Abstract: A bio-feedback method for training persons in the self-regulation of physiological functions by means of displaying to the person a continuous representation of a value of such physiological functions upon, and together with, a metric which is continuously and automatically variable as a function of such values and the rate of change of such values so as to provide to the person a display in which changes in the physiological function are highly resolvable and therefore easily noticed, and apparatus for practicing such method and disclosed. Means are also optionally provided additionally displaying a target or goal to which the person is to attempt to direct the value of the physiological function; the target is automatically adjusted as a function of the value of the physiological function in such manner that it appears that the target is attainable, but is readjusted to prevent actual attainment of the target. If desired, the target may used without the automatically adjusted metric.