Selective association learning in the rat: Generality of response system

Three experiments with rats examined the possibility that the cue-consequence specificity effect is not mediated by the conditioning of selective associations, but instead reflects the selective behavioral expression of taste-illness and exteroceptive-shock conditioning. Experiment 1 showed that the selective aversion performance could be obtained despite the use of locomotor withdrawal from the CS as the index of conditioning. Experiment 2 compared the response profiles of animals conditioned with footshock or illness to presentation of a saccharin or noise CS. During the test with the noise CS, lithium-conditioned subjects did not differ from control rats on any of several behavioral categories, but shock-conditioned rats showed high levels of freezing in response to the noise cue. During the saccharin test, lithium-treated rats engaged in behaviors such as chin wiping, head shaking, and gaping; these behaviors were rarely or never seen in shock-conditioned rats or controls, whose behavioral profiles during the saccharin test were almost identical. Experiment 3, using a blocking design, found that a noise-lithium pairing did not attenuate subsequent conditioning of a saline-lithium association, nor did a saccharin-shock pairing interfere with conditioning of a noise-shock association. These results confirm that the cue-consequence specificity effect is mediated by the selective associability of taste with illness and of exteroceptive cues with footshock.     

Mechanisms of blocking by contextual stimuli

The influence of contextual stimuli on the conditioning and performance of responding to a discrete stimulus was examined in the US preexposure paradigm using both context shift manipulations and a measure of context conditioning. Four groups of rats received both repeated exposure to an electric shock US in one context (Context 1), and repeated nonshocked exposure to a second context (Context 2). Two additional groups of rats received exposure to these contexts, but never received shock presentations. Rats exposed to shock learned to escape from the stimuli of Context 1, but did not escape from the stimuli provided by Context 2. Rats not exposed to shock failed to escape from either context. All rats then received a single CER conditioning session in which four pairings of a 3-min noise CS and shock US were presented. Half the rats received those CS-US pairings in the excitatory Context 1, while the remaining rats received those pairings in the neutral Context 2. Finally, half the rats in each of the CER conditioning treatments received extinction test trials of the noise CS in Context 1, while the remaining rats received those test trials in Context 2. Thus, this design factorially manipulated the presence of excitatory or neutral contextual stimuli during both conditioning and testing of a discrete CS. In comparison with the two groups of rats never preexposed to shock alone, attenuation in acquisition of conditioned suppression observed during test trials occurred only when CER conditioning had been administered in the excitatory Context 1, and this effect was manifested when testing occurred in either the excitatory Context 1 or the neutral Context 2. These results support the model of R. A. Rescorla and A. R. Wagner (1972) (in A. H. Black & W. F. Prokasy (Eds.) Classical Conditioning II, pp. 64–99, New York: Appleton-Century-Crofts) which asserts that contextual stimuli and sicrete CSs compete for limited associative strength supportable by a given US.     

The influence of flavor preexposure and test interval on conditioned taste aversions in the rat

The effects of flavor preexposure and test interval on conditioned taste aversions were examined in four experiments. In the first three experiments, prior experience with a flavor different from that used as a conditioned-stimulus (CS) produced attenuated aversions when testing occurred after a 1-day interval but not after a 21-day interval. Preexposure to the same stimulus used as a CS produced attenuated aversions at both 1- and 21-day intervals. In Experiment 4, a delay interval between flavor preexposure and conditioning eliminated the attenuating effect of preexposure, but only when different stimuli were used for preexposure and conditioning. These data could not be easily accounted for by contemporary interpretations of preexposure as an event that interferes with subsequent acquisition of a conditioned aversion. An alternative retrieval interference hypothesis was outlined.     

Feedback during exposure to inescapable shocks and subsequent shock-escape performance

In two experiments, we assessed the ability of a feedback stimulus during helplessness training to reduce the performance deficits common to inescapable shock. In each experiment, four groups of rats were exposed to either escapable shock (E), inescapable shock with a feedback stimulus following shock termination (Y-FS), inescapable shock with no feedback stimulus (Y-NFS), or no shock (N). The feedback stimulus eliminated the interference effects of inescapable shock when tested with an FR-3 lever press escape task (Experiment 1) or on an FR-1 task with a 3-s delay between the response and shock termination (Experiment 2). These results suggest that stress-induced biochemical changes may mediate the interference effects seen in inescapably shocked rats.     

