Neuroscience Letters 461 (2009) 65–68 Contents lists available at ScienceDirect Neuroscience Letters journal homepage: www.elsevier.com/locate/neulet Gaze-related mimic word activates the frontal eye field and related network in the human brain: An fMRI study Naoyuki Osaka a,∗ , Mariko Osaka b a Department of Psychology, Graduate School of Letters, Kyoto University, Kyoto 606-8501, Japan b Department of Psychology, Graduate School of Human Science, Osaka University, Japan article info Article history: Received 14 March 2009 Received in revised form 7 June 2009 Accepted 11 June 2009 Keywords: fMRI Active gaze Mimic word Frontal eye field abstract This is an fMRI study demonstrating new evidence that a mimic word highly suggestive of an eye gaze, heard by the ear, significantly activates the frontal eye field (FEF), inferior frontal gyrus (IFG), dorsolateral premotor area (PMdr) and superior parietal lobule (SPL) connected with the frontal–parietal network. However, hearing a non-sense words that did not imply gaze under the same task does not activate this area in humans. We concluded that the FEF would be a critical area for generating/processing an active gaze, evoked by an onomatopoeia word that implied gaze closely associated with social skill. We suggest that the implied active gaze may depend on prefrontal–parietal interactions that modify cognitive gaze led by spatial visual attention associated with the SPL. © 2009 Elsevier Ireland Ltd. All rights reserved. Recent neuroimaging studies unveiled brain mechanisms bridging language and implied action [15]. Action verbs could activate spe- cific brain areas related with perception and gaze [14]. For example, generation of action words activated an area in the middle tempo- ral gyrus anterior to the area involved in the perception of motion while generation of color words selectively activated a brain area in the ventral temporal lobe anterior to the area involved in the subjective perception of color in humans [7]. Mimic words (imitate actions) related with a mental state such as laughter also selectively stimulate specific brain areas connected with the perception of laughter and smile. Osaka et al. [10] used fMRI to show that laughter modules using mimic words highly suggestive of laughter, heard by the ear with the eyes closed, sig- nificantly activated the extrastriate visual cortex near the inferior occipital gyrus in which the laughing face could easily be repre- sented. However, whether a mimic word expressing active gaze, for example gazing restlessly or fixing one’s eyes on someone with- out averting one’s gaze, had an effect on the brain region involved in manipulating the mind’s active gaze has not previously been investigated. An active mimic word could essentially be defined as sound symbolism used to describe various human emotions and psycho- logical states. A rough English equivalent would be, for example, “butterflies in the stomach”. The role of active onomatopoeia (for- mation of a word from a sound associated with that being named) in the Japanese language is a very critical because Japanese has a ∗ Corresponding author. Tel.: +81 75 753 2796; fax: +81 75 753 2796. E-mail address: nosaka@bun.kyoto-u.ac.jp (N. Osaka). very limited number of verbs. Therefore, one role of mimic words is to fill in the gap and provide a means for concise expression when a sufficiently descriptive verb does not exist. Such words make the language very vivid and instantly conjure up images in the mind of a native Japanese speaker, thus producing a strong synaesthetic effect. Japanese is uniquely rich in this type of expression, which is frequently used in daily conversation, magazines and newspapers, especially for headlines, because of its brevity and power to project vivid imagery including active gaze [3]. The expressions are classi- fied into categories of different sensory and emotional expressions such as laughter, gazing and other more cerebral states. Osaka et al. [9] suggested that onomatopoeia forms unique action words that express various human conscious states and classified, using multidimensional scaling based on rated subjective intensity, the six top onomatopoeia words inducing gaze into Euclidian space. The uniqueness of this type of expression frequently represents a peculiar Japanese way of expressing feelings and/or mentality [3]. Although there is a considerable amount of knowledge about the neural representation of gaze perception, little is known about higher cognitive brain function with regard to gaze in connection with language function. Some mimic words involve very salient gaze components and sounds of gaze-related onomatopoeia can convey a subjective quality of gaze related to one’s intentional stance [6]. The perception of gaze is a critical social skill for the people since it could reflect the internal mental states of others and thus it pro- vides clues to interpret another person’s thought process. Further, the direction of gaze is an excellent guide to the focus of another person’s attention. Although, the present experiment is not directly associate with social cognition, but investigated the social brain’s 0304-3940/$ – see front matter © 2009 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.neulet.2009.06.023