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In an artistic exploration, clay hands and nonhand-like, unfeasible clay objects were created by the participant and used to perform an alternative version of the rubber hand illusion. Most participants felt ownership even over these unfeasible objects, raising questions about the embodied experience of objects that we make.

This study investigated whether reduced visual attention to an observed action might account for altered imitation in autistic adults. A total of 22 autistic and 22 non-autistic adults observed and then imitated videos of a hand producing sequences of movements that differed in vertical elevation while their hand and eye movements were recorded. Participants first performed a block of imitation trials with general instructions to imitate the action. They then performed a second block with explicit instructions to attend closely to the characteristics of the movement. Imitation was quantified according to how much participants modulated their movement between the different heights of the observed movements. In the general instruction condition, the autistic group modulated their movements significantly less compared to the non-autistic group. However, following instructions to attend to the movement, the autistic group showed equivalent imitation modulation to the non-autistic group. Eye movement recording showed that the autistic group spent significantly less time looking at the hand movement for both instruction conditions. These findings show that visual attention contributes to altered voluntary imitation in autistic individuals and have implications for therapies involving imitation as well as for autistic people’s ability to understand the actions of others.

Problems with timing and time perception have been suggested as key characteristics of autism spectrum condition (ASC). Studies and personal accounts from clinicians, parents, caregivers, and self-reports from autistic people themselves often refer to problems with time. Although a number of empirical studies have examined aspects relating to time in autistic individuals, there remains no clear consensus on whether or how timing mechanisms may be affected in autism. A key reason for this lack of clarity is the wide range of timing processes that exist and subsequently the wide range of methodologies, research paradigms, and samples that time-based studies have used with autism populations. In order to summarize and organize the available literature on this issue, a systematic review was conducted. Five electronic databases were consulted. From an initial 597 records (after duplicates were removed), 45 papers were selected and reviewed. The studies are reviewed within different sections based on the different types of timing ability that have been explored in the neurotypical (NT) population: time sensitivity, interval timing, and higher-order time perception. Within each section cognitive models, methodologies, possible clinical implications, and research results are discussed. The results show different consistency across studies between the three types of timing ability. The highest consistency of results showing atypical time perception abilities is found in high-level time perception studies. It remains unclear if autism is characterized by a fundamental time perception impairment. Suggestions for future research are discussed. Autism Res 2019, 12: 1440-1462. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: This systematic review examines the different types of timing and time perception behavior that have been investigated in autism. Overall, there are a number of studies that show differences between autistic and non-autistic individuals, but some studies do not find such differences. Group differences are more consistent across studies using complex tasks rather than simpler more fundamental timing tasks. We suggest that experiments across a range of timing tasks would be fruitful to address gaps in our knowledge.

Background Drug-based therapeutic approaches for Parkinson’s disease dementia (PDD) and dementia with Lewy bodies (DLB) are moderately effective and not always tolerated. Tailoring psychosocial approaches in PDD and DLB may offer additional support and improve outcomes. We adapted home-based, care partner-delivered Cognitive Stimulation Therapy (CST) for individuals with PDD or DLB and their care partners (CST-PD). Objectives To evaluate the feasibility, acceptability, and tolerability of CST-PD. Methods This randomised controlled trial used mixed methods, including a process evaluation. People with PDD, DLB or mild cognitive impairment in PD (PD-MCI) and their care partners were randomised to 12 weeks of treatment as usual (TAU) or CST-PD. Outcomes were feasibility of the study conduct (i.e., recruitment, retention rate) and acceptability and tolerability of the intervention. Measures included rating scales, researcher field notes, therapy diaries, and exploratory clinical and care partner efficacy measures. Results The recruitment target was met with 76 consenting participant-dyads. Retention in both arms was high at over 70%. More than 90% of dyads undertook discrete sessions greater than 20 min duration, but the average number of sessions completed was lower than the recommended dose. Acceptability ratings (i.e., interest, motivation and sense of achievement) of the intervention were high. Participants reported no serious adverse events related to the intervention. Conclusions The field of psychosocial interventions for PDD and DLB is newly emerging, and we demonstrated that this type of intervention is acceptable and well tolerated. Evaluating its clinical effectiveness in a full-scale randomized controlled clinical trial is warranted. Trial registration number The trial is a psychosocial intervention with an allocated ISRCTN number 11455062. Electronic supplementary material The online version of this article (10.1007/s00415-019-09329-6) contains supplementary material, which is available to authorized users.

The “uncanny phenomenon” describes the feeling of unease associated with seeing an image that is close to appearing human. Prosthetic hands in particular are well known to induce this effect. Little is known, however, about this phenomenon from the viewpoint of prosthesis users. We studied perceptions of eeriness and human-likeness for images of different types of mechanical, cosmetic, and anatomic hands in upper-limb prosthesis users (n=9), lower-limb prosthesis users (n=10), prosthetists (n=16), control participants with no prosthetic training (n=20), and control participants who were trained to use a myoelectric prosthetic hand simulator (n=23). Both the upper- and lower-limb prosthesis user groups showed a reduced uncanny phenomenon (i.e., significantly lower levels of eeriness) for cosmetic prosthetic hands compared to the other groups, with no concomitant reduction in how these stimuli were rated in terms of human-likeness. However, a similar effect was found neither for prosthetists with prolonged visual experience of prosthetic hands nor for the group with short-term training with the simulator. These findings in the prosthesis users therefore seem likely to be related to limb absence or prolonged experience with prostheses.

Background: Action observation (AO) activates the motor system, influencing movement and increasing learning, and has been shown to improve speed and timing of movement in people with Parkinson's disease (PD). Importantly, however, effects on movement amplitude have not been quantitatively demonstrated. Additionally, motor imagery (MI) can increase behavioural and neural effects of AO, but the combined effects of AO+MI have never previously been explored in PD. The aim of this study was to investigate imitation of hand movement amplitude in people with PD following (i) AO and (ii) combined AO+MI. Methods: Twenty-four participants with mild to moderate PD and 24 healthy older adults observed and imitated videos showing a human hand moving between horizontal positions. Kinematics were recorded and modulation of vertical amplitude when replicating elevated vs. direct movements provided an index of imitation. After an initial set of AO trials, participants were instructed to engage in MI during observation for the remaining trials (AO+MI), emphasizing kinaesthetic (sensory) imagery. Results: Movement amplitude was imitated (modulated) for elevated vs. direct stimuli by both groups, and this imitation increased following MI instructions. Conclusions: These results demonstrate quantitatively for the first time that people with PD are able to modulate the amplitude of their hand movements following action observation, and that combining AO and MI increases imitation in PD. The effects parallel findings in healthy young participants, and indicate that combined action observation and motor imagery could be a promising therapeutic approach for PD.

