Protective effects of physical activity on episodic memory during aging are explained by executive functioning.

Aging is marked by a memory decline related to an executive function decline. Physical activity (PA) has beneficial effects on both executive functions and memory, especially in aging. The protective effects of PA on these two cognitive abilities have always been studied separately, despite the well-established relationship between memory and executive functions. Our objective was to explore whether the benefits of PA on memory could be explained by reduced age-related changes in executive functions.Nineteen young adults (27.16 years old) and 25 older adults (69.64 years old) performed a resource-dependent memory task, three executive tasks and completed a PA questionnaire (measuring sports and leisure PA). Age group and PA effects on memory and executive performance were analyzed with generalized linear models. Mediation analyses were calculated using method of causal steps approach with a non-parametric bootstrapping procedure.The results confirmed the effects of age and PA on memory and executive performance. A significant interaction confirmed the protective effect of PA on age-related cognitive performance. PA was positively correlated with performance in both memory and executive tasks, but only in the older adults. Although each predictor alone (age, executive functions and PA) significantly explained memory performance in older adults, only the effect of PA on memory performance remained significant when all the predictors were introduced in the analyses.PA mediates the effects of age and executive functions on memory performance. This suggests that PA protects older adults against memory decline by reducing the decline in executive functioning.

Arm cooling selectively impacts sensorimotor control.

The benefits of cold have long been recognized in sport and medicine. However, it also brings costs, which have more rarely been investigated, notably in terms of sensorimotor control. We hypothesized that, in addition to peripheral effects, cold slows down the processing of proprioceptive cues, which has an impact on both feedback and feedforward control. We therefore compared the performances of participants whose right arm had been immersed in either cold water (arm temperature: 14°C) or lukewarm water (arm temperature: 34°C). In experiment 1, we administered a Fitts's pointing task and performed a kinematic analysis to determine whether sensorimotor control processes were affected by the cold. Results revealed 1) modifications in late kinematic parameters, suggesting changes in the use of proprioceptive feedback, and 2) modifications in early kinematic parameters, suggesting changes in action representations and/or feedforward processes. To explore our hypothesis further, we ran a second experiment in which no physical movement was involved, and thus no peripheral effects. Participants were administrated a hand laterality task, known to involve implicit motor imagery and assess the internal representation of the hand. They were shown left- and right-hand images randomly displayed in different orientations in the picture plane and had to identify as quickly and as accurately as possible whether each image was of the left hand or the right hand. Results revealed slower responses and more errors when participants had to mentally rotate the cooled hand in the extreme orientation of 160°, further suggesting the impact of cold on action representations.NEW & NOTEWORTHY We investigated how arm cooling modulates sensorimotor representations and sensorimotor control. Arm cooling induced changes in early kinematic parameters of pointing, suggesting an impact on feedforward processes or hand representation. Arm cooling induced changes in late kinematic parameters of pointing, suggesting an impact on feedback processes. Arm cooling also affected performance on a hand laterality task, suggesting that action representations were modified.

Effects of short-term hand immobilization on anticipatory mechanism for tool use.

The short-term immobilization of a limb such as the right arm can impair sensorimotor mechanisms, which in turn reduces motor control of this arm. However, it is not known whether immobilization also impairs the anticipatory mechanism for tool use without actual enactment. In two experiments, we asked participants to judge how they would use a tool in a particular environment (e.g., "Take the pencil to write on a sheet of paper"). Prior to this tool-use judgment task, some participants had been immobilized (right arm) for 24 h. Results revealed that compared to controls, immobilized participants performed more poorly on the tool-use judgment task (accuracy and response time) as well as in a manual dexterity task. As our tool-use judgment task involved anticipating the expected perceptual effect of using a tool to achieve an environmental goal (e.g., writing on a sheet of paper), our data are discussed in line with theories of motor control (e.g., ideomotor theory) that emphasize the expected perceptual consequences of the action.

