Higher-Order Conditioning With Simultaneous and Backward Conditioned Stimulus: Implications for Models of Pavlovian Conditioning

Abstract

In a new environment, humans and animals can detect and learn that cues predict meaningful outcomes, and use this information to adapt their responses. This process is termed Pavlovian conditioning. Pavlovian conditioning is also observed for stimuli that predict outcome-associated cues; a second type of conditioning is termed higher-order Pavlovian conditioning. In this review, we will focus on higher-order conditioning studies with simultaneous and backward conditioned stimuli. We will examine how the results from these experiments pose a challenge to models of Pavlovian conditioning like the Temporal Difference (TD) models, in which learning is mainly driven by reward prediction errors. Contrasting with this view, the results suggest that humans and animals can form complex representations of the (temporal) structure of the task, and use this information to guide behavior, which seems consistent with model-based reinforcement learning. Future investigations involving these procedures could result in important new insights on the mechanisms that underlie Pavlovian conditioning.

Disinhibition account of the conditioned response (DACR).

“…Temporal difference learning, a reward prediction error-based learning model that relates to the integrator model (Bush & Mosteller, 1951) and the Rescorla-Wagner learning model (Rescorla & Wagner, 1972), accounts for SOC. However, it fails to explain SPC as the CS1 has no predictive value during Phase 1 of SPC, while it does in Phase 2 of SOC (for a review, see Prével & Krebs, 2021). The structure and timing of integration in higher order conditioning is still a matter of debate (for a review, see Holmes, Wong, et al, 2022).…”

Audible pain squeaks can mediate emotional contagion across pre-exposed rats with a potential effect of auto-conditioning

“…Can auto-conditioning thus happen at all? Several studies have found that a CS can gain excitatory value even if it starts after the US, be it in a simultaneous or even backward conditioning configuration (e.g., Barnet et al 31 ; Cole and Miller 32 ; Prével et al 33 ), although the boundary conditions for simultaneous or backward conditioning to occur are likely more constrained compared to forward conditioning. For a long time, this seemed at odds with the basic tenets of learning theory, that stimuli need to be predictive to trigger learning (for an overview, see Chang et al 34 ).…”