The effects of FG7142 on overexpectation of Pavlovian fear conditioning.

Abstract

Six experiments studied the role of GABA A receptor activation in expression of overexpectation of Pavlovian fear conditioning. After separate pairings of CSA and CSB with shock in Stage I, rats received pairings of the compound AB with shock in Stage II, producing overexpectation of fear. The expression of overexpectation was attenuated, in a dose-dependent manner, by the benzodiazepine partial inverse agonist FG7142. FG7142 had no effect on responding to a CS paired with a low magnitude US or a CS subjected to associative blocking. These results suggest that the negative prediction error generated during overexpectation training may impose a mask on fear rather than erasing the original fear learning. They support claims that overexpectation shares features with extinction.

The dual role of the context in postpeak performance decrements resulting from extended training

“…In other words, we observed the PPD with elemental training but not after compound (overexpectation) training. The loss of the PPD with compound training agrees with a recent report in which different amounts of Phase 2 overexpectation were assessed using freezing as dependent measure (Garfield & McNally, 2009). Thus, the results of Experiment 3 allowed us to reject, at least with rather massed training parameters, the view that the PPD observed in Experiment 1 was due to habituation to the CS or the US.…”

“…Because habituation-like processes and generalization decrement offer alternative explanations of portions of the observations in Experiments 1 and 2, in Experiment 3 we tested whether the PPD would also decrease conditioned responding to a stimulus that underwent extended compound (i.e., overexpectation) training. The results of Experiment 3 agree with recent reports (Garfield & McNally, 2009) in showing that, contrary to what we observed with extensive training of a single CS (Exps. 1 and 2), extensive reinforcement of the target CS in compound with another CS does not result in the PPD, but rather in recovery from the cue competition observed with few training trials (see the introduction to Exp.…”

Normalization between stimulus elements in a model of Pavlovian conditioning: Showjumping on an elemental horse

“…For example, AMAN is equivalent to other models that use a summed error term (e.g., Rescorla & Wagner, 1972) as the means by which they explain the following keystone phenomena: overshadowing (weaker conditioning to a CS when it is conditioned in compound with another stimulus than when it is conditioned in isolation); blocking (weaker conditioning to a CS when it is conditioned in compound with a previously conditioned CS than when it is conditioned in compound with a neutral stimulus); unblocking by increasing the magnitude of the US (Kamin, 1968); the US preexposure effect (weaker conditioning when a US has been repeatedly presented on its own, prior to CS-US pairings; Randich & LoLordo, 1979;Wagner, 1969); and relative validity (superior conditioning to a CS when it is conditioned in compound with a stimulus that is less well correlated with the US; Wagner, Logan, Haberlandt, & Price, 1968). As such, it should not be surprising that the model accounts for both the decrease in responding when two separately conditioned CSs are conditioned in compound ("overexpectation") and the facilitation of learning about a CS when it is paired with a conditioned inhibitor during conditioning ("superconditioning") (Garfield & McNally, 2009;Lattal, 1998;Pearce & Redhead, 1995;Rescorla, 1971). The model can also account for faster learning with longer intertrial intervals (Gibbon, Baldock, Locurto, Gold, & Terrace, 1977;Spence & Norris, 1950) in terms of differential extinction of the context over the intertrial interval, thereby permitting faster discrimination between the presence and absence of the CS.…”

Effects of recent exposure to a conditioned stimulus on extinction of Pavlovian fear conditioning

“…These restoration phenomena are also shared with other procedures that produce decrements in conditioned responding, such as overexpectation (Rescorla 2006a;Garfield and McNally 2009) and US habituation (Storsve et al 2010). This strongly suggests that restoration or relapse is a common consequence of most procedures that are designed to reduce conditioned responding and produce behavioral change.…”