The role of implicit motor simulation on action verb memory.

Observation is known to improve memory for action. Previous findings linked such an effect with an easier relation processing of action components following observation compared to mere sentence reading. However, action observation also elicits implicit motor simulation, that is a processing of one's movement through the observer own motor system. We aimed to assess whether encoding of implicit motor simulation can also explain why observation is better than reading for action memory. To prevent influence of item relation processing, two studies about isolated action verbs learning were designed. In Experiment 1, action verbs were encoded with short videos of point-light human movements or with written definitions. Subsequent free recall indicated better memory for the verbs within the video clip condition. Experiment 2 compared two encoding conditions based on point-light human movement videos. Half of the verbs were learned with their normal corresponding movement (biological kinematic). For the other half of the verbs, the velocity of point-light movements was modified to create abnormal nonbiological kinematic actions. We observed better free recall for the verbs learned with biological kinematics. Taken together, those results suggest that action observation is beneficial because it allows the encoding of motor-related information (implicit motor simulation). Semantic resonance between linguistic and motor representations of action could also contribute to memory improvement. Contrary to previous studies, our results cannot be explained by an improvement of items relation processing. However, it suggests that the basic level of action verb memory is sensorimotor perception, such as implicit motor simulation.

The Link Between Action Verb Processing and Action Observation: A Developmental Study.

In this work we aimed to assess the typical link in human development between action observation and language. For this, we studied, in 68 children aged 5-11 years of age, how action verbs can prime action representation. While children 7-8 years of age benefited from a congruent action verb prime when they had to judge an image representing an action, this effect was not present in 5-6-year-olds. Thus, the link between language and action observation changes during development at about age 7. We discussed these findings in consideration of current theories proposed to account for the action-language link.

Episodic memory and aging: Benefits of physical activity depend on the executive resources required for the task.

Physical activity has beneficial effects on executive functions and episodic memory, two processes affected by aging. These benefits seem to depend on the type of memory task, but only a few studies have evaluated them despite their importance in understanding aging. This study aimed to confirm that the benefits of physical activity on episodic memory in older adults vary according to the executive resources required by the memory task, comparing free recall and cued recall. Thirty-seven young adults and 37 older adults performed two memory tasks and an updating task. The two groups had a similar level of physical activity over the preceding 12 months, assessed by a questionnaire. Both the memory and the updating tasks were performed better by the younger than the older adults. A similar cueing effect was observed in the two groups. Physical activity was positively correlated with updating and free recall, but not with cued-recall, and only in older adults. Regression analyses indicated that physical activity accounted for 24% of the variance in free recall in older adults. Updating did not predict free recall (ns) when physical activity was entered in the analysis. The present results show that the benefits of physical activity vary with age and episodic memory task. Only free-recall performance, which relies on updating, seems to depend on physical activity, suggesting that the executive resources required for the task play an important role in the effect of physical activity on memory performance. This should be investigated in greater depth in subsequent studies.

Translation and validation of the movement imagery questionnaire-3 second French version.

INTRODUCTION: Motor imagery (MI) can be defined as the mental simulation of an action without performing it. Its effectiveness can be substantially influenced by imagery ability, and it is currently accepted that three main modalities are used in MI (kinaesthetic imagery, and internal or external visual imageries). In the context of rehabilitation, MI combined with physical therapy is further known to facilitate functional improvements, and promote cortical reorganization and long-term recovery. This study aimed to test the reproducibility and the validity of constructs (internal consistency and factorial structure) of the Movement Imagery Questionnaire-3 Second French version (MIQ-3Sf). METHOD: The internal consistency as well as the validity of constructs and the test-retest inter-rate reproducibility of the MIQ-3Sf was examined, in 553 participants, for the kinaesthetic and visual items. RESULTS: The composite reliability scores (≥0.92) and the intraclass correlation coefficients (>0.88) for the kinaesthetic, internal visual and external visual imagery subscales revealed satisfactory internal consistency and reproducibility. Moreover, Pearson correlations revealed a strong relationship between the MIQ-3Sf and the MIQ-3f. CONCLUSIONS: /Implications. The MIQ-3Sf can be considered as a valid, reliable and useful questionnaire for examining MI ability in the context of rehabilitation.

