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1.
Schizophr Bull ; 2024 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-38616053

RESUMEN

BACKGROUND AND HYPOTHESIS: The current study investigated the extent to which changes in attentional control contribute to performance on a visual perceptual discrimination task, on a trial-by-trial basis in a transdiagnostic clinical sample. STUDY DESIGN: Participants with schizophrenia (SZ; N = 58), bipolar disorder (N = 42), major depression disorder (N = 51), and psychiatrically healthy controls (N = 92) completed a visual perception task in which stimuli appeared briefly. The design allowed us to estimate the lapse rate and the precision of perceptual representations of the stimuli. Electroencephalograms (EEG) were recorded to examine pre-stimulus activity in the alpha band (8-13 Hz), overall and in relation to behavior performance on the task. STUDY RESULTS: We found that the attention lapse rate was elevated in the SZ group compared with all other groups. We also observed group differences in pre-stimulus alpha activity, with control participants showing the highest levels of pre-stimulus alpha when averaging across trials. However, trial-by-trial analyses showed within-participant fluctuations in pre-stimulus alpha activity significantly predicted the likelihood of making an error, in all groups. Interestingly, our analysis demonstrated that aperiodic contributions to the EEG signal (which affect power estimates across frequency bands) serve as a significant predictor of behavior as well. CONCLUSIONS: These results confirm the elevated attention lapse rate that has been observed in SZ, validate pre-stimulus EEG markers of attentional control and their use as a predictor of behavior on a trial-by-trial basis, and suggest that aperiodic contributions to the EEG signal are an important target for further research in this area, in addition to alpha-band activity.

2.
Schizophr Res ; 266: 190-196, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38422889

RESUMEN

Screening for psychosis spectrum disorders in primary care could improve early identification and reduce the duration of untreated psychosis. However, the accuracy of psychosis screening in this setting is unknown. To address this, we conducted a diagnostic accuracy study of screening for psychosis spectrum disorders in eight behavioral health services integrated into primary care clinics. Patients attending an integrated behavioral health appointment at their primary care clinic completed the Prodromal Questionnaire - Brief (PQ-B) immediately prior to their intake assessment. This was compared to a diagnostic phone interview based on the Structured Interview for Psychosis Risk Syndromes (SIPS). In total, 145 participants completed all study procedures, of which 100 screened positive and 45 negative at a provisional PQ-B threshold of ≥20. The PQ-B was moderately accurate at differentiating psychosis spectrum from no psychosis spectrum disorders; a PQ-B distress score of ≥27 had a sensitivity and specificity of 71.2 % and 57.0 % respectively. In total, 66 individuals (45.5 %) met criteria for a psychosis spectrum disorder and 24 (16.7 %) were diagnosed with full psychosis, indicating a high prevalence of psychosis in the sample. Overall, screening for psychosis spectrum disorders in an IBH primary care setting identified a relatively high number of individuals and may identify people that would otherwise be missed. The PQ-B performed slightly less well than in population-based screening in community mental health settings. However, the findings suggest this may represent an effective way to streamline the pathway between specialty early psychosis programs and primary care clinics for those in need.


Asunto(s)
Psiquiatría , Trastornos Psicóticos , Humanos , Trastornos Psicóticos/diagnóstico , Trastornos Psicóticos/epidemiología , Trastornos Psicóticos/psicología , Encuestas y Cuestionarios , Sensibilidad y Especificidad , Atención Primaria de Salud , Síntomas Prodrómicos
3.
Schizophr Bull ; 50(2): 339-348, 2024 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-37901911

