Individual placement and support focusing on employment and education for young people at clinical high risk of psychosis: A feasibility study.

OBJECTIVE: This study aimed to assess the feasibility of implementing Individual Placement and Support (IPS) with a focus on educational and employment goals, within a clinical service for the early detection of individuals at clinical high risk (CHR) of psychosis. METHOD: Between June 2019 and April 2021, participants were recruited and received up to 6 (± 2) months support. Primary outcome: Enrolled participants, attended sessions, and disengagement rates were analyzed to assess feasibility. SECONDARY OUTCOMES: Enrollment in mainstream education or/and employment, hours spent working or/and studying, salary, level of functioning, and self-efficacy at baseline and follow-up were compared. RESULTS: Thirty-one participants were recruited, 13 of whom were remotely recruited after the first COVID-19 lockdown. Dropout rates were relatively low (16.1%), and 26 participants (83.9%) completed the program. Each participant received on average nine sessions (M = 9.65; SD = 4.92). Secondary outcomes: At follow-up, 73.1% participants were employed, working on average more hours per week, t(25) = -2.725; p = .012, and were earning significantly more money, t(25) = -3.702; p = .001, compared to baseline. Gains in educational outcomes were less clear. Global Assessment of Functioning, t = 248.50; p = .001, and Social Occupational Functioning, t(25) = -3.273; p = .003, were significantly higher at 6-month follow-up compared to baseline. No differences were found in participants' self-efficacy. CONCLUSIONS AND IMPLICATIONS FOR PRACTICE: Findings indicate that research procedures are appropriate and that IPS implementation within a CHR clinical team is feasible. Secondary outcomes also suggest that IPS may be a beneficial intervention for young people at CHR. A longer follow-up might be needed to assess its impact on educational outcomes. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

The impact of brain lesions on tDCS-induced electric fields.

Transcranial direct current stimulation (tDCS) can enhance motor and language rehabilitation after stroke. Though brain lesions distort tDCS-induced electric field (E-field), systematic accounts remain limited. Using electric field modelling, we investigated the effect of 630 synthetic lesions on E-field magnitude in the region of interest (ROI). Models were conducted for two tDCS montages targeting either primary motor cortex (M1) or Broca's area (BA44). Absolute E-field magnitude in the ROI differed by up to 42% compared to the non-lesioned brain depending on lesion size, lesion-ROI distance, and lesion conductivity value. Lesion location determined the sign of this difference: lesions in-line with the predominant direction of current increased E-field magnitude in the ROI, whereas lesions located in the opposite direction decreased E-field magnitude. We further explored how individualised tDCS can control lesion-induced effects on E-field. Lesions affected the individualised electrode configuration needed to maximise E-field magnitude in the ROI, but this effect was negligible when prioritising the maximisation of radial inward current. Lesions distorting tDCS-induced E-field, is likely to exacerbate inter-individual variability in E-field magnitude. Individualising electrode configuration and stimulator output can minimise lesion-induced variability but requires improved estimates of lesion conductivity. Individualised tDCS is critical to overcome E-field variability in lesioned brains.

Inter-individual variability in current direction for common tDCS montages.

The direction of applied electric current relative to the cortical surface is a key determinant of transcranial direct current stimulation (tDCS) effects. Inter-individual differences in anatomy affect the consistency of current direction at a cortical target. However, the degree of this variability remains undetermined. Using current flow modelling (CFM), we quantified the inter-individual variability in tDCS current direction at a cortical target (left primary motor cortex, M1). Three montages targeting M1 using circular electrodes were compared: PA-tDCS directed current perpendicular to the central sulcus in a posterior-anterior direction relative to M1, ML-tDCS directed current parallel to the central sulcus in a medio-lateral direction, and conventional-tDCS applied electrodes over M1 and the contralateral forehead. In 50 healthy brain scans from the Human Connectome Project, we extracted current direction and intensity from the grey matter surface in the sulcal bank (M1BANK) and gyral crown (M1CROWN), and neighbouring primary somatosensory cortex (S1BANK and S1CROWN). Results confirmed substantial inter-individual variability in current direction (50%-150%) across all montages. Radial inward current produced by PA-tDCS was predominantly located in M1BANK, whereas for conventional-tDCS it was clustered in M1CROWN. The difference in radial inward current in functionally distinct subregions of M1 raises the testable hypothesis that PA-tDCS and conventional-tDCS modulate cortical excitability through different mechanisms. We show that electrode locations can be used to closely approximate current direction in M1 and precentral gyrus, providing a landmark-based method for tDCS application to address the hypothesis without the need for MRI. By contrast, ML-tDCS current was more tangentially orientated, which is associated with weaker somatic polarisation. Substantial inter-individual variability in current direction likely contributes to variable neuromodulation effects reported for these protocols, emphasising the need for individualised electrode montages, including the control of current direction.

Increasing human motor skill acquisition by driving theta-gamma coupling.