Self-partner inclusion predicts performance of romantically involved individuals in a body-scaled action-anticipation task.

Previous research has shown that romantic relationships can lead to the cognitive inclusion of a romantic partner into one's own self-representation, resulting in blurred boundaries between self and intimate other. Recent work suggests that this self-other integration process encompasses the two dimensions of the self-the conceptual and the bodily self. In line with this, it has been proposed that romantic love is associated with cognitive states that blur or reduce the saliency of self-boundaries in the bodily domain. The present study tested this hypothesis by investigating the influence of the self-other integration process in romantic love on passability judgments of door-like apertures, an action-anticipation task that rests on the representation of bodily boundaries. Romantically involved and single participants estimated whether they could pass through apertures of different widths. Moreover, inclusion of romantic partner in the self was assessed using the Inclusion of Other in the Self (IOS) scale. The pattern of correlation and the ratio between participants' shoulder width and aperture judgments did not differ between romantically involved participants and singles. However, our results revealed that in romantically involved participants, the relationship between individuals' shoulder width and aperture judgements was moderated by IOS scores. A greater inclusion of romantic partner in the self was associated with a weaker prediction of aperture judgment by participants' shoulder width. A similar moderating effect of the intensity of romantic feelings (as measured by the passionate love scale) on shoulder width-aperture judgment relationship was found. IOS scores, but not romantic feelings, also moderated aperture judgments made for another individual (third person perspective). Together, these findings are consistent with the view that inclusion of romantic partner in the self triggers cognitive states affecting self-boundaries in the bodily domain.

Short-term upper limb immobilization and the embodied view of memory: A pilot study.

The present study aimed to explore the contribution of the manual sensorimotor system to the memory of graspable objects. Participants in the experimental group underwent a short-term upper limb immobilization design to decrease arousal to their dominant hand. Such designs are known to elicit updating of sensorimotor representations and to hardened use of implicit motor simulation, a process that occurs when observing graspable objects. Subsequently, a free recall and a recognition task of graspable and non-graspable objects took place. We found slower recognition for graspable than for non-graspable objects in the control group, while no differences appeared for the immobilized group. Moreover, the recognition latency for graspable objects tended to be slower for the control than for the immobilized group. These results suggest that a time demanding reactivation of motor simulation is elicited when a graspable object is correctly recognized by control participants. The effect of immobilization could prevent this reactivation, leading to faster recognition. Hence, immobilization selectively affects graspable object memory, showing a close relationship with the manual sphere of the sensorimotor system. We suggest that recognition accuracy would probably be affected in cases of stronger disruption of sensorimotor arousal.

Short-term upper limb immobilisation impairs grasp representation.

The present experiment aimed to gain more information on the effect of limb nonuse on the cognitive level of actions and, more specifically, on the content of the motor programme used for grasping an object. For that purpose, we used a hand-grasping laterality task that is known to contain concrete information on manipulation activity. Two groups participated in the experiment: an immobilised group, including participants whose right hand and arm were fixed with a rigid splint and an immobilisation vest for 24 hr, and a control group, including participants who did not undergo the immobilisation procedure. The main results confirmed the slowdown of sensorimotor processes, which is highlighted in the literature, with slower response times when the participants identified the laterality of hand images that corresponded to the immobilised hand. Importantly, the grip-precision effect, highlighted by slower response times for hands grasping a small sphere versus a large sphere, is impaired by 24 hr of limb nonuse. Overall, this study provided additional evidence of the disengagement of sensorimotor processes due to a short period of limb immobilisation.

Short-Term Sensorimotor Deprivation Impacts Feedforward and Feedback Processes of Motor Control.

