A computing device is configured to verify a user's identity, intent to authenticate, and/or possession of secret knowledge by evaluating biometric and/or environmental data. In embodiments, such verification is performed by evaluating a user's reaction to a stimulus based on such data. Biometric data may comprise eye tracking data, and a computing device may be configured to use such data to verify that the person has gazed through objects in a predetermined order. In embodiments, the user's intent to authenticate is verified by combining such eye tracking data with other biometric data. Physiological and other types of biometric data may be used to evaluate the user for indicia of duress. Embodiments may be configured to provide modified access to the computing device or resources stored thereon where indicia of duress have been detected. Such modified access may comprise hiding information stored on the device.