Glossary of technical terms
| Term | Definition |
|---|---|
| BSR | The effect that leads the subject to seek additional stimulation. |
| Curve-shift scaling | A method for scaling the effect of a manipulation in terms of the offsetting change in the stimulation strength required to hold operant performance for BSR constant. Performance (e.g., time allocation or response rate) is plotted on the y-axis and is measured as a function of stimulation strength, which is plotted on the x-axis; lateral displacement of the resulting psychometric curve is measured. |
| Fhm | The pulse frequency at which reward intensity is half maximal. |
| Fm50 | The pulse frequency along a frequency-sweep curve at which time allocation lies halfway between the lower (TAmin) and upper (TAmax) asymptotes. (Fm50 = Fhm only when the price is one half of Pe.) |
| ICSS | Intracranial self-stimulation |
| Location parameters | (Fhm, Pe), the parameters of the reward mountain that determine its location in the plane defined by the common logarithms of the pulse frequency and the price. |
| Opportunity cost | Price, the work time required to earn a reward, scaled in terms of the value of alternate activities forgone. |
| Pe | The price at which time allocation for a maximal reward lies halfway between the lower (TAmin) and upper (TAmax) asymptotes. |
| Price | Opportunity cost, the cumulative time the lever must be held down in order to earn a train of rewarding stimulation. |
| Psychometric curve | A curve expressing a dependent behavioral variable (e.g., time allocation) as a function of an independent physical variable (e.g., pulse frequency). |
| Psychometric surface | A surface expressing a dependent behavioral variable (e.g., time allocation) as a function of two independent physical variables (e.g., pulse frequency and price) |
| Reward intensity | The subjective strength of the reward, analogous to the subjective variable that makes a highly concentrated sucrose solution more rewarding than a more dilute one. |
| Reward mountain | A psychometric surface in a 3D space describing how time allocation (z-axis) varies as a function of the strength (y-axis) and cost (x-axis) of BSR. |
| TAmax | Maximal time allocation; the upper asymptote of 2D psychometric curves or 3D psychometric surfaces. |
| TAmin | Minimal time allocation; the lower asymptote of 2D psychometric curves or 3D psychometric surfaces. |
| TA | The proportion of trial time spent working for BSR. |