A system comprising: one or more stored naturalistic sensory stimuli configured to evoke a neural response of a subject; one or more processors (125,130) implementing a processing unit configured to determine an indication of the cognitive function of a subject to the one or more naturalistic sensory stimuli by: receiving a measurement of a neural response in the subject exposed to the one or more naturalistic sensory stimuli; determining a statistical relationship between the at least one signal feature of the one or more naturalistic sensory stimuli and the measurement of the cortical neural response of the subject, wherein the at least one signal feature, received by the one or more processors, is a sensory envelope of the one or more stored naturalistic sensory stimuli, and the statistical correlation is the cross-correlation between the measurement of the cortical neural response of the subject with the sensory envelope, and wherein the determining the statistical relationship further comprises bandpass filtering the measurement of the cortical neural response; identifying a latency value based on the determined statistical relationship between the at least one signal feature of the one or more naturalistic sensory stimuli and the measurement of the cortical neural response of the subject; determining an indication of the cognitive function of the subject based on the identified latency value, wherein determining the cognitive function of the subject based on the identified latency value comprises classifying the subject as being in a minimally conscious state, having emerged from a minimally conscious state, being in a vegetative state, being in a cognitive motor dissociation command following state, or as being in a healthy state; and an output module for outputting the determined cognitive function of the subject. one or more stored naturalistic sensory stimuli configured to evoke a neural response of a subject; one or more processors (125,130) implementing a processing unit configured to determine an indication of the cognitive function of a subject to the one or more naturalistic sensory stimuli by: receiving a measurement of a neural response in the subject exposed to the one or more naturalistic sensory stimuli; determining a statistical relationship between the at least one signal feature of the one or more naturalistic sensory stimuli and the measurement of the cortical neural response of the subject, wherein the at least one signal feature, received by the one or more processors, is a sensory envelope of the one or more stored naturalistic sensory stimuli, and the statistical correlation is the cross-correlation between the measurement of the cortical neural response of the subject with the sensory envelope, and wherein the determining the statistical relationship further comprises bandpass filtering the measurement of the cortical neural response; identifying a latency value based on the determined statistical relationship between the at least one signal feature of the one or more naturalistic sensory stimuli and the measurement of the cortical neural response of the subject; determining an indication of the cognitive function of the subject based on the identified latency value, wherein determining the cognitive function of the subject based on the identified latency value comprises classifying the subject as being in a minimally conscious state, having emerged from a minimally conscious state, being in a vegetative state, being in a cognitive motor dissociation command following state, or as being in a healthy state; and an output module for outputting the determined cognitive function of the subject. receiving a measurement of a neural response in the subject exposed to the one or more naturalistic sensory stimuli; determining a statistical relationship between the at least one signal feature of the one or more naturalistic sensory stimuli and the measurement of the cortical neural response of the subject, wherein the at least one signal feature, received by the one or more processors, is a sensory envelope of the one or more stored naturalistic sensory stimuli, and the statistical correlation is the cross-correlation between the measurement of the cortical neural response of the subject with the sensory envelope, and wherein the determining the statistical relationship further comprises bandpass filtering the measurement of the cortical neural response; identifying a latency value based on the determined statistical relationship between the at least one signal feature of the one or more naturalistic sensory stimuli and the measurement of the cortical neural response of the subject; determining an indication of the cognitive function of the subject based on the identified latency value, wherein determining the cognitive function of the subject based on the identified latency value comprises classifying the subject as being in a minimally conscious state, having emerged from a minimally conscious state, being in a vegetative state, being in a cognitive motor dissociation command following state, or as being in a healthy state; and an output module for outputting the determined cognitive function of the subject.