Autism is a developmental condition currently identified by experts using observation, interview, and questionnaire techniques and primarily assessing social and communication deficits. Motor function and movement imitation are also altered in autism and can be measured more objectively. In this study, motion and eye tracking data from a movement imitation task were combined with supervised machine learning methods to classify 22 autistic and 22 non-autistic adults. The focus was on a reliable machine learning application. We have used nested validation to develop models and further tested the models with an independent data sample. Feature selection was aimed at selection stability to assure result interpretability. Our models predicted diagnosis with 73% accuracy from kinematic features, 70% accuracy from eye movement features and 78% accuracy from combined features. We further explored features which were most important for predictions to better understand movement imitation differences in autism. Consistent with the behavioural results, most discriminative features were from the experimental condition in which non-autistic individuals tended to successfully imitate unusual movement kinematics while autistic individuals tended to fail. Machine learning results show promise that future work could aid in the diagnosis process by providing quantitative tests to supplement current qualitative ones.

Previous research suggests that the ability to adapt motor behaviour to sudden environmental changes may be impaired in older adults. Here, we investigated whether the adaptation of grasping behaviour in response to a visual–haptic size conflict is also affected by increasing age. 30 older and 18 young adults were instructed to grasp a hidden block whilst viewing a second block in a congruent position. Initially block sizes were equal, but after a set number of trials a sensory conflict was introduced by covertly changing the hidden block for a smaller or larger block. The scale and speed of maximum grasp aperture adaptation to the increase or decrease in the size of the hidden block was measured. Older adults successfully adapted to the visual–haptic size conflict in a similar manner to young adults, despite a tendency to adapt less when the hidden block increased in size. This finding is attributed to the physical capabilities of the grasping hand of older adults, rather than an effect of age-related sensory or cognitive decline. The speed of grasp adaptation did not differ between age groups; however, awareness of the visual–haptic conflict lead to faster adaptation. These findings suggest that sensorimotor adaptation for grasping is intact for cognitively healthy older adults.

Suppression of unwanted motor responses can be disrupted by Parkinson’s disease. People with Parkinson’s (PwP) can show maladaptive reward-driven behaviours in the form of impulse control behaviours, which are associated with use of the dopaminergic treatments used to alleviate the motor symptoms of the disease. However, the effects of Parkinson’s itself on impulsive behaviour and control are unclear – empirical studies have yielded mixed findings, and some imaging studies have shown a functional deficit in the absence of a measurable change in behaviour. Here, we investigated the effects of Parkinson’s on response activation and control by studying the dynamics of response in standard inhibitory control tasks – the Stop Signal and Simon tasks – using a continuous measure of response force. Our results are largely in favour of the conclusion that response inhibition appears to be intact in PwP, even when using a more sensitive measure of behavioural control relative to traditional button-press measures. Our findings provide some clarity as to the effects of Parkinson’s on response inhibition and show continuous response force measurement can provide a sensitive means of detecting erroneous response activity in PwP, which could also be generalised to studying related processes in other populations.Open dataData and analysis can be found on the Open Science Framework (osf.io/kx6h3/)Pre-print templateWiernik, B.M. (2019, October 11). Preprint templates. osf.io/hsv6a/

Multisensory integration typically follows the predictions of a statistically optimal model whereby the contribution of each sensory modality is weighted according to its reliability. Previous research has shown that multisensory integration is affected by ageing, however it is less certain whether older adults follow this statistically optimal model. Additionally, previous studies often present multisensory cues which are conflicting in size, shape or location, yet naturally occurring multisensory cues are usually non-conflicting. Therefore, the mechanisms of integration in older adults might differ depending on whether the multisensory cues are consistent or conflicting. In the current experiment, young () and older () adults were asked to make judgements regarding the height of wooden blocks using visual, haptic or combined visual–haptic information. Dual modality visual–haptic blocks could be presented as equal or conflicting in size. Young and older adults’ size discrimination thresholds (i.e., precision) were not significantly different for visual, haptic or visual–haptic cues. In addition, both young and older adults’ discrimination thresholds and points of subjective equality did not follow model predictions of optimal integration, for both conflicting and non-conflicting cues. Instead, there was considerable between subject variability as to how visual and haptic cues were processed when presented simultaneously. This finding has implications for the development of multisensory therapeutic aids and interventions to assist older adults with everyday activities, where these should be tailored to the needs of each individual.

Action observation activates brain areas involved in performing the same action and has been shown to increase motor learning, with potential implications for neurorehabilitation. Recent work indicates that the effects of action observation on movement can be increased by motor imagery or by directing attention to observed actions. In voluntary imitation, activation of the motor system during action observation is already increased. We therefore explored whether imitation could be further enhanced by imagery or attention. Healthy participants observed and then immediately imitated videos of human hand movement sequences, while movement kinematics were recorded. Two blocks of trials were completed, and after the first block participants were instructed to imagine performing the observed movement (Imagery group, N = 18) or attend closely to the characteristics of the movement (Attention group, N = 15), or received no further instructions (Control group, N = 17). Kinematics of the imitated movements were modulated by instructions, with both Imagery and Attention groups being closer in duration, peak velocity and amplitude to the observed model compared with controls. These findings show that both attention and motor imagery can increase the accuracy of imitation and have implications for motor learning and rehabilitation. Future work is required to understand the mechanisms by which these two strategies influence imitation accuracy.

Does our brain treat non-biological movements (e.g. moving abstract shapes or robots) in the same way as human movements? The current work tested whether the movement of a non-biological rectangular object, believed to be based on a human action is represented within the observer's motor system. A novel visuomotor priming task was designed to pit true imitative compatibility, due to human action representation against more general stimulus response compatibility that has confounded previous belief experiments. Stimulus response compatibility effects were found for the object. However, imitative compatibility was found when participants repeated the object task with the belief that the object was based on a human finger movement, and when they performed the task viewing a real human hand. These results provide the first demonstration that non-biological stimuli can be represented as a human movement if they are believed to have human agency and have implications for interactions with technology and robots.