RESUMEN

BACKGROUND: Research suggests that effort-cost decision-making (ECDM), the estimation of work required to obtain reward, may be a relevant framework for understanding motivational impairment in psychotic and mood pathology. Specifically, research has suggested that people with psychotic and mood pathology experience effort as more costly than controls, and thus pursue effortful goals less frequently. This study examined ECDM across psychotic and mood pathology. HYPOTHESIS: We hypothesized that patient groups would show reduced willingness to expend effort compared to controls. STUDY DESIGN: People with schizophrenia (N = 33), schizoaffective disorder (N = 28), bipolar disorder (N = 39), major depressive disorder (N = 40), and controls (N = 70) completed a physical ECDM task. Participants decided between completing a low-effort or high-effort option for small or larger rewards, respectively. Reward magnitude, reward probability, and effort magnitude varied trial-by-trial. Data were analyzed using standard and hierarchical logistic regression analyses to assess the subject-specific contribution of various factors to choice. Negative symptoms were measured with a clinician-rated interview. STUDY RESULTS: There was a significant effect of group, driven by reduced choice of high-effort options in schizophrenia. Hierarchical logistic regression revealed that reduced choice of high-effort options in schizophrenia was driven by weaker contributions of probability information. Use of reward information was inversely associated with motivational impairment in schizophrenia. Surprisingly, individuals with major depressive disorder and bipolar disorder did not differ from controls. CONCLUSIONS: Our results provide support for ECDM deficits in schizophrenia. Additionally, differences between groups in ECDM suggest a seemingly similar behavioral phenotype, reduced motivation, could arise from disparate mechanisms.


Asunto(s)
Trastorno Depresivo Mayor , Trastornos Psicóticos , Esquizofrenia , Humanos , Trastornos del Humor/complicaciones , Trastorno Depresivo Mayor/complicaciones , Toma de Decisiones , Trastornos Psicóticos/complicaciones , Esquizofrenia/complicaciones , Motivación , Recompensa
4.
Front Psychol ; 14: 1210259, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37691809

RESUMEN

Introduction: Recent work challenged past findings that documented relational memory impairments in autism. Previous studies often relied solely on explicit behavioral responses to assess relational memory integrity, but successful performance on behavioral tasks may rely on other cognitive abilities (e.g., executive functioning) that are impacted in some autistic individuals. Eye-tracking tasks do not require explicit behavioral responses, and, further, eye movements provide an indirect measure of memory. The current study examined whether memory-specific viewing patterns toward scenes differ between autistic and non-autistic individuals. Methods: Using a long-term memory paradigm that equated for complexity between item and relational memory tasks, participants studied a series of scenes. Following the initial study phase, scenes were re-presented, accompanied by an orienting question that directed participants to attend to either features of an item (i.e., in the item condition) or spatial relationships between items (i.e., in the relational condition) that might be subsequently modified during test. At test, participants viewed scenes that were unchanged (i.e., repeated from study), scenes that underwent an "item" modification (an exemplar switch) or a "relational" modification (a location switch), and scenes that had not been presented before. Eye movements were recorded throughout. Results: During study, there were no significant group differences in viewing directed to regions of scenes that might be manipulated at test, suggesting comparable processing of scene details during encoding. However, there was a group difference in explicit recognition accuracy for scenes that underwent a relational change. Marginal group differences in the expression of memory-based viewing effects during test for relational scenes were consistent with this behavioral outcome, particularly when analyses were limited to scenes recognized correctly with high confidence. Group differences were also evident in correlational analyses that examined the association between study phase viewing and recognition accuracy and between performance on the Picture Sequence Memory Test and recognition accuracy. Discussion: Together, our findings suggest differences in the integrity of relational memory representations and/or in the relationships between subcomponents of memory in autism.

5.
Psychiatry Res ; 328: 115420, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37657201

RESUMEN

Recreational cannabis use has recently gained considerable interest as an environmental risk factor that triggers the onset of psychosis. To date, however, the evidence that cannabis is associated with negative outcomes in individuals at clinical high risk (CHR) for psychosis is inconsistent. The present study tracked cannabis usage over a 2-year period and examined its associations with clinical and neurocognitive outcomes, along with medication rates. CHR youth who continuously used cannabis had higher neurocognition and social functioning over time, and decreased medication usage, relative to non-users. Surprisingly, clinical symptoms improved over time despite the medication decreases.

