1. A method comprising: dividing a media instance into a first component and a second component, the first component and second component concurrently presented; correlating first physiological response data from a first subject exposed to media with the first component and the second component to form first correlated data and second correlated data; processing, using a processor, the first correlated data to identify a first transition representative of a first change; processing, using the processor, the second correlated data to identify a second transition representative of a second change; parsing the first component into a first plurality of events based on the first transition; parsing the second component into a second plurality of events based on the second transition; identifying a first event of the first plurality of events as a first candidate for modification based on the first change; and identifying a second event of the second plurality of events as a second candidate for modification based on the second change.