Objective High symptom reporting (HSR) and medically unexplained symptoms (MUS) are associated with considerable distress, disability, healthcare utilization and costs, but are poorly understood, and current treatments are of limited benefit. Most models of HSR and MUS implicate cognitive-perceptual factors, such as increased body-focused attention, reduced perceptual thresholds and a tendency to experience somatic misperception, but little is known about the causal role of these variables. We investigated this issue by studying whether there is a longitudinal relationship between perceptual-attentional variables and later clinical outcomes in primary care patients. Method Primary care patients (N = 102) completed clinical (physical symptom reporting, health anxiety and healthcare utilization) and perceptual-attentional (body-focused attention, perceptual threshold, somatic misperception) measures at baseline and then again six months later (N = 72). Hierarchical regression was used to examine cross-lagged relationships between baseline and follow-up scores. Results Contrary to expectation, attending away from the body at baseline predicted increased not decreased symptom reporting six months later. Neither perceptual threshold nor somatic misperception predicted clinical outcomes at six months. Conclusions These findings suggest that body avoidance, rather than increased body focus, contribute to the development of HSR. Future studies should consider the potential clinical benefits of reducing bodily avoidance, via techniques that promote adaptive engagement with bodily sensations.

We have previously observed that participants with autism spectrum condition (ASC) are more influenced by visual distractors during a tactile task compared with controls (Poole, Gowen, Warren, & Poliakoff, 2015). This finding suggests that changes in multisensory processing could underpin differences in sensory reactivity in ASC. Here we explore the cognitive mechanisms underlying this effect. Adults with ASC (n = 22) and matched neurotypical (NT) controls (n = 22) completed 3 tasks involving similar stimuli. In Experiment 1, we again showed that when participants with ASC were performing a tactile task they were distracted more by visual stimuli compared with NTs. In Experiment 2, however, no differences between the groups were observed on an alternative visual-tactile task (temporal order judgment) requiring attention to both the stimuli. That is, ASC performance was typical when the task did not require the visual stimuli to be suppressed. Furthermore, in Experiment 3 the effects of visual distractors were comparable between the groups when the tactile target was replaced with a visual target. When comparing performance across Experiments 1 and 3, NT participants were better able to suppress visual distractors when the target was tactile than when the target was visual (Experiment 1 vs. 3), but this crossmodal benefit was not observed in participants with ASC. The effects of visual distractors were comparable regardless of the target modality suggesting that the efficacy of visual-tactile selective attention may be reduced in ASC. (PsycINFO Database Record

Background - In 1970, Mori hypothesised the existence of an 'uncanny valley', whereby stimuli falling short of being fully human are found to be creepy or eerie.Objectives - To investigate how eerie people find different prosthetic hands and whether perceptions of eeriness can be accounted for by categorical ambiguity.Study design - Students participated in computerised experiments during which photographic images of hands were presented.Methods - We compared photographs of prosthetic hands pre-selected as more (H+) or less human-like (H-), as well as mechanical and real hands. Participants rated the hands for eeriness and human-likeness, as well as performing a speeded classification (human/non-human) and location judgment (control) task.Results - The H- prosthetic hands were rated as more eerie than the H+ prosthetic, mechanical and real hands, and this was unaffected by hand orientation. Participants were significantly slower to categorise the H+ prosthetic hands compared to the H- prosthetic and real hands, which was not due to generally slower responses to the H+ prosthetic hands (control task).Conclusion - People find prosthetic hands to be eerie, most consistently for less human-like prosthetic hands. This effect is not driven by ambiguity about whether to categorise the prosthetic hand as human or artificial. Clinical relevance More obviously artificial, less-realistic, prosthetic hands consistently generate a sense of eeriness, while more realistic prosthetic hands avoid the uncanny valley, at least on initial viewing. Thus, greater realism in prosthetic design may not always incur a cost, although the role of movement and cutaneous input requires further investigation.

Previous research has shown that spatially and temporally disparate multisensory events are more likely to interact for older adults. For visuotactile interactions, this suggests that the representation of peripersonal space is expanded and temporal perception within this space is less precise. Previously, visuotactile space has been found to expand horizontally into the opposite hemispace, and here we sought to replicate and extend this by exploring both horizontal and vertical space from the hand. Moreover, we investigated whether both spatial and temporal domains are affected for an individual, which have previously been measured using distinct tasks and different participants. We presented a modified cross-modal congruency task (Poole et al. in Multisens Res. doi: 10.1163/22134808-00002475 , 2015a) to thirty older participants (age range 65-85 years), with unisensory tactile performance equated for each individual. For the temporal manipulation, the timings of visual distractors and tactile targets were offset. For the spatial manipulation, visual distractors were presented from multiple positions in ipsilateral and contralateral hemispaces. Whilst the temporal modulation of visuotactile interactions for older adults was equivalent to that observed in young adults, spatial modulation was reduced; significant visuotactile interactions were observed for visual distractors presented in the same and opposite hemispace to the stimulated hand, in the lower visual field. This suggests an expanded representation of visuotactile space surrounding the hand in older adults, which occurs horizontally into the contralateral hemispace only, rather than expanding both vertically and horizontally. This is likely to have consequences for perception of space and goal-directed action in ageing.

The crossmodal congruency task (CCT) is a commonly used paradigm for measuring visual–tactile interactions and how these may be influenced by discrepancies in space and time between the tactile target and visual distractors. The majority of studies which have used this paradigm have neither measured, nor attempted to control, individual variability in unisensory (tactile) performance. We have developed a version of the CCT in which unisensory baseline performance is constrained to enable comparisons within and between participant groups. Participants were instructed to discriminate between single and double tactile pulses presented to their dominant hand, at their own approximate threshold level. In Experiment 1, visual distractors were presented at −30 ms, 100 ms, 200 ms and 400 ms stimulus onset asynchronies. In Experiment 2, ipsilateral visual distractors were presented 0 cm, 21 cm, and 42 cm vertically from the target hand, and 42 cm in a symmetrical, contralateral position. Distractors presented −30 ms and 0 cm from the target produced a significantly larger congruency effect than at other time points and spatial locations. Thus, the typical limits of visual–tactile interactions were replicated using a version of the task in which baseline performance can be constrained. The usefulness of this approach is supported by the observation that tactile thresholds correlated with self-reported autistic traits in this non-clinical sample. We discuss the suitability of this adapted version of the CCT for measuring visual–tactile interactions in populations where unisensory tactile ability may differ within and between groups.

