RESUMEN
Detection of transient changes in interaural correlation is based on the temporal precision of the central representations of acoustic signals. Whether schizophrenia impairs the temporal precision in the interaural correlation process is not clear. In both participants with schizophrenia and matched healthy-control participants, this study examined the detection of a break in interaural correlation (BIC, a change in interaural correlation from 1 to 0 and back to 1), including the longest interaural delay at which a BIC was just audible, representing the temporal extent of the primitive auditory memory (PAM). Moreover, BIC-induced electroencephalograms (EEGs) and the relationships between the early binaural psychoacoustic processing and higher cognitive functions, which were assessed by the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), were examined. The results showed that compared to healthy controls, participants with schizophrenia exhibited poorer BIC detection, PAM and RBANS score. Both the BIC-detection accuracy and the PAM extent were correlated with the RBANS score. Moreover, participants with schizophrenia showed weaker BIC-induced N1-P2 amplitude which was correlated with both theta-band power and inter-trial phase coherence. These results suggested that schizophrenia impairs the temporal precision of the central representations of acoustic signals, affecting both interaural correlation processing and higher-order cognitions.
Asunto(s)
Esquizofrenia , Estimulación Acústica , Percepción Auditiva , Electroencefalografía , Potenciales Evocados Auditivos del Tronco Encefálico , Humanos , PsicoacústicaRESUMEN
Schizophrenia (SZ) is characterized by a series of cognitive impairments, including automatic processing impairment of basic auditory information, indexed by mismatch negativity (MMN). Existing studies mainly focus on MMN induced by deviant of single acoustic features, and relatively few studies have focused on complex acoustic stimuli, especially speech-induced MMN. Many cognitive impairments in SZ are related to speech function. Thus, the present study aimed to examine the reduction of phonetic MMN in SZ as a potential biomarker and its relationship with illness course and functional outcomes. Electroencephalogram (EEG) signals were recorded from 32 SZ and 32 healthy controls (HC) in a double oddball paradigm, with /da/ as the standard stimulus and /ba/ and /du/ as the deviant stimuli. MMN was computed for vowel and consonant deviants separately. Clinical symptoms were assessed using the Positive and Negative Symptom Rating Scale (PANSS). Illness duration and illness relapse were acquired by combining clinical interviews and electronic medical records. Functional outcomes were assessed using the Global Assessment of Functioning scale (GAF). Compared with HC, SZ showed lower amplitudes of phonetic MMN, especially for vowel deviants. In addition, the MMN amplitude of the vowel deviant was significantly correlated with illness duration, illness relapse, and functional outcomes among patients with SZ. These findings indicate that the pre-attentive automatic phonetic processing of SZ was impaired for both consonants and vowels, while the vowel processing deficit may be the key speech processing deficit in SZ, which could depict the illness course and predict the functional outcomes.
Asunto(s)
Esquizofrenia , Estimulación Acústica , Electroencefalografía , Potenciales Evocados Auditivos , Humanos , Fonética , HablaRESUMEN
This work presents an automatically annotated fiber cluster (AAFC) method to enable identification of anatomically meaningful white matter structures from the whole brain tractography. The proposed method consists of 1) a study-specific whole brain white matter parcellation using a well-established data-driven groupwise fiber clustering pipeline to segment tractography into multiple fiber clusters, and 2) a novel cluster annotation method to automatically assign an anatomical tract annotation to each fiber cluster by employing cortical parcellation information across multiple subjects. The novelty of the AAFC method is that it leverages group-wise information about the fiber clusters, including their fiber geometry and cortical terminations, to compute a tract anatomical label for each cluster in an automated fashion. We demonstrate the proposed AAFC method in an application of investigating white matter abnormality in emotional processing and sensorimotor areas in major depressive disorder (MDD). Seven tracts of interest related to emotional processing and sensorimotor functions are automatically identified using the proposed AAFC method as well as a comparable method that uses a cortical parcellation alone. Experimental results indicate that our proposed method is more consistent in identifying the tracts across subjects and across hemispheres in terms of the number of fibers. In addition, we perform a between-group statistical analysis in 31 MDD patients and 62 healthy subjects on the identified tracts using our AAFC method. We find statistical differences in diffusion measures in local regions within a fiber tract (e.g. 4 fiber clusters within the identified left hemisphere cingulum bundle (consisting of 14 clusters) are significantly different between the two groups), suggesting the ability of our method in identifying potential abnormality specific to subdivisions of a white matter structure.