Sensory loss involves irreversible behavioral and neural changes. Paradigms of short-term limb immobilization mimic deprivation of proprioceptive inputs and motor commands, which occur after the loss of limb use. While several studies have shown that short-term immobilization induced motor control impairments, the origin of such modifications is an open question. A Fitts' pointing task was conducted, and kinematic analyses were performed to assess whether the feedforward and/or feedback processes of motor control were impacted. The Fitts' pointing task specifically required dealing with spatial and temporal aspects (speed-accuracy trade-off) to be as fast and as accurate as possible. Forty trials were performed on two consecutive days by Control and Immobilized participants who wore a splint on the right arm during this 24 h period. The immobilization modified the motor control in a way that the full spatiotemporal structure of the pointing movements differed: A global slowdown appeared. The acceleration and deceleration phases were both longer, suggesting that immobilization impacted both the early impulse phase based on sensorimotor expectations and the later online correction phase based on feedback use. First, the feedforward control may have been less efficient, probably because the internal model of the immobilized limb would have been incorrectly updated relative to internal and environmental constraints. Second, immobilized participants may have taken more time to correct their movements and precisely reach the target, as the processing of proprioceptive feedback might have been altered.

Short-term upper-limb immobilization alters peripersonal space representation.

Peripersonal space is a multisensory interface between the environment and the body subserving motor interactions with the physical and social world. Although changing body properties has been shown to alter the functional processing of space, little is known about the effect of short-term limb immobilization specifically on the motor representation of peripersonal space. In the present study, we investigated the effect of a right upper-limb immobilization for a duration of 24 h on a reachability judgment task and a brightness judgment task. Analyses of perceptual thresholds revealed a reduction of peripersonal space representation after the immobilization period, which was not observed when there was no immobilization (control group). In contrast, no variation appeared in the brightness judgment task, suggesting no presence of specific visual perception or decisional deficits in the limb immobilization group. Considered together, the results confirm the crucial role of the motor system in the representation of peripersonal space. They also highlight the plasticity of the motor system resulting in a rapid change of its activity following limb immobilization, with a concomitant effect on motor-related perceptual and cognitive processes.

Beneficial Influence of Mindfulness Training Promoted by Text Messages on Self-Reported Aerobic Physical Activity in Older Adults: A Randomized Controlled Study.

Inactivity is known to have harmful effects on the physical and mental health of older adults. This study used a randomized, parallel trial design to evaluate whether daily text prompts to practice mindfulness would have a positive impact on the time that adults aged 50 years or older spend in aerobic physical activity. The participants were recruited from a certified fitness center and divided into mindfulness and control groups. For 4 weeks, they were exposed to the experimental conditions, with or without the morning text message. In the morning message condition, the mindfulness groups received a text message with the instruction to practice audio-guided mindfulness for 10 min, and the control group received a placebo message. The participants practicing mindfulness reported significantly more weekly minutes of aerobic physical activity and higher intrinsic motivation than the control participants. Mindfulness training was effective at increasing aerobic physical activity duration and might complement physical activity programs.

Does the Improvement of Position Sense Following Motor Imagery Practice Vary as a Function of Age and Time of Day?

The effectiveness of motor imagery practice is known to depend on age and on the ability to form motor images. In the same individual, motor imagery quality changes during the day, being better late in the morning for older adults and in the afternoon for younger adults. Does this mean that motor imagery practice should be done at specific time of the day depending on the age of participants to maximize motor learning? To examine whether the effect of motor imagery practice varies as a function of time of day and age, the authors used an arm configuration reproduction task and measured position sense accuracy before and after 135 kinesthetic motor imagery trials. Younger and older participants were randomly assigned to either a morning or an afternoon session. Data showed that the accuracy for reproducing arm configurations improved following imagery practice regardless of time of day for both younger and older adults. Moreover, the authors observed that the position sense was less accurate in the afternoon than in the morning in older participants (before and after motor imagery practice), while performance did not change during the day in younger participants. These results may have practical implications in motor learning and functional rehabilitation programs. They highlight the effectiveness of motor imagery practice for movement accuracy in both younger and older adults regardless of time of day. By contrast, they reveal that the assessment of position sense requires that the time of day be taken into account when practitioners want to report on the older patients' progress without making any mistakes.