Operant conditioning has been shown to influence perceptual decision making in the auditory and visual modalities but the effects of conditioning on touch perception are unknown. If conditioning can be used to reduce the tendency to misinterpret somatic noise as signal (tactile false alarms), there may be the potential to use similar procedures in the treatment of excessive physical symptom reporting in clinical settings. We explored this possibility in 4 experiments investigating whether the false alarm (FA) rate in a somatic signal detection task (SSDT) could be altered with operant conditioning, and whether the resultant learning would transfer to other sensory decisions. In Experiments 1a and 2a, nonclinical participants were rewarded for hits and punished for misses on the SSDT, with a view to increasing their FA rate. In Experiments 1b and 2b, participants were rewarded for correct rejections and punished for FAs, with a view to decreasing their FA rate. Control participants received no treatment in Experiments 1a and 1b and underwent sham training in Experiments 2a and 2b. As predicted, operant conditioning increased (Experiments 1a, 2a) and decreased (Experiments 1b, 2b) FAs on the SSDT. Training effects did not transfer to an unrelated somatosensory task and there was only weak evidence for transfer to an auditory task in Experiment 2a. Auditory and tactile FAs correlated positively in the baseline phase. The results indicate that the tactile FA rate is trainable, but that the conditioning effect does not transfer across sensory decisions with this brief training paradigm. (PsycINFO Database Record

Fluctuations of pre-stimulus oscillatory activity in the somatosensory alpha band (8-14 Hz) observed using human EEG and MEG have been shown to influence the detection of supra- and peri-threshold somatosensory stimuli. However, some reports of touch occur even without a stimulus. We investigated the possibility that pre-stimulus alpha oscillations might also influence these false reports of touch known as tactile misperceptions. We recorded EEG while participants performed the Somatic Signal Detection Task (SSDT), in which participants must detect brief, peri-threshold somatosensory targets. We found that pre-stimulus oscillatory power in the somatosensory alpha range exhibited a negative linear relationship with reporting of touch at electrode clusters over both contralateral and ipsilateral somatosensory regions. As pre-stimulus alpha power increased, the probability of reporting a touch declined; as it decreased, the probability of reporting a touch increased. This relationship was stronger on trials without a somatosensory stimulus than on trials with a somatosensory stimulus, although was present for both trial types. Spatio-temporal cluster-based permutation analysis also found that pre-stimulus alpha was lower on trials when touch was reported irrespective of whether it was present over contralateral and ipsilateral somatosensory cortices, as well as left frontocentral areas. We argue that alpha power may reflect changes in response criterion rather than sensitivity alone. Low alpha power relates to a low barrier to reporting a touch even when one is not present, while high alpha power is linked to less frequent reporting of touch overall. © 2017 Elsevier Ltd

Observation of movement activates the observer's own motor system, influencing the performance of actions and facilitating social interaction. This motor resonance is demonstrated behaviourally through visuomotor priming, whereby response latencies are influenced by the compatibility between an intended action and an observed (task-irrelevant) action. The impact of movement disorders such as Parkinson's disease (PD) on motor resonance is unclear, as previous studies of visuomotor priming have not separated imitative compatibility (specific to human movement) from general stimulus-response compatibility effects. We examined visuomotor priming in 23 participants with mild-to-moderate PD and 24 healthy older adults, using a task that pitted imitative compatibility against general stimulus-response compatibility. Participants made a key press after observing a task-irrelevant moving human finger or rectangle that was either compatible or incompatible with their response. Imitative compatibility effects, rather than general stimulus-response compatibility effects, were found specifically for the human finger. Moreover, imitative compatibility effects did not differ between groups, indicating intact motor resonance in the PD group. These findings constitute the first unambiguous demonstration of imitative priming in both PD and healthy ageing, and have implications for therapeutic techniques to facilitate action, as well as the understanding of social cognition in PD.

The presence of a light flash near to the body not only increases the ability to detect a weak touch but also increases reports of feeling a weak touch that did not occur. The somatic signal detection task (SSDT) provides a behavioural marker by which to clarify the spatial extent of such visuotactile interactions in peripersonal space. Whilst previous evidence suggests a limit to the spatial extent over which visual input can distort the perception of tactile stimulation during the rubber hand illusion, the spatial boundaries of light-induced tactile sensations are not known. In a repeated measures design, 41 participants completed the SSDT with the light positioned 1 cm (near), 17.5 cm (mid) or 40 cm (far) from the tactile stimulation. In the far condition, the light did not affect hit, or false alarm rates during the SSDT. In the near and mid conditions, the light significantly increased hit rates and led to a more liberal response criterion, that is, participants reported feeling the touch more often regardless of whether or not it actually occurred. Our results demonstrate a spatial boundary over which visual input influences veridical and non-veridical touch perception during the SSDT, and provide further behavioural evidence to show that the boundaries of the receptive fields of visuotactile neurons may be limited to reach space.

We have previously found that attention to internal somatic sensations (interoceptive attention) during a heart beat perception task increases the misperception of external touch on a somatic signal detection task (SSDT), during which healthy participants erroneously report feeling near-threshold vibrations presented to their fingertip in the absence of a stimulus. However, it has been suggested that mindful interoceptive attention should result in more accurate somatic perception, due to its non-evaluative and controlled nature. To investigate this possibility, 62 participants completed the SSDT before and after a period of brief body-scan mindfulness meditation training, or a control intervention (listening to a recorded story). The meditation intervention reduced tactile misperception and increased sensitivity during the SSDT. This finding suggests that the perceptual effects of interoceptive attention depend on its particular nature, and raises the possibility that body-scan meditation could reduce the misperception of physical symptoms in individuals with medically unexplained symptoms.

