464 research outputs found
The guilty brain: the utility of neuroimaging and neurostimulation studies in forensic field
Several studies have aimed to address the natural inability of humankind to detect deception and accurately discriminate lying from truth in the legal context. To date, it has been well established that telling a lie is a complex mental activity. During deception, many functions of higher cognition are involved: the decision to lie, withholding the truth, fabricating the lie, monitoring whether the receiver believes the lie, and, if necessary, adjusting the fabricated story and maintaining a consistent lie. In the previous 15 years, increasing interest in the neuroscience of deception has resulted in new possibilities to investigate and interfere with the ability to lie directly from the brain. Cognitive psychology, as well as neuroimaging and neurostimulation studies, are increasing the possibility that neuroscience will be useful for lie detection. This paper discusses the scientific validity of the literature on neuroimaging and neurostimulation regarding lie detection to understand whether scientific findings in this field have a role in the forensic setting. We considered how lie detection technology may contribute to addressing the detection of deception in the courtroom and discussed the conditions and limits in which these techniques reliably distinguish whether an individual is lying
Transcranial Direct Current Stimulation: Challenges, Opportunities, and Impact on Psychiatry and Neurorehabilitation
Integrating home monitoring for transcranial direct current stimulation (tDCS) therapy to professional care environment
Daily management of neurodegenerative diseases is one of the most striking scenarios
where an integrated health care system is essential for the continuous assistance to the
patient and requires qualification of the caregivers and their training. In particular,
patients affected by depression or chronic pain, as well as rehabilitating after stroke,
can be treated at home with non-invasive electrical neuromodulation (transcranial
Direct Current Stimulation, tDCS) in order to reduce daily travel expenses between
home and hospital. Home monitoring of patient undergoing tDCS is essential to (1)
optimize the stimulation parameters according to the current health status and to the
stimulation outcomes, and (2) assess disease progression. However, monitoring
effectiveness depends on the exchange of this information between the patient at home
and his/her reference neurologist. Currently, the health IT scenario is composed by two
independent environments, one dedicated to healthcare professionals (e.g., Electronic
Health Records, EHRs), and one including mobile devices applications dedicated to
citizens, caregivers and patients. Safety, communication and interoperability gaps
prevented from an effective data exchange between these two environments. The aim
of our work is to implement an integrated home monitoring system for tDCS patients,
in which a web-based platform for EHR management exchanges data with a patient\u2019s
mobile app
Web-based telemonitoring and delivery of caregiver support for patients with Parkinson disease after deep brain stimulation: protocol
The increasing number of patients, the high costs of management, and the chronic progress of the disease that prevents patients from performing even simple daily activities make Parkinson disease (PD) a complex pathology with a high impact on society. In particular, patients implanted with deep brain stimulation (DBS) electrodes face a highly fragile stabilization period, requiring specific support at home. However, DBS patients are followed usually by untrained personnel (caregivers or family), without specific care pathways and supporting systems
Transcutaneous Spinal Direct Current Stimulation (tsDCS) Modulates Human Corticospinal System Excitability
This study aimed to assess the effects of thoracic anodal and cathodal transcutaneous spinal direct current stimulation (tsDCS) on upper- and lower-limb corticospinal excitability. Yet, despite studies assessing thoracic tsDCS influences the spinal ascending tract and reflexes, none assessed the effects of this technique over upper- and lower-limb corticomotorneuronal connections. In 14 healthy subjects we recorded motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) from abductor hallucis (AH) and hand abductor digiti minimi (ADM) muscles before (baseline, B), and at a different time-points (0 and 30 minutes) after anodal or cathodal tsDCS (2.5 mA, 20 minutes, T9-T11 level). In 8 of the 14 subjects we also tested the soleus H-reflex, the F-waves from AH and ADM before and after tsDCS. Both anodal and cathodal tsDCS left the upper-limb MEPs and F-wave unchanged. Conversely, while leaving lower-limb H-reflex unchanged, they oppositely affected lower-limb MEPs: whereas anodal tsDCS increased resting motor threshold (mean\ub1SEM 107.33 \ub1 3.3%, increase immediately after tsDCS, and 108.37 \ub1 3.2% increase 30 min after tsDCS compared to baseline), and had no effects on MEP area and latency, cathodal tsDCS increased MEP area (139.71 \ub1 12.9% increase immediately after tsDCS and 132.74 \ub122.0% increase 30 min after tsDCS compared to baseline) without affecting resting motor threshold and MEP latency. Our results show that tsDCS induces polarity specific changes in corticospinal excitability that last for more than 30 min after tsDCS offset and selectively affect responses in lower-limb muscles innervated by lumbar and sacral motorneurons
Ethical safety of deep brain stimulation: A study on moral decision-making in Parkinson's disease
INTRODUCTION: The possibility that deep brain stimulation (DBS) in Parkinson's disease (PD) alters patients' decisions and actions, even temporarily, raises important clinical, ethical and legal questions. Abnormal moral decision-making can lead to ethical rules violations. Previous experiments demonstrated the subthalamic (STN) activation during moral decision-making. Here we aim to study whether STN DBS can affect moral decision-making in PD patients.
