Automatic Priming of Semantically Related Words Reduces Activity in the Fusiform Gyrus

Abstract

We used rapid, event-related fMRI to identify the neural systems underlying object semantics. During scanning, subjects silently read rapidly presented word pairs (150 msec, SOA = 250 msec) that were either unrelated in meaning (ankle-carrot), semantically related (fork-cup), or identical (crow-crow). Activity in the left posterior region of the fusiform gyrus and left inferior frontal cortex was modulated by word-pair relationship. Semantically related pairs yielded less activity than unrelated pairs, but greater activity than identical pairs, mirroring the pattern of behavioral facilitation as measured by word reading times. These findings provide strong support for the involvement of these areas in the automatic processing of object meaning. In addition, words referring to animate objects produced greater activity in the lateral region of the fusiform gyri, right superior temporal sulcus, and medial region of the occipital lobe relative to manmade, manipulable objects, whereas words referring to manmade, manipulable objects produced greater activity in the left ventral premotor, left anterior cingulate, and bilateral parietal cortices relative to animate objects. These findings are consistent with the dissociation between these areas based on sensory- and motor-related object properties, providing further evidence that conceptual object knowledge is housed, in part, in the same neural systems that subserve perception and action.

Aging Influences the Neural Correlates of Lexical Decision but Not Automatic Semantic Priming

“…Also in each group, the largest focus of fMRI priming was observed in the mid-FFG of the left hemisphere. The peak coordinates of fMRI priming effect were close to those previously reported in 2 previous imaging studies involving young adults (Wheatley et al 2005;Gold et al 2006), demonstrating the reproducibility of the fMRI priming associated with the automatic semantic priming behavioral effects. These results demonstrate that older adults can show a preserved fMRI response pattern during LD when the task is automated via the presentation of a brief semantic prime.…”

Functional Neuroanatomy of Contextual Acquisition of Concrete and Abstract Words

“…There were no areas with significant activation for the opposite contrast. This pattern is consistent with the repetitive suppression phenomenon (Grill-Spector, Henson, & Martin, 2006;Wheatley, Weisberg, Beauchamp, & Martin, 2005) due to priming on the second occurrence of the word (Ganel et al, 2006;Schacter, Dobbins, & Schnyer, 2004;Dehaene et al, 2001;Wiggs & Martin, 1998).…”

Task and semantic relationship influence both the polarity and localization of hemodynamic modulation during lexico‐semantic processing

“…These distinctions, however, are not absolute. For example, Copland et al (2003) and Wheatley et al (2005), reported response suppression within the left inferior frontal cortex at short SOAs. And, at long SOAs, several studies have reported modulation within temporal cortices (Gold, et al 2006;Matsumoto, et al 2005;Rissman, et al 2003;Wible, et al 2006).…”