Investigations of the reinstatement of extinguished fear

In two experiments, fear was conditioned to the situational cues in one compartment of a hurdle-jumping apparatus and was then extinguished. Subsequently, either one shock (Experiment 1) or three or nine shocks (Experiment 2) were given in a situation distinctively different from that in which conditioning and extinction had taken place. Although some associative strength between the situational cues and fear was shown to have remained after extinction, in neither experiment did the postextinction-shock treatment increase the fear elicited by these cues: Escape-from-fear performance was no better in the shocked groups than in control groups given no additional shock. Thus, the nonassociative hypothesis which postulates that inflating the value of the representation of the UCS with shock-alone presentations can reinstate the extinguished fear of a stimulus was not supported. Rather, the results showed that, after extinction, an increase in fear of a simulus depended on further conditioning to that stimulus. The data also indicated that the nonvisual components of the situational cues predominated over the visual component.     

Variations in explicitly unpaired training are differentially effective in producing conditioned inhibition

To evaluate a contingency interpretation of conditioned inhibition (CI), rats were given “explicity unpaired” training in which the locus and duration of a CS within the inter-US (shock) interval were systematically manipulated for different groups. Summation and retardation tests in Experiment 1 indicated that stronger CI resulted from both a backward and a trace CS than from a midlocus CS of equal or greater duration. Complementing these findings, the same tests in Experiment 2 showed that, by comparison with novel-stimulus controls, CI developed to a trace CS but not to a mid-locus CS, nor to a trace CS that was accompanied by an immediate signal for the US. These findings argue against a contingency interpretation of CI and favor a contiguity interpretation stressing the short-term rehearsal of stimulus events. Such rehearsal of the US allows a backward CS, but not a mid-locus CS with an extended US-CS interval, to be discriminated as a signal for nonreinforcement, and thus to develop as a conditioned inhibitor. Similarly, excitatory conditioning to the memory trace of a CS allows the nominal trace CS to develop as a signal for nonreinforcement, and thus as a conditioned inhibitor, but not when its memory trace is overshadowed by another CS that immediately precedes the US. In short, the development of CI is facilitated when excitation is mediated by the memorial processing of either the US or a discrete CS for the US rather than by contextual cues.     

Human Agency in the Missio Dei and the Problem of Discipleship

At the heart of this article is an inquiry into the relationship between human and divine agency in the doctrine of the missio Dei and a critique of the turn to the language of discipleship in looking to articulate this agency. Taking the World Council of Churches’ Commission of World Mission and Evangelism's two recent documents, Together towards Life: Mission and Evangelism in Changing Landscapes (TTL) and the “Arusha Call to Discipleship,” as a case study, this article will seek to articulate an account of human participation in the missio Dei which maintains the emphasis on spirituality in TTL. Through a close reading of TTL and the Arusha Call, the article will demonstrate that the introduction of discipleship language has not solved the issue of agency but rather has changed the account of agency and, as a result, the missiology. By turning to accounts of faithful participation from qualitative research into British Methodism, to John V. Taylor's Go-between God, and to Pope Francis’ Evangelii gaudium, I will suggest that a better account of human agency in the missio Dei can be developed by emphasizing the pneumatology of TTL and by turning to language of attentiveness, accompaniment, and discernment.     

Further evaluation of prompt density,rate of reinforcement,and the persistence of manding

Previous research has evaluated the effects of prompt rates on the rate of communicative behavior. More recent research has suggested that dense prompting can result in communicative behavior that is more resistant to change. However, existing research has not considered the impact that higher response rates had on reinforcement rate, a variable known to impact response persistence. The current study systematically replicated previous research by evaluating communicative responding in contexts associated with dense- and lean-prompt schedules and extended existing research by (a) holding reinforcement rates similar across the two prompting schedules (lean and dense), and (b) evaluating the persistence of communicative responding in the contexts associated with each prompting schedule. The results for Experiment 1 clearly replicated and extended previous research. The results for Experiment 2 were equivocal and suggested that previous reinforcement history and response class size impacted outcomes.     

Le médecin expert confronté aux confidences de la personne expertisée

During an expertise, if the expert “discovers” or is entrusted with information concerning an offence, should he report it to the authorities? Could the expert be sanctioned in the absence of denunciation of a tort or criminal act? The answer will be nuanced on a case-by-case basis. The expert confronted with the revelation of a crime or misdemeanor must decide in good conscience what he reveals in his report, or even report it to the prosecution.     

Affection deprivation is more aversive than excessive affection: A test of affection exchange theory

Affection exchange theory predicts that both excessive affection and affection deprivation are associated with poorer health, compared with receiving the level of affectionate communication that one desires. A similar yet-untested prediction is that affection deprivation is more aversive than excessive affection. This preregistered study tested both hypotheses on a battery of mental and physical health outcomes, including depression, loneliness, stress, physical pain, frequency of nightmares, and sleep quality, using a Census-matched sample of U.S. American adults (N = 827). As hypothesized, receiving the right amount of affection was associated with more health-supportive scores on all outcomes than either excessive or deficient affection. Similarly, excessive affection was associated with lower depression, loneliness, stress, and pain, and higher sleep quality, than affection deprivation.