An attentional perspective on differential fear conditioning in chronic pain: The informational value of safety cues.

Abstract

Differences in fear conditioning between individuals suffering from chronic pain and healthy controls may indicate a learning bias that contributes to the acquisition and persistence of chronic pain. However, evidence from lab-controlled conditioning studies is sparse and previous experiments have produced inconsistent findings. Twenty-five participants suffering from chronic back pain and twenty-five controls not reporting chronic pain took part in a differential fear conditioning experiment measuring attention (eye tracking) and autonomic arousal (pupil dilation and skin conductance) elicited by visual cues predicting the presence or absence of electric shock. In contrast to the healthy control group, participants with chronic pain did not acquire differential autonomic responding to cues of threat and safety and specifically failed to acquire any attentional preference for the safety cue over irrelevant contextual cues (while such preference was intact for the threat cue). We present simulations of a reinforcement learning model to show how the pattern of data can be explained by assuming that participants with chronic pain might have experienced less positive emotion (relief) when the electric shock was absent following safety cues. Our model shows how this assumption can explain both, reduced differential responding to cues of threat and safety as well as less selective attention to the safety cue.

Vigilance: A novel conditioned fear response that resists extinction

“…We found that both components were engaged by fear conditioning, with a spike in preferential viewing of the CS+ in the first second of the trial, followed by sustained preferential viewing. These findings are consistent with two recent fear conditioning studies that recorded eye movements during an acquisition procedure prior to a subsequent visual search task (Koenig, Körfer, et al, 2021;Torrents-Rodas et al, 2021). Similar to the present study, a CS+ (colored circle used as distractor in subsequent search task) and a non-predictive stimulus (colored diamond used as target in subsequent search task) were presented simultaneously, and participants viewed the CS+ longer than the non-predictive stimulus across the course of the 5-s trial (Koenig, Körfer, et al, 2021;Torrents-Rodas et al, 2021).…”

“…These findings are consistent with two recent fear conditioning studies that recorded eye movements during an acquisition procedure prior to a subsequent visual search task (Koenig, Körfer, et al, 2021;Torrents-Rodas et al, 2021). Similar to the present study, a CS+ (colored circle used as distractor in subsequent search task) and a non-predictive stimulus (colored diamond used as target in subsequent search task) were presented simultaneously, and participants viewed the CS+ longer than the non-predictive stimulus across the course of the 5-s trial (Koenig, Körfer, et al, 2021;Torrents-Rodas et al, 2021). These studies varied the level of US reinforcement for different CS+ colors, but did not include a CS-that reliably predicted the omission of the US.…”