The lateralized effects of Parkinson's Disease on motor imagery: Evidence from mental chronometry.

Alterations to the content of action representations may contribute to the movement challenges that characterize Parkinson's Disease (PD). One way to investigate action representations is through motor imagery. As PD motor symptoms typically have a unilateral onset, disease-related deficits related to action representations may follow a similarly lateralized pattern. The present study examined if temporal accuracy of motor imagery in individuals with PD differed according to the side of the body involved in the task. Thirty-eight participants with PD completed a mental chronometry task using their more affected and less affected side. Participants had significantly shorter mental versus physical movement times for the more affected. Higher imagery vividness in the kinaesthetic domain predicted shorter mental versus physical movement times for the more affected side, as did lower imagery vividness in the visual domain and poorer cognitive function. These results indicate that people with PD imagine movements differently when the target actions their more affected versus less affected side. It is additionally possible that side-specific deficits in the accurate processing of kinaesthetic information lead to an increased reliance on visual processes and cognitive resources to successfully execute motor imagery involving the more affected side.

Handedness effects on imagery of dominant- versus non-dominant-hand movements: An electroencephalographic investigation.

Mental representations of our bodies are thought to influence how we interact with our surroundings. We can examine these mental representations through motor imagery, the imagination of movement using scalp EEG recordings. The visual modality of motor imagery emphasises 'seeing' the imagined movement and is associated with increased activity in the alpha rhythm (8-14 Hz) measured over the occipital regions. The kinaesthetic modality emphasises 'feeling' the movement and is associated with decreased activity in the mu rhythm (8-14 Hz) measured over the sensorimotor cortices. These two modalities can be engaged in isolation or together. We recorded EEG activity while 37 participants (17 left-hand dominant) completed an objective hand motor imagery task. Left-handers exhibited significant activity differences between occipital and motor regions only during imagery of right-hand (non-dominant-hand) movements. This difference was primarily driven by less oscillatory activity in the mu rhythm, which may reflect a shift in imagery strategy wherein participants placed more effort into generating the kinaesthetic sensations of non-dominant-hand imagery. Spatial features of 8-14 Hz activity generated from principal component analysis (PCA) provide further support for a strategy shift. Right-handers also exhibited significant differences between alpha and mu activity during imagery of non-dominant movements. However, this difference was not primarily driven by either rhythm, and no differences were observed in the group's PCA results. Together, these findings indicate that individuals imagine movement differently when it involves their dominant versus non-dominant hand, and left-handers may be more flexible in their motor imagery strategies.

Mu oscillations and motor imagery performance: A reflection of intra-individual success, not inter-individual ability.

Mu oscillations (8-13 Hz), recorded over the human motor cortex, have been shown to consistently suppress during both the imagination and performance of movements; however, its functional significance in the imagery process is currently unclear. Here we examined human electroencephalographic (EEG) oscillations in the context of motor imagery performance as measured by imagery success within participants and imagery ability between participants. We recorded continuous EEG activity while participants performed the Test of Ability in Movement Imagery (TAMI), an objective test of motor imagery task. Results demonstrated that mu oscillatory activity significantly decreased during successful as compared to unsuccessful imagery trials. However, the extent of reduction in mu oscillations did not correlate with overall imagery ability as measured by the total TAMI score. These findings provide further support for the involvement of mu oscillations in indexing motor imagery performance and suggest that mu oscillations may reflect important processes related to imagery accuracy, processes likely related to those underlying overt motor production and motor understanding.

Convergent and Distinct Effects of Multisensory Combination on Statistical Learning Using a Computer Glove.

Learning to play a musical instrument involves mapping visual + auditory cues to motor movements and anticipating transitions. Inspired by the serial reaction time task and artificial grammar learning, we investigated explicit and implicit knowledge of statistical learning in a sensorimotor task. Using a between-subjects design with four groups, one group of participants were provided with visual cues and followed along by tapping the corresponding fingertip to their thumb, while using a computer glove. Another group additionally received accompanying auditory tones; the final two groups received sensory (visual or visual + auditory) cues but did not provide a motor response-all together following a 2 × 2 design. Implicit knowledge was measured by response time, whereas explicit knowledge was assessed using probe tests. Findings indicate that explicit knowledge was best with only the single modality, but implicit knowledge was best when all three modalities were involved.