6.
Schizophr Bull ; 49(5): 1281-1293, 2023 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-37382553

RESUMEN

BACKGROUND AND HYPOTHESIS: Impairments in function (ie, the ability to independently accomplish daily tasks) have been established in psychotic disorders. Identifying factors that contribute to these deficits is essential to developing effective interventions. The current study had several goals: examine potential differential relationships across domains of neurocognition, assess whether reinforcement learning is related to function, identify if predictors of function are transdiagnostic, determine whether depression and positive symptoms contribute to function, and to explore whether the modality of assessment impacts observed relationships. STUDY DESIGN: Data from 274 participants were examined with schizophrenia/schizoaffective disorder (SZ; n = 195) and bipolar disorder (BD; n = 79). To reduce dimensionality, a PCA was completed on neurocognitive tasks which resulted in 3 components. These components and clinical interview data were used to investigate predictors of functional domains across measures of function (self- and informant-report SLOF and UPSA). RESULTS: Two components, working memory/processing speed/episodic memory (ßs = 0.18-0.42), and negative/positive reinforcement learning (ß = -0.04), predicted different functional domains. Predictors of function were largely transdiagnostic with two exceptions: reinforcement learning had a positive association with self-reported interpersonal relationships for SZ and a negative association for BD (ß = 0.34), and the negative association between positive symptoms and self-reported social acceptability was stronger for BD than for SZ (ß = 0.93). Depression robustly predicted self-reported but not informant-reported function, and anhedonia predicted all domains of informant-reported function. CONCLUSIONS: These findings imply that reinforcement learning may differentially relate to function across disorders, traditional domains of neurocognition can be effective transdiagnostic targets for interventions, and positive symptoms and depression play a critical role in self-perceived functional impairments.


Asunto(s)
Depresión , Trastornos Psicóticos , Humanos , Depresión/diagnóstico , Pruebas Neuropsicológicas , Trastornos Psicóticos/diagnóstico , Trastornos Psicóticos/psicología , Aprendizaje , Refuerzo en Psicología
7.
JAMA Psychiatry ; 80(2): 119-126, 2023 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-36598770

RESUMEN

Importance: Reducing the duration of untreated psychosis (DUP) is essential to improving outcomes for people with first-episode psychosis (FEP). Current US approaches are insufficient to reduce DUP to international standards of less than 90 days. Objective: To determine whether population-based electronic screening in addition to standard targeted clinician education increases early detection of psychosis and decreases DUP, compared with clinician education alone. Design, Setting, and Participants: This cluster randomized clinical trial included individuals aged 12 to 30 years presenting for services between March 2015 and September 2017 at participating sites that included community mental health clinics and school support and special education services. Eligible participants were referred to the Early Diagnosis and Preventative Treatment (EDAPT) Clinic. Data analyses were performed in September and October 2019 for the primary and secondary analyses, with the exploratory subgroup analyses completed in May 2021. Interventions: All sites in both groups received targeted education about early psychosis for health care professionals. In the active screening group, clients also completed the Prodromal Questionnaire-Brief using tablets at intake; referrals were based on those scores and clinical judgment. In the group receiving treatment as usual (TAU), referrals were based on clinical judgment alone. Main Outcomes and Measures: Primary outcomes included DUP, defined as the period from full psychosis onset to the date of the EDAPT diagnostic telephone interview, and the number of individuals identified with FEP or a psychosis spectrum disorder. Exploratory analyses examined differences by site type, completion rates between conditions, and days from service entry to telephone interview. Results: Twenty-four sites agreed to participate, and 12 sites were randomized to either the active screening or TAU group. However, only 10 community clinics and 4 school sites were able to fully implement population screening and were included in the final analysis. The total potentially eligible population size within each study group was similar, with 2432 individuals entering at active screening group sites and 2455 at TAU group sites. A total of 303 diagnostic telephone interviews were completed (178 [58.7%] female individuals; mean [SD] age, 17.09 years [4.57]). Active screening sites reported a significantly higher detection rate of psychosis spectrum disorders (136 cases [5.6%], relative to 65 [2.6%]; P < .001) and referred a higher proportion of individuals with FEP and DUP less than 90 days (13 cases, relative to 4; odds ratio, 0.30; 95% CI, 0.10-0.93; P = .03). There was no difference in mean (SD) DUP between groups (active screening group, 239.0 days [207.4]; TAU group 262.3 days [170.2]). Conclusions and Relevance: In this cluster trial, population-based technology-enhanced screening across community settings detected more than twice as many individuals with psychosis spectrum disorders compared with clinical judgment alone but did not reduce DUP. Screening could identify people undetected in US mental health services. Significant DUP reduction may require interventions to reduce time to the first mental health contact. Trial Registration: ClinicalTrials.gov Identifier: NCT02841956.


