System and method for neurotransmitter measurement

A method for identifying a level of a neurotransmitter in a subject, comprising:

• displaying to the subject, on a display, a fixation point;
• providing an instructional, conditional stimulus to the subject;
• simultaneously displaying to the subject, on the display, a reward target and a non-reward target;
• measuring a non-reward saccade movement parameter of the subject from the fixation point to the non-reward target and a reward saccade movement parameter of the subject from the fixation point to the reward target;
• determining a saccade movement parameter reward modulation, the saccade movement parameter reward modulation being equal to a difference between the reward saccade movement parameter measurement and the non-reward saccade movement parameter measurement;
• comparing the saccade movement parameter reward modulation of the subject to a reference saccade movement parameter reward modulation;
• and
• identifying the level of the neurotransmitter in the subject based upon the comparing of the saccade movement parameter reward modulation of the subject and the reference saccade movement parameter reward modulation;
• wherein, in the identifying step, a processor executing a software program determines when there is a statistically measurable difference between the reward modulation of the subject and the reference reward modulation, and in the identifying step the subject includes a deficiency of the neurotransmitter if the reward modulation of the subject is statistically lower than the reference reward modulation;
• wherein one or both of the measuring steps are performed with a camera configured to track the reward saccade movement parameter;
• and
• further comprising diagnosing the subject with a neurodegenerative condition if the subject includes the deficiency of the neurotransmitter.