There is accumulating evidence for the benefits of exercise in Parkinson's disease (PD), but less is known about group exercise interventions. We evaluated the effect of gym-training programme on people with PD. Thirty-two adults with mild to moderate PD, not currently exercising formally, were randomised to an immediate 20-week biweekly gym training programme at a local leisure complex, or a 10-week programme starting 10 weeks later. Assessments at baseline (T1), 10 weeks (T2) and 20 weeks (T3) included reaction time, motor performance (UPDRS), quality of life and illness perceptions. Experiences of the programme were assessed via questionnaire and a focus group. Overall UPDRS motor function score did not change over time. However, gym training was associated with significant improvements in reaction times and some timed tests in the immediate training group (T1-T2). The delayed group showed similar improvements following gym training (T2-T3). Participants reported enjoyment, obtaining social benefits, and increased confidence. However, the questionnaire measures did not show improvements in subjective health ratings or illness perceptions. Although benefits were not apparent in the questionnaire measures or overall UPDRS scores, our findings suggest that a 10-week gym training programme in a community setting can provide some benefits for people with PD.

Repetitive auditory stimulation (with click trains) and visual velocity signals both have intriguing effects on the subjective passage of time. Previous studies have established that prior presentation of auditory clicks increases the subjective duration of subsequent sensory input, and that faster moving stimuli are also judged to have been presented for longer (the time dilation effect). However, the effect of clicks on velocity estimation is unknown, and the nature of the time dilation effect remains ambiguous. Here were present a series of five experiments to explore these phenomena in more detail. Participants viewed a rightward moving grating which traveled at velocities ranging from 5 to 15°/s and which lasted for durations of 500 to 1500. ms. Gratings were preceded by clicks, silence or white noise. It was found that both clicks and higher velocities increased subjective duration. It was also found that the time dilation effect was a constant proportion of stimulus duration. This implies that faster velocity increases the rate of the pacemaker component of the internal clock. Conversely, clicks increased subjective velocity, but the magnitude of this effect was not proportional to actual velocity. Through considerations of these results, we conclude that clicks independently affect velocity and duration representations. © 2012 Elsevier B.V.

When asked to judge the presence or absence of near-threshold tactile stimuli, participants often report touch experiences when no tactile stimulation has been delivered ('false alarms'). The simultaneous presentation of a light flash during the stimulation period can increase the frequency of touch reports, both when touch is and is not present. Using fMRI, we investigated the BOLD response during both light-present and light-absent false alarms, testing predictions concerning two possible neural mechanisms underlying these illusory touch experiences: activation of a tactile representation in primary somatosensory cortex (SI) and/or activation of a tactile representation in late processing areas outside of sensory-specific cortex, such as medial prefrontal cortex (MPC). Our behavioural results showed that participants made false alarms in light-present and light-absent trials, both of which activated regions of the medial parietal and medial prefrontal cortex including precuneus, posterior cingulate and paracingulate cortex, suggesting the same underlying mechanism. However, only a non-significant increase in SI activity was measured in response to false alarm vs. correct rejection trials. We argue that our results provide evidence for the role of top-down regions in somatic misperception, consistent with findings from studies in humans and non-human primates.

Expectations about a food can impact on its taste, but this may represent a perceptual change or a bias in response at the decision-making stage. We hypothesised that expectation of taste intensity should be underpinned by modulation of activity in primary taste cortex. Using functional magnetic resonance imaging, we found that expecting a very sweet drink, but receiving a less sweet drink, enhanced the reported sweetness and bolstered activity in taste cortex, relative to a less sweet drink without this expectation. The activation overlapped with primary taste cortex activation found in 11 recent taste studies. Our findings provide evidence that taste expectation modulates activity in an area consistently reported as primary taste cortex, implying that expectation effects do indeed impact on taste perception.

Observation of human actions influences the observer's own motor system, termed visuomotor priming, and is believed to be caused by automatic activation of mirror neurons. Evidence suggests that priming effects are larger for biological (human) as opposed to non-biological (object) stimuli and enhanced when viewing stimuli in mirror compared to anatomical orientation. However, there is conflicting evidence concerning the extent of differences between biological and non-biological stimuli, which may be due to stimulus related confounds. Over three experiments, we compared how visuomotor priming for biological and non-biological stimuli was affected over views, over time and when attention to the moving stimulus was manipulated. The results indicated that the strength of priming for the two stimulus types was dependent on attentional location and load. This highlights that visuomotor priming is not an automatic process and provides a possible explanation for conflicting evidence regarding the differential effects of biological and non-biological stimuli.

To investigate attentional shifting in perihand space, we measured performance on a covert visual orienting task under different hand positions. Participants discriminated visual shapes presented on a screen and responded using footpedals placed under their right foot. With the right hand positioned by the right side of the screen, mean cueing effects were significantly greater for targets presented on the right compared to the left side, at the shortest stimulus onset asynchrony. The right hand still affected attention when the left foot was used to respond and when the right hand was crossed over the midline, indicating that this effect is not restricted to the right hemifield and cannot be accounted for by greater stimulus-response compatibility with the right (responding) foot. These experiments provide preliminary evidence that the presence of the right hand can modulate shifts of visual attention but emphasise the importance of stimulus-response compatibility effects in such investigations.

Research suggests that attention has a significant effect on somatic perception in both healthy people and those who suffer from somatic disturbance. The current study investigates the effects of attending to the body on somatic awareness and a particular type of somatic disturbance: erroneous reports of touch sensation, as measured by the Somatic Signal Detection Task (SSDT). During the SSDT, participants are required to detect near-threshold tactile stimulation at their fingertip. Previous research has found that healthy participants erroneously report touch sensations in the absence of a stimulus on this task and that such false alarms are increased when a simultaneous light flash is presented next to their fingertip. Thirty-seven participants completed the SSDT under two conditions: non-informative vision of the hand and no vision of the hand. False alarms were significantly higher in light trials in the non-informative vision condition compared to light trials in the no-vision condition. However, hit rates, sensitivity (d') and response criterion (c) were not affected by non-informative vision of the hand. Using the SSDT, we found that viewing the body increased somatic interference, possibly due to raised awareness of internal bodily sensations. This work provides evidence that viewing the body can have a detrimental effect on simple detection of near-threshold tactile stimulation.

Recent studies have reported that in normal healthy individuals, the perception of illusory sensations in one modality can be induced by the presentation of a stimulus in another modality. These illusory sensations may arise from the activation of a tactile representation in memory induced by the non-target stimulus, in a process mirroring that thought to be responsible for many forms of medically unexplained symptoms. The reliability of illusory-touch reports was investigated here in two experiments with a novel perceptual paradigm designed to simulate the occurrence of somatoform symptoms in the laboratory. A concurrent light significantly increased the number of tactile stimuli reported, and resulted in a higher number of illusory-touch reports, while the modality of the trial start cue did not affect subsequent responses. In addition, a strong relationship was found between the rates of illusory sensations that participants produced in successive sessions, indicating that the tendency to report illusory sensations is a robust phenomenon.