When context modulates the influence of action observation on language processing.

Numerous studies in the field of embodied cognition have shown a crosstalk between language and sensorimotor processes. In particular, it has been demonstrated that perceiving an action influences subsequent language processing. However, when studying the effect of action observation on language processing it has not been considered whether the context of action presentation could modulate this influence. To test this assumption, the participants in our study observed a prime, specifically a cartoon picture of a person performing an action in either a usual or an unusual context, and then had to perform a semantic decision task involving action verbs that could be congruent or incongruent with the action in the prime. Data analyses showed a significant difference on response times for congruent action verbs compared with incongruent action verbs in the usual context, whereas no difference was observed in the unusual context. This finding indicates that the influence of action observation on language appears only with usual actions, suggesting that the context of action presentation is crucial to enable the influence of action observation on action verbs processing.

Massage can (re-)activate the lower limb sensorimotor representation of older adult inpatients.

Understanding how changes in afferent signal processing may impact the sensorimotor processes is essential for physical therapists whose objective is to actively improve the reorganization of motor function in patients suffering from sensorimotor system disturbance. Because the sensorimotor processes are slowed with the advance in age, we examined whether a single massage session can reactivate the sensorimotor processes of older adult inpatients. Participants were randomly assigned to the experimental (with massage) or control (without massage) groups. Massage was realized on both feet with 7.30 min spent on each foot (Experiment 1), the right foot or the right foot and knee for 10 min (Experiment 2). Body and nonbody mental rotation tasks were used to assess the lower limb motor representation before (pretest), immediately after (Posttest 1) and 24 hr after the massage (Posttest 2). Results showed the positive impact of massage on the body mental rotation task. The activation of the sensorimotor processes can last up to 24 hr depending on the extent of the massaged area. Importantly, the activation of the sensorimotor representation concerned not only the massaged leg but also the contralateral leg. No difference between groups appeared in the nonbody mental rotation task which did not solicit the sensorimotor processes. These results highlighted that peripheral activation via a massage had a specific impact on the sensorimotor processes. Massage is an interesting technique which can help older adult inpatients cope with the slowdown of the signal processing related to advancing age. (PsycINFO Database Record

Testing the perceptual equivalence hypothesis in mental rotation of 3D stimuli with visual and tactile input.

Previous studies on mental rotation (i.e., the ability to imagine objects undergoing rotation; MR) have mainly focused on visual input, with comparatively less information about tactile input. In this study, we examined whether the processes subtending MR of 3D stimuli with both input modalities are perceptually equivalent (i.e., when learning within-modalities is equal to transfers-of-learning between modalities). We compared participants' performances in two consecutive task sessions either in no-switch conditions (Visual→Visual or Tactile→Tactile) or in switch conditions (Visual→Tactile or Tactile→Visual). Across both task sessions, we observed MR response differences with visual and tactile inputs, as well as difficult transfer-of-learning. In no-switch conditions, participants showed significant improvements on all dependent measures. In switch conditions, however, we only observed significant improvements in response speeds with tactile input (RTs, intercepts, slopes: Visual→Tactile) and close to significant improvement in response accuracy with visual input (Tactile→Visual). Model fit analyses (of the rotation angle effect on RTs) also suggested different specification in learning with tactile and visual input. In "Session 1", the RTs fitted similarly well to the rotation angles, for both types of perceptual responses. However, in "Session 2", trend lines in the fitting analyses changed in a stark way, in the switch and tactile no-switch conditions. These results suggest that MR with 3D objects is not necessarily a perceptually equivalent process. Specialization (and priming) in the exploration strategies (i.e., speed-accuracy trade-offs) might, however, be the main factor at play in these results-and not MR differences in and of themselves.

