Reduced P300 amplitude during retrieval on a spatial working memory task in a community sample of adolescents who report psychotic symptoms

Abstract

BackgroundDeficits in working memory are widely reported in schizophrenia and are considered a trait marker for the disorder. Event-related potentials (ERPs) and imaging data suggest that these differences in working memory performance may be due to aberrant functioning in the prefrontal and parietal cortices. Research suggests that many of the same risk factors for schizophrenia are shared with individuals from the general population who report psychotic symptoms.MethodsForty-two participants (age range 11–13 years) were divided into those who reported psychotic symptoms (N = 17) and those who reported no psychotic symptoms, i.e. the control group (N = 25). Behavioural differences in accuracy and reaction time were explored between the groups as well as electrophysiological correlates of working memory using a Spatial Working Memory Task, which was a variant of the Sternberg paradigm. Specifically, differences in the P300 component were explored across load level (low load and high load), location (positive probe i.e. in the same location as shown in the study stimulus and negative probe i.e. in a different location to the study stimulus) and between groups for the overall P300 timeframe. The effect of load was also explored at early and late timeframes of the P300 component (250-430 ms and 430-750 ms respectively).ResultsNo between-group differences in the behavioural data were observed. Reduced amplitude of the P300 component was observed in the psychotic symptoms group relative to the control group at posterior electrode sites. Amplitude of the P300 component was reduced at high load for the late P300 timeframe at electrode sites Pz and POz.ConclusionsThese results identify neural correlates of neurocognitive dysfunction associated with population level psychotic symptoms and provide insights into ERP abnormalities associated with the extended psychosis phenotype.

Verbal working memory‐related neural network communication in schizophrenia

“…Results indicate that event-related time-domain responses were smaller in SZ than in HC, supporting Hypothesis 1. Contrary to predictions for event-related responses (e.g., Rawdon et al, 2013) but consistent with overt performance, abnormal timelocked neural activity to WM item presentation did not vary with WM load.…”

“…fMRI studies have reported less activity in SZ than in healthy controls (HC) in brain regions associated with WM encoding and retention, including dorsolateral prefrontal cortex (DLPFC), anterior cingulate cortex (ACC), superior temporal cortex, and posterior cortex (e.g., Cannon et al, ; Eich, Nee, Insel, Malapani, & Smith, ; Glahn et al, ; Karlsgodt et al, ; Unschuld et al, ; Van Snellenberg et al, ; Wible et al, ). Electromagnetic (EEG, MEG) neuroimaging has reported smaller ERP amplitude and event‐related desynchronization in SZ than in HC related to WM encoding and retention (Berger et al, ; Hsieh & Ranganath, ; Johannessen, Bi, Jiang, Kenney, & Chen, ; Light et al, ; Raghavachar et al, ; Rawdon et al, ; Roux, Wibral, Mohr, Singer, & Uhlhaas, ; Sauseng et al, ; Stephane et al, ; Zanto, Rubens, Thangavel, & Gazzaley, ). Lower power in gamma‐band responses has been interpreted as an indication of less efficient item encoding, whereas lower power in theta‐band responses has been considered a sign of less efficient item retention in SZ.…”

“…desynchronization in SZ than in HC related to WM encoding and retention (Berger et al, 2016;Hsieh & Ranganath, 2014;Johannessen, Bi, Jiang, Kenney, & Chen, 2016;Light et al, 2006;Raghavachar et al, 2001;Rawdon et al, 2013;Roux, Wibral, Mohr, Singer, & Uhlhaas, 2012;Sauseng et al, 2009;Stephane et al, 2008;Zanto, Rubens, Thangavel, & Gazzaley, 2011). Lower power in gamma-band responses has been interpreted as an indication of less efficient item encoding, whereas lower power in theta-band responses has been considered a sign of less efficient item retention in SZ.…”

Psychotic-Like Experiences

“…At the anatomical and physiological levels, adolescents who report PLEs, compared to those who do not report these, show structural (Satterthwaite et al 2016) and functional brain abnormalities (Wolf et al 2015), functional disconnectivity (Satterthwaite et al 2015), and a reduced amplitude of the P300 (event-related potentials) (Rawdon et al 2013) similar to those found in patients with psychosis.…”

Neural correlates of absolute pitch: A review

“…The P300 usually reflects stimulus evaluation and category, as well as updating of working memory (WM). P300 amplitudes correlate negatively with WM function, whereas P300 latencies correlate positively (see Christopher, Adam, & Robert, 2006; Polich, 2007; Rawdon et al, 2013; Steiner, Barry, & Gonsalvez, 2013). Because AP musicians presumably possess an internally fixed and long-term tonal template in which tone names are attached to given frequencies, they are able to name tones without references (Hirose et al, 2002; Levitin & Rogers, 2005; Siegel, 1974; Takeuchi & Hulse, 1993).…”