Asunto(s)
Servicios de Salud Mental , Trastornos Psicóticos , Humanos , Femenino , Adolescente , Masculino , Trastornos Psicóticos/diagnóstico , Trastornos Psicóticos/terapia , Trastornos Psicóticos/psicología , Escolaridad , Salud Mental , Instituciones Académicas
8.
Cogn Affect Behav Neurosci ; 23(1): 203-215, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36418846

RESUMEN

Cognitive control deficits are associated with impaired executive functioning in schizophrenia. The Dual Mechanisms of Control framework suggests that proactive control requires sustained dorsolateral prefrontal activity, whereas reactive control marshals a larger network. However, primate studies suggest these processes are maintained by dual-encoding regions. To distinguish between these theories, we compared the distinctiveness of proactive and reactive control functional neuroanatomy. In a reanalysis of data from a previous study, 47 adults with schizophrenia and 56 controls completed the Dot Pattern Expectancy task during an fMRI scan examining proactive and reactive control in frontoparietal and medial temporal regions. Areas suggesting specialized control or between-group differences were tested for association with symptoms and task performance. Elastic net models additionally explored these areas' predictive abilities regarding performance. Most regions were active in both reactive and proactive control. However, evidence of specialized proactive control was found in the left middle and superior frontal gyri. Control participants showed greater proactive control in the left middle and right inferior frontal gyri. Elastic net models moderately predicted task performance and implicated various frontal gyri regions in control participants, with additional involvement of anterior cingulate and posterior parietal regions for reactive control. Elastic nets for patient participants implicated the inferior and superior frontal gyri, and posterior parietal lobe. Specialized cognitive control was unassociated with either performance or schizophrenia symptomatology. Future work is needed to clarify the distinctiveness of proactive and reactive control, and its role in executive deficits in severe psychopathology.


Asunto(s)
Neuroanatomía , Esquizofrenia , Humanos , Esquizofrenia/diagnóstico por imagen , Lóbulo Frontal , Corteza Prefrontal/diagnóstico por imagen , Lóbulo Temporal , Imagen por Resonancia Magnética
9.
Psychol Med ; 53(13): 6280-6287, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-36420704

RESUMEN

BACKGROUND: Motivational impairment associated with deficits in processing the anticipation of future reward is hypothesized to be a cardinal feature of schizophrenia spectrum disorders (SZ). Evidence from short-term follow-up (6-week post-treatment) studies suggests that these deficits may improve or be reversed with treatment, although longer-term outcomes are unknown. Here we examined the one-year trajectory of functional activation in brain circuitry associated with reward anticipation in people with recent onset SZ who participated in coordinated specialty care (CSC) treatment, hypothesizing normalization of brain response mirroring previous short-term findings in first-episode individuals. METHOD: Blood oxygen level-dependent (BOLD) response in the dorsal anterior cingulate cortex, anterior insula, and ventral striatum (VS) associated with reward anticipation during the Incentivized Control Engagement Task (ICE-T) was analyzed in a baseline sample of 49 healthy controls (HCs) and 52 demographically matched people with SZ, with follow-up data available for 35 HCs and 17 people with SZ. RESULTS: In agreement with our hypothesis, significant time × diagnosis interactions were observed across all regions, in which reward anticipation-associated BOLD response increased in SZ to above baseline HC levels at follow-up. Increased VS activation was associated with decreased reality distortion symptoms over the follow-up period. Baseline reward anticipation-associated BOLD response in the right anterior insula was associated with improvement in reality distortion symptoms. CONCLUSIONS: These findings suggest that functional deficits in reward anticipation may be reversed after one year of CSC in recent onset participants with SZ, and that this improvement is associated with reduced positive symptoms in the illness.


