Activation in left primary visual cortex representing parafoveal visual field during reading Japanese texts

作者：Shimada Yoichi^*; Hirayama Kazumi; Nakadomari Satoshi; Furuta Ayumu; Misaki Masaya; Kan Shigeyuki; Koike Takahiko; Miyauchi Satoru; Mori Etsuro

来源：Brain Research, 2011, 1408: 72-80.

DOI：10.1016/j.brainres.2011.06.043

• Parafoveal activation
• Reading saccade
• Attentional modulation
• Primary visual cortex
• Japanese text
• Functional magnetic resonance imaging

Activation in the left primary visual cortex (V1) representing the parafoveal field during text reading has been interpreted as attentional modulation in the process of deciding saccadic target for reading ahead. Kanji words serve the main cue to decide the goal of saccades in Japanese. We aimed to determine the exact location of this modulation in the V1 and to determine whether the area of the modulation changes according to the location where the next Kanji word appears or it is fixed on a certain region in V1. Using functional magnetic resonance imaging, we determined the area in V1 representing each eccentricity on the horizontal meridian of the visual field for each participant. Then we investigated brain activation while they were reading two sets of Japanese texts that scrolled leftward as the participants. In set 1, the distance between the heads of adjacent Kanji words was about 3 degrees. In set 2, the distance was about 5 degrees. From the results of these experiments, we obtained activation amplitude of the area corresponding to each eccentricity. We recorded eye movements simultaneously with the acquisition of fMRI data. The maximum peak of the activation was found in the region representing about 4.5 degrees of eccentricity on the horizontal meridian in the left V1 for each participant. The activation pattern did not essentially differ between the two text conditions, although the location of the saccades made for reading next section of the text corresponds to the head of the next Kanji word. The activation modulation during reading Japanese texts occurs in the parafoveal V1 of the left hemisphere. The attentional modulation did not change with the distance to the next goal of saccade but was fixed on the area representing about 4.5 degrees of eccentricity.

• 出版日期2011-8-23