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Purpose: Schizophrenia is associated with alterations in neural structure and function of the retina that are similar to changes seen in the retina and brain in multiple neurodegenerative disorders. Preliminary evidence suggests that retinal microvasculature may also be compromised in schizophrenia. The goal of this study was to determine, using optical coherence tomography angiography (OCTA), whether 1) schizophrenia is associated with alterations in retinal microvasculature density; and 2) microvasculature reductions are associated with retinal neural layer thinning and performance on a measure of verbal IQ. Patients and Methods: Twenty-eight outpatients with schizophrenia or schizoaffective disorder and 37 psychiatrically healthy control subjects completed OCT and OCTA exams, and the Wechsler Test of Adult Reading. Results: Schizophrenia patients were characterized by retinal microvasculature density reductions, and enlarged foveal avascular zones, in both eyes. These microvascular abnormalities were generally associated with thinning of retinal neural (macular and peripapillary nerve fiber layer) tissue (but the data were stronger for the left than the right eye) and lower scores on a proxy measure of verbal IQ. First-and later-episode patients did not differ significantly on OCTA findings. Conclusion:The retinal microvasculature impairments seen in schizophrenia appear to be a biomarker of overall brain health, as is the case for multiple neurological conditions. Additional research is needed, however, to clarify contributions of social disadvantage and medical comorbidities to the findings.

In human electrophysiology research, the high gamma part of the power spectrum (~>60 Hz) is a relatively new area of investigation. Despite a low signal‐to‐noise ratio, evidence exists that it contains significant information about activity in local cortical networks. Here, using magnetoencephalography (MEG), we found high gamma activity when comparing data from an n‐back working memory task to resting data in a large sample of normal volunteers. Initial analysis of power spectra from 0‐back, 2‐back, and rest trials showed three frequency bands exhibiting task‐related differences: alpha, beta, and high gamma. Unlike alpha and beta, the high gamma spectrum was broad, without a peak at a single frequency. In addition, power in high gamma was highest for the 2‐back and lowest during rest, while the opposite pattern occurred in the other bands. Beamformer source localization of each of the three frequency bands revealed a distinct set of sources for high gamma. These included several regions of prefrontal cortex that exhibited greater power when both n‐back conditions were compared to rest. A subset of these regions had more power when the 2‐back was compared to 0‐back, which indicates a role in working memory performance. Our results show that high gamma will be important for understanding cortical processing during cognitive and other tasks. Furthermore, data from human intracortical recordings suggest that high gamma is the aggregate of spiking in local cortical networks, which implies that MEG could serve to bridge experimental modalities by noninvasively observing task‐related modulation of spiking rates.