This study took a quantitative approach to investigate movement kinematics during the imitation of goal-directed and non-goal directed movements. Motion tracking equipment was used to record the hand movements of 15 healthy participants during an imitation task involving aiming movements that varied in speed. We predicted that movement kinematics would be most similar to the observed movements in the non-goal condition, as a result of direct visuomotor mapping of the action, and least similar in the goal-directed condition because more importance would be given to the end goal. We also predicted that precues (prior information about the movement) would increase imitation accuracy in the non-goal condition by reducing cognitive demand, and that precues would reduce accuracy in the goal-directed condition, as less attention would be paid to the movement. Results showed that imitation was modulated by the speed of the observed action in the non-goal condition only. Contrary to predictions, precues did not improve imitation in the non-goal condition or improve imitation accuracy in the goal-directed condition. These results demonstrate that visuomotor mapping is favoured in non-goal imitation, regardless of prior information, and that accurate imitation of movement detail is compromised by the presence of goals. Such differences in movement kinematics indicate that different processes mediate the imitation of non-goal and goal-directed actions.

The observer's motor system has been shown to be involved in observing the actions of another person. Recent findings suggest that people with Parkinson's disease do not show the same motor facilitatory effects when observing the actions of another person. We studied whether Parkinson's patients were able to make unspeeded judgements about another person's action. Participants were asked to watch video clips of an actor lifting a box containing different weights (100, 200, 300 or 400 g) and to guess the weight that was being lifted on a 9-point scale. We compared the performance of 16 patients with PD with 16 healthy age-matched controls. Both groups were able to do the task, showing a significant relationship between the real weight and the guessed weight, albeit with a tendency to overestimate the lowest weight and underestimate the heaviest weight. The PD patients, however, showed a reduced slope value. These results show that despite their own motor deficits, PD patients are still able to judge the weight being lifted by another person, albeit with a slight reduction in accuracy. Further research will be required to determine whether PD patients use a motor simulation or a visual compensatory strategy to achieve this.

Previous research suggests that there is overlap between the systems used for tracking visible and occluded moving targets. Both visually derived and stored velocity information provide input to the tracking system when the target is visible, but after occlusion the system receives its input solely from stored velocity representations. We used EEG to investigate the transition to purely memory guided tracking after the initial period of occlusion. Participants fixated while they covertly tracked targets moving horizontally rightward at velocities of 12 or 20°/s. The targets were either continuously visible or disappeared for a short interval mid trajectory. Similar positive event related components were recorded over the right occipitoparietal region in both tasks, providing further evidence that the same neural systems are involved in tracking both visible and occluded targets. Furthermore, when the target was visible, the development of this positivity was linked to the spatial location of the target, peaking earlier in the 20°/s condition. However, in the occluded condition the positive deflection began around 200 ms following the onset of occlusion and was not modulated by target velocity or location. This indicates a neural response after occlusion is cortically registered, consistent with the hypothesis that there is increased reliance on memory guided tracking at this point. © 2009 Elsevier Ltd. All rights reserved.

Previous work indicates that extrapolation of object motion during occlusion is affected by the velocity of the immediately preceding trial. Here we ask whether longer-term velocity representations can also influence motion extrapolation. Red, blue or green targets disappeared behind an occluder. Participants pressed a button when they thought the target had reached the other side. Red targets were slower (10-20 deg/s), blue targets moved at medium velocities (14-26 deg/s) and green targets were faster (20-30 deg/s). We compared responses on a subset of red and green trials which always travelled at 20 deg/s. Although trial velocities were identical, participants responded as if the green targets moved faster (M = 22.64 deg/s) then the red targets (M = 19.72 deg/s). This indicates that motion extrapolation is affected by longer-term information about the typical velocity of different categories of stimuli.

There is preliminary evidence for interference between subsequently encoded velocities. We explored this effect using a motion extrapolation paradigm. In Experiments 1 and 2, moving targets disappeared behind an occluder. Participants responded at the time when they thought the target should reappear. Participants responded as if the current velocity was faster after a previous trial with a fast velocity and vice versa. In Experiment 3 the targets reappeared either on-time, early or late. A greater proportion of early trials were reported ‘correct’ following a fast previous trial. These experiments indicate that blending occurs between successively encoded velocity representations.

OBJECTIVE: This study aimed to develop an experimental paradigm, using healthy controls, to measure change in tactile sensitivity and response bias for subsequent testing of patients with medically unexplained symptoms (MUS). METHODS: Participants judged whether or not they detected a weak tactile pulse (presented in 50% of trials). Performance in two conditions (tactile pulses presented with or without a concomitant light) was compared using signal detection analysis to assess whether a task-irrelevant light can invoke the sensation of touch, even in its absence. RESULTS: The results showed that the presence of a concurrent light significantly improved participants' detection of the tactile stimulus by 13.7% [t(18)=4.24, P

Viewing a threatening stimulus can bias visual attention toward that location. Such effects have typically been investigated only in the visual modality, despite the fact that many threatening stimuli are most dangerous when close to or in contact with the body. Recent multisensory research indicates that a neutral visual stimulus, such as a light flash, can lead to a tactile attention shift towards a nearby body part. Here, we investigated whether the threat value of a visual stimulus modulates its effect on attention to touch. Participants made speeded discrimination responses about tactile stimuli presented to one or other hand, preceded by a picture cue (snake, spider, flower or mushroom) presented close to the same or the opposite hand. Pictures of snakes led to a significantly greater tactile attentional facilitation effect than did non-threatening pictures of flowers and mushrooms. Furthermore, there was a correlation between self-reported fear of snakes and spiders and the magnitude of early facilitation following cues of that type. These findings demonstrate that the attentional bias towards threat extends to the tactile modality and indicate that perceived threat value can modulate the cross-modal effect that a visual cue has on attention to touch.

