TEMPORAL CODING AFFECTS TRANSFER OF SERIAL AND SIMULTANEOUS INHIBITORS

In three experiments with rats, the temporal relationships under which a conditioned inhibitor would transfer its inhibitory potential to an independently trained exciter in a summation test were investigated. Each experiment varied the temporal relationship between the inhibitor and the transfer exciter at test (serial or simultaneous) and, in add ition, manipulated either the inhibitor-training exciter (serial or si multaneous), training excitor-unconditioned stimulus (US) (trace or de lay), or the transfer excitor-US (trace or delay)temporal relationship s. Conditioned inhibition was found only when the no-US expectation ev oked by the conditioned inhibitor was temporally aligned with the US e xpectation evoked by the transfer exciter, independent of whether the inhibitor was trained as a serial or simultaneous signal for US omissi on. Results are discussed in terms of the temporal coding hypothesis a nd the comparator hypothesis.