| dc.contributor.author | Droungas, Anastasia. | en_US |
| dc.date.accessioned | 2014-10-21T12:34:52Z | |
| dc.date.available | 1991 | |
| dc.date.issued | 1991 | en_US |
| dc.identifier.other | AAINN64501 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/55200 | |
| dc.description | Two of the goals of the study of Pavlovian conditioning are to understand (a) the nature of the relationships between the conditioned stimulus (CS) and the unconditioned stimulus (US) that give rise to excitatory and inhibitory conditioning and (b) the nature of the excitatory and inhibitory conditioned responses (CRs). These goals still challenge students of Pavlovian conditioning phenomena. In the explicitly unpaired procedure the CS and the US occur on separate trials. Furthermore, the CS is made contiguous with the omission of the US. Expectancy of the US is mediated by the excitatory contextual cues. Although in most reports the explicitly unpaired procedure has been shown to yield a conditioned inhibitory CS some studies have not obtained this result. The current experiments were aimed at examining the conditions under which the explicitly unpaired procedure does not yield an inhibitory CS. These experiments showed that the explicitly unpaired CS was an inhibitor when the CS and US trials had been alternated singly or randomly under both extensive (60 sessions) and moderate (20 sessions) amounts of training. The single alternation variant of the explicitly unpaired procedure yielded a conditioned inhibitor with intertrial intervals which were either long (420 s) or intermediate (45-55 s) with extensive and moderate training, respectively. An explicitly unpaired CS also became inhibitory following extensive training with short intertrial intervals (25 s). However, following limited training (8 sessions) the explicitly unpaired CS (10-s or 60-s long) with intermediate or short intervals functioned as a conditioned excitor relative to the latent inhibition control. This excitatory property was not affected by a lengthy retention interval during which rats remained in their home cage but was weakened by prolonging the conditioning phase. The excitatory property of the explicitly unpaired CS was also weakened by increasing the interval separating the onset of the CS and the US by either lengthening CS-duration or lengthening the intertrial interval. Finally, the explicitly unpaired CS functioned as a conditioned inhibitor if it had undergone extinction following either limited or prolonged training. The inhibitory effect of the explicitly unpaired CS was also manifested when only the contextual cues of the conditioning chamber were extinguished following limited conditioning. This latter finding was taken as evidence that a CS-context within-compound association had been formed which imbued the CS with enough excitation to not only obscure inhibition but to make the CS a net excitor. | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 1991. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Psychology, Psychobiology. | en_US |
| dc.title | Analysis of Pavlovian conditioned inhibition in the explicitly unpaired procedure. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