Differences in attentional control and white matter microstructure in adolescents with attentional, affective, and behavioral disorders.

Adolescence is a critical time of physiological, cognitive, and social development. It is also a time of increased risk-taking and vulnerability for psychopathology. White matter (WM) changes during adolescence have been better elucidated in the last decade, but how WM is impacted by psychopathology during this time remains unclear. Here, we examined the link between WM microstructure and psychopathology during adolescence. Twenty youth diagnosed with affective, attentional, and behavioral disorders (clinical sample), and 20 age-matched controls were recruited to examine group differences in WM microstructure, attentional control, and the link between them. The main results showed that clinical sample had relatively lower attentional control and fractional anisotropy (FA) in WM throughout the brain: two association tracts were identified, and many differences were found in areas rich in callosal and projection fibers. Moreover, increased FA was positively associated with attention performance in the clinical sample in structures supporting ventral WM pathways, whereas a similar link was identified in controls in dorsal WM association fibers. Overall, these results support a model of general impairment in WM microstructure combined with reliance on altered, perhaps less efficient, pathways for attentional control in youth with affective, attentional, and behavioral disorders.

Integration of spatio-temporal dynamics in emotion-cognition interactions: A simultaneous fMRI-ERP investigation using the emotional oddball task.

Although a large corpus of evidence has identified brain regions and networks involved in emotion-cognition interactions, it remains unclear how spatial and temporal dynamics of the mechanisms by which emotion interfaces with cognition are integrated. Capitalizing on multi-modal brain imaging approaches, we used simultaneous functional magnetic resonance imaging (fMRI) and event-related potential (ERP) recordings, to investigate the link between spatial and temporal aspects of processing in an emotional oddball task, and in relation to personality measures reflecting basic affective responses and emotion control. First, fMRI captured expected dorso-ventral dissociations, with greater response to targets in regions of dorsal brain networks (e.g., dorsolateral prefrontal cortex) and to emotional distracters in regions of ventral networks (e.g., ventrolateral prefrontal cortex, vlPFC). Also, ERP responses to targets were associated with a prominent P300, and responses to distracters with the late positive potential (LPP). Second, providing evidence for spatio-temporal integration of brain signals, ERP-informed fMRI analyses showed a link between LPP amplitude at parietal electrodes and the fMRI signal in the vlPFC, to emotional distraction. Third, regarding the link to personality measures, increased emotional arousability and attentional impulsiveness was associated with greater LPP differences between negative distracters and targets and enhanced response to negative distracters in the amygdala, respectively. Furthermore, we identified opposing relations between responses to emotional distraction and individual scores for cognitive reappraisal and self-control impulsiveness in posterior vlPFC. This suggests a greater engagement of this region in participants with reduced tendencies to employ reappraisal as a coping strategy and those with reduced ability to control impulsive responses during emotional distraction. Together, supporting the feasibility of integrating multi-dimensional approaches to clarify neural mechanisms of emotion-cognition interactions, these results point to convergence and complementarity between measures that differentially capture spatio-temporal dynamics of brain activity, and their associations with measures of individual differences in affective responses and control.

Mindfulness-based stress reduction for mental health in youth: a cluster randomized controlled trial.

