The Effects of Metaphoricity and Presentation Style on Brain Activation During Text Comprehension

Evidence from neuroimaging studies suggests that the right hemisphere contributes significantly to the processing of 2-word metaphoric expressions, whereas metaphoric sentences activate mainly left hemispheric areas. Yet the pattern of brain activation during the processing of metaphors at the text level, beyond simple word pairs or sentences, is still unknown. We used functional magnetic resonance imaging to examine brain activation patterns while 15 healthy participants read either 4-line metaphoric or nonmetaphorical texts. The findings indicate that both text types showed activation in the left and right posterior and anterior superior temporal gyri. Surprisingly, metaphoric texts resulted in significantly lower activation than nonmetaphoric texts in the anterior superior temporal gyri. The results are interpreted as indicating that presentation style affects brain activation, and that text processing may rely on a complicated interaction between metaphoricity (metaphoric, nonmetaphoric) and text presentation style