions very close to, or directly on the top of the model. This peculiar behavior, known as closing-in, is the focus of the present literature review, which will provide a critical picture of the research in this field, highlighting the difficulties in defining and assessing closing-in and the contrasting results about the nature and the characteristics of this phenomenon. Most importantly, we will discuss the 2 hypotheses proposed to explain closing-in, namely the compensation and the attraction account, in light of the most recent work. This critical review will provide substantial evidence that closing-in represent a primitive default tendency in which movements are attracted toward the focus of attention. On the other hand, the possibility that this interpretation might not be fully exhaustive and that different components of closing-in might exist will also be discussed. (PsycINFO Database Record, ((c) 2016 APA, all rights reserved).)

Food is so central to humans' life that keeping our mind away from it is not an easy task. Because of its strong motivational value, food cues attract our attention. However, often food is truly not relevant to our on-going activities. In the present study we investigated the distracting role that task-irrelevant foods (natural and manufactured) and food-cues play in performing goal-directed reaching movements. We explored whether spatial and temporal parameters of reaching movement were influenced by the presence of task-irrelevant stimuli (i.e., distractor effect), and whether this effect was modulated by participants' implicit and explicit ratings of food items and participants' tendency to restrain their diet. First we found that the movement trajectory veered consistently toward food items and food-related distractors. Second, we found that participants' own evaluation of natural and manufactured food played a differential predicting role of the magnitude of temporal and spatial parameters of the distractor effect induced by these types of food. We conclude that perceptual and attentional systems provide preferential access to stimuli in the environment with high significance for organisms., (Copyright © 2015 Elsevier Inc. All rights reserved.)

People's interaction with the social environment depends on the ability to attend social cues with human faces being a key vehicle of this information. This study explores whether directing the attention to gender or emotion of a face interferes with ongoing actions. In two experiments, participants reached for one of two possible targets by relying on one of two features of a face, namely, emotion (Experiment 1) or gender (Experiment 2) of a non-target stimulus (a task-relevant distractor). Participants' reaching movements deviated toward the task-relevant distractor in both experiments. However, when attending to the gender of the face the distractor effect was modulated by both gender (task-relevant feature) and emotion (task-irrelevant feature), with the largest movement deviation being observed toward angry male faces. Endogenous allocation of attention toward faces elicits a competing motor response to the ongoing action and the emotional content of the face contributes to this process at a more automatic and implicit level.

A person can be appraised as an individual or as a member of a social group. In the present study we tested whether the knowledge about social groups is represented independently of the living and non-living things. Patients with frontal and temporal lobe tumors involving either the left or the right hemisphere performed three tasks--picture naming, word-to-picture matching and picture sorting--tapping the lexical semantic knowledge of living things, non-living things and social groups. Both behavioral and voxel-based lesion-symptom mapping (VLSM) analyses suggested that social groups might be represented differently from other categories. VLSM analysis carried out on naming errors revealed that left-lateralized lesions in the inferior frontal gyrus, amygdala, insula and basal ganglia were associated with the lexical-semantic processing of social groups. These findings indicate that the social group representation may rely on areas associated with affective processing., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Emotional expressions are important cues that capture our attention automatically. Although a wide range of work has explored the role and influence of emotions on cognition and behavior, little is known about the way that emotions influence motor actions. Moreover, considering how critical detecting emotional facial expressions in the environment can be, it is important to understand their impact even when they are not directly relevant to the task being performed. Our novel approach was to explore this issue from the attention-and-action perspective, using a task-irrelevant distractor paradigm in which participants are asked to reach for a target while a nontarget stimulus is also presented. We tested whether the movement trajectory would be influenced by irrelevant stimuli-faces with or without emotional expressions. The results showed that reaching paths veered toward faces with emotional expressions, in particular happiness, but not toward neutral expressions. This reinforces the view of emotions as attention-capturing stimuli that are, however, also potential sources of distraction for motor actions.

