Associations of mismatch negativity with psychotic symptoms and functioning transdiagnostically across psychotic disorders.

Mismatch negativity (MMN) amplitude has been widely shown to be diminished in schizophrenia and, more recently, in other psychotic disorders. Although there is considerable evidence linking MMN reduction to cognitive and functional deficits in schizophrenia, there is little evidence of associations with specific psychotic symptoms. Further, it is unclear if MMN reductions relate to specific symptoms, cognitive, and functional deficits transdiagnostically across different psychotic disorders. The present study examines MMN amplitude in a large cohort of cases diagnosed with psychotic disorders including schizophrenia and schizoaffective disorder (N = 116); bipolar disorder and major depressive disorder (N = 75); and other psychotic disorders (N = 25), as well as individuals with no psychotic disorder diagnoses (N = 248). Furthermore, we examined the association of MMN with symptoms, cognitive functioning, and real-world functioning to determine whether these relationships differ by diagnosis. Results showed that MMN amplitude was reduced in cases overall compared to never-psychotic individuals, with no differences between psychotic disorders. Furthermore, there were transdiagnostic associations of reduced duration MMN (MMN-D) with worse auditory hallucinations (r = .14) and disorganization (r = .14), frequency MMN (MMN-F) with real-word functioning (r = .20) and episodic memory (r = -.22), and both components with executive functioning (MMN-D: r = -.17; MMN-F: r = -.15). Our findings relating MMN reductions with cognitive and real-world functioning replicate earlier research in schizophrenia and extend these relationships to other psychotic disorders. Furthermore, our correlations with MMN-D are consistent with computational modeling research and theoretical proposals that view MMN reduction, cognitive dysfunction, and psychotic symptoms as reflecting underlying predictive coding deficits. However, differences in relationships with MMN-F suggest that additional work is warranted on this topic. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Variation in reward- and error-related neural measures attributable to age, gender, race, and ethnicity.

Event-related potentials (ERPs) have been widely applied to the study of individual differences in reward and error processing, including recent proposals of several ERPs as possible biomarkers of mental illness. A criterion for all biomarkers, however, is that they be generalizable across the relevant populations, something which has yet to be demonstrated for many commonly studied reward- and error-related ERPs. The aim of this study was to examine variation in reward and error-related ERPs across core demographic variables: age, gender, race, and ethnicity. Data was drawn from three studies with relatively large samples (N range 207-527). Results demonstrated that ERPs varied across the demographic variables of interest. Several examples include attenuated reward-related ERPs with increasing age, larger error-related ERPs for men than women, and larger ERPs to feedback after losses for individuals who identified as Hispanic/Latino. Overall, these analyses suggest systematic variation in ERPs that is attributable to core demographic variables, which could give rise to seemingly inconsistent results across studies to the extent that these sample characteristics differ. Future psychophysiological studies should include these analyses as standard practice and assess how these differences might exacerbate, mask, or confound relationships of interest.

Individual differences in the time course of reward processing: Stage-specific links with depression and impulsivity.

Reward dysfunction has been implicated in a wide range of psychological disorders, including internalizing and externalizing psychopathology. Basic neuroscience research has shown that reward is a multistage process, yet it is unclear how specific stages relate to individual differences in reward sensitivity. The current study utilized event-related potentials elicited during a monetary incentive task to parse sub-stages within anticipatory and consummatory reward processing. Effects of depressive symptoms and trait impulsivity were examined at each sub-stage (N=92). Reward anticipation modulated neural activity across three sub-stages: cue detection (cue-P3), approach behavior (contingent negative variation, CNV), and outcome anticipation (stimulus preceding negativity). Reward delivery modulated activity across two sub-stages: initial evaluation (reward positivity, RewP), and allocation of attention (feedback-P3). Sensation seeking predicted faster reaction times, as well as cue-P3 and RewP amplitudes. Depression and lack of premeditation interacted to predict CNV and RewP amplitudes. Results demonstrate that individual differences in reward functioning are stage-specific.

Teasing apart the anticipatory and consummatory processing of monetary incentives: An event-related potential study of reward dynamics.

The monetary incentive delay (MID) task has been widely used in fMRI studies to investigate the neural networks involved in anticipatory and consummatory reward processing. Previous efforts to adapt the MID task for use with ERPs, however, have had limited success. Here, we sought to further decompose reward dynamics using a comprehensive set of anticipatory (cue-N2, cue-P3, contingent negative variation [CNV]) and consummatory ERPs (feedback negativity [FN], feedback P3 [fb-P3]). ERP data was recorded during adapted versions of the MID task across two experiments. Unlike previous studies, monetary incentive cues modulated the cue-N2, cue-P3, and CNV; however, cue-related ERPs and the CNV were uncorrelated with one another, indicating distinct anticipatory subprocesses. With regard to consummatory processing, FN amplitude primarily tracked outcome valence (reward vs. nonreward), whereas fb-P3 amplitude primarily tracked outcome salience (uncertain vs. certain). Independent modulation of the cue-P3 and fb-P3 was observed, indicating that these two P3 responses may uniquely capture the allocation of attention during anticipatory and consummatory reward processing, respectively. Overall, across two samples, consistent evidence of both anticipatory and consummatory ERP activity was observed on an adapted version of the MID paradigm, demonstrating for the first time how these ERP components may be integrated with one another to more fully characterize the time course of reward processing. This ERP-MID paradigm is well suited to parsing reward dynamics, and can be applied to both healthy and clinical populations.