Conceptual representations of action in the lateral temporal cortex.

Area of Science:

• Neuroscience
• Cognitive Psychology
• Psycholinguistics

Background:

• Previous research indicated distinct brain activations for processing action pictures versus object pictures.
• Action pictures elicited greater activation in motion-sensitive areas (MT/MST) and adjacent temporal regions.
• Action words, however, primarily activated left temporal regions, anterior and dorsal to MT/MST.

Purpose of the Study:

• To replicate and extend findings on the neural correlates of processing action words.
• To investigate the role of the middle temporal gyrus in accessing conceptual information about motion.
• To differentiate between motion-attribute-based and lexical/grammatical accounts of temporal lobe activation.

Main Methods:

• Two functional magnetic resonance imaging (fMRI) experiments were conducted.
• Participants performed conceptual judgments on action, object, manipulable object, and animal words.
• Conditions were designed to emphasize visual semantic information processing.

Main Results:

• Action words consistently activated posterior temporal regions, near but not identical to MT/MST.
• Both action and manipulable object word judgments showed greater activation in the posterior middle temporal gyrus compared to animal words.
• These findings support the hypothesis that middle temporal gyrus activation is linked to motion attribute conceptualization.

Conclusions:

• Middle temporal gyrus activation during word processing is associated with accessing conceptual information about motion attributes.
• Results support a concrete-to-abstract gradient of motion representations in the lateral occipito-temporal cortex.
• Findings argue against purely lexical or grammatical explanations for these observed brain activations.