Normally we can perform a variety of goal-directed movements effortlessly. However, damage to the parietal cortex may dramatically reduce this ability, giving rise to optic ataxia and limb apraxia. Patients with optic ataxia show clear misreaches towards targets when presented in the peripheral visual field, whereas limb apraxia refers to the inability to use common tools or to imitate simple gestures. In the present paper we describe the case of a left-brain damaged patient, who presented both symptoms. We systematically investigated both spatial and temporal parameters of his movements, when asked to reach and grasp common objects to move (Experiment 1) or to use them (Experiment 2), presented either in the central or peripheral visual field. Different movement parameters changed in relation to the goal of the task (grasp to move vs. grasp to use), reflecting a normal modulation of the movement to accomplish tasks with different goals. On the other hand, grip aperture appeared to be more affected from both task goal and viewing condition, with a specific decrement observed when CF was asked to use objects presented peripherally. On the contrary, a neat effect of the viewing condition was observed in the spatial distribution of the end-points of the movements, and of the horizontal end point in particular, which were shifted towards the fixation point when reaching towards peripheral targets. We hypothesized that optic ataxia and limb apraxia have a differential effect on the patient's performance. The specific presence of optic ataxia would have an effect on the movement trajectory, but both symptoms might interact and influence the grasping component of the movement. As a 'cognitive side of motor control impairment', the presence of limb apraxia may have increased the task demands in grasping to use the objects thus exacerbating optic ataxia., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Grasping is a complex action which requires high-level motor control. Although the impact of aging on grasping has been investigated in some studies, to date little is known as to how the aging process interacts with the purpose of the movement. The aims of the present study were (i) to investigate the effect of aging on grasping movements, and to explore on how this effect is modulated by (ii) the goal of the task, and by (iii) the characteristics of the target such as its location in the visual field, its orientation and its size. Young and elderly adults were asked to grasp to move or to grasp to use objects of different sizes and orientations, presented either in the central or the peripheral visual field. Movement duration did not differ between the two groups. However, elderly participants required a longer approach phase and showed a different grasping strategy, characterized by larger grip aperture and smaller percentage of wrist rotation in comparison to young adults. Elderly adults showed a decrease in accuracy when grasping objects presented in the peripheral, but not in the central visual field. A similar modulation of the kinematic parameters consisting in longer planning and execution phases in the grasp to use in comparison to the grasp to move condition was observed in both groups, suggesting that the effect of aging might be minimized and compensated in more goal-directed tasks., (Copyright © 2014 Elsevier B.V. All rights reserved.)

This study explored Closing-in behavior (CIB), the tendency in figure copying to draw very close to or on top of the model, in mild cognitive impairment (MCI). The files of 154 people diagnosed with MCI were reviewed and CIB was identified in 21% of cases. Two approaches were used to explore CIB. First, we capitalized on the diverse cognitive profiles within MCI, subdividing the overall sample into people with and without memory deficits. The frequency of CIB was significantly higher in multidomain non-amnestic MCI than in multidomain amnestic MCI, suggesting that CIB is not associated with specific memory impairment. Second, we assessed the cognitive correlates of CIB, by selecting patients with MCI who completed a battery of executive, visuo-constructional and memory tasks. Sub-groups of patients with and without CIB showed a similar overall severity of cognitive decline and comparable performance in visuo-constructional and memory tasks, but those with CIB were slightly but significantly more impaired on executive function tasks. The study provides evidence against memory-based accounts of CIB, and supports recent suggestions that executive impairments are the dominant cognitive correlate of this clinical sign.

