A method of monitoring the cognitive function of an individual the method including the steps of: repeatedly measuring at least one physical parameter associated with the individual using a sensor worn by the individual, in real-time so as to reflect the current state of the individual; a processor comparing the measurements of said physical parameter against a predetermined baseline of either normal behaviour for that parameter or of abnormal behaviour for that parameter, in real-time so as to reflect the current state of the individual; the processor determining whether the measured physical parameter deviates from the baseline of normal behaviour by more than a pre-defined amount, or whether the measured physical parameter matches the baseline of abnormal behaviour within a predetermined tolerance, in real-time so as to reflect the current state of the individual; in response to said determination, trigger a user interface to present at least one cognitive test to the individual, for the individual to perform, said test being able to provide information about the individual's cognitive function, and recording the individual's response to the cognitive test, in real-time so as to reflect the current state of the individual; and collecting behavioural data based on the individual's response and characterised in: the processor comparing said behavioural data against a further predetermined baseline, in real-time, so as to reflect the current state of the individual, the baseline including one or more of: historic data of the individual, relevant validated data sets for general populations, and relevant validated data sets for populations with specific neurological disorders. repeatedly measuring at least one physical parameter associated with the individual using a sensor worn by the individual, in real-time so as to reflect the current state of the individual; a processor comparing the measurements of said physical parameter against a predetermined baseline of either normal behaviour for that parameter or of abnormal behaviour for that parameter, in real-time so as to reflect the current state of the individual; the processor determining whether the measured physical parameter deviates from the baseline of normal behaviour by more than a pre-defined amount, or whether the measured physical parameter matches the baseline of abnormal behaviour within a predetermined tolerance, in real-time so as to reflect the current state of the individual; in response to said determination, trigger a user interface to present at least one cognitive test to the individual, for the individual to perform, said test being able to provide information about the individual's cognitive function, and recording the individual's response to the cognitive test, in real-time so as to reflect the current state of the individual; and collecting behavioural data based on the individual's response and characterised in: the processor comparing said behavioural data against a further predetermined baseline, in real-time, so as to reflect the current state of the individual, the baseline including one or more of: historic data of the individual, relevant validated data sets for general populations, and relevant validated data sets for populations with specific neurological disorders.