BACKGROUND: Mental illness is among the most common causes of morbidity, mortality, and disability in childhood. Mindfulness-based stress reduction (MBSR) has shown significant benefit in mental health; however, evidence of its effectiveness in youth is limited. The objective of this study was to compare the efficacy of MBSR plus usual care versus usual care alone for reducing mental health symptoms in youth. METHODS: A two-arm, mixed methods, randomized cluster-controlled trial of 12-18 year olds who were residents of CASA House, a voluntary residential treatment program for adolescents, between January 2011 and March 2013 (clinicaltrials.gov, NCT01307943). INTERVENTIONS: Treatment terms were randomized to usual care, or MBSR plus usual care, which included eight MBSR sessions of 2 hr/week. OUTCOMES: The primary outcome was impact on emotions and behavior at the end of the program, using the Behavior Assessment System for Children, Second Edition (BASC-2). Secondary outcomes included perceived stress levels, mindfulness, and emotional regulation. RESULTS: A total of 85 participants were randomized to either the MBSR arm (n = 45) or control arm (n = 40). Significant differences in favor of MBSR were found on Teacher ratings of the Internalizing Problems (p = .038) and Adaptive Skills subscales (p = .022) on the BASC-2. No significant differences were found on other outcomes. A post hoc analysis found that the MBSR arm had a significantly shorter time to discharge (p = .02). CONCLUSION: The results of this study indicate that MBSR is effective for improved coping with internalizing problems and adaptive emotional skills in our sample. Future studies should focus on larger, longer-term studies in youth.

Culture and neuroscience: How Japanese and European Canadians process social context in close and acquaintance relationships.

Recent cultural psychology findings suggest that social orientation affects neural social attention. Whereas independent cultures process people as separate from social context, interdependent cultures process people as dependent on social context. This research expands upon these findings, investigating what role culture plays in people's neural processing of social context for two relationship contexts, close and acquaintance relationships. To investigate, we had European Canadian and Japanese participants rate the emotions of center faces in face lineups while collecting ERP data. Lineups were either congruent, with all faces showing similar emotions, or incongruent, with center face emotions differing from background faces. To investigate relationship types, we framed face lineups to be in close or acquaintance relationships. We found that for acquaintances, only Japanese processed incongruent social context as meaningful, as seen through N400 incongruity effects. Contrasting with these patterns, only European Canadians showed N400 incongruity effects for close relationships. These patterns were seen whether or not the two groups noticed the emotional conflict, as seen by N2 incongruity effects. Finally, we found that social orientation was differentially related to the neural incongruity effects for the two relationships. These findings further elucidate the nuances of how culture affects neural social attention.

Handedness effects of imagined fine motor movements.

Previous studies of movement imagery have found inter-individual differences in the ability to imagine whole-body movements. The majority of these studies have used subjective scales to measure imagery ability, which may be confounded by other factors related to effort. Madan and Singhal [2013. Introducing TAMI: An objective test of ability in movement imagery. Journal of Motor Behavior, 45(2), 153-166. doi: 10.1080/00222895.2013.763764 ] developed the Test of Ability in Movement Imagery (TAMI) to address these confounds by using a multiple-choice format with objectively correct responses. Here we developed a novel movement imagery questionnaire targeted at assessing movement imagery of fine-motor hand movements. This questionnaire included two subscales: Functionally-involved Movement (i.e., tool-related) and Isolated Movement (i.e., hand-only). Hand-dominance effects were observed, such that right-handed participants were significantly better at responding to right-hand questions compared to left-hand questions for both imagery types. A stronger handedness effect was observed for Functionally-involved Movement imagery, and it did not correlate with the Edinburgh Handedness Inventory. We propose that the Functionally-involved Movement imagery subscale provides an objective hand imagery test that induces egocentric spatial processing and a greater involvement of memory processes, potentially providing a better skill-based measure of handedness.

Recruitment of Foveal Retinotopic Cortex During Haptic Exploration of Shapes and Actions in the Dark.

