Effects of intertrial interval and exteroceptive feedback duration on discriminative avoidance acquisition in the gerbil

Abstract

A series of studies of shuttlebox-avoidance learning in the gerbil evaluated the efficacy of an exteroceptive feedback stimulus (FS). Experiment 1 assessed the relative effectiveness of a FS at 30-and 90-sec intertrial intervals (ITls), and found that the FS and warning signal termination contingencies were additive sources of avoidance reinforcement; i.e., they produced "supernormal acquisition" at the short ITI, but not at the 90-sec ITI. The effectiveness of a FS at the 30·sec ITI was further explored in Experiments 2 and 3, in which FS duration was varied in delayed and trace avoidance conditioning, respectively. In both studies, a FS facilitated acquisition but FS duration was not a critical determinant of performance. These results were interpreted in terms of an expectancy account of the informational value of a FS, and the problem of experimentally distinguishing between cognitive and inhibition-of-fear accounts of avoidance learning was discussed.There presently exists a considerable literature demonstrating the, efficacy of an exteroceptive feedback stimulus (FS) on avoidance acquisition (Bolles & Grossen, 1969, 1970 Bower, Starr, & Lazarovitz, 1965; D'Amato, Fazarro, & Etkin, 1968;Galvani, 1977;Keehn & Nakkash, 1959). The typical finding has been that, in the absence of response-produced warning signal termination (WST), a responseproduced FS results in avoidance learning equivalent to that produced by the traditional WST contingency. Recent formulations of avoidance learning have proposed that the FS reinforces avoidance behavior because it functions as a safety signal (Bolles & Grossen, 1970) or an inhibitor of fear (Morris, 1974; Weisman & Litner, 1972). Regardless of the terms employed in conceptualizing the functional significance of feedback in controlling avoidance responses, there seems to be agreement that the efficacy of a FS can be quantified in terms of the duration of the shock-free interval that is contingent upon FS presentation (Bolles & Grossen, 1970;Morris, 1974).In the discriminative avoidance paradigm, the contingency between the avoidance response and FS insures that the FS consistently precedes the shockSupported by National ScienceFoundation Grant B043556-001 awarded to the first author. This paper is based, in part, upon Michael Twitty's master's thesis, directed by P. , 1970). Indeed, relative to the baseline provided by animals lacking both a WS and FS, evidence of learning was at best marginal. Moreover, Morris (1974, Experiment 3) has provided indirect evidence suggesting that a FS might not be an effective reinforcer at a short ITI. In a transfer-of-training test, he failed to obtain evidence of the development of inhibition to a FS at a 3D-sec ITI, although conditioned inhibition to a FS was evidenced at an ISO-sec ITI. Taken together, these results raise serious questions about the effectiveness of feedback at a short ITI.Accordingly, the purpose of Experiment I was to assess the efficacy of feedback at a short (3D-sec) compared to a long (9O-sec) ITI in the Mongol...

Effects of duration of feedback on signaled avoidance

“…However, the temporal manipulation of feedback in Galvani and Twitty's (1978) study was very limited, 00cause the assumed reinforcement mechanism (relaxation) may require a longer period of time than that employed by these researchers. Denny (1971) suggested that relaxation requires about 150 sec in a safe compartment, although Cändido et al, (1989) found reliable effects from 15 sec.…”

“…Other authors (Galvani & Twitty, 1978) have suggested that feedback has both motivational and informative characteristics, and that these characteristics are affected differentially by feedback duration. According to this view, if feedback signals that electric shock has been avoided and a shock-free period is to follow, then the amount of stimulus change, but not its duration, is important.…”

“…However, if the feedback has motivational properties, then varying its duration should bring about differences in performance. Galvani and Twitty (1978), using the two-way shuttle response with an intertrial interval (ITI) of 30 sec, exposed their subjects to feedback of different durations (2, 5, or 10 sec) and to no feedback. They observed differences in performance only between the feedback groups and the no-feedback group; the groups with varying feedback durations did not differ significantly from one another.…”

Inhibition of delay of the two-way avoidance response and warning-signal salience

“…Shortening of the two-way avoidance response latency was noted during a single training session (Bond, 1981;Galvani & Twitty, 1978). In Starr and Mineka's (1977) experiments, the mean avoidance response latency…”

Conditioned inhibition of emotional responses: Retardation and summation with cues for IAPS outcomes

“…Safety signal stimuli generated by the animal"s actions, provide feedback confirming the successful execution of the avoidance response and can thus act as secondary reinforcers of this behaviour (Cándido et al, 1991;Cicala & Owen, 1976;Dickinson, 1980;Dinsmoor, 2001;Galvany & Twitty, 1978;Morris 1975). In the case of human participants, CSs and CIs would be predicted to be rated differently for emotional valence (Konorski, 1967 (Grillon & Ameli, 2001;He et al, 2011He et al, , 2012Kantini et al, 2011aKantini et al, , 2011bKarazinov & Boakes, 2004;McNally & Reiss, 1984;Migo et al, 2006;Neumann et al, 1997, Wilkinson, 1989 but also in animal studies (Cole et al, 1997;Horne & Pearce, 2010;Pineño, 2010;Rescorla & Holland, 1977;Sansa et al, 2009;Urcelay et al, 2008).…”