Asunto(s)
Esquizofrenia , Humanos , Esquizofrenia/diagnóstico por imagen , Esquizofrenia/terapia , Imagen por Resonancia Magnética , Encéfalo/diagnóstico por imagen , Recompensa , Motivación , Anticipación Psicológica/fisiología
10.
Curr Top Behav Neurosci ; 63: 19-60, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36173600

RESUMEN

The development of treatments for impaired cognition in schizophrenia has been characterized as the most important challenge facing psychiatry at the beginning of the twenty-first century. The Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia (CNTRICS) project was designed to build on the potential benefits of using tasks and tools from cognitive neuroscience to better understanding and treat cognitive impairments in psychosis. These benefits include: (1) the use of fine-grained tasks that measure discrete cognitive processes; (2) the ability to design tasks that distinguish between specific cognitive domain deficits and poor performance due to generalized deficits resulting from sedation, low motivation, poor test taking skills, etc.; and (3) the ability to link cognitive deficits to specific neural systems, using animal models, neuropsychology, and functional imaging. CNTRICS convened a series of meetings to identify paradigms from cognitive neuroscience that maximize these benefits and identified the steps need for translation into use in clinical populations. The Cognitive Neuroscience Test Reliability and Clinical Applications for Schizophrenia (CNTRaCS) Consortium was developed to help carry out these steps. CNTRaCS consists of investigators at five different sites across the country with diverse expertise relevant to a wide range of the cognitive systems identified as critical as part of CNTRICs. This work reports on the progress and current directions in the evaluation and optimization carried out by CNTRaCS of the tasks identified as part of the original CNTRICs process, as well as subsequent extensions into the Positive Valence systems domain of Research Domain Criteria (RDoC). We also describe the current focus of CNTRaCS, which involves taking a computational psychiatry approach to measuring cognitive and motivational function across the spectrum of psychosis. Specifically, the current iteration of CNTRaCS is using computational modeling to isolate parameters reflecting potentially more specific cognitive and visual processes that may provide greater interpretability in understanding shared and distinct impairments across psychiatric disorders.


Asunto(s)
Trastornos Psicóticos , Esquizofrenia , Animales , Reproducibilidad de los Resultados , Esquizofrenia/tratamiento farmacológico , Cognición , Modelos Animales de Enfermedad
11.
Artículo en Inglés | MEDLINE | ID: mdl-35618258

RESUMEN

BACKGROUND: Theories suggest that people with schizophrenia (SZ) have problems generating predictions based on past experiences. The dorsolateral prefrontal cortex (DLPFC) and hippocampus participate in memory-based prediction. We used functional magnetic resonance imaging to investigate DLPFC and hippocampal function in healthy control (HC) subjects and people with SZ during memory-based prediction. METHODS: Prior to scanning, HC subjects (n = 54) and people with SZ (n = 31) learned 5-object sequences presented in fixed or random orders on each repetition. During scanning, participants made semantic decisions (e.g., "Can this object fit in a shoebox?") on a continuous stream of objects from fixed and random sequences. Sequence prediction was demonstrated by faster semantic decisions for objects in fixed versus random sequences because memory could be used to anticipate and more efficiently process semantic information about upcoming objects in fixed sequences. Representational similarity analyses were used to determine how each sequence type was represented in the posterior hippocampus and DLPFC. RESULTS: Sequence predictions were reduced in individuals with SZ relative to HC subjects. Representational similarity analyses revealed stronger memory-based predictions in the DLPFC of HC subjects than people with SZ, and DLPFC representations correlated with more successful predictions in HC subjects only. For the posterior hippocampus, voxel pattern similarity was increased for fixed versus random sequences in HC subjects only, but no significant between-group differences or correlations with prediction success were observed. CONCLUSIONS: Individuals with SZ are capable of learning temporal sequences; however, they are impaired using memory to predict upcoming events as efficiently as HC subjects. This deficit appears related to disrupted neural representation of sequence information in the DLPFC.