Text Messages Promoting Mental Imagery Increase Self-Reported Physical Activity in Older Adults: A Randomized Controlled Study.

OBJECTIVE: This study tested whether text messages prompting adults 50 years of age and older to perform mental imagery would increase aerobic physical activity (APA) duration using a randomized parallel trial design. METHOD: Participants were assigned to an Imagery 1, Imagery 2, or placebo group. For 4 weeks, each group was exposed to two conditions (morning text message vs. no morning text message). In the morning message condition, the imagery groups received a text message with the instruction to mentally imagine performing an APA, and the placebo group received a placebo message. All participants received an evening text message of "Did you do your cardio today? If yes, what did you do?" for 3 days per week. RESULTS: Participants of the imagery groups reported significantly more weekly minutes of APA in the morning text message condition compared with the no morning message condition. CONCLUSION: Electronic messages were effective at increasing minutes of APA.

Short-term upper limb immobilization affects action-word understanding.

The present study aimed to investigate whether well-established associations between action and language can be altered by short-term upper limb immobilization. The dominant arm of right-handed participants was immobilized for 24 hours with a rigid splint fixed on the hand and an immobilization vest restraining the shoulder, arm, and forearm. The control group did not undergo such immobilization. In 2 experiments, participants had to judge whether a verb involved movements of the hands or feet. In Experiment 1, the response times for controls were shorter for hand-action verbs than for foot-action verbs, whereas there was no significant difference in the immobilized group. Experiment 2 confirmed these results with a pre/posttest procedure. Shorter response times were shown for hand-action verbs than for foot-action verbs in the pretests and posttests for the control group and in the pretest for the immobilized group (i.e., before immobilization). This difference was not observed for participants undergoing 24 hr of hand immobilization, who showed little progress in assessing hand-action verbs between pretest and posttest. Moreover, participants with the highest motor imagery capacities clearly demonstrated shorter response times in Experiment 2 for both hand-action and foot-action verbs, regardless of hand immobilization. Overall, these findings demonstrate for the first time that short-term sensorimotor deprivation can affect action verb processing. We discuss our results in light of the embodiment view, which considers that cognition is grounded in sensorimotor experiences. (PsycINFO Database Record

The specificity of practice hypothesis in goal-directed movements: visual dominance or proprioception neglect?

The study aimed to examine whether modifying the proprioceptive feedback usually associated with a specific movement would decrease the dominance of visual feedback and/or decrease, which appears to be the neglect of proprioceptive feedback in ensuring the accuracy of goal-directed movements. We used a leg positioning recall task and measured the recall error after 15 and 165 acquisition trials performed with both vision and proprioception or proprioception only, under either a normal or a modified proprioception condition (i.e., with a 1-kg load attached to the participants' ankle). Participant learning was evaluated in transfer with proprioception only. In support of the specificity of practice hypothesis, the recall errors in acquisition were significantly smaller when practice occurred with both vision and proprioception, in either the loaded or the unloaded leg condition, and they increased significantly in transfer when vision was withdrawn. An important finding of the study highlighted that withdrawing vision after 165 acquisition trials had less deleterious effects on the recall errors when practice occurred under the loaded leg condition. Under that modified condition, recall errors in transfer were similar when practice occurred with and without vision, whereas larger errors were observed following practice with vision under the normal proprioceptive condition. Overall, these results highlighted the dominance of vision in ensuring accurate leg positioning recall and revealed that the dominance of vision is such that the processing of proprioceptive feedback may be neglected. Importantly, modifying the proprioceptive feedback has the advantage of reducing what appears to be the neglect of proprioceptive information when movement execution occurs in a visuo-proprioceptive context. Practical considerations for rehabilitation are discussed at the end of the manuscript.