102,132 research outputs found
Validation of the Italian version of the Northoff Catatonia Rating Scale
No full textPURPOSE: Catatonia is a psychomotor syndrome characterized by heterogeneous motor, behavioral and affective alterations, and, in some cases, neurovegetative abnormalities that can be life-threatening. Although the prevalence estimates of catatonia are 10-20% of the hospitalized population, its clinical recognition remains a challenge for most clinicians. Differently from other catatonia rating scales, the Northoff Catatonia Rating Scale (NCRS) also evaluates the affective alterations that patients experience during catatonia and thus provides a more inclusive assessment of the alterations associated with this condition. To provide clinicians with a valuable tool for diagnosis, we translated the NCRS in Italian and validated it on a sample of 52 hospitalized patients with psychiatric disorders. METHODS: An Italian version of the NCRS was prepared using the forward-backwards translation from English and administered to a sample of 52 in-patients (age 46.9±2.37 years). The inter-rater reliability, score correlations, internal coherence and decision statistics were computed. RESULTS: The inter-rater agreement was higher for the motor subscale (100% agreement) than for the behavioral (94%) or affective subscales (92.3%). The inter-rater agreement was 100% for the diagnosis of catatonia. The NCRS correctly identified all patients with catatonia according to DSM-5 (sensitivity= 100%) and had a specificity of 88.9%, and its subscale scores were highly inter-correlated. CONCLUSIONS: This validation shows that the NCRS yields a good accuracy in diagnosing catatonia and high inter-rater reliability. Moreover, the high correlation between its subscales supports the view that catatonia is a multi-faceted truly psycho-motor syndrome. In conclusion, the validation and Italian translation of the NCRS provides the clinicians with a helpful tool for diagnosing catatonia which is easy to use and assesses the full psychomotor complexity of the syndrome
Slow Resting State Fluctuations Enhance Neuronal and Behavioral Responses to Looming Sounds
No full textWe investigate both experimentally and using a computational model how the power of the electroencephalogram (EEG) recorded in human subjects tracks the presentation of sounds with acoustic intensities that increase exponentially (looming) or remain constant (flat). We focus on the link between this EEG tracking response, behavioral reaction times and the time scale of fluctuations in the resting state, which show considerable inter-subject variability. Looming sounds are shown to generally elicit a sustained power increase in the alpha and beta frequency bands. In contrast, flat sounds only elicit a transient upsurge at frequencies ranging from 7 to 45 Hz. Likewise, reaction times (RTs) in an audio-tactile task at different latencies from sound onset also present significant differences between sound types. RTs decrease with increasing looming intensities, i.e. as the sense of urgency increases, but remain constant with stationary flat intensities. We define the reaction time variation or “gain” during looming sound presentation, and show that higher RT gains are associated with stronger correlations between EEG power responses and sound intensity. Higher RT gain further entails higher relative power differences between loom and flat in the alpha and beta bands. The full-width-at-half-maximum of the autocorrelation function of the eyes-closed resting state EEG also increases with RT gain. The effects are topographically located over the central and frontal electrodes. A computational model reveals that the increase in stimulus–response correlation in subjects with slower resting state fluctuations is expected when EEG power fluctuations at each electrode and in a given band are viewed as simple coupled low-pass filtered noise processes jointly driven by the sound intensity. The model assumes that the strength of stimulus-power coupling is proportional to RT gain in different coupling scenarios, suggesting a mechanism by which slower resting state fluctuations enhance EEG response and shorten reaction times
From pre-stimulus activity to the contents of consciousness - A spatiotemporal view: Reply to comments on "Beyond task response-Pre-stimulus activity modulates contents of consciousness"
No full textWhat are the exact neuronal mechanisms of pre-post-stimulus interaction and how can that account for the intrinsically subjective nature of the contents of consciousness? This is the key question lurking behind the various excellent and very thoughtful commentaries to our target article which we group along four main topics and questions. (i) What is the role of neural features like alpha power, phase dynamics, trial-to-trial variability and fractal scale-free dynamics in yielding pre-post-stimulus interaction and its conscious contents. (ii) What do we mean by 'content' of consciousness? This concerns its meaning, its characterization as internal or external, and its relation to the basic subjectivity of consciousness. (iii) How does our approach stand to other theories of consciousness like the Dendritic Integration Theory (DIT), GNWT and IIT? This concerns the convergence among the different theories that highlight distinct aspects. (iv) How can we detail the spatiotemporal shaping of the contents of consciousness including their intrinsically subjective nature through pre-post-stimulus interaction? This concerns the details of how the non-additive pre-post-stimulus interaction shapes the subjective nature of our experience of conscious contents, that is, how the neuronal activity connects to the phenomenal features of consciousness. Together, we conclude that the contents of consciousness are shaped primarily in a temporal-dynamic and spatial-topographic way through the non-additive pre-post-stimulus interaction. Such spatiotemporal shaping of the contents in our consciousness constitutes their intrinsically subjective nature which must be distinguished from their (more objective) modulation by cognitive, sensory, affective, and motor functions