This study relates two behaviours, each well documented within its own literature but not previously considered together: closing-in behaviour (CIB) and the effect of visual distractors on reaching. CIB is common in typically developing children, and in adults with dementia, and classically manifests as the tendency to perform graphic copying tasks very close to, or on the top of the model. The effect of visual distractors on reaching has been studied extensively in normal adults. Distractors induce characteristic deviations of the reach, usually away from the distractor, which imply that a competing response towards the distractor is automatically primed, and actively suppressed. It is possible that CIB reflects a failure to inhibit motor distraction, such that the acting hand is attracted automatically to a salient stimulus (the model, during copying tasks). This hypothesis predicts that CIB should be associated with distractor effects during reaching, characterised by veering towards, rather than away from the distractor. We tested this prediction in groups of pre-school children with and without CIB, and in young adults, using task-relevant and task-irrelevant distractors. Both groups of children showed greater veering towards distractors than did adults, implying a lower capacity to inhibit automatic responses. Crucially, this effect was stronger in children with CIB than without CIB when a task-irrelevant distractor was presented. These findings support the idea that CIB reflects a failure to inhibit automatically primed actions towards salient stimuli., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Many pre-school children show closing-in behaviour (CIB) in graphic copying tasks: a tendency to place their copy abnormally close to or even on top of the model. Similar phenomena have been studied in patients with dementia, though it is unclear whether the superficial similarities between CIB in development and dementia reflect common underlying cognitive mechanisms. The aim of the present study was to investigate the cognitive functions involved in CIB in pre-school children. Forty-one children (3-5 years) were assessed for CIB, and completed a neuropsychological battery targeting visuospatial abilities, short term memory (verbal and spatial) and attention (sustained attention, selective attention and attention switching). Binary logistic regression found that performance on the attention subtests was the best unique predictor of CIB. A second analysis, in which the three attention subtests were entered as separate predictors, suggested that attention switching ability was most strongly related to CIB. These results support the view that CIB in children reflects inadequate attentional control. The convergence of these results with similar observations in patients with dementia further suggests that similar cognitive factors underlie CIB in these two populations.

The frequency and characteristics of closing-in behavior (CIB) were examined in 797 patients with Alzheimer's disease (AD), 132 of whom were followed up longitudinally. The frequency of CIB increased with the complexity of the graphic copying task and with the severity of Alzheimer's disease. Regression analyses suggested that attentional deficits are critical factors for the appearance of CIB, but that visuospatial impairments also play an important role in the emergence of severe forms of CIB.

Many pre-school children show 'Closing-in behaviour' (CIB) in graphic copying, placing their copy excessively close to, or even on top of the original. This behaviour can also be observed in patients with dementia, though it is unclear whether the superficial similarities between CIB in development and dementia reflect common underlying mechanisms. Two main hypotheses have been proposed to account for CIB: the compensation hypothesis considers CIB as a strategic adaptation to underlying deficits in visuospatial and/or memory functions; the attraction hypothesis proposes that CIB is a primitive default behaviour in which the acting hand is drawn towards the focus of visual attention. The present study tested between these hypotheses in a group of 15 pre-school children. The children performed a simple straight-line drawing task whilst naming line drawings of animals printed at the top or bottom of the sheet. The drawn lines veered reliably towards the named animals, mimicking CIB in copying tasks. This pattern is not predicted by the compensation hypothesis, but is consistent with the attraction account. We suggest that this default attraction may emerge in children with insufficiently developed attentional and/or executive control.

"Closing-in behaviour" (CIB) is a phenomenon observed on copying and imitation tasks, in which the copy is made inappropriately close to or on top of the model. CIB is classified clinically as a manifestation of constructional apraxia (CA), but its underlying causes are not understood. Compensation hypotheses propose that CIB is a strategic adaptation to underlying deficits in visuospatial and/or memory functions. The attraction hypothesis suggests that CIB reflects a primitive default behaviour in which the acting hand is drawn towards the focus of visual attention. We tested between these hypotheses in a 62-year-old woman with moderate Alzheimer's disease precipitating CA and apraxia, who showed marked CIB in graphic copying and gesture imitation. We presented two dual tasks: In the first, a straight-line drawing task was combined with a letter-reading task; in the second, simple gesture production was combined with a letter-reading task. In each case, the patient's productions deviated markedly towards the location of the reading task. These data provide strong support for the attraction hypothesis and show that CIB is not specific to copying.