Independent manipulation of stimulus change and unexpectedness dissociates indices of the orienting response

Abstract

Results obtained with the standard repetition-change paradigm of orienting research cannot be attributed unambiguously to either stimulus change or to unexpectedness. By adding announcement conditions, in which participants were told about an impending stimulus change, these two factors were disentangled. In Experiment 1, reaction times (RTs) were longer and ratings of surprise were higher with unannounced than with announced stimulus change. In contrast, larger skin conductance response (SCR) magnitudes occurred following change, irrespective of its congruence with participants' expectations. Experiment 2 replicated the results for SCR magnitude and, furthermore, revealed the same pattern of results for the evoked cardiac response. Surprise ratings again reflected the unexpectedness of stimulus presentations. The dissociation between RT and autonomic measures provides difficulties for resource allocation accounts of the orienting response.

The Cognitive‐Evolutionary Model of Surprise: A Review of the Evidence

“…These include a color change in a simple visual stimulus (e.g., Meyer, Niepel, Rudolph, & Sch€ utzwohl, 1991), the change in the voice of a speaker from male to female (Niepel, Rudolph, Sch€ utzwohl, & Meyer, 1994), the appearance of the participant's own, secretly photographed face as the last picture in a face-judgment task (Reisenzein, B€ ordgen, Holtbernd, & Matz, 2006, Exp. 6 & 7), the violation of a rule concerning the temporal sequence of the stimuli, previously induced via a rule-learning task (Horstmann & Sch€ utzwohl, 1998;Reisenzein et al, 2006, Exp. 3), and the nonoccurrence of an announced stimulus change (Niepel, 2001). Manipulation checks included in several repetition-change experiments confirmed that the stimulus changes staged in the surprise trials were not only experienced as surprising but were also perceived as unexpected by the participants.…”

“…The repetition-change paradigm has been used most often for this purpose. In this paradigm, which exists in many variants, participants are first exposed to a series of homogenous baseline (or "habituation") trials that serve to establish, typically but not exclusively (e.g., Horstmann & Sch€ utzwohl, 1998;Niepel, 2001) through incidental learning, a schema or set of expectations about the kind, the properties, and the temporal sequence of the stimuli that occur in the experiment. In the subsequent "surprise trial," one or more of these expectations are disconfirmed by changing one or more properties of the stimuli presented in the baseline trials or by presenting an entirely novel stimulus.…”

“…1 & 4), the number of schema-discrepant components of the surprise stimulus (Reisenzein et al, 2006, Exp. 1), or the variability in the stimulus pattern presented in the baseline trials (Sch€ utzwohl, 1998, Exp. 3); by giving the participants different amounts of verbal information about an upcoming stimulus change (Niepel, 2001;Reisenzein & Ritter, 2000, Exp. 2;Sch€ utzwohl & Reisenzein, 1999, Exp.…”

“…2;Sch€ utzwohl & Reisenzein, 1999, Exp. 3); and by repeating the stimulus change (e.g., Meyer et al, 1997;Niepel, 2001;Reisenzein et al, 2006, Exp. 1 & 4).…”

“…(b) Novelty is not necessary for surprise, as even familiar events can elicit surprise if they are unexpected, for example because they have a low occurrence probability or occur at an unexpected time. Experimental surprise events that match this description include repeatedly occurring, comparatively improbable lottery outcomes (Juergensen et al, 2014), unexpected solutions to quiz items that were shown to the subjects beforehand as possible answers (Reisenzein, 2000b), and the nonoccurrence of an announced stimulus change (Niepel, 2001). (c) The question of whether novelty is sufficient for surprise is more difficult to answer, because the strongest test case (an event that is expected but novel) is hard to find.…”