The role of the early visual cortex and higher-order occipitotemporal cortex has been studied extensively for visual recognition and to a lesser degree for haptic recognition and visually guided actions. Using a slow event-related fMRI experiment, we investigated whether tactile and visual exploration of objects recruit the same "visual" areas (and in the case of visual cortex, the same retinotopic zones) and if these areas show reactivation during delayed actions in the dark toward haptically explored objects (and if so, whether this reactivation might be due to imagery). We examined activation during visual or haptic exploration of objects and action execution (grasping or reaching) separated by an 18 s delay. Twenty-nine human volunteers (13 females) participated in this study. Participants had their eyes open and fixated on a point in the dark. The objects were placed below the fixation point and accordingly visual exploration activated the cuneus, which processes retinotopic locations in the lower visual field. Strikingly, the occipital pole (OP), representing foveal locations, showed higher activation for tactile than visual exploration, although the stimulus was unseen and location in the visual field was peripheral. Moreover, the lateral occipital tactile-visual area (LOtv) showed comparable activation for tactile and visual exploration. Psychophysiological interaction analysis indicated that the OP showed stronger functional connectivity with anterior intraparietal sulcus and LOtv during the haptic than visual exploration of shapes in the dark. After the delay, the cuneus, OP, and LOtv showed reactivation that was independent of the sensory modality used to explore the object. These results show that haptic actions not only activate "visual" areas during object touch, but also that this information appears to be used in guiding grasping actions toward targets after a delay.SIGNIFICANCE STATEMENT Visual presentation of an object activates shape-processing areas and retinotopic locations in early visual areas. Moreover, if the object is grasped in the dark after a delay, these areas show "reactivation." Here, we show that these areas are also activated and reactivated for haptic object exploration and haptically guided grasping. Touch-related activity occurs not only in the retinotopic location of the visual stimulus, but also at the occipital pole (OP), corresponding to the foveal representation, even though the stimulus was unseen and located peripherally. That is, the same "visual" regions are implicated in both visual and haptic exploration; however, touch also recruits high-acuity central representation within early visual areas during both haptic exploration of objects and subsequent actions toward them. Functional connectivity analysis shows that the OP is more strongly connected with ventral and dorsal stream areas when participants explore an object in the dark than when they view it.

Shock and awe: Distinct effects of taboo words on lexical decision and free recall.

Taboo stimuli are highly arousing, but it has been suggested that they also have inherent taboo-specific properties such as tabooness, offensiveness, or shock value. Prior studies have shown that taboo words have slower response times in lexical decision and higher recall probabilities in free recall; however, taboo words often differ from other words on more than just arousal and taboo properties. Here, we replicated both of these findings and conducted detailed item analyses to determine which word properties drive these behavioural effects. We found that lexical-decision performance was best explained by measures of lexical accessibility (e.g., word frequency) and tabooness, rather than arousal, valence, or offensiveness. However, free-recall performance was primarily driven by emotional word properties, and tabooness was the most important emotional word property for model fit. Our results suggest that the processing of taboo words is influenced by distinct sets of factors and by an intrinsic taboo-specific property.

Impact of a mindfulness-based stress reduction program from the perspective of adolescents with serious mental health concerns.

BACKGROUND: While studies on mindfulness-based stress reduction (MBSR) for youth have recently emerged, there is a shortage of research on how adolescents from clinical populations experience MBSR. The purpose of this qualitative study was to explore the impact of MBSR from the subjective perspective of adolescents with serious mental health concerns. METHOD: Adolescents (n = 28) from a residential treatment center participated in an adapted 8-week MBSR program in which they learned a range of mindfulness skills and were encouraged to apply the skills to their everyday lives. At the end of the program and at a 3-month follow-up, the youth participated in semistructured interviews in which they were asked to describe the impact of the program from their perspectives. Basic interpretive qualitative analysis methods were used to code the data and to group the codes into higher level themes. RESULTS: Six main themes were found, including improved mood, enhanced relationship to self, increased self-control, improved problem-solving, awareness of the present, and enhanced interpersonal relationships. DISCUSSION: Results from this study suggest that the MBSR program was perceived as beneficial both in the short-term and follow-up in several aspects of emotional, cognitive, and interpersonal functioning.

A neural marker of medical visual expertise: implications for training.