Asunto(s)
Esquizofrenia , Humanos , Corteza Prefrontal , Trastornos de la Memoria , Hipocampo
12.
Psychol Med ; 52(6): 1115-1125, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-32799938

RESUMEN

BACKGROUND: Schizophrenia is a disorder characterized by pervasive deficits in cognitive functioning. However, few well-powered studies have examined the degree to which cognitive performance is impaired even among individuals with schizophrenia not currently on antipsychotic medications using a wide range of cognitive and reinforcement learning measures derived from cognitive neuroscience. Such research is particularly needed in the domain of reinforcement learning, given the central role of dopamine in reinforcement learning, and the potential impact of antipsychotic medications on dopamine function. METHODS: The present study sought to fill this gap by examining healthy controls (N = 75), unmedicated (N = 48) and medicated (N = 148) individuals with schizophrenia. Participants were recruited across five sites as part of the CNTRaCS Consortium to complete tasks assessing processing speed, cognitive control, working memory, verbal learning, relational encoding and retrieval, visual integration and reinforcement learning. RESULTS: Individuals with schizophrenia who were not taking antipsychotic medications, as well as those taking antipsychotic medications, showed pervasive deficits across cognitive domains including reinforcement learning, processing speed, cognitive control, working memory, verbal learning and relational encoding and retrieval. Further, we found that chlorpromazine equivalency rates were significantly related to processing speed and working memory, while there were no significant relationships between anticholinergic load and performance on other tasks. CONCLUSIONS: These findings add to a body of literature suggesting that cognitive deficits are an enduring aspect of schizophrenia, present in those off antipsychotic medications as well as those taking antipsychotic medications.


Asunto(s)
Antipsicóticos , Esquizofrenia , Humanos , Antipsicóticos/uso terapéutico , Dopamina , Cognición , Memoria a Corto Plazo , Pruebas Neuropsicológicas
13.
Schizophr Bull ; 48(1): 262-272, 2022 01 21.
Artículo en Inglés | MEDLINE | ID: mdl-34510196

RESUMEN

OBJECTIVE: Cognitive impairment in schizophrenia predicts functional outcomes and is largely unresponsive to pharmacology or psychotherapy; it is thus a critical unmet treatment need. This article presents the impact of remotely completed, intensive, targeted auditory training (AT) vs control condition computer games (CG) in a double-blind randomized trial in young adults with recent-onset schizophrenia. METHOD: Participants (N = 147) were assessed for cognition, symptoms, and functioning at baseline, post-intervention, and at 6-month follow-up. All participants were provided with laptop computers and were instructed to complete 40 hours remotely of training or computer games. An intent-to-treat analysis (N = 145) was performed using linear mixed models with time modeled as a continuous variable. Planned contrasts tested the change from baseline to post-training, baseline to 6-month follow-up, and post-training to 6-month follow-up. RESULTS: Global Cognition, which had improved in the AT group relative to the CG group at post-training, showed durable gains at 6-month follow-up in an omnibus group-by-time interaction test (F(1,179) = 4.80, P = .030), as did Problem-Solving (F(1,179) = 5.13, P = .025), and Speed of Processing improved at trend level significance (F(1,170) = 3.80, P = .053). Furthermore, the AT group showed significantly greater improvement than the CG group in positive symptoms (F(1,179) = 4.06, P = .045). CONCLUSIONS: These results provide the first evidence of durable cognitive gains and symptom improvement at follow-up of cognitive training (CT) in early schizophrenia completed independently and remotely. While functioning did not show significant improvement, these findings suggest that intensive targeted CT of auditory processing is a promising component of early intervention to promote recovery from psychosis.


Asunto(s)
Disfunción Cognitiva/rehabilitación , Remediación Cognitiva , Trastornos Psicóticos/rehabilitación , Esquizofrenia/rehabilitación , Adulto , Disfunción Cognitiva/etiología , Método Doble Ciego , Femenino , Estudios de Seguimiento , Humanos , Masculino , Evaluación de Resultado en la Atención de Salud , Trastornos Psicóticos/complicaciones , Esquizofrenia/complicaciones , Adulto Joven
15.
Biol Psychiatry Cogn Neurosci Neuroimaging ; 7(10): 1035-1046, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33878489

