Implications of Stimulation Modality and Control Condition on BOLD Response: An Example From the MOUS Dataset

Area of Science:

• Neuroscience
• Cognitive Science
• Psycholinguistics

Background:

• Functional MRI (fMRI) studies investigating language processing are sensitive to methodological choices.
• The selection of appropriate control conditions and sensory modalities (auditory vs. visual) is crucial for reliable fMRI results.
• Previous research has not systematically evaluated the combined impact of control conditions and stimulation modality in sentence processing.

Purpose of the Study:

• To systematically investigate the influence of control conditions and stimulation modality on fMRI results during sentence processing.
• To compare brain activation patterns elicited by auditory versus visual presentation of linguistic stimuli.
• To provide guidance for optimizing fMRI study design in language research.

Main Methods:

• Utilized the Mother of Unification Studies (MOUS) dataset comprising fMRI data from 187 subjects.
• Compared fMRI data from sentence comprehension tasks with auditory (listening) and visual (reading) stimuli.
• Employed randomly scrambled words as control conditions, derived from simple and complex sentences.

Main Results:

• Auditory stimulation led to significant activation in bilateral auditory cortices.
• Visual stimulation showed greater activation in the anterior temporal lobe compared to word stimuli, but not sentence stimuli.
• Direct modality comparison revealed distinct patterns: auditory stimulation engaged primary auditory cortices, while visual stimulation involved the left inferior frontal gyrus.

Conclusions:

• Both stimulation modality and control condition significantly impact fMRI findings in sentence processing.
• Researchers must carefully consider these factors during the planning stages of fMRI language studies.
• The choice of control stimuli and sensory input modality can shape observed neural activity patterns.