Implicit and explicit motor imagery ability after SCI: Moving the elbow makes the difference.

Cervical spinal cord injury (SCI) causes dramatic sensorimotor deficits that restrict both activity and participation. Restoring activity and participation requires extensive upper limb rehabilitation focusing elbow and wrist movements, which can include motor imagery. Yet, it remains unclear whether MI ability is impaired or spared after SCI. We investigated implicit and explicit MI ability in individuals with C6 or C7 SCI (SCIC6 and SCIC7 groups), as well as in age- and gender-matched controls without SCI. Inspired by previous studies, implicit MI evaluations involved hand laterality judgments, hand orientation judgments (HOJT) and hand-object interaction judgments. Explicit MI evaluations involved mental chronometry assessments of physically possible or impossible movements due to the paralysis of upper limb muscles in both groups of participants with SCI. HOJT was the paradigm in which implicit MI ability profiles differed the most between groups, particularly in the SCIC6 group who had impaired elbow movements in the horizontal plane. MI ability profiles were similar between groups for explicit MI evaluations, but reflected task familiarity with higher durations in the case of unfamiliar movements in controls or attempt to perform movements which were no longer possible in persons with SCI. Present results, obtained from a homogeneous population of individuals with SCI, suggest that people with long-term SCI rely on embodied cognitive motor strategies, similar to controls. Differences found in behavioral response pattern during implicit MI mirrored the actual motor deficit, particularly during tasks that involved internal representations of affected body parts.

Body Schema as Assessed by Upper Limb Left/Right Judgment Tasks Is Altered in Stroke: Implications for Motor Imagery Training.

BACKGROUND AND PURPOSE: Individuals with stroke often experience significant impairment of the upper limb. Rehabilitation interventions targeting the upper limb are typically associated with only small to moderate gains. The knowledge that body schema can be altered in other upper limb conditions has contributed to the development of tailored rehabilitation approaches. This study investigated whether individuals with stroke experienced alterations in body schema of the upper limb. If so, this knowledge may have implications for rehabilitation approaches such as motor imagery. METHODS: An observational study performed online consisting of left/right judgment tasks assessed by response time and accuracy of: (i) left/right direction recognition; (ii) left/right shoulder laterality recognition; (iii) left/right hand laterality recognition; (iv) mental rotation of nonembodied objects. Comparisons were made between individuals with and without stroke. Secondary comparisons were made in the stroke population according to side of stroke and side of pain if experienced. RESULTS: A total of 895 individuals (445 with stroke) participated. Individuals with stroke took longer for all tasks compared to those without stroke, and were less accurate in correctly identifying the laterality of shoulder (P < 0.001) and hand (P < 0.001) images, and the orientation of nonembodied objects (P < 0.001). Moreover, the differences observed in the hand and shoulder tasks were greater than what was observed for the control tasks of directional recognition and nonembodied mental rotation. No significant differences were found between left/right judgments of individuals with stroke according to stroke-affected side or side of pain. DISCUSSION AND CONCLUSIONS: Left/right judgments of upper limb are frequently impaired after stroke, providing evidence of alterations in body schema. The knowledge that body schemas are altered in individuals with longstanding stroke may assist in the development of optimal, well-accepted motor imagery programs for the upper limb.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A394).

The cortical organization of listening effort: New insight from functional near-infrared spectroscopy.

Everyday challenges impact our ability to hear and comprehend spoken language with ease, such as accented speech (source factors), spectral degradation (transmission factors), complex or unfamiliar language use (message factors), and predictability (context factors). Auditory degradation and linguistic complexity in the brain and behavior have been well investigated, and several computational models have emerged. The work here provides a novel test of the hypotheses that listening effort is partially reliant on higher cognitive auditory attention and working memory mechanisms in the frontal lobe, and partially reliant on hierarchical linguistic computation in the brain's left hemisphere. We specifically hypothesize that these models are robust and can be applied in ecologically relevant and coarse-grain contexts that rigorously control for acoustic and linguistic listening challenges. Using functional near-infrared spectroscopy during an auditory plausibility judgment task, we show the hierarchical cortical organization for listening effort in the frontal and left temporal-parietal brain regions. In response to increasing levels of cognitive demand, we found (i) poorer comprehension, (ii) slower reaction times, (iii) increasing levels of perceived mental effort, (iv) increasing levels of brain activity in the prefrontal cortex, (v) hierarchical modulation of core language processing regions that reflect increasingly higher-order auditory-linguistic processing, and (vi) a correlation between participants' mental effort ratings and their performance on the task. Our results demonstrate that listening effort is partly reliant on higher cognitive auditory attention and working memory mechanisms in the frontal lobe and partly reliant on hierarchical linguistic computation in the brain's left hemisphere. Further, listening effort is driven by a voluntary, motivation-based attention system for which our results validate the use of a single-item post-task questionnaire for measuring perceived levels of mental effort and predicting listening performance. We anticipate our study to be a starting point for more sophisticated models of listening effort and even cognitive neuroplasticity in hearing aid and cochlear implant users.

