Influence of Individual Differences in Intolerance of Uncertainty and Sensation Seeking in the context of Aversive and Appetitive Conditioning

In differential conditioning and generalization paradigms, a neutral stimulus becomes a conditioned stimulus (CS+) through repeated pairing with an unconditioned stimulus (UCS), while another neutral stimulus (CS–) is never paired. Characteristics of conditioned responses (e.g., subjective ratings, physiological responses) to the CS+, CS–, and to perceptually or conceptually related generalization stimuli (GSs) may shed light on the underlying associative learning processes (Lonsdorf et al., 2017). Processes associated with the acquisition, extinction, and generalization of conditioned responses have been linked to the emergence and persistence of psychopathology (e.g., Dunsmoor & Paz, 2015; Dymond et al., 2015) and are assumed to play a central role in the development and maintenance of various mental disorders. Especially aversive conditioning processes have been extensively studied in this context. They have been associated with disorders such as anxiety and depression (see e.g. Duits et al., 2015; Dymond et al., 2015; Lissek et al., 2005). Appetitive learning has received considerably less attention (Andreatta & Pauli, 2019) - despite its clear relevance for various disorders including substance use and eating disorders (Martin-Soelch et al., 2007). Direct comparisons of aversive and appetitive conditioning processes remain rare (Andreatta & Pauli, 2015; Petrenko et al., 2025), although such studies might yield important transdiagnostic insights. Compared with appetitive conditioning, aversive conditioning has been shown to yield stronger physiological responses and clearer CS+/CS− discrimination, while appetitive conditioning may result in slower extinction of conditioned responses (Andreatta & Pauli, 2015; Petrenko et al., 2025). However, it remains unclear whether differences between aversive and appetitive learning extend to generalization and the generalization of extinction (see Wong, 2025). Moreover, individual differences may critically shape acquisition, extinction, and generalization processes. Intolerance of uncertainty (IU), for example, has been linked to heightened responding to threat cues, overgeneralization and slower extinction learning (Morriss et al., 2016; 2021), suggesting a tendency toward persistent and overgeneralized conditioned responses in the context of aversive learning. Sensation seeking, in contrast, reflects an approach-oriented motivational style associated with altered arousal and reward processing (Tapia León et al., 2019) and may therefore be particularly relevant for appetitive learning. Together, these constructs represent distinct avoidance versus approach-related dispositions that may differentially modulate conditioning across aversive and appetitive domains. However, their specific roles, especially regarding stimulus generalization and generalization of extinction, remain largely unexplored. The present study therefore aims to compare aversive and appetitive conditioning processes, with a particular focus on the direct comparison of generalization and the generalization of extinction. In addition, we will examine the role of individual difference variables, such as intolerance of uncertainty and sensation seeking in shaping these learning processes, in order to advance our understanding of their transdiagnostic relevance for psychopathology.