RESUMEN

BACKGROUND: Psychiatric diagnosis and treatment have historically taken a symptom-based approach, with less attention on identifying underlying symptom-producing mechanisms. Recent efforts have illuminated the extent to which different underlying circuitry can produce phenotypically similar symptomatology (e.g., psychosis in bipolar disorder vs. schizophrenia). Computational modeling makes it possible to identify and mathematically differentiate behaviorally unobservable, specific reinforcement learning differences in patients with schizophrenia versus other disorders, likely owing to a higher reliance on prediction error-driven learning associated with basal ganglia and underreliance on explicit value representations associated with orbitofrontal cortex. METHODS: We used a well-established probabilistic reinforcement learning task to replicate those findings in individuals with schizophrenia both on (n = 120) and off (n = 44) antipsychotic medications and included a patient comparison group of bipolar patients with psychosis (n = 60) and healthy control subjects (n = 72). RESULTS: Using accuracy, there was a main effect of group (F3,279 = 7.87, p < .001), such that all patient groups were less accurate than control subjects. Using computationally derived parameters, both medicated and unmediated individuals with schizophrenia, but not patients with bipolar disorder, demonstrated a reduced mixing parameter (F3,295 = 13.91, p < .001), indicating less dependence on learning explicit value representations as well as greater learning decay between training and test (F1,289 = 12.81, p < .001). Unmedicated patients with schizophrenia also showed greater decision noise (F3,295 = 2.67, p = .04). CONCLUSIONS: Both medicated and unmedicated patients showed overreliance on prediction error-driven learning as well as significantly higher noise and value-related memory decay, compared with the healthy control subjects and the patients with bipolar disorder. Additionally, the computational model parameters capturing these processes can significantly improve patient/control classification, potentially providing useful diagnosis insight.


Asunto(s)
Antipsicóticos , Trastornos Psicóticos , Esquizofrenia , Antipsicóticos/uso terapéutico , Simulación por Computador , Humanos , Trastornos Psicóticos/tratamiento farmacológico , Refuerzo en Psicología , Esquizofrenia/tratamiento farmacológico
16.
Artículo en Inglés | MEDLINE | ID: mdl-33862254

RESUMEN

BACKGROUND: People with schizophrenia (SZ) exhibit impaired episodic memory when relating objects to each other in time and space. Empirical studies and computational models suggest that low-frequency neural oscillations may be a mechanism by which the brain keeps track of temporal relationships during encoding and retrieval, with modulation of oscillatory power as sequences are learned. It is unclear whether sequence memory deficits in SZ are associated with altered neural oscillations. METHODS: Using electroencephalography, this study examined neural oscillations in 51 healthy control subjects and 37 people with SZ during a temporal sequence learning task. Multiple 5-object picture sequences were presented across 4 study-test blocks in either fixed or random order. Participants answered semantic questions for each object (e.g., living/nonliving), and sequence memory was operationalized as faster responses for fixed versus random sequences. Differences in oscillatory power between fixed versus random sequences provided a neural index of temporal sequence memory. RESULTS: Although both groups showed reaction time differences in late blocks (blocks 3 and 4), this evidence of sequence memory was reduced in people with SZ relative to healthy control subjects. Decreases in globally distributed prestimulus alpha (8-12 Hz) and beta 1 (13-20 Hz) power for fixed versus random sequences in late blocks were also attenuated in people with SZ relative to healthy control subjects. Moreover, changes in oscillatory power predicted individual reaction time differences and fully mediated the relationship between group and sequence memory. CONCLUSIONS: Disrupted modulation of alpha and beta 1 electroencephalography oscillations is a candidate mechanism of temporal sequence memory deficits in people with SZ.


Asunto(s)
Esquizofrenia , Encéfalo/fisiología , Electroencefalografía , Humanos , Trastornos de la Memoria/etiología , Tiempo de Reacción , Esquizofrenia/complicaciones
17.
Neuropsychopharmacology ; 46(6): 1152-1160, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33452432

