Fear of the CS and of the context in two-way avoidance learning: Between- and within-subjects manipulations

Abstract

The roles of es fear and of context fear in signaled two-way avoidance learning were examined in two experiments in which shock intensity was manipulated either between or within subjects. For each subject, two discrete ess, a light and a white noise, were used. For between-subjects comparisons, both ess were paired with the same shock intensity, weak or strong. Under this condition, in which fear of the ess and the context was greater with strong than with weak shock, avoidance performance varied inversely with shock intensity. For within-subjects comparisons, the light was paired with strong shock and the white noise with weak shock, or vice versa. In this case, context fear was constant during presentation of each es, and avoidance performance varied directly with shock intensity. Additionally, intertrial responding was directly related to the amount of context fear. These results support effective reinforcement theory, an extension of two-factor theory, which acknowledges the contribution to avoidance learning both of es fear and of context fear. The interchangeable effectiveness of visual and auditory stimuli as ess is discussed with regard to stimulus specificity in avoidance learning.One of the most reliable findings in the avoidancelearning literature is that in either a signaled or an unsignaled two-way avoidance task performance is better with weak than with strong shock at the levels of shock usually employed (e.g., Bauer, 1972;Cicala & Kremer, 1969;Dieter, 1977;Johnson & Church, 1965 1964;Scoles, 1982Scoles, /1983 Theios, Lynch, & Lowe, 1966). This finding poses a difficulty for many theories of avoidance learning because generally it is assumed that the greater amount of fear that is conditioned with strong shock should lead to better avoidance learning.A theory proposed in 1971 by W. R. McAllister et a1. can, however, account for the inverse relationship and can also predict how certain variables can alter this relationship. Their effective reinforcement theory (see also W. R. McAllister, D. E. McAllister, Dieter, & James, 1979) is an elaboration of Mowrer's (1947) two-factor theory of avoidance learning. The important role played by fear of the conditioned stimulus (CS) in accounting for two-way avoidance learning is acknowledged, but in addition, the contribution of the fear conditioned to the contextual cues is emphasized. When shock is received on escape trials during avoidance training, fear becomes conThe experiments reported herein were supported in part by Grant MH-36610 from the National Institute of Mental Health awarded to Wallace R. McAllister and Dorothy E. McAllister, to whom the author is indebted for their valuable assistance throughout this research, and by a fellowship awarded to the author from Northern Illinois University. Requests for reprints should be sent to Edward J. Callen, Department of Psychology, Northern Illinois University, DeKalb, IL 60115. ditioned to both of these sources. On avoidance trials, when shock is not received, it is assumed that the effective reinforceme...

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

“…If one accepts the notions that the ITR rate is an index of fear conditioned to the experimental context (Callen, 1986;Mowrer & Lamoreaux, 1951;Owen, Cicala, & Herdegen, 1978;Zielinski, 1993) and that high avoidance performance combined with low ITR rate denotes successful fear reduction after the CS termination, the results of the present experiment may be considered as confirmation of the hypothesis proposed recently . Presentation of auditory and visual stimuli during the same session resulted in maintenance of a high level of fear of situational cues.…”

“…The degree of intertrial responding is related to the amount of fear of the contextual cues (Callen, 1986;Mowrer & Lamoreaux, 1951). Differing levels offear of the CS and of the situational cues may be achieved by using stimuli of different modalities.…”

Species-specific defense reactions: Retrospect and prospect.

“…Is this because the feedback signal had acquired greater fear-reducing properties or because pretraining enhanced its salience? It has also been argued that CS termination is more effective when there is a greater contrast in the level of fear between the CS-on and CS-off conditions (Callen, 1986;McAllister, McAllister, Dieter, & James, 1979). However, this may have more to do with increasing the amount of feedback than with fear reduction.…”