Knowledge-Based Inferences Are Not General

Abstract

Although knowledge-based inferences (Graesser, Singer, & Trabasso, 1994) depend on general knowledge, there may be differences across knowledge areas in how they support these processes. This study explored processing differences between 2 areas of knowledge (physical cause–effect vs. goals and planning) to establish (a) that each would support knowledge-based inferences and (b) that differences in knowledge areas, but not inference abilities, would impact comprehension after acquired brain injury (ABI). ABI participants were compared to matched noninjured participants (NI). The hypothesis was that ABI participants would make physical, but not planning, inferences. NI participants were expected to make inferences from both knowledge areas. Participants read 2-sentence texts and provided measures of inference processes by probe recognitions and knowledge-validating questions. NI participants demonstrated equal inference processes across knowledge areas. ABI participants demonstrated inferences primarily for physical knowledge, indicating that inference processes were intact, yet were less available from planning knowledge. These data support the dissociation of physical cause and effect from planning knowledge, consistent with causal reasoning theory (Trabasso, van den Broek, & Suh, 1989). Further, these findings suggest that areas of general knowledge may differentially support the inference processes involved in comprehension.