Researchers have identified a component of the EEG that discriminates visual experts from novices. The marker indexes a comprehensive model of visual processing, and if it is apparent in physicians, it could be used to investigate the development and training of their visual expertise. The purpose of this study was to determine whether a neural marker of visual expertise-the enhanced N170 event-related potential-is apparent in the EEGs of physicians as they interpret diagnostic images. We conducted a controlled trial with 10 cardiologists and 9 pulmonologists. Each participant completed 520 trials of a standard visual processing task involving the rapid evaluation of EKGs and CXRs-indicating-lung-disease. Ostensibly, each participant is expert with one type of image and competent with the other. We collected behavioral data on the participants' expertise with EKGs and CXRs and electrophysiological data on the magnitude, latency, and scalp location of their N170 ERPs as they interpreted the two types of images. Cardiologists demonstrated significantly more expertise with EKGs than CXRs, and this was reflected in an increased amplitude of their N170 ERPs while reading EKGs compared to CXRs. Pulmonologists demonstrated equal expertise with both types of images, and this was reflected in equal N170 ERP amplitudes for EKGs and CXRs. The results suggest provisionally that visual expertise has a similar substrate in medical practice as it does in other domains that have been studied extensively. This provides support for applying a sophisticated body of literature to questions about training and assessment of visual expertise among physicians.

ERPs Differentially Reflect Automatic and Deliberate Processing of the Functional Manipulability of Objects.

It is known that the functional properties of an object can interact with perceptual, cognitive, and motor processes. Previously we have found that a between-subjects manipulation of judgment instructions resulted in different manipulability-related memory biases in an incidental memory test. To better understand this effect we recorded electroencephalography (EEG) while participants made judgments about images of objects that were either high or low in functional manipulability (e.g., hammer vs. ladder). Using a between-subjects design, participants judged whether they had seen the object recently (Personal Experience), or could manipulate the object using their hand (Functionality). We focused on the P300 and slow-wave event-related potentials (ERPs) as reflections of attentional allocation. In both groups, we observed higher P300 and slow wave amplitudes for high-manipulability objects at electrodes Pz and C3. As P300 is thought to reflect bottom-up attentional processes, this may suggest that the processing of high-manipulability objects recruited more attentional resources. Additionally, the P300 effect was greater in the Functionality group. A more complex pattern was observed at electrode C3 during slow wave: processing the high-manipulability objects in the Functionality instruction evoked a more positive slow wave than in the other three conditions, likely related to motor simulation processes. These data provide neural evidence that effects of manipulability on stimulus processing are further mediated by automatic vs. deliberate motor-related processing.

The effects of taboo-related distraction on driving performance.

Roadside billboards containing negative and positive emotional content have been shown to influence driving performance, however, the impact of highly arousing taboo information is unknown. Taboo information more reliably evokes emotional arousal and can lead to greater attentional capture due to its inherent 'shock value.' The objective of the present study was to examine driver distraction associated with four types of information presented on roadside billboards: highly arousing taboo words, moderately arousing positive and negative words, and non-arousing neutral words. Participants viewed blocks of taboo, positive, negative and neutral words presented on roadside billboards while operating a driving simulator. They also responded to target (household-related) words by pressing a button on the steering wheel. At the end of the session, a surprise recall task was completed for all the words they saw while driving. Results showed that taboo words captured the most attention as revealed by better memory recall compared to all the other word types. Interestingly, taboo words were associated with better lane control compared to the other word types. We suggest that taboo-related arousal can enhance attentional focus during a complex task like simulated driving. That is, in a highly arousing situation, attention is selectively narrowed to the road ahead, resulting in better lane control.

Reliability and reactivity of the prefrontal hemodynamic responses in essential hypertension: a functional near infrared spectroscopy study.

