An apparatus for analyzing virtual reality content, the apparatus comprising: a virtual reality presentation device adapted to display the virtual reality content for exposure to a user, wherein the virtual reality content includes a video stream; a neurological data collector adapted to access first neurological response data collected from the user during exposure to the virtual reality content; the apparatus being characterized by: a predictor adapted to generate a prediction on a likelihood that exposure to a first portion of the video stream, which has not yet been presented to the user, will cause the user to suffer a photosensitive epileptic seizure, based on the first neurological response data and a first vector, the first vector representing the visual appearance of the frames of the first portion of the video stream; and a content modifier (114, 230) adapted to modify the first portion of the video stream to generate a modified first portion of the video stream if the generated prediction indicates that the user is likely to get a photosensitive epileptic seizure, the modified first portion being generated by adjusting the visual appearance of the frames of the first portion of the video stream so as to reduce the likelihood of the occurrence of the photosensitive epileptic seizure, the modification being based in part on the first neurological response data, wherein the content modifier is adapted to further transmit the modified first portion of the video stream to the virtual reality presentation device, wherein the virtual reality presentation device is adapted to present the modified content to the user. a virtual reality presentation device adapted to display the virtual reality content for exposure to a user, wherein the virtual reality content includes a video stream; a neurological data collector adapted to access first neurological response data collected from the user during exposure to the virtual reality content; the apparatus being characterized by: a predictor adapted to generate a prediction on a likelihood that exposure to a first portion of the video stream, which has not yet been presented to the user, will cause the user to suffer a photosensitive epileptic seizure, based on the first neurological response data and a first vector, the first vector representing the visual appearance of the frames of the first portion of the video stream; and a content modifier (114, 230) adapted to modify the first portion of the video stream to generate a modified first portion of the video stream if the generated prediction indicates that the user is likely to get a photosensitive epileptic seizure, the modified first portion being generated by adjusting the visual appearance of the frames of the first portion of the video stream so as to reduce the likelihood of the occurrence of the photosensitive epileptic seizure, the modification being based in part on the first neurological response data, wherein the content modifier is adapted to further transmit the modified first portion of the video stream to the virtual reality presentation device, wherein the virtual reality presentation device is adapted to present the modified content to the user. a predictor adapted to generate a prediction on a likelihood that exposure to a first portion of the video stream, which has not yet been presented to the user, will cause the user to suffer a photosensitive epileptic seizure, based on the first neurological response data and a first vector, the first vector representing the visual appearance of the frames of the first portion of the video stream; and a content modifier (114, 230) adapted to modify the first portion of the video stream to generate a modified first portion of the video stream if the generated prediction indicates that the user is likely to get a photosensitive epileptic seizure, the modified first portion being generated by adjusting the visual appearance of the frames of the first portion of the video stream so as to reduce the likelihood of the occurrence of the photosensitive epileptic seizure, the modification being based in part on the first neurological response data, wherein the content modifier is adapted to further transmit the modified first portion of the video stream to the virtual reality presentation device, wherein the virtual reality presentation device is adapted to present the modified content to the user.