Coupled oscillations enable rapid temporal recalibration to audiovisual asynchrony.

The brain naturally resolves the challenge of integrating auditory and visual signals produced by the same event despite different physical propagation speeds and neural processing latencies. Temporal recalibration manifests in human perception to realign incoming signals across the senses. Recent behavioral studies show it is a fast-acting phenomenon, relying on the most recent exposure to audiovisual asynchrony. Here we show that the physiological mechanism of rapid, context-dependent recalibration builds on interdependent pre-stimulus cortical rhythms in sensory brain regions. Using magnetoencephalography, we demonstrate that individual recalibration behavior is related to subject-specific properties of fast oscillations (>35 Hz) nested within a slower alpha rhythm (8-12 Hz) in auditory cortex. We also show that the asynchrony of a previously presented audiovisual stimulus pair alters the preferred coupling phase of these fast oscillations along the alpha cycle, with a resulting phase-shift amounting to the temporal recalibration observed behaviorally. These findings suggest that cross-frequency coupled oscillations contribute to forming unified percepts across senses.

Understanding the "gut instinct" of expert coaches during talent identification.

Coaches are an integral part of talent identification in sport and are often used as the "gold standard" against which scientific methods of talent identification are compared. However, their decision-making during this process is not well understood. In this article, we use an ecological approach to explore talent identification in combat sports. We interviewed twenty-four expert, international-level coaches from the Olympic disciplines of boxing, judo, and taekwondo (age: 48.7 + 7.5 years; experience: 20.8 + 8.3 years). Findings indicated that when coaches identify talent they rely on "gut instinct": intuitive judgements made without conscious thought, used to direct attention to particular athletes or characteristics. Our analysis revealed four major contributors to coaches' intuition: experiential knowledge, temporal factors, seeing athletes in context, and what can be worked with. Our findings demonstrate that i) athlete selections may be influenced by the coaches' perceived ability to improve certain athletes (rather than solely on athlete ability); and ii) "instinctual" decisions are the result of years of experience, time spent with the athlete, and the context surrounding the decision. Based on these findings, we recommend that future research focuses on the duration and conditions that are required for coaches to confidently and reliably identify talented athletes.

Investigating holistic face processing within and outside of face-responsive brain regions.

It has been shown that human faces are processed holistically (i.e. as indecomposable wholes, rather than by their component parts) and this holistic face processing is linked to brain activity in face-responsive brain regions. Although several brain regions outside of the face-responsive network are also sensitive to relational processing and perceptual grouping, whether these non-face-responsive regions contribute to holistic processing remains unclear. Here, we investigated holistic face processing in the composite face paradigm both within and outside of face-responsive brain regions. We recorded participants' brain activity using fMRI while they performed a composite face task. Behavioural results indicate that participants tend to judge the same top face halves as different when they are aligned with different bottom face halves but not when they are misaligned, demonstrating a composite face effect. Neuroimaging results revealed significant differences in responses to aligned and misaligned faces in the lateral occipital complex (LOC), and trends in the anterior part of the fusiform face area (FFA2) and transverse occipital sulcus (TOS), suggesting that these regions are sensitive to holistic versus part-based face processing. Furthermore, the retrosplenial cortex (RSC) and the parahippocampal place area (PPA) showed a pattern of neural activity consistent with a holistic representation of face identity, which also correlated with the strength of the behavioural composite face effect. These results suggest that neural activity in brain regions both within and outside of the face-responsive network contributes to the composite-face effect.

