*2.3. Procedure*

Participants participated in one 1-h session, which started with an explanation of the procedure, followed by the attachment of the PPG heart rate sensor on the fingers of the non-dominant hand, and by two practice trials. Participants were seated in front of a laptop with a webcam (Microsoft LifeCam) that recorded their face. Instructions and images of the unbranded or branded soy sauces were shown on the laptop screen using E-Prime software (E-Prime, Science Plus Group, Groningen, The Netherlands). Participants were instructed that their perception of soy sauces was studied, and that to avoid unnecessary movements that may interfere with the measurements, small samples of rice with soy sauce would be put in their mouth by the experimenter. The sample should be chewed normally, and the participant was instructed to signal the swallow with a hand signal, after which scores were entered by a mouse click.

Next, participants received three blocks of stimulus trials in which he/she received taste samples of cooked rice mixed one of three soy sauces. In each trial, participants, either familiar or unfamiliar with soy sauces, first received an auditory warning signal followed after 5 s by an image (*viewing phase*) for 5 s showing either a generic volume of soy sauce in a white cup (unbranded block 1), or the same white cup with soy sauce combined with the bottle of one of the soy sauces showing the package of the product (blocks 2 and 3, with matched branding and non-matched branding, respectively). After the 5 s viewing period, the image disappeared during an anticipatory waiting period of approximately 5 s. Next, the image reappeared and the participants were given a spoon of the mixture of rice and soy sauce in the mouth by the experimenter who simultaneously pressed the enter key of the keyboard to signal the start of tasting (*tasting phase*) in the data recordings. In the branded match block 2, the brand shown in the image and the tasted soy sauce were the same, whereas they were different in the branded non-match block 3 (results will not be reported in here). After each sample, which was chewed typically for at least 10 s, the participant first scored the liking of the sample using a visual analogue scale (VAS), followed by a just-right scale for saltines. Next, participants indicated the perceived valence and arousal using a so-called "EmojiGrid" [26,30] (see Figure 1). Only the Emoji scores of valence and arousal will be reported here. Heart rate responses and facial expressions were recorded during each of the phases in all trials. Each of the three soy sauces was presented twice in block 1 and four times in block 2 in a randomized order. To avoid possible unwanted interference of the non-matched condition with the other conditions, the non-matched condition (not reported here) was tested last in block 3 with only two of the three soy sauces presented once. This resulted in a total number of 20 trials presented at a rate of approximately 1 trial per 150 s. The order of the blocks was the same for all participants. The procedures are shown schematically in Scheme 1.

Scheme 1

Scheme 1

**Scheme 1.** Schematic representation of the study procedure. Participants were presented with 3 blocks of trials. Each trial started with an attention signal (asterisk), followed by an image of branded or unbranded image soy sauce, a viewing/an-

facial expressions were recorded continuously. VAS and EmojiGrid scores were recorded at the end of each trial. Heart

rates, facial expressions, and Emoji scores for block 1 and 2 are reported in this manuscript.

**Figure 1.** The EmojiGrid used in the study to measure valence and arousal [25]. **Figure 1.** The EmojiGrid used in the study to measure valence and arousal [25].

**Scheme 1.** Schematic representation of the study procedure. Participants were presented with 3 blocks of trials. Each trial started with an attention signal (asterisk), followed by an image of branded or unbranded image soy sauce, a viewing/anticipation period, and a period where rice with soy sauce was chewed. ECG and RPPG heart rate, skin conductance, and facial expressions were recorded continuously. VAS and EmojiGrid scores were recorded at the end of each trial. Heart rates, facial expressions, and Emoji scores for block 1 and 2 are reported in this manuscript. **Scheme 1.** Schematic representation of the study procedure. Participants were presented with 3 blocks of trials. Each trial started with an attention signal (asterisk), followed by an image of branded or unbranded image soy sauce, a viewing/anticipation period, and a period where rice with soy sauce was chewed. ECG and RPPG heart rate, skin conductance, and facial expressions were recorded continuously. VAS and EmojiGrid scores were recorded at the end of each trial. Heart rates, facial expressions, and Emoji scores for block 1 and 2 are reported in this manuscript.
