Effects of color-flavor association on visual search process for reference pictures on beverage packaging: behavioral, electrophysiological, and causal mechanisms

Abstract

The visual search for product packaging involves intricate cognitive processes that are prominently impacted by learned associations derived from extensive long-term experiences. The present research employed EEG technology and manipulated the color display of reference pictures on beverage bottles to explore the underlying neurocognitive pathways. Specifically, we aimed to investigate the influence of color-flavor association strength on the visual processing of such stimuli as well as the in-depth neural mechanisms. The behavioral results revealed that stimuli with strong association strength triggered the fastest response and the highest accuracy, compared with the stimuli with weak association strength and the achromatic ones. The EEG findings further substantiated that the chromatic stimuli evoked a more pronounced N2 component than achromatic ones, and the stimuli with strong association strength elicited larger P3 and smaller N400 amplitudes than the ones with weak association strength. Additionally, the source localization using sLORETA showed significant activations in the inferior temporal gyrus. In conclusion, our research suggests that (1) color expectations would guide visual search process and trigger faster responses to congruent visual stimuli, (2) both the initial perceptual representation and subsequent semantic representation play pivotal roles in effective visual search for the targets, and (3) the color-flavor association strength potentially exerts an impact on visual processing by modulating memory accessibility.

Keywords: association strength; color expectation; inferior temporal gyrus; perceptual representation; semantic representation; visual processing.

Figure 1

The experimental design with three conditions. Taking “柠檬味” (lemon flavor) as an example of the target flavor label to illustrate the specific experimental design under the three conditions. From left to right shows the strong association color, weak association color, and achromatic color conditions, and the images circled in the red circles were the targets that participants should select under these conditions.

Figure 2

The experimental procedure in three conditions. Taking “柠檬味” (lemon flavor) in the strong association color condition as an example to illustrate that the participants should use their left middle finger to press “S” key on the computer keyboard when the target was presented in the upper left quadrant.

Figure 3

Grand-averaged ERPs and the topographic maps of N2 (160–240 ms), P3 (300–400 ms), and N400 (400–500 ms) elicited by different conditions on electrodes Fz, Cz, and Pz.

Figure 4

The difference waves (strong minus weak) and its topographic maps. (A) Strong association minus weak association difference waves in electrodes Fz, Cz, and Pz. (B) The topographic maps illustrating the mean difference in component amplitudes with time windows of 300–400 ms and 400–500 ms at interval of 20 ms.

Figure 5

The electroencephalogram source locations of the difference waves (strong minus weak). (A) The sLORETA displays of activated neural source on cortex and MRI for the time window of 300–400 ms. (B) The sLORETA displays of activated neural source on cortex and MRI for the time window of 400–500 ms.