Hormonal and modality specific effects on males' emotion recognition ability.

Successful emotion recognition is a key component of human socio-emotional communication skills. However, little is known about the factors impacting males' accuracy in emotion recognition tasks. This pre-registered study examined potential candidates, focusing on the modality of stimulus presentation, emotion category and individual baseline hormone levels. In an additional exploratory analysis, we examined the association of testosterone x cortisol interaction with recognition accuracy and reaction times. We obtained accuracy and reaction time scores from 282 males who categorized voice, face and voice-face stimuli for nonverbal emotional content. Results showed that recognition accuracy was significantly higher in the audio-visual than in the auditory or visual modality. While Spearman's rank correlations showed no significant association of testosterone (T) with recognition accuracy or with response times for specific emotions, the logistic and linear regression models uncovered some evidence for a positive association between T and recognition accuracy as well as between cortisol (C) and reaction time. In addition, the overall effect size of T by C interaction with recognition accuracy and reaction time was significant, but small. Our results establish that audio-visual congruent stimuli enhance recognition accuracy and provide novel empirical support by showing that the interaction of testosterone and cortisol relates to males' accuracy and response times in emotion recognition tasks.

Performing the hand laterality judgement task does not necessarily require motor imagery.

When people judge the laterality of rotated hand images, that is they perform the laterality judgement task (LJT), they are thought to use motor imagery. However, recent studies have suggested that its completion does not necessarily require the use of motor imagery. In this study, we investigated whether and how many people preferentially use motor imagery to perform the LJT in 37 healthy adults. We assessed the presence of behavioural features associated with motor imagery at the individual level, namely, the linear angle-response time (RT) relationship and the biomechanical constraints effect in the LJT and in the same-different judgement task (SDJT), in which people are not thought to use motor imagery. We found that at most 50% of participants showed both behavioural features in the palmar view condition of the LJT. Moreover, this proportion did not differ from that in the dorsal view condition of the LJT or that in both view conditions of the SDJT. These results demonstrate that a motor imagery-based strategy is not universally and specifically used to perform the LJT. Therefore, previous results of the LJT, in particular, regarding the biomechanical constraints effect, should be reinterpreted in light of our findings.

Are alpha oscillations instrumental in multisensory synchrony perception?

Different inputs from a multisensory object or event are often integrated into a coherent and unitary percept, despite differences in sensory formats, neural pathways, and processing times of the involved modalities. Presumably, multisensory integration occurs if the cross-modal inputs are presented within a certain window of temporal integration where inputs are perceived as being simultaneous. Here, we examine the role of ongoing neuronal alpha (i.e. 10-Hz) oscillations in multimodal synchrony perception. While EEG was measured, participants performed a simultaneity judgement task with visual stimuli preceding auditory ones. At stimulus onset asynchronies (SOA's) of 160-200 ms, simultaneity judgements were around 50%. For trials with these SOA's, occipital alpha power was smaller preceding correct judgements, and the individual alpha frequency was correlated with the size of the temporal window of integration. In addition, simultaneity judgements were modulated as a function of oscillatory phase at 12.5 Hz, but the latter effect was only marginally significant. These results support the notion that oscillatory neuronal activity in the alpha frequency range, which has been taken to shape perceptual cycles, is instrumental in multisensory perception.

Atypical Multisensory Integration and the Temporal Binding Window in Autism Spectrum Disorder.

The present study examined the relationship between multisensory integration and the temporal binding window (TBW) for multisensory processing in adults with Autism spectrum disorder (ASD). The ASD group was less likely than the typically developing group to perceive an illusory flash induced by multisensory integration during a sound-induced flash illusion (SIFI) task. Although both groups showed comparable TBWs during the multisensory temporal order judgment task, correlation analyses and Bayes factors provided moderate evidence that the reduced SIFI susceptibility was associated with the narrow TBW in the ASD group. These results suggest that the individuals with ASD exhibited atypical multisensory integration and that individual differences in the efficacy of this process might be affected by the temporal processing of multisensory information.

Cardiovascular effects of brief mindfulness meditation among perfectionists experiencing failure.

