In described embodiments, a device and method for diagnosing brain and neurological issues is provided. The device measures the performance of Convergence, Divergence, and binocular tracking capabilities of a subject's eyes, which can be used to determine whether a subject has experienced a brain or other neurological event.

Methods, systems, and devices are disclosed for monitoring electrical signals of the brain. In one aspect, a system for monitoring electrical brain activity associated with visual field of a user includes a sensor unit to acquire electroencephalogram (EEG) signals including a plurality of EEG sensors attached to a casing attachable to the head of a user, a visual display unit attachable to the head of the user over the user's eyes to present visual stimuli, in which the visual stimuli is configured to evoke multifocal steady-state visual-evoked potentials (mfSSVEP) in the EEG signals exhibited by the user acquired by the sensor unit, and a data processing unit in communication with the sensor unit and the visual display unit to analyze the acquired EEG signals and produce an assessment of the user's visual field, in which the assessment indicates if there is a presence of visual field defects in the user's visual field.

Applications for a Content Engagement Power (CEP) value include generating a script, text, or other communication content or for controlling playout of communication content based on neuro-physiological data, gathering neuro-physiological data correlated to consumption of communication content, or rating effectiveness of personal communications. The CEP is computed based on neuro-physiological sensor data processed to express engagement with content along multiple dimensions such as valence, arousal, and dominance. An apparatus is configured to perform the method using hardware, firmware, and/or software.

The application describes treatment of hepatic encephalopathy using gastrointestinal specific antibiotics. One example of a gastrointestinal specific antibiotic is rifaximin. The instant application also provides methods for determining if a subject has a neurological condition or hepatic encephalopathy by determining the critical flicker frequency and/or the venous ammonia level of the subject at two or more time points. The invention further provides methods for treating these subjects.

A method for obtaining an optical prescription. The method includes determining a value of a fatigue parameter for at least two intermediate optical prescriptions among a plurality of intermediate optical prescriptions, the fatigue parameter associated with a visual fatigue level of a subject carrying out a visual task involving any kind of visual content, wherein each determined value of the fatigue parameter is associated with a respective one of the plurality of intermediate optical prescriptions; comparing the determined values of the fatigue parameter; and obtaining the optical prescription, based on the comparison of the determined values of the fatigue parameter. A system for obtaining an optical prescription is also disclosed.

One example provides a head-mounted display (HMD) device comprising a display system, a logic subsystem, and a storage subsystem comprising instructions executable by the logic subsystem. The instructions are executable to project images at a first frame rate using the display system, detect a change in a stimulus attribute of the images that modifies a critical flicker fusion (CFF) threshold of a human eye, and in response, adjust a frame rate of the display system to project the images at a second frame rate.