Prefrontal (PFC) cerebral vasoreactivity may be altered in hypertension but has not been studied during postural change and carbon dioxide (CO2) rebreathing. In this study, a dual procedure of 5% CO2 rebreathing with positional change (standing to supine and reverse) was performed on normotensive (N = 24) and essential hypertensive males (N = 16) (18-55 years) to assess reliability of PFC responses using functional near infrared spectroscopy. The groups (matched on age levels, N = 13) were also compared on their hemodynamic reactivity (change of oxyhemoglobin or total hemoglobin as a function of change in end tidal CO2). Test-retest reliability within one session and 7 days later was moderate to high (intraclass correlation coefficient = .63-.901) in both normotensive and hypertensive groups for all hemodynamic measures; whereas reliability of reactivity measures for oxyhemoglobin and total hemoglobin was moderate (intraclass correlation coefficient = .68-.762). Functional near infrared spectroscopy-measured PFC hemodynamic responses are highly reproducible in normotensive and adult essential hypertensive males.

Hemodynamic changes in the prefrontal cortex during working memory in essential hypertension.

Behavioral performance and hemodynamic changes in the prefrontal cortex (PFC) represent cerebrovascular reserve and may indicate functional deficits related to essential hypertension. Fifteen stage 1 hypertensive and normotensive males (19-55 years) were compared on four tests of working memory (digit span and auditory consonant trigrams), and accompanying hemodynamic changes measured by functional near infrared spectroscopy (fNIRS). With participants blindfolded, the four tests were randomized while fNIRS was used to monitor bilateral PFC changes in oxyhemoglobin (O2Hb), deoxyhemoglobin (HHb), total hemoglobin (tHb), and hemoglobin difference. The hypertensive group demonstrated significant impairment in performance on the working memory tests with a trend of decreased efficiency performance scores (tests score/O2Hb and tHb changes). Significant correlations were noted in the hypertensive group between test performance and changes in O2Hb and tHb in both the left and right PFC. These findings suggest that fNIRS combined with cognitive testing may provide important measures of cerebrovascular reserve in essential hypertension.

No sex differences in the TAMI.

The Test of Ability in Movement Imagery (TAMI; Madan and Singhal in J Mot Behav 45:153-166, 2013) has recently been developed as an objective measure for evaluating individual ability in movement imagery. Other tests of imagery have reported sex differences, including the mental rotations test (MRT) and the Vividness of Movement Imagery Questionnaire (VMIQ). However, some have attributed these observed sex differences to other processes, such as difference in spatial abilities and confidence. Here, we tested for sex differences in the TAMI in a large sample of young adults (N = 246). In the same sample, we also administered a modified version of the MRT that included both block configurations and human figures and the VMIQ2. This modified MRT was used, as the imagery processes involved in the TAMI may be more similar to those involved in the rotations of human figures. While strong sex differences were found in both subscales of the modified MRT, no sex differences were observed in the TAMI.

A perception-based ERP reveals that the magnitude of delay matters for memory-guided reaching.

Delayed action research has suggested that perceptual information about a visual stimulus decays over several seconds. With event-related potential (ERP) methodology, one should be able to track the time course of the electrophysiological processes associated with this decay. Recently, Cruikshank et al. (J Vis 12:29, 2012) found that the N170 ERP component reflected ventral stream processes linked to motor planning and perception for action. Specifically, the N170 was larger for actions that relied on perceptual-based information. However, the delay interval was very short (tens of ms). Behavioral and neuroimaging studies suggest that when longer delays are employed, reactivation of ventral areas is necessary in order to access a stored representation of the target's characteristics. Therefore, the N170 may reflect not only the perception-for-action processes, but also the accuracy of the representation. In order to test this, we traced the time course of the N170 in memory-guided reaching when 1-, 2-, and 3-s delays separated target occlusion and response initiation. During reach initiation, the N170 was more negative and peaked earlier for the 1 s than the 2- and 3-s delays and correlated significantly with performance at the longest delay. These results suggest that the neural mechanisms involved in movement planning change for delays beyond 1 s. The smaller N170 may reflect an impoverished visual perceptual representation in the ventral stream. To our knowledge, these are the first electrophysiological results to suggest that there is decay of visual perceptual information that occurs with increasing time.