Research links perfectionism, the tendency to hold and pursue unrealistically high standards, to negative mental health outcomes such as eating disorders, anxiety, and depression. Previous research used high frequency heart rate variability (HF-HRV) to measure recovery from stress during a mindfulness meditation in perfectionistic university students and found that only nonperfectionists demonstrated HF-HRV recovery from stress, suggesting that mindfulness was not effective for perfectionists. However, the mindfulness meditation did not incorporate a nonjudgment element, which may be a key component for perfectionists. In the current study, we examined whether mindfulness with a focus on nonjudgment helps university student perfectionists (n = 120) recover from failure (measured by heart rate (HR), HF-HRV, pNN50). Students were randomly assigned to one of four meditation groups: nonjudgment mindfulness, general mindfulness (i.e., attentional awareness without a nonjudgment component), progressive muscle relaxation, and nothing. Cardiac data were recorded during a 5-min baseline, failure task, and 10-min meditation session. HR results suggest that both mindfulness conditions and "nothing" encouraged cardiovascular recovery, but that the mindfulness conditions showed even further recovery during the last five minutes of the meditations. HF-HRV results indicated that participants in the nonjudgment mindfulness condition had marginally higher HF-HRV during the last five minutes of the meditation than at baseline, while participants in the other conditions did not. Therefore, mindfulness with a focus on nonjudgment of emotions may be especially important to help perfectionists improve HF-HRV after failure.

Reduced Temporal Sensitivity in Obesity: Evidence From a Simultaneity Judgement Task.

Preliminary evidence showed a reduced temporal sensitivity (i.e., larger temporal binding window) to audiovisual asynchrony in obesity. Our aim was to extend this investigation to visuotactile stimuli, comparing individuals of healthy weight and with obesity in a simultaneity judgment task. We verified that individuals with obesity had a larger temporal binding window than healthy-weight individuals, meaning that they tend to integrate visuotactile stimuli over an extended range of stimulus onset asynchronies. We point out that our finding gives evidence in support of a more pervasive impairment of the temporal discrimination of co-occurrent stimuli, which might affect multisensory integration in obesity. We discuss our results referring to the possible role of atypical oscillatory neural activity and structural anomalies in affecting the perception of simultaneity between multisensory stimuli in obesity. Finally, we highlight the urgency of a deeper understanding of multisensory integration in obesity at least for two reasons. First, multisensory bodily illusions might be used to manipulate body dissatisfaction in obesity. Second, multisensory integration anomalies in obesity might lead to a dissimilar perception of food, encouraging overeating behaviours.

Prospective examination of synthetic 5-methoxy-N,N-dimethyltryptamine inhalation: effects on salivary IL-6, cortisol levels, affect, and non-judgment.

RATIONALE: 5-methoxy-N,N-dimethyltryptamine is a psychotropic substance found in various plant and animal species and is synthetically produced. 5-methoxy-N,N-dimethyltryptamine is used in naturalistic settings for spiritual exploration, recreation, or to address negative affect and mood problems. However, scientific knowledge on the effects of 5-methoxy-N,N-dimethyltryptamine in humans is scarce. OBJECTIVES: The first objective was to assess the effects of inhalation of vaporized synthetic 5-methoxy-N,N-dimethyltryptamine on neuroendocrine markers. The second objective was to assess effects of the substance on affect and mindfulness. In addition, we assessed whether ratings of subjective measures were associated with changes in stress biomarkers (i.e., cortisol) and immune response (i.e., IL-6, CRP, IL-1ß), as well as the acute psychedelic experience. METHODS: Assessments (baseline, immediately post-session, and 7-day follow-up) were made in 11 participants. Salivary samples were collected at baseline and post-session and analyzed by high-sensitivity enzyme-linked immunosorbent assay (ELISA). RESULTS: 5-methoxy-N,N-dimethyltryptamine significantly increased cortisol levels and decreased IL-6 concentrations in saliva immediately post-session. These changes were not correlated to ratings of mental health or the psychedelic experience. Relative to baseline, ratings of non-judgment significantly increased, and ratings of depression decreased immediately post-session and at follow-up. Ratings of anxiety and stress decreased from baseline to 7-day follow-up. Participant ratings of the psychedelic experience correlated negatively with ratings of affect and positively with ratings of non-judgment. CONCLUSION: Inhalation of vaporized synthetic 5-methoxy-N,N-dimethyltryptamine produced significant changes in inflammatory markers, improved affect, and non-judgment in volunteers. Future research should examine the effect of 5-methoxy-N,N-dimethyltryptamineamine with healthy volunteers in a controlled laboratory setting.