Skill learning is a fundamental adaptive process, but the mechanisms remain poorly understood. Some learning paradigms, particularly in the memory domain, are closely associated with gamma activity that is amplitude modulated by the phase of underlying theta activity, but whether such nested activity patterns also underpin skill learning is unknown. Here, we addressed this question by using transcranial alternating current stimulation (tACS) over sensorimotor cortex to modulate theta-gamma activity during motor skill acquisition, as an exemplar of a non-hippocampal-dependent task. We demonstrated, and then replicated, a significant improvement in skill acquisition with theta-gamma tACS, which outlasted the stimulation by an hour. Our results suggest that theta-gamma activity may be a common mechanism for learning across the brain and provides a putative novel intervention for optimizing functional improvements in response to training or therapy.

Dose-controlled tDCS reduces electric field intensity variability at a cortical target site.

BACKGROUND: Variable effects limit the efficacy of transcranial direct current stimulation (tDCS) as a research and therapeutic tool. Conventional application of a fixed-dose of tDCS does not account for inter-individual differences in anatomy (e.g. skull thickness), which varies the amount of current reaching the brain. Individualised dose-control may reduce the variable effects of tDCS by reducing variability in electric field (E-field) intensities at a cortical target site. OBJECTIVE: To characterise the variability in E-field intensity at a cortical site (left primary motor cortex; M1) and throughout the brain for conventional fixed-dose tDCS, and individualised dose-controlled tDCS. METHODS: The intensity and distribution of the E-field during tDCS was estimated using Realistic Volumetric Approach to Simulate Transcranial Electric Stimulation (ROAST) in 50 individual brain scans taken from the Human Connectome Project, for fixed-dose tDCS (1 mA & 2 mA) and individualised dose-controlled tDCS targeting left M1. RESULTS: With a fixed-dose (1 mA & 2 mA), E-field intensity in left M1 varied by more than 100% across individuals, with substantial variation observed throughout the brain as well. Individualised dose-control ensured the same E-field intensity was delivered to left M1 in all individuals. Its variance in other regions of interest (right M1 and area underneath the electrodes) was comparable with fixed- and individualised-dose. CONCLUSIONS: Individualised dose-control can eliminate the variance in E-field intensities at a cortical target site. Assuming that the current delivered to the brain directly determines its physiological and behavioural consequences, this approach may allow for reducing the known variability of tDCS effects.

The efficacy of transcranial random noise stimulation (tRNS) on mood may depend on individual differences including age and trait mood.

OBJECTIVES: To assess whether changes in brain microstructures associated with ageing and presence of cardiovascular risk factors (CVRF) reduce the efficacy of transcranial electrical stimulation (tES) improving mood in euthymic older adults. METHODS: Using excitatory high-frequency transcranial random noise stimulation (tRNS) over bilateral dorsolateral prefrontal cortex, the effect on mood was assessed in euthymic young adults (YA), older adults (HOA) and older adults with CVRF (OVR). Active-tRNS or sham was applied over two sessions. Positive and Negative Affect Schedule and Warwick Edinburgh Mental Well-being Scale measured self-reported state mood before and after stimulation. Trait mood was also measured using the Geriatric Depression Scale. RESULTS: Response to tRNS seemed dependent on individual differences in age and trait mood. In HOA, more negative trait mood was associated with more positive mood change after tRNS. OVR showed a similar but reduced pattern of mood change to HOA. In YA, more positive trait mood was associated with greater positive mood change after tRNS. CONCLUSIONS: Age and trait mood may be important factors when examining the efficacy of tES as an alternative treatment for depression. SIGNIFICANCE: Future studies should consider how response to tES is affected by individual differences.

Dissociation between Semantic Representations for Motion and Action Verbs: Evidence from Patients with Left Hemisphere Lesions.

This multiple single case study contrasted left hemisphere stroke patients (N = 6) to healthy age-matched control participants (N = 15) on their understanding of action (e.g., holding, clenching) and motion verbs (e.g., crumbling, flowing). The tasks required participants to correctly identify the matching verb or associated picture. Dissociations on action and motion verb content depending on lesion site were expected. As predicted for verbs containing an action and/or motion content, modified t-tests confirmed selective deficits in processing motion verbs in patients with lesions involving posterior parietal and lateral occipitotemporal cortex. In contrast, deficits in verbs describing motionless actions were found in patients with more anterior lesions sparing posterior parietal and lateral occipitotemporal cortex. These findings support the hypotheses that semantic representations for action and motion are behaviorally and neuro-anatomically dissociable. The findings clarify the differential and critical role of perceptual and motor regions in processing modality-specific semantic knowledge as opposed to a supportive but not necessary role. We contextualize these results within theories from both cognitive psychology and cognitive neuroscience that make claims over the role of sensory and motor information in semantic representation.

Perceptual decisions regarding object manipulation are selectively impaired in apraxia or when tDCS is applied over the left IPL.

