نهمین کنگره نقشه برداری مغز

نمایش مقاله

Title:

Neural Correlates of Graded Embodiment in Persian Olfactory Metaphors: An fMRI Study

Subject:

Advanced Techniques in Signal Acquisition and Image Processing

Presenter Author:
Name:	Maryam Akbarian

Author:
Name 1:	Maryam Akbarian - Presenter
Affiliation 1:	Institute for Cognitive Sciences, Shahid Beheshti University, Tehran, Iran. akbarian_m@icss.ac.ir

Name 2:	Reza Khosrowabadi - Corresponding
Affiliation 2:	Institute for Cognitive and Brain Sciences, Shahid Beheshti University, Tehran, Iran. r_khosroabadi@sbu.ac.ir

Name 3:	Mehdi Purmohammad
Affiliation 3:	Department of Education, University of Alberta, Canada. purmoham@ualberta.ca

Name 4:	Alireza Talesh Jafadide
Affiliation 4:	Faculty of Engineering Sciences, University of Tehran, Tehran, Iran. Alireza.talesh@ut.ac.ir

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Abstract

Original Research

introduction :

Metaphorical language enables abstract concepts to be understood through concrete sensory experiences and constitutes a central mechanism of embodied cognition (Lakoff & Johnson, 1980; Barsalou, 2008). Neuroimaging studies of metaphor comprehension have shown that abstract language can partially recruit perceptual and motor systems, supporting graded rather than fully embodied representations (Pulvermüller, 2013; Desai et al., 2011). While visual and auditory metaphors have been extensively investigated, olfactory metaphors remain largely unexplored. This gap is theoretically important because olfaction is weakly connected to primary language networks and relies heavily on secondary semantic and affective regions such as the orbitofrontal cortex (OFC) and insula (Olofsson & Gottfried, 2015; Rolls, 2004). Olfactory metaphors, therefore, provide a critical test case for graded embodiment models, which predict partial, context-dependent engagement of sensory systems during abstract language processing. We tested two hypotheses: (1) olfactory metaphors and literal olfactory sentences rely on partially distinct semantic integration networks, and (2) neural responses in both conditions scale with lexical olfactory salience, with nouns eliciting stronger activation than action-related verbs

Methods:

Twenty-six right-handed native Persian-speaking women participated in an event-related fMRI experiment. Participants silently read sentences belonging to three conditions: olfactory metaphors (OM), literal olfactory sentences (OL), and a visual baseline. Stimuli were selected through a prior norming study in which 140 undergraduate students rated 101 candidate olfactory metaphor sentences on familiarity, emotional valence, and arousal using 5-point Likert scales. Sentences with familiarity scores within ±3 standard deviations of the mean were retained, yielding 48 neutral olfactory metaphor stimuli. Literal olfactory sentences were matched for length and lexical properties. Whole-brain analyses were conducted using SPM12, with additional parametric modulation testing the effect of lexical olfactory salience.

Results:

Both metaphorical and literal olfactory sentences activated secondary olfactory–semantic networks, including the orbitofrontal cortex and temporal regions, indicating shared semantic processing mechanisms. Literal olfactory sentences elicited stronger activation in limbic and sensory–affective regions, including the amygdala, hippocampus, and posterior insula. In contrast, olfactory metaphors showed reduced limbic involvement and preferential engagement of higher-order semantic and inferential regions, including inferior frontal and parietal cortices. Parametric analyses revealed that olfactory nouns produced stronger neural responses than action-related verbs across both conditions, particularly within the OFC and temporal cortex. Hemispheric effects reflected task-related processing demands rather than fixed lateralization.

Conclusion:

These findings support graded embodiment accounts of olfactory language comprehension, demonstrating that abstract metaphorical meaning arises from selective and partial engagement of sensory-related networks rather than full sensory simulation. The OFC appears to function as a central semantic hub integrating perceptual, affective, and abstract information across literal and metaphorical contexts. This study provides the first neuroimaging evidence for graded embodiment in Persian olfactory metaphors and contributes to a more nuanced understanding of how sensory experience shapes abstract language in the human brain.

Keywords:

metaphors, fMRI, Semantic integration, Graded embodiment, Orbitofrontal cortex