Inhibition of return (IOR) refers to the slowing of a response to a target stimulus presented in the same location as a previous stimulus. Increased IOR has been observed in older adults, despite a reduction in other 'inhibitory' processes. However, cue-target tasks have been used in all previous studies and because of this, IOR may have been overestimated due to non-ocular response inhibition associated with withholding a response from the cue. Could increased levels of response inhibition account for the observations of increased IOR in older adults? This confound can be circumvented by using a target-target paradigm, in which a response is made to all stimuli. We tested three groups of 24 subjects: young (mean 22.5 years), young-old (mean 61.9 years) and old-old (mean 74.8 years). Subjects completed both visual cue-target and target-target tasks with identical inter-stimulus intervals of 1400 and 1800ms. IOR magnitude increased with age in both the cue-target task and the target-target task. Furthermore, the magnitude of visual IOR was found to increase with age even when individual differences in baseline response speed were taken into account. Thus, there appears to be a genuine increase in IOR magnitude with age.

It has been suggested that the sensory symptoms which affect many people with autism spectrum conditions (ASC) may be related to alterations in multisensory processing. Typically, the likelihood of interactions between the senses increases when information is temporally and spatially coincident. We explored visual-tactile interactions in adults with ASC for the first time in two experiments using low-level stimuli. Both participants with ASC and matched neurotypical controls only produced crossmodal interactions to near simultaneous stimuli, suggesting that temporal modulation is unaffected in the adult population. We also provide preliminary evidence that visual-tactile interactions may occur over greater spatial distances in participants with ASC, which merits further exploration.

Inhibition of return (IOR) is an attentional effect that has been much researched in the spatial domain, whereby people are slower to respond to stimuli presented in a previously attended location. Recently, Chao (2010) reported that participants were slower to respond to a negative schematic facial target compared with a positive facial target if they had previously viewed a cue with a negative expression, which he interpreted as IOR in the purely emotional domain. That is, once their attention is drawn away, people are slower to reattend to negative emotions. Here, we investigated whether this effect could be observed when controlling for the valence of the target and when using a more naturalistic human facial expression as a cue. We replicated Chao's findings using real face cues, observing slower responses for negative cues followed by negative versus positive targets, and faster responses for positive cues followed by positive versus negative targets. However, our reanalysis indicates that these effects are better accounted for by the valence (positive/negative) of the target, with responses being slower to negative compared with positive facial expressions regardless of the preceding cue. In conclusion, orienting in the emotional domain could not be measured using a cue-target task, as the effect of responding to emotional targets eclipsed any potential emotional cuing effect.

We investigated whether ageing affects crossmodal selective attention (the ability to focus on a relevant sensory modality and ignore an irrelevant modality) and the spatial constraints on such selective processing. Three groups of 24 participants were tested: Young (19-25 years), Young-Old (65-72 years) and Old-Old (76-92 years). The participants had to judge the elevation of vibrotactile targets (upper/index finger and lower/thumb), presented randomly to either hand while ignoring concurrent visual distractors. In a second task, the role of the target and distractor modalities was reversed. Crossmodal selective attention was assessed by comparing performance in the presence versus absence of distractors. Spatial constraints on selective attention were also investigated by comparing the effect of distractors presented on the same versus opposite side as the target. When attending to touch, the addition of visual distractors had a significantly larger effect on error rates in both of the older groups as compared to the Young group. This indicates that ageing has a detrimental effect on crossmodal selective attention. In all three age groups, performance was impaired when the target and distractor were presented at incongruent as compared to congruent elevations in both tasks. This congruency effect was modulated by the relative spatial location of the target and distractor in certain conditions for the Young and the Young-Old group. That is, participants in the two younger age groups found it harder to attend selectively to targets in one modality, when distractor stimuli came from the same side rather than from the opposite side. However, no significant spatial modulation was found in the Old-Old group. This suggests that ageing may also compromise spatial aspects of crossmodal selective attention.

Humans cannot typically produce smooth eye movements in the absence of a moving stimulus. However, they can produce predictive smooth eye movements if they expect a target of a known velocity to reappear. Here, we observed that participants could extract velocity information from two simultaneously presented moving targets in order to produce a subsequent predictive smooth eye movement for one of the two targets. Subjects fixated a stationary cross during the presentation of two targets, moving rightward at different velocities. In the next presentation, a single target was presented, which participants tracked with their eyes. A static cue, presented 700 ms before the moving target, indicated which of the two targets would be presented. Predictive eye movements were of an appropriate velocity, even when participants did not know in advance which of the two targets would subsequently be cued. However, the scaling of predictive eye velocity was marginally less accurate in this divided attention condition than when participants knew the identity of the cued target in advance, or a single target was presented during fixation. In a second experiment, we found that the velocity cued on the previous trial had a greater effect than the uncued velocity on the current trial. The negligible effect of the uncued velocity indicates that participants were extremely effective at selectively reproducing one of two recently viewed velocities. However, other influences, such as past history, also affected predictive smooth eye movements.

Introduction Parkinson9s disease (PD) with mild cognitive impairment (MCI-PD) or dementia (PDD) and dementia with Lewy bodies (DLB) are characterised by motor and ‘non-motor’ symptoms which impact on quality of life. Treatment options are generally limited to pharmacological approaches. We developed a psychosocial intervention to improve cognition, quality of life and companion burden for people with MCI-PD, PDD or DLB. Here, we describe the protocol for a single-blind randomised controlled trial to assess feasibility, acceptability and tolerability of the intervention and to evaluate treatment implementation. The interaction among the intervention and selected outcome measures and the efficacy of this intervention in improving cognition for people with MCI-PD, PDD or DLB will also be explored. Methods and analysis Dyads will be randomised into two treatment arms to receive either ‘treatment as usual’ (TAU) or cognitive stimulation therapy specifically adapted for Parkinson9s-related dementias (CST-PD), involving 30 min sessions delivered at home by the study companion three times per week over 10 weeks. A mixed-methods approach will be used to collect data on the operational aspects of the trial and treatment implementation. This will involve diary keeping, telephone follow-ups, dyad checklists and researcher ratings. Analysis will include descriptive statistics summarising recruitment, acceptability and tolerance of the intervention, and treatment implementation. To pilot an outcome measure of efficacy, we will undertake an inferential analysis to test our hypothesis that compared with TAU, CST-PD improves cognition. Qualitative approaches using thematic analysis will also be applied. Our findings will inform a larger definitive trial. Ethics and dissemination Ethical opinion was granted (REC reference: 15/YH/0531). Findings will be published in peer-reviewed journals and at conferences. We will prepare reports for dissemination by organisations involved with PD and dementia. Trial registration number ISRCTN (ISRCTN11455062).

