von Helversen, B., Gendolla, G. H. E., Winkielman, P., & Schmidt, R.E. (2008).  Exploring the hardship of ease: Subjective and objective effort in the ease-of-processing paradigm. Motivation and Emotion.

Numerous studies examined the role of processing effort in judgments using the ‘‘ease-of-processing’’ paradigm in which participants generate or retrieve few or many issue-relevant thoughts. Because earlier studies only assessed the subjective effort, it is unclear if this paradigm also mobilizes objective effort, and how such effort relates to subjective effort. These questions were addressed in two experiments modeled on standard tasks from the processing effort literature: ‘‘ease of argument generation’’ (Study 1) and ‘‘ease of retrieval’’ (Study 2). In both experiments we simultaneously measured subjective effort (via self-report) and objective effort (via cardiovascular reactivity). The results showed that processing ease manipulations (generation or retrieval of few vs. many exemplars) influence not only subjective effort, but also objective effort, as reflected especially by increases of systolic blood pressure in the many exemplars condition. However, only subjective effort was related to judgment. In the discussion, we consider the role of various forms of effort and other relevant variables in ‘‘processing ease’’ effects.