The study explores the use of neurophysiological methods like eye-tracking and EEG to understand consumer motivation, a field gaining traction in both academia and business. Many companies have started to apply these techniques to gain insights into consumer behavior and optimize marketing strategies. The research aims to provide a methodological framework for future neurophysiological consumer motivation studies. Neurophysiological tools are considered less susceptible to biases compared to traditional subjective methods, offering more objective insights into consumer behavior. While theoretical discussion on applying these tools is extensive, empirical research lags. This study bridges that gap by presenting a detailed procedure combining neurophysiological methods with conventional experimental methods to examine motivating functions of consumer behavior. The research uses the concept of motivating operations (MOs) to analyze the relationship between situational antecedents, consumer behavior (attention, neural responses, choice, consumption), and consequences. The primary goal is to comprehensively understand the functional relationship between antecedent events (with motivating functions), consumer behaviors, and their outcomes.

The study leverages the concept of motivating operations (MOs), which are environmental events that alter the value of a reinforcer (value-altering effect) and evoke related behaviors (behavior-altering effect). MOs are categorized as establishing operations (EOs) – increasing the effectiveness of a reinforcer – and abolishing operations (AOs) – decreasing the effectiveness. Deprivation functions as an EO, while satiation functions as an AO. The literature review highlights the use of deprivation (e.g., water deprivation) as an EO in research, emphasizing the need for ecologically sound manipulation to avoid causing discomfort while still inducing a strong EO. The review also considers alternative EOs, such as ingesting salty foods, that similarly enhance the reinforcing value of water. The behavior-altering effect of MOs encompasses changes in attention, neural responses, and behavioral tendencies. The research aims to improve the understanding of how antecedent events, particularly deprivation, influence consumer behavior across various behavioral domains.

Thirty-two right-handed, normal-weight participants (18 males, 14 females; mean age = 24.2 years) were randomly assigned to either an experimental group (water deprivation) or a control group (no water restriction). The study involved three experimental sessions. **Session 1 (Baseline):** The experimental group consumed salty biscuits (to increase thirst), while the control group drank flavored water (to maintain hydration). Thirst levels were measured using a Likert scale. **Session 2 (Attention & Neural Responses):** Participants viewed neutral images and images of salty snacks and beverages. Eye-tracking (Tobii X2-30) and EEG (ABM B-Alert X10) data were collected to measure attention (fixation count, average fixation duration) and neural responses (frontal EEG asymmetry, measuring approach/withdrawal motivation). Twelve neutral GAPED images were presented initially to establish a baseline for EEG data. **Session 3 (Choice & Consumption):** Participants engaged in 25 paired choice trials, choosing between images of salty snacks and beverages. Following choices, they were given a 500 ml bottle of water to measure actual consumption. Data was analyzed using IBM SPSS Statistics v28. Data quality for eye-tracking was checked using metrics reported by the iMotions software. EEG data was analyzed using the NeuroSpec toolbox, calculating mean frontal alpha asymmetry (FAA) based on differences between F3 and F4 electrodes. A within-subject design was used for FAA, employing the average of the 12 neutral images as a baseline for each participant. Statistical tests used included dependent samples t-tests (where normality assumptions were met) and Wilcoxon signed-rank tests (for non-normal data). For choice data, a Chi-square test of independence was used.

**Session 1:** The manipulation check confirmed that the experimental group reported significantly higher thirst levels than the control group (p < 0.001). **Session 2 (Eye-tracking):** The experimental group showed significantly longer average fixation duration on water images compared to salty biscuit images (p = 0.037), indicating that deprivation influenced attention. Fixation count analysis revealed a significantly higher fixation count on the salty biscuit compared to water images for the experimental group (p = 0.003). No significant differences were found in either fixation count or average fixation duration for the control group. **Session 2 (EEG):** No significant differences in frontal EEG asymmetry were found between the water and salty biscuit images for either group. However, the experimental group trended toward significant differences, warranting further study. **Session 3:** The experimental group chose liquid beverages significantly more often (81%) compared to the control group (58%) (p < 0.001). The experimental group consumed significantly more water (Mdn = 254 ml) than the control group (Mdn = 99.5 ml) (p < 0.001).

The findings largely support the hypotheses. The experimental group's increased fixation duration on water images and significantly higher water choice and consumption demonstrate the EO effect of deprivation on attention and subsequent choice/consumption. The lack of significant difference in frontal EEG asymmetry might be due to the sample size; further research with larger samples could shed more light. The results are consistent with the concept of motivating operations, showing how antecedent events influence behavior across multiple levels. The multi-method approach offers a more comprehensive understanding than single-method approaches, capturing complex interactions between situational factors, neurophysiological responses, and overt behavior.

This study provides a novel methodological procedure for examining the motivating functions of consumer behavior using a multi-method approach combining behavioral and neurophysiological measures. The findings demonstrate the effectiveness of this approach, showing the impact of water deprivation on attention, choice, and consumption. Future research should focus on replicating these findings with larger samples and exploring other antecedent factors beyond water deprivation to further refine the understanding of consumer motivation.

The sample size was relatively small, and the study was conducted in a laboratory setting, potentially limiting the generalizability of the findings to real-world consumer environments. The lack of significant results for EEG data necessitates further investigation with larger samples and exploring different analysis methods.