It is postulated that there is an uncanny valley, whereby human-like stimuli such as robots or animated characters that fall short of being fully human are perceived as eerie or unsettling. Previous research has explored the existence of this effect for faces and whole bodies, while here we explore responses to photographs of real and artificial hands. In keeping with the notion of an uncanny valley, prosthetic hands that were of intermediate human-likeness were given the highest ratings of eeriness. However, within the categories of hands, ratings of eeriness reduced as human-likeness increased, suggesting a more complex pattern. Further investigation of this effect will be of relevance to the design of prosthetic limbs and could be used to test theories of the uncanny valley and social perception with simple stimuli.

Some people perceive themselves to look more, or less attractive than they are in reality. We investigated the role of emotions in enhancement and derogation effects; specifically, whether the propensity to experience positive and negative emotions affects how healthy we perceive our own face to look and how we judge ourselves against others. A psychophysical method was used to measure healthiness of self-image and social comparisons of healthiness. Participants who self-reported high positive (N = 20) or negative affectivity (N = 20) judged themselves against healthy (red-tinged) and unhealthy looking (green-tinged) versions of their own and stranger’s faces. An adaptive staircase procedure was used to measure perceptual thresholds. Participants high in positive affectivity were un-biased in their face health judgement. Participants high in negative affectivity on the other hand, judged themselves as equivalent to less healthy looking versions of their own face and a stranger’s face. Affective traits modulated self-image and social comparisons of healthiness. Face health judgement was also related to physical symptom perception and self-esteem; high physical symptom reports were associated a less healthy self-image and high self-reported (but not implicit) self-esteem was associated with more favourable social comparisons of healthiness. Subject to further validation, our novel face health judgement task could have utility as a perceptual measure of well-being. We are currently investigating whether face health judgement is sensitive to laboratory manipulations of mood.

In Experiment 1, normal subjects' ability to localize tactile stimuli (locognosia) delivered to the upper arm was significantly higher when they were instructed explicitly to direct their attention selectively to that segment than when they were instructed explicitly to distribute their attention across the whole arm. This elevation of acuity was eliminated when subjects' attentional resources were divided by superimposition of an effortful, secondary task during stimulation. In Experiment 2, in the absence of explicit attentional instruction, subjects' locognosic acuity on one of three arm segments was significantly higher when stimulation of that segment was 2.5 times more probable than that of stimulation of the other two segments. We surmise that the attentional mechanisms responsible for such modulations of locognosic acuity in normal subjects may contribute to the elevated sensory acuity observed on the stumps of amputees.

Previous research has demonstrated faster reaction times in response to appropriately oriented action-inducing stimuli (affordance effect, e.g. Tucker and Ellis in J Exp Psychol Hum Percept Perform 24:830-846, 1998). However, it has been argued that faster responses may be due to a spatial compatibility effect. In the current investigation, we aimed to dissociate the affordance and spatial compatibility effects. Moreover, we explored these effects beyond button-press responses by measuring detailed kinematics of the arms and hands during a naturalistic reach response. Participants were presented with images of a door handle (affording) or an abstract (non-affording) stimulus and made a pantomimed reach response with either hand depending on a colour change of the stimulus (i.e. Blue = left, Green = right). Stimuli could be aligned as spatially compatible or incompatible with the responding hand. The colour change occurred after a delay of 0, 500 or 1,000 ms. Only spatially compatible affordance stimuli facilitated reach onset compared to other stimuli and compatibility combinations, replicating previous reaction time studies. Therefore, in the absence of graspable stimuli, spatial compatibility alone was not sufficient to facilitate reach onset. There was also a larger outwards deviation of reach trajectory for spatially incompatible abstract stimuli compared to spatially compatible abstract stimuli, which waned with stimulus onset delay. However, no such affect was observed for the affording stimuli. Accordingly, later kinematics of the reaching action was influenced by the spatial compatibility of the stimulus alone. Overall, the dissociation of affordance and spatial compatibility effects suggests that these effects are driven by visuomotor priming and the inhibition of the incompatible spatial location, respectively.

Theory suggests that a tendency to experience distortions in somatosensory awareness is associated with physical symptom reporting (i.e., somatization) but empirical evidence for this is lacking. This article describes research designed to test this hypothesis.Somatosensory distortion was operationalized as the frequency of illusory touch experiences (i.e., false alarm rate) on the Somatic Signal Detection Task. Two studies correlated false alarms on this task with physical symptom reporting on the 15-item Patient Health Questionnaire, the first using a nonclinical sample (n = 35), the second using a clinical sample of endoscopy patients who were identified as having either medically explained (n = 25) or medically unexplained symptoms (n = 30).Scores on the 15-item Patient Health Questionnaire were positively correlated with false alarm rate in both studies (r = 0.288-0.506), even after controlling for trait anxiety, depression, anxiety (standardized β range = 0.793-0.932, all p.0001) and (in Study 2) somatosensory amplification and hypochondriacal worry (standardized β range = 0.345-0.375, both p.05). There was no difference in false alarm rate between patients with medically explained and medically unexplained symptoms (medically explained median range = 6.8 [3.7] to 6.8 [4.0] versus medically unexplained median range = 4.3 [3.9] to 5.6 [3.1], both p.1).There seems to be a robust link between physical symptom reporting and the tendency to experience somatosensory distortion, consistent with recent cognitive theories. It may be possible to reduce the impact of somatization by developing treatments that target this tendency.

Evidence suggests that interoceptive and exteroceptive attention might have different perceptual effects. However, the effects of these different types of body-focused attention have never been directly compared. The current research investigated how interoceptive and exteroceptive attention affect subsequent performance on the somatic signal detection task (SSDT). In Experiment 1, 37 participants completed the SSDT under usual testing conditions and after performing an interoceptive heartbeat perception task. This task led to a more liberal response criterion, leading to increased touch reports in the presence and absence of a target vibration. This finding is consistent with suggestions that attending internally contributes to physical symptom reporting in patients with medically unexplained symptoms (MUS). In Experiment 2, 40 participants completed the SSDT before and after an exteroceptive grating orientation task. This task led to a more stringent response criterion, leading to decreased touch reports in the presence and absence of the target, possibly via a reduction in sensory noise. This work demonstrates that internal and external body-focused attention can have opposite effects on subsequent somatic perceptual decision making and suggests that attentional training could be useful for patients reporting MUS. © 2012 Copyright The Experimental Psychology Society.