Speed of person perception affects immediate and ongoing aesthetic evaluation.

Recent studies have shed light on how aesthetic judgments are formed following presentations lasting less than a second. Meanwhile, dedicated neural mechanisms are understood to enable the rapid detection of human faces, bodies, and actions. On the basis of cognitive studies of: (i) the speed and acuity of person perception, and (ii) preferential attention given to human imagery (e.g., faces and bodies), we hypothesize that the visual detection of humans in portraits increases the magnitude and stability (i.e., similarity to later responses) of aesthetic ratings. Ease of person perception is also expected to elicit longer durations of preferential viewing time, a surplus measure of viewing behavior that should be positively related to subsequent ratings. To test these ideas, we use a set of cubist portraits previously established to be more or less categorizable in terms of the aggregate time required to perceive the depicted person. Using these images, we track aesthetic judgments made following short and unconstrained presentations; in an intervening task, we measure viewing behavior when subjects are able to selectively reveal regions of these images. We find that highly categorizable artworks (those that require less time to identify the figure as human) elicit higher and more predictive aesthetic ratings following 30 ms presentations while also eliciting longer viewing durations. Changes in ratings throughout the task are positively correlated with cumulative viewing time; critically, an image's categorizability level further moderates the strength of this relationship. These results demonstrate that a particular kind of visual object recognition - the recognition of human forms - modulates aesthetic preferences at a glance, subsequent viewing patterns, as well as rating changes over time.

Behind the face of holistic perception: Holistic processing of Gestalt stimuli and faces recruit overlapping perceptual mechanisms.

Holistic processing, demonstrated by a failure of selective attention to individual parts within stimuli, is often considered a relatively unique feature of the processing of faces and objects of expertise. However, face-like holistic processing has been recently demonstrated for novel line stimuli with salient Gestalt perceptual grouping cues. Further, disrupting such cues within face stimuli disrupts holistic face perception. There is evidence that holistic processing of these gestalt stimuli and faces does not overlap mechanistically in the same way as does the processing of faces and objects of expertise. However, the relationship between these different manifestations of holistic processing is unclear. We developed a task to probe whether a holistic processing-specific overlap occurs at an earlier, perceptual level between the mechanisms supporting processing of faces and strong gestalt stimuli. Faces and gestalt line stimuli were overlaid, and participants made part judgments about either the faces (Experiment 1) or line stimuli (Experiment 2) in a composite task indexing holistic perception. The data revealed evidence of reciprocal interference between holistic processing of line and face stimuli, with indices of holistic processing of face and line stimuli reduced when the overlaid stimuli were also processed holistically (e.g., intact line/face stimuli) compared with when the overlaid stimuli did not commandeer holistic processing resources (e.g., misaligned line/face stimuli). This pattern is consistent with a mechanistic overlap between the holistic perception of faces and gestalt stimuli. Our results support a dual-stimulus-based and experienced-based-pathway model of holistic processing, with face stimuli using both.

Iranian Herbalists, But Not Cooks, Are Better at Naming Odors Than Laypeople.

Odor naming is enhanced in communities where communication about odors is a central part of daily life (e.g., wine experts, flavorists, and some hunter-gatherer groups). In this study, we investigated how expert knowledge and daily experience affect the ability to name odors in a group of experts that has not previously been investigated in this context-Iranian herbalists; also called attars-as well as cooks and laypeople. We assessed naming accuracy and consistency for 16 herb and spice odors, collected judgments of odor perception, and evaluated participants' odor meta-awareness. Participants' responses were overall more consistent and accurate for more frequent and familiar odors. Moreover, attars were more accurate than both cooks and laypeople at naming odors, although cooks did not perform significantly better than laypeople. Attars' perceptual ratings of odors and their overall odor meta-awareness suggest they are also more attuned to odors than the other two groups. To conclude, Iranian attars-but not cooks-are better odor namers than laypeople. They also have greater meta-awareness and differential perceptual responses to odors. These findings further highlight the critical role that expertise and type of experience have on olfactory functions.