Discovering imaging endophenotypes for major depression
No full textPsychiatry research lacks an in-depth understanding of mood disorders phenotypes, leading to limited success of genetics studies of major depressive disorder (MDD). The dramatic progress in safe and affordable magnetic resonance-based imaging methods has the potential to identify subtle abnormalities of neural structures, connectivity and function in mood disordered subjects. This review paper presents strategies to improve the phenotypic definition of MDD by proposing imaging endophenotypes derived from magnetic resonance spectroscopy measures, such as cortical gamma-amino butyric acid (GABA) and glutamate/glutamine concentrations, and from measures of resting-state activity and functional connectivity. The proposed endophenotypes are discussed regarding specificity, mood state-independence, heritability, familiarity, clinical relevance and possible associations with candidate genes. By improving phenotypic definitions, the discovery of new imaging endophenotypes will increase the power of candidate gene and genome-wide associations studies. It will also help to develop and evaluate novel therapeutic treatments and enable clinicians to apply individually tailored therapeutic approaches. Finally, improvements of the phenotypic definition of MDD based on neuroimaging measures will contribute to a new classification system of mood disorders based on etiology and pathophysiology
Intrinsic neural network dynamics in catatonia
No full textCatatonia is a transnosologic psychomotor syndrome with high prevalence in schizophrenia spectrum disorders (SSD). There is mounting neuroimaging evidence that catatonia is associated with aberrant frontoparietal, thalamic and cerebellar regions. Large-scale brain network dynamics in catatonia have not been investigated so far. In this study, resting-state fMRI data from 58 right-handed SSD patients were considered. Catatonic symptoms were examined on the Northoff Catatonia Rating Scale (NCRS). Group spatial independent component analysis was carried out with a multiple analysis of covariance (MANCOVA) approach to estimate and test the underlying intrinsic components (ICs) in SSD patients with (NCRS total score ≥ 3; n = 30) and without (NCRS total score = 0; n = 28) catatonia. Functional network connectivity (FNC) during rest was calculated between pairs of ICs and transient changes in connectivity were estimated using sliding windowing and clustering (to capture both static and dynamic FNC). Catatonic patients showed increased static FNC in cerebellar networks along with decreased low frequency oscillations in basal ganglia (BG) networks. Catatonic patients had reduced state changes and dwelled more in a state characterized by high within-network correlation of the sensorimotor, visual, and default-mode network with respect to noncatatonic patients. Finally, in catatonic patients according to DSM-IV-TR (n = 44), there was a significant correlation between increased within FNC in cortico-striatal state and NCRS motor scores. The data support a neuromechanistic model of catatonia that emphasizes a key role of disrupted sensorimotor network control during distinct functional states
How to link brain and experience? Spatiotemporal Psychopathology of the Lived Body
No full textThe focus of the present paper is on sketching a psychopathology of the body in schizophrenia. Our hypothesis is that the psychopathological alterations of the lived body are closely related to spatiotemporal alterations in the brain’s resting state. Hence our plea for a spatiotemporal psychopathology of embodiment. We will shed some light on the resting state itself, its spatiotemporal structure and self-specific organisation and then address the resting state’s spatial and temporal abnormalities in schizophrenia and how they account for the abnormal experience of body, time, and space in this psychopathological condition. Finally, we sketch the implications of such spatiotemporal psychopathology of embodiment that concerns the spatialization and temporalization and self-specification of the lived body and its intero-, proprio- and extero-ceptive input by the resting state’s spatiotemporal structure and self-specific organisation
Individual alpha frequency predicts perceived visuotactile simultaneity
No full textTemporal encoding is a key feature in multisensory processing that leads to the integration versus segregation of perceived events over time. Whether or not two events presented at different offsets are perceived as simultaneous varies widely across the general population. Such tolerance to temporal delays is known as the temporal binding window (TBW). It has been recently suggested that individual oscillatory alpha frequency (IAF) peak may represent the electrophysiological correlate of TBW, with IAF also showing a wide variability in the general population (8–12 Hz). In our work, we directly tested this hypothesis by measuring each individual’s TBW during a visuotactile simultaneity judgment task while concurrently recording their electrophysiological activity. We found that the individual’s TBW significantly correlated with their left parietal IAF, such that faster IAF accounted for narrower TBW. Furthermore, we found that higher prestimulus alpha power measured over the same left parietal regions accounted for more veridical responses of non-simultaneity, which may be explained either by accuracy in perceptual simultaneity or, alternatively, in line with recent proposals by a shift in response bias from more conservative (high alpha power) to more liberal (low alpha power). We propose that the length of an alpha cycle constrains the temporal resolution within which perceptual processes take place
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