Potential of Questionnaire and Projective Color Association Method to Reflect Physiological Responses to Stimuli with Different Emotional Charge

Procedure The focus and procedure of the study will be explained to all participants. Their physiological responses (cerebral blood flow, brain electrical activity, heart rate variability, and skin conductance response) to visual word and picture stimuli will be measured in the Multimodal and Functional Imaging Laboratory (MAFIL). The measurement lasts about 35 minutes, total time spent in MAFIL is approx. 60 minutes. After the measurement of physiological responses, participants are asked to complete the online CA method application and the online questionnaire within the next 24 hours. Both the CA method application and the online questionnaire are focused on capturing the participants' perception of word and picture stimuli using different measurement methods, i.e., the colour association and questioning method. On average, this task takes approximately 20 minutes for each method. It should be noted that the different time period for measuring physiological reactions to and the perception of stimuli by participants is given by necessity to capture only brain activation connected with the perception of the stimuli, and not with answering online questionnaire and CA method application.

In the case of all kinds of measurement, i.e. physiological responses, CA method, and questionnaire, the respondents are exposed to the same 145 stimuli. They are 115 words (three sets of 35 words with positive, neutral, and negative content) and 30 pictures (two sets of 15 photos with positive and negative content). Combining stimuli with different content ensures greater variability of reactions, which supports the robustness and relevancy of the results. The content of the stimuli was evaluated according to the national norm of the CA method for words and the International Affective Picture System for pictures. It should be noted that participants are exposed to 21 stimuli twice during the measurement of physiological responses to check the stability of physiological reactions. The order of the stimuli is identical for all participants, and the stimuli combine words and pictures regardless of their content.

Participants The sample will consist of 101 individuals aged 18-64 years, of whom 23 will repeat the entire procedure twice to allow the robustness check of the results in time. Participants will be recruited by a market and media research agency.

Measurement Physiological responses In the study, physiological responses to word and pictorial stimuli will be measured and compared. Four measurement modalities will be used to record data: functional magnetic resonance imaging (fMRI), surface skulk electroencephalography EEG, heart rate activity, and galvanic skin response (GSR) representing electrodermal activity of the body.

Functional magnetic resonance imaging (fMRI) will be used for the quantification of cerebral blood flow. Measurement will be carried out with Siemens Prisma 3T MRI scanner (Siemens Medical Solutions USA, Inc.) with 64 channels head-neck coil, Syngo version VE11c, accompanied by standard Anatomical T1 MPRAGE scan. Multi-echo MB-EPI fMRI acquisition based on CMRR EPI sequences with TR=700 ms and TE=15/34/53 ms at 1570 scans. GRAPPA PAT factor 2 and slice acceleration (MB factor) set to 6 are used. The dimension of the recorded voxel is 3x3x3 mm with a slice thickness of 3 mm. The number of axial slices is 48 (transverse) in the inplane FoV=192 mm and the setting of the flip angle is 45°.