Brain Activity Related to Sound Symbolism: Cross-modal Effect of an Aurally Presented Phoneme on Judgment of Size.

Sound symbolism is the idea that a sound makes a certain impression (e.g., phoneme "p" is associated with an impression of smallness) and could be the psychological basis of the word-meaning association. In this study, we investigated the neural basis of sound symbolism. Subjects were required to compare the visual sizes of standard and target stimuli while listening to syllables assumed to create either a larger or smaller impression. Stimulus-response congruence is defined as the agreement between the target size and the syllable's impression. Behavioral data showed that the subjects displayed a longer reaction time under the incongruent condition than under the congruent condition, indicating that they tended to associate the object size with certain syllables. We used functional magnetic resonance imaging to evaluate the cerebral activity during the task, and found that both semantic- and phonetic-process-related areas of the brain (left middle temporal gyrus and right superior temporal gyrus, respectively) were activated under the incongruent condition. These results suggest that these regions are associated with the incongruence of sound symbolism.

Temporal boundary of auditory event formation: An electrophysiological marker.

The formation of auditory events requires integration between successive sounds. There is a temporal limit below which a single sound event is perceived while above which a second perceptual event is formed. Behavioral studies applying the Temporal Order Judgment paradigm showed that this boundary is between 20 and 70 ms. Here we provide event-related potential (ERP) evidence from two experiments showing a qualitative change in the processing of tone pairs between 25 and 75 ms within-pair inter-stimulus intervals (ISI). We also show that this temporal boundary can be influenced by the immediate acoustical context, the statistical distribution of the ISIs within the sequence of tone-pairs.

Mindfulness and negative affectivity in real time: a within-person process model.

To extend our understanding of the proximal etiology of personality pathology, this study examined the dynamic, in-the-moment relations between mindfulness and negative affectivity (NA; emotional lability, anxiousness, separation insecurity) as defined by the alternative model for personality disorders. We tested predictions based upon the Monitor and Acceptance Theory that when people monitored their attention judgmentally, their state NA would be higher than usual; by contrast, when they monitored their attention nonjudgmentally, their state NA would be lower than usual. Sixty-five undergraduates participated in an experience sampling study wherein they completed five reports per day for eight days about their states of mindfulness and NA. Multi-level models revealed an interaction wherein participants exhibited more state NA when they monitored their attention judgmentally than when they monitored their attention nonjudgmentally. Analyses of simple slopes revealed that participants exhibited more state NA than usual when they monitored their attention judgmentally. These findings emerged for only one of two attention monitoring processes, however: monitoring relations between thoughts, emotions, and behaviours, but not monitoring sensory stimuli. Analyses including non-reactivity instead of nonjudgment replicated these findings. Implications for theory, research, and treatment are discussed.

Disruption of motor imagery performance following inhibition of the left inferior parietal lobe.

The left inferior parietal lobe (IPL), a brain region localized to the ventro-dorsal stream, is known to be critical to motor imagery (MI) performance. Yet its specific role in processes underlying MI, namely the generation, maintenance, manipulation, and controllability of motor images, is conflicting in the literature. To determine the specific role of the left IPL in MI, the current study sought to examine the effect inhibition of the left IPL has on performance on two disparate measures thought to probe different MI processes within the same participants. Participants (N = 31) completed the hand laterality judgment task (HLJT), employed to probe processes related to manipulation and controllability, and mental chronometry, employed to probe processes related to generation and maintenance, after receiving either inhibitory transcranial magnetic stimulation to the left IPL (Active-TMS group), or with the coil angled away from the scalp (Sham group). Impaired performance on the HLJT was observed following active TMS relative to sham. Similar mental chronometry performance resulted regardless of left IPL inhibition. In showing that inhibition of the left IPL selectively disrupted performance on the HLJT but not mental chronometry, our findings indicate that the left IPL is specifically involved in image manipulation and controllability during MI. Ultimately, the current study extends our understanding of the role of the left IPL in MI.