Altered short-term neural plasticity related to schizotypal traits: Evidence from visual adaptation

Abstract

Abnormalities in synaptic plasticity are argued to underlie the neural dysconnectivity observed in schizophrenia. One way to measure synaptic plasticity is through sensory adaptation, whereby sensory neurons exhibit reduced sensitivity after sustained stimulus exposure. Evidence for decreased adaptation in individuals with schizophrenia is currently inconclusive, possibly due to heterogeneity in clinical and medication status across samples. Here we circumvent these confounds by examining whether altered adaptation is represented sub-clinically in the general population. To test this we used three paradigms from visual perception research that provide a precise and non-invasive index of adaptation in the visual system. Two paradigms involve a class of illusory percepts termed visual aftereffects. The third relies on a visual phenomenon termed binocular rivalry, where incompatible stimuli are presented to the two eyes and observers alternate between perceiving exclusively one stimulus or a combination of the two (i.e. mixed perception). We analyzed the strength and dynamics of visual adaptation in these paradigms, in relation to schizotypy. Our results showed that increased schizotypal traits were related to reduced orientation, but not luminance, aftereffect strength (Exp. 1). Further, increased schizotypy was related to a greater proportion of mixed perception during binocular rivalry (Exp. 1 and 2). Given that visual adaption is well understood at cellular and computational levels, our data suggest that short-term plasticity in the visual system can provide important information about the disease mechanisms of schizophrenia.

Stronger tilt aftereffects in persons with schizophrenia.

“…Findings in non-clinical samples may provide further insights into a potential role of medication. In an undergraduate sample, we found that the strength of tilt aftereffects, but not negative afterimages, was related to schizotypal traits (Thakkar, Antinori, et al, 2019). However, the direction of that relationship was opposite to what the current findings would predict; increased schizophrenia-like traits were associated with weaker tilt aftereffects.…”

“…To ensure data quality, we applied several previously employed data exclusion criteria, (Brascamp, Becker, & Hambrick, 2018;Thakkar, Antinori, Carter, & Brascamp, 2019), which are detailed in the Supplemental Methods. 3 PSZ and 1 HC were excluded from the negative afterimage analysis (leaving a total sample of 33 PSZ and 21 HC), and 6 PSZ and 1 HC were excluded from the tilt aftereffect analysis (leaving a total sample of 30 PSZ and 21 HC).…”

Frequency of alpha oscillation predicts individual differences in perceptual stability during binocular rivalry

“…Anxiety patients have been shown to have faster durations (Nagamine et al, ). Individuals with higher schizotypal traits show a higher proportion of mixed percepts during rivalry (Thakkar, Antinori, Carter, & Brascamp, ). A study looking at the Big Five personality scale found that industrious or self‐disciplined people had longer perceptual durations during rivalry (Antinori, Smillie, & Carter, ).…”

“…Individuals diagnosed with bipolar disorder have repeatedly been shown to have slower durations compared to controls (Miller et al, 2003;Nagamine, Yoshino, Miyazaki, Takahashi, & Nomura, 2009;Ngo, Mitchell, Martin, & Miller, 2011;Pettigrew & Miller, 1998;Vierck et al, 2013), as have those diagnosed with autism (Robertson, Kravitz, Freyberg, Baron-Cohen, & Baker, 2013); however see, (Said, Egan, Minshew, Behrmann, & Heeger, 2013) to have faster durations (Nagamine et al, 2007). Individuals with higher schizotypal traits show a higher proportion of mixed percepts during rivalry (Thakkar, Antinori, Carter, & Brascamp, 2018). A study looking at the Big Five personality scale found that industrious or self-disciplined people had longer perceptual durations during rivalry (Antinori, Smillie, & Carter, 2017).…”

A multivariate neuromonitoring approach to neuroplasticity-based computerized cognitive training in recent onset psychosis

“…Previous research on selective attention demonstrates marked malleability of neural systems in charge of potential changes in response to intervention [16]. Dysplasticity in schizophrenia has been known for decades, and while it has predominantly been reported in motor and frontal areas [17,18], it is also expressed in multiple brain regions including sensory systems [19]. The underlying mechanism of neuroplasticity-based CCT is meant to induce widespread changes in both cortical and subcortical representations and may not be captured by singleregion activation maps measured by task-based MRI [3,20,21].…”