This study evaluated whether apraxia can be understood as due to impaired motor representations or motor imagery necessary for appropriate object-use, imitation, and pantomime. The causal role of the left inferior parietal lobe (IPL), which is heavily implicated in apraxia, is also evaluated. These processes are appraised in light of the proposed ventro-dorsal sub-stream of the classic two visual pathway model, where perceptual information from the ventral stream and the dorsal action stream are integrated and essential for object manipulation. Using a task assessing object-use perception, stroke patients with apraxia demonstrated a selective deficit during perceptual decisions reliant on the integration of visible and known object properties to select the appropriate grasp for object-use. This deficit increased with apraxia severity. A dissociation was evident in these patients showing intact non-motoric perceptual decisions regarding the functional semantic relationship between two objects in the absence of the actor (e.g. how a hammer hits a nail). Converging evidence was found using a modified version of the same task in a neuromodulation study that directly targeted the left IPL in healthy participants using transcranial direct current stimulation (tDCS). Application of inhibitory stimulation over the left IPL reduced performance during perceptual decisions regarding object manipulation whilst performance was unaffected during functional semantic decisions. Excitatory stimulation of the left IPL did not affect performance in either task. Combined, these results suggest that the left inferior parietal lobe is critical for motor imagery, and that apraxia may be caused by an inability to use internal motor representations of object manipulation. These results are discussed in terms of motoric and non-motoric perceptual processes and the proposal of an additional ventro-dorsal sub-stream within the dorsal and ventral visual pathways model.

Impaired Communication Between the Dorsal and Ventral Stream: Indications from Apraxia.

Patients with apraxia perform poorly when demonstrating how an object is used, particularly when pantomiming the action. However, these patients are able to accurately identify, and to pick up and move objects, demonstrating intact ventral and dorsal stream visuomotor processing. Appropriate object manipulation for skilled use is thought to rely on integration of known and visible object properties associated with "ventro-dorsal" stream neural processes. In apraxia, it has been suggested that stored object knowledge from the ventral stream may be less readily available to incorporate into the action plan, leading to an over-reliance on the objects' visual affordances in object-directed motor behavior. The current study examined grasping performance in left hemisphere stroke patients with (N = 3) and without (N = 9) apraxia, and in age-matched healthy control participants (N = 14), where participants repeatedly grasped novel cylindrical objects of varying weight distribution. Across two conditions, object weight distribution was indicated by either a memory-associated cue (object color) or visual-spatial cue (visible dot over the weighted end). Participants were required to incorporate object-weight associations to effectively grasp and balance each object. Control groups appropriately adjusted their grasp according to each object's weight distribution across each condition, whereas throughout the task two of the three apraxic patients performed poorly on both the memory-associated and visual-spatial cue conditions. A third apraxic patient seemed to compensate for these difficulties but still performed differently to control groups. Patients with apraxia performed normally on the neutral control condition when grasping the evenly weighted version. The pattern of behavior in apraxic patients suggests impaired integration of visible and known object properties attributed to the ventro-dorsal stream: in learning to grasp the weighted object accurately, apraxic patients applied neither pure knowledge-based information (the memory-associated condition) nor higher-level information given in the visual-spatial cue condition. Disruption to ventro-dorsal stream predicts that apraxic patients will have difficulty learning to manipulate new objects on the basis of information other than low-level visual cues such as shape and size.

Optic ataxia affects the lower limbs: evidence from a single case study.

Optic ataxia represents a spatial impairment of visually guided reaching following bilateral or unilateral damage to the posterior parietal cortex that is independent of purely motor or visual deficits. Research to date has focused on reaching actions performed with the upper limbs but has neglected to explore whether or not optic ataxia affects the lower limbs, that is, whether it is effector-specific. We asked patient M.H., who suffers from unilateral optic ataxia from left hemispheric damage, and eight age-matched controls, to perform leg movements by stepping down from a wooden block towards a visually presented target. Steps were performed using the left or the right leg, in conditions of central fixation or free viewing. Patient M.H. performed significantly worse than controls. His errors in step accuracy were most pronounced when stepping into the visual periphery (during central fixation), particularly while using the contralesional right foot towards the contralesional right hemispace. This behaviour is consistent with M.H.'s impairments in optic ataxia previously recorded for reaching and grasping actions with the upper limbs. The lesion affecting M.H.'s brain is quite large, encompassing functional areas associated with visuomotor transformations performed with different effectors such as arm and eye (superior parietal-occipital cortex and medial intraparietal sulcus). Our data suggest that optic ataxia is not completely effector-specific, and that neurons encoding visuomotor transformations for both arm and leg are probably both affected by the damage. Our results support the notion that lesions affecting the medial portion of the left posterior parietal cortex similarly affect different effectors (arm and leg) when visually guided actions are directed towards the same contralesional hemispace. In addition they may help explain why patients with optic ataxia have been reported to have difficulties in certain aspects of visually guided locomotion.

Offending behaviour in adults with Asperger syndrome.

Considerable speculation is evident both within the scientific literature and popular media regarding possible links between Asperger syndrome and offending. A survey methodology that utilised quantitative data collection was employed to investigate the prevalence of offending behaviour amongst adults with Asperger Syndrome in a large geographical area of South Wales, UK; qualitative interviews were then conducted with a sub-sample of those identified. A small number of participants meeting the study criteria were identified. For those who had offended, their experience of the criminal justice system was essentially negative. Possible implications of the results were discussed.