RESUMEN

Blunted and exaggerated neuronal response to rewards are hypothesized to be core features of schizophrenia spectrum disorders (SZ) and bipolar disorder (BD), respectively. Nonetheless, direct tests of this hypothesis, in which response between SZ and BD is compared in the same study, are lacking. Here we examined the functional correlates of reward processing during the Incentivized Control Engagement Task (ICE-T) using 3T fMRI. Reward-associated activation was examined in 49 healthy controls (HCs), 52 recent-onset individuals with SZ, and 22 recent-onset individuals with Type I BD using anterior cingulate (ACC), anterior insula, and ventral striatal regions of interest. Significant group X reward condition (neutral vs. reward) interactions were observed during reward anticipation in the dorsal ACC (F(2,120) = 4.21, P = 0.017) and right insula (F(2,120) = 4.77, P = 0.010). The ACC interaction was driven by relatively higher activation in the BD group vs. HCs (P = 0.007) and vs. individuals with SZ (P = 0.010). The insula interaction was driven by reduced activation in the SZ group relative to HCs (P = 0.018) and vs. people with BD (P = 0.008). A composite of reward anticipation-associated response across all associated ROIs also differed significantly by diagnosis (F(1,120) = 5.59, P = 0.02), BD > HC > SZ. No effects of group or group X reward interactions were observed during reward feedback. These results suggest that people with SZ and BD have opposite patterns of activation associated with reward anticipation but not reward receipt. Implications of these findings in regard to Research Domain Criteria-based classification of illness and the neurobiology of reward in psychosis are discussed.


Asunto(s)
Trastorno Bipolar , Esquizofrenia , Trastorno Bipolar/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética , Recompensa , Esquizofrenia/diagnóstico por imagen
18.
Schizophr Res ; 223: 186-191, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32739345

RESUMEN

BACKGROUND: Providing early psychosis (EP) individuals with family psychoeducation (FPE) can reduce symptoms and improve clinical outcomes. However, relational memory problems may limit prospective utilization of FPE information. This study examines whether memory for FPE can be improved by testing participants during the initial FPE workshop presentation. METHOD: Data were obtained from 20 people with EP and 20 demographically matched healthy comparison subjects (HC). During session one, FPE was presented in small group workshops, with half of the information re-studied twice (re-study condition) and the remaining information tested twice using cued recall tasks (retrieval practice condition). One week later (session two), delayed cued recall was tested for all FPE information. "Testing effects" (i.e., better memory following retrieval practice versus re-study) were examined across all items (standard analysis) and also limited to items successfully retrieved during session one (conditionalized analysis). RESULTS: HC had better initial recall and learned more over the two retrieval practice trials than EP. However, HC also lost more information than EP over the one-week delay. Both groups produced a significant testing effect. This effect was smaller in EP versus HC across all test items, but did not differ for the conditionalized analysis. Negative symptoms were inversely correlated with delayed cued recall in EP. CONCLUSIONS: EP participants benefit from retrieval practice, with participants with less severe negative symptoms showing the greatest benefit. These results encourage use of memory tests during group psychoeducation to improve subsequent long-term recall of clinically relevant information.


Asunto(s)
Recuerdo Mental , Trastornos Psicóticos , Señales (Psicología) , Humanos , Memoria , Estudios Prospectivos , Trastornos Psicóticos/terapia
19.
J Cogn Neurosci ; 32(11): 2117-2130, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32573383

RESUMEN

Prior studies demonstrated that neural oscillations are enhanced during working memory (WM) maintenance and that this activity can predict behavioral performance in healthy individuals. However, it is unclear whether the relationship holds for people with WM deficits. People with schizophrenia have marked WM deficits, and such deficits are most prominent when patients are required to process relationships between items, such as temporal order. Here, we used EEG to compare the relationship between oscillatory activity and WM performance in patients and controls. EEG was recorded as participants performed tasks requiring maintenance of complex objects ("Item") or the temporal order of objects ("Order"). In addition to testing for group differences, we examined individual differences in EEG power and WM performance across groups. Behavioral results demonstrated that patients showed impaired performance on both Item and Order trials. EEG analyses revealed that patients showed an overall reduction in alpha power, but the relationship between alpha activity and performance was preserved. In contrast, patients showed a reduction in theta power specific to Order trials, and theta power could predict performance on Order trials in controls, but not in patients. These findings demonstrate that WM impairments in patients may reflect two different processes: a general deficit in alpha oscillations and a specific deficit in theta oscillations when temporal order information must be maintained. At a broader level, the results highlight the value of characterizing brain-behavior relationships, by demonstrating that the relationship between neural oscillations and WM performance can be fundamentally disrupted in those with WM deficits.


Asunto(s)
Ondas Encefálicas , Esquizofrenia , Encéfalo , Humanos , Memoria a Corto Plazo , Ritmo Teta
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