Asunto(s)
Corteza Cerebral/patología , Trastorno Depresivo Mayor/patología , Imagen de Difusión Tensora/métodos , Emociones , Sistema Límbico/patología , Tálamo/patología , Sustancia Blanca/patología , Adulto , Corteza Cerebral/diagnóstico por imagen , Trastorno Depresivo Mayor/diagnóstico por imagen , Femenino , Humanos , Sistema Límbico/diagnóstico por imagen , Masculino , Fibras Nerviosas Mielínicas/patología , Vías Nerviosas/diagnóstico por imagen , Vías Nerviosas/patología , Tractos Piramidales/diagnóstico por imagen , Tractos Piramidales/patología , Corteza Sensoriomotora/diagnóstico por imagen , Corteza Sensoriomotora/patología , Tálamo/diagnóstico por imagen , Sustancia Blanca/diagnóstico por imagen , Adulto JovenRESUMEN
The superior temporal gyrus (STG) is involved in speech recognition against informational masking under cocktail-party-listening conditions. Compared to healthy listeners, people with schizophrenia perform worse in speech recognition under informational speech-on-speech masking conditions. It is not clear whether the schizophrenia-related vulnerability to informational masking is associated with certain changes in FC of the STG with some critical brain regions. Using sparse-sampling fMRI design, this study investigated the differences between people with schizophrenia and healthy controls in FC of the STG for target-speech listening against informational speech-on-speech masking, when a listening condition with either perceived spatial separation (PSS, with a spatial release of informational masking) or perceived spatial co-location (PSC, without the spatial release) between target speech and masking speech was introduced. The results showed that in healthy participants, but not participants with schizophrenia, the contrast of either the PSS or PSC condition against the masker-only condition induced an enhancement of functional connectivity (FC) of the STG with the left superior parietal lobule and the right precuneus. Compared to healthy participants, participants with schizophrenia showed declined FC of the STG with the bilateral precuneus, right SPL, and right supplementary motor area. Thus, FC of the STG with the parietal areas is normally involved in speech listening against informational masking under either the PSS or PSC conditions, and declined FC of the STG in people with schizophrenia with the parietal areas may be associated with the increased vulnerability to informational masking.
Asunto(s)
Esquizofrenia/fisiopatología , Psicología del Esquizofrénico , Percepción del Habla/fisiología , Lóbulo Temporal/fisiopatología , Estimulación Acústica , Adulto , Encéfalo/fisiopatología , Mapeo Encefálico , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Vías Nerviosas , Enmascaramiento PerceptualRESUMEN
Integrated care can reduce rate of relapse and improve personal and social functions in patients with schizophrenia. We established and evaluated a new model of "intensive-consolidation" two-stage integrated care (IC) for inpatients with schizophrenia. Data were collected between 2012 and 2015. Chinese inpatients with schizophrenia (n=170) diagnosed according to DSM-IV were randomly assigned to antipsychotic medication-alone (n=84) or two-stage IC (n=86) and followed up for 12 months. The IC model included intensive treatments (antipsychotics plus the cognitive behavior therapy and rehabilitation treatment) during hospitalization and 3-time consolidation treatments with 3-month intervals at clinics. Outcome measures included the rate of relapse, psychiatric symptoms and social functioning. Compared with medication-alone group, the rate of relapse were significantly lower in IC group (p=0.012); the Mixed-Effects Model for Repeated-Measures analyses showed that the IC group significantly improved in positive symptoms over time; greater improvement in self-care and less aggressive behaviors were observed over time in IC group (all p<0.008). The findings support the feasibility and effectiveness of the new two-stage model of integrated care as an intervention for middle-acute-phase inpatients with schizophrenia. The model is particularly informative to countries where medical resources are mainly distributed in developed regions.