The parameters dialogue box looks like this:
Particular things to note:
| • | Reinforcer limits (specified in the schedules) apply to whatever is being delivered by that schedule - so in the SD task, the "max no. of reinforcers" for the Noncontingent Schedule sets the total maximum number of SDs to be delivered. |
| • | The "always reinforce the first of each response..." is superimposed upon the underlying schedule. So in an FR10 schedule, if this is ticked, then responses 1 and 10 and 20 will be reinforced (not 1 and 11 and 21). |
| • | When a reinforcer limit has been reached, the task ends. |
| • | In the ANR phase, any timeout (triggered by either lever) applies to both levers. |
| • | In the ANR phase, responses during an ongoing stimulus are not reinforced. |
| • | When the session time limit expires, any ongoing CSs are cut off, but the task waits for any ongoing primary reinforcement to finish. |
| • | "Debouncing" applies especially to levers (though debouncing is applied to all onset/offset events from levers and nosepokes, if selected). Levers tend to bounce mechanically, generating spurious but rapid electrical signals. "Debouncing to 10 ms" means ignoring any response that occurs within 10 ms of a previous response (on the same device). 10 ms is behaviourally extremely short, yet electrically quite long, so it serves to discriminate true from false responses quite well. |
Schedule selection
The schedules (both response-contingent and noncontingent) are:
| • | CRF - continuous reinforcement (FR-1). One reinforcer per response. |
| • | EXT - extinction. No reinforcers. |
| • | FR x - fixed ratio. One reinforcer per x responses. |
| • | VR x to y - variable ratio (specifying min, max). After a variable number of responses (randomly chosen from min to max inclusive), one reinforcer is delivered. |
| • | RR x - random ratio. P(reinforcer | response) = 1/x. |
| • | PROB p - probabilistic. P(reinforcer | response) = p. |
| • | FI x - fixed interval. The first response after x seconds is reinforced. The first response of the schedule is also reinforced. |
| • | RI x - random interval. Reinforcement is set up on a random-time schedule (see below); after reinforcement has been set up, the next response is reinforced. |
| • | VI x to y - variable interval (specifying min, max). After a variable time (from min to max seconds), the next response is reinforced. |
| • | FT x - fixed time (NONCONTINGENT). No lever is present. Reinforcement is delivered every x seconds. |
| • | VT x to y - variable time (specifying min, max) (NONCONTINGENT). No lever is present. The schedule waits for between min and max seconds, then delivers a reinforcer, then repeats. |
| • | RT x - random time (NONCONTINGENT). Every second, p(reinforcer delivered this second) = 1/x. Thus, on average, reinforcement is delivered once every x seconds, but the subject cannot predict the likelihood of reinforcement based on how long it has waited (unlike a typical VT schedule). |
| • | PR - progressive ratio - add one (1,2,3,4...) - progressive ratio schedule, adding one to the ratio requirement at each step. The schedule termination is determined by the parameter; if parameter is >0, then when parameter minutes have elapsed since the last reinforcer (or response - see below), the schedule stops. We suggest 60 as a sensible value. |
| • | PR - progressive ratio - double (1,2,4,8...) - progressive ratio schedule, doubling the ratio requirement at each step. The schedule termination is determined by the parameter; if parameter is >0, then when parameter minutes have elapsed since the last reinforcer (or response - see below), the schedule stops. We suggest 60 as a sensible value. |
| • | PR - progressive ratio - Fibonacci (1,1,2,3,5...) - progressive ratio schedule with a Fibonacci progression. The schedule termination is determined by the parameter; if parameter is >0, then when parameter minutes have elapsed since the last reinforcer (or response - see below), the schedule stops. We suggest 60 as a sensible value. |
| • | PR - progressive ratio - Roberts exponential (A * exp(reinfnum * B) - A) - progressive ratio schedule with an exponential progression, based on Roberts DCS & Richardson NR (1992), Self-administration of psychomotor stimulants using progressive ratio schedules of reinforcement, Neuromethods 24: 233-269 (eds Boulton A, Baker G, Wu PH; Humana Press). The ratio requirement is (A * exp(reinforcer number * B)) - A, rounded to the nearest integer. Typically, A is 5. A typical schedule might have B=0.2; these values yield ratio requirements {1, 2, 4, 6, 9, 12, 15, 20, 25, 32, 40, 50, 62, 77, 95, 118, 145, 178, 219, 268, 328, 402, 492, 603, 737, 901, 1102, 1347, ...}. A steeper PR schedule is obtained with B=0.25, giving {1, 3, 6, 9, 12, 17, 24, 32, 42, 56, 73, 95, 124, 161, 208, 268, 346, 445, 573, 737, 948, 1218, 1566, 2012, 2585, 3321, 4265, 5478, ...} The schedule termination is determined by the other parameter (on the left, labelled (min)); if this parameter is >0, then when this many minutes have elapsed since the last reinforcer (or response - see below), the schedule stops. We suggest 60 as a sensible value. |
| • | DELAYFR1 - FR1 with delayed reinforcement. This is an FR1 schedule, but there is a delay between responding and reinforcement. This delay is the sole parameter (specified in seconds). |
| • | PR - progressive ratio - double increment every A reinforcers. The increment starts at 1, and doubles every A reinforcers. If A is 8, then the ratio requirements are 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 16, 18, 20, 22, 24, 28, 32, 36... The schedule termination is determined by the parameter; if parameter is >0, then when parameter minutes have elapsed since the last reinforcer (or response - see below), the schedule stops. We suggest 60 as a sensible value. |
Special case: the first response on contingent interval schedules (FI, RI, VI) is always reinforced.
Database selection
To pick an ODBC database in advance of finishing, click Pick and you will be offered the ODBC Data Source picker (below). Your choice will be recorded and will apply to this subject from now on (or until you specify a different source).
If you don't specify an ODBC data source now, or you delete the value in the "ODBC data source name" box, you'll be asked to choose when the task ends (and that choice will only apply to the session in progress).
What happens if you can't find an appropriate ODBC source?