Identifying objects at different levels of hierarchy: A positron emission tomography study

Abstract

AbstractSubjects decided whether names were appropriate for accompanying pictures while their local cerebral blood flow was monitored using positron emission tomography (PET); in one condition, the names were at the “entry” level (i.e., the level spontaneously named, as in “bird” for a robin), in another condition they were at a superordinate level (e.g., “animal”), and in another they were at a subordinate level (e.g., “robin”). The results indicated that different processes are used to evaluate terms at the different levels of analysis. Specifically, there was evidence that memory search is used to evaluate superordinates, but one must collect additional perceptual information to evaluate subordinates. In addition, in another condition the subjects saw written words that named the entry‐level term and decided whether the object could be named by superordinate terms. Similar, but not identical, activation was observed as was found when subjects evaluated superordinate terms for pictures. © 1995 Wiley‐Liss, Inc.