METHODS:
Eleven patients with PD and bilateral STN DBS implant performed a computerized moral task in ON and OFF stimulation conditions. A control group of PD patients without DBS implant performed the same experimental protocol. All patients underwent motor, cognitive and psychological assessments.
RESULTS:
STN stimulation was not able to modify neither reaction times nor responses to moral task both when we compared the ON and the OFF state in the same patient (reaction times, p = .416) and when we compared DBS patients with those treated only with the best medical treatment (reaction times: p = .408, responses: p = .776).
CONCLUSIONS:
Moral judgment is the result of a complex process, requiring cognitive executive functions, problem-solving, anticipations of consequences of an action, conflict processing, emotional evaluation of context and of possible outcomes, and involving different brain areas and neural circuits. Our data show that STN DBS leaves unaffected moral decisions thus implying relevant clinical and ethical implications for DBS consequences on patients' behavior, on decision-making and on judgment ability. In conclusion, the technique can be considered safe on moral behavior
Cathodal transcranial direct current stimulation improves focal hand dystonia in musicians: A two-case study
Focal hand dystonia (FHD) in musicians is a movement disorder causing abnormal movements and irregularities in playing. Since weak electrical currents applied to the brain induce persistent excitability changes in humans, cathodal tDCS was proposed as a possible non-invasive approach for modulating cortical excitability in patients with FHD. However, the optimal targets and modalities have still to be determined. In this pilot study, we delivered cathodal (2 mA), anodal (2 mA) and sham tDCS over the motor areas bilaterally for 20 min daily for five consecutive days in two musicians with FHD. After cathodal tDCS, both patients reported a sensation of general wellness and improved symptoms of FHD. In conclusion, our pilot results suggest that cathodal tDCS delivered bilaterally over motor-premotor (M-PM) cortex for 5 consecutive days may be effective in improving symptoms in FHD
Adaptive deep brain stimulation in a freely moving parkinsonian patient
The future of deep brain stimulation (DBS) for Parkinson\u2019s disease (PD) lies in new closed-loop systems that continuously
supply the implanted stimulator with new settings obtained by analyzing a feedback signal related to the patient\u2019s current
clinical condition
Amplitude and frequency modulation of subthalamic beta oscillations jointly encode the dopaminergic state in Parkinson's disease.
Brain states in health and disease are classically defined by the power or the spontaneous amplitude modulation (AM) of neuronal oscillations in specific frequency bands. Conversely, the possible role of the spontaneous frequency modulation (FM) in defining pathophysiological brain states remains unclear. As a paradigmatic example of pathophysiological resting states, here we assessed the spontaneous AM and FM dynamics of subthalamic beta oscillations recorded in patients with Parkinson's disease before and after levodopa administration. Even though AM and FM are mathematically independent, they displayed negatively correlated dynamics. First, AM decreased while FM increased with levodopa. Second, instantaneous amplitude and instantaneous frequency were negatively cross-correlated within dopaminergic states, with FM following AM by approximately one beta cycle. Third, AM and FM changes were also negatively correlated between dopaminergic states. Both the slow component of the FM and the fast component (i.e. the phase slips) increased after levodopa, but they differently contributed to the AM-FM correlations within and between states. Finally, AM and FM provided information about whether the patients were OFF vs. ON levodopa, with partial redundancy and with FM being more informative than AM. AM and FM of spontaneous beta oscillations can thus both separately and jointly encode the dopaminergic state in patients with Parkinson's disease. These results suggest that resting brain states are defined not only by AM dynamics but also, and possibly more prominently, by FM dynamics of neuronal oscillations
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