Analyzing motivating functions of consumer behavior: Evidence from attention and neural responses to choices and consumption

The study addresses how antecedent motivational events—conceptualized as motivating operations—affect consumer behavior across attention, neural responses, choices, and consumption. With growing adoption of neurophysiological methods in industry and academia, the authors seek a rigorous experimental procedure integrating eye-tracking and EEG with behavioral measures to objectively assess consumer motivation. Focusing on deprivation (specifically water deprivation) as an establishing operation (EO), the research aims to test whether deprivation alters the reinforcing value of beverages and evokes related behaviors, offering a fuller, multi-method account of the functional relation between antecedents and consumer behavior.

The literature review frames motivating operations (MOs) as environmental events that alter the value of reinforcers and the probability of related behaviors, distinguishing establishing operations (EOs) and abolishing operations (AOs). Deprivation functions as an EO for food and water, while satiation serves as an AO. Prior work has applied MOs to consumer behavior and purchasing contexts. Deprivation can be produced naturally (time since last intake) or via events such as salty food ingestion that similarly increase water’s reinforcing value. Evidence links MOs to changes in attention, neural responses, and behavioral tendencies. Eye-tracking research shows motivationally relevant stimuli capture visual attention; fixation counts and durations predict choices. EEG frontal alpha asymmetry indexes approach versus withdrawal motivation, with relatively greater left frontal activation reflecting approach; past studies show deprivation and appetitive cues can modulate asymmetry. The review concludes that integrating attention (eye-tracking), neural (EEG), and behavioral outcomes (choice and consumption) can capture the complexity of motivating antecedents in consumer contexts.

Design: Randomized controlled experimental study with three sessions to assess effects of water deprivation (EO) versus satiation (AO) on attention (eye-tracking), neural responses (EEG frontal asymmetry), choices, and consumption. Participants: 32 right-handed adults (18 male, 14 female; age 19–37, M=24.2, SD=3.54), recruited from a university community; compensated 200 NOK. Inclusion restricted to right-handed to avoid confounds in hemispheric asymmetry. Random assignment to experimental (water deprivation) and control groups (each n=16). Blinding/cover story framed study as taste-neurophysiology to mask manipulation. Measures: thirst (7-point Likert), mood (1–7), handedness (Chapman & Chapman Inventory), eye-tracking metrics (fixation count; average fixation duration), EEG frontal alpha asymmetry (F3/F4, 8–12 Hz, baseline-corrected using neutral images), choices in paired forced-choice trials (liquid vs salty snack), and actual water consumption (ml) from a 500 ml bottle. Session 1 (Baseline/manipulation): Experimental group arrived ~3 h after normal wake time without morning liquids, producing ~11–12 h water deprivation; they tasted salty biscuits (further enhancing EO for water). Control group had no intake restrictions and tasted flavored water (AO for thirst). Both completed mood, handedness, thirst, and taste credibility questions. Session 2 (Attention and neural responses): Both groups viewed 12 randomized neutral GAPED images (15 s each) to establish EEG baseline; then viewed 10 test images (5 liquids: still water, sparkling water, milk, cola, juice; 5 salty snacks: pretzel sticks, peanuts, chips, crackers, salty biscuits) separated by 20 s black screens. Eye-tracking and EEG recorded continuously. Thirst re-assessed post viewing. Eye-tracking apparatus: Tobii X2-30 (30 Hz), AOIs defined around water and salty biscuit images; data quality checks performed (screen viewing %). EEG apparatus: ABM B-Alert X10 with 9 channels (F3, Fz, F4, C3, Cz, C4, P3, POz, P4), 256 Hz; impedances <20 kΩ; linked mastoid references; PSD computed for 8–12 Hz using 1-s segments, no overlap; frontal alpha asymmetry computed as mean log power difference (F4 − F3) and baseline-adjusted using neutral images. Session 3 (Choice and consumption): 25 two-alternative forced-choice trials (5 liquids × 5 salty snacks), position counterbalanced, order randomized; then demographic questions. Participants were then offered a 500 ml water bottle and free to drink; remaining water weighed to calculate consumption. Statistical analysis: Normality assessed with Shapiro–Wilk; between-group comparisons with Mann–Whitney U for thirst and consumption when non-normal; within-group paired comparisons for eye-tracking and EEG with paired t-tests or Wilcoxon signed-rank tests as appropriate; chi-square test (with Yates correction) for group differences in choice proportions. Data processed in iMotions; EEG PSD with NeuroSpec toolbox in MATLAB; analyses in SPSS 28.

Manipulation checks: - Session 1 thirst: Experimental (Mdn=5.50, n=16) > Control (Mdn=4.00, n=16); Mann–Whitney U=24.50, z=−3.98, p<0.001, r=0.70. - Session 2 thirst: Experimental (Mdn=6.00) > Control (Mdn=4.00); U=26.00, z=−3.96, p<0.001, r=0.70. Eye-tracking (Session 2): - Fixation count (within experimental group): Salty biscuit M=31.94 (SD=6.72) > Water M=26.81 (SD=6.97); t(15)=3.58, p=0.003, Hedges’ g=0.85. Control: no significant difference (Wilcoxon z=−1.35, p=0.176). - Average fixation duration (ms): Experimental group showed longer fixations on water vs salty biscuit: Water M=351.81 (SD=118.37) > Biscuit M=305.50 (SD=71.62); t(15)=−2.29, p=0.037, g=−0.54. Control: no difference; Water M=288.25 (SD=82.51) vs Biscuit M=285.88 (SD=62.37); t(15)=−0.172, p=0.866. EEG frontal alpha asymmetry (Session 2): - Experimental group: No significant difference between water (M=0.033, SD=0.59) and salty biscuit (M=−0.009, SD=0.59); t(15)=2.07, p=0.056. - Control group: No significant difference; Wilcoxon z=−0.83, p=0.41. Choices (Session 3): - Liquid beverages chosen more often by experimental group (81%; 323/400) than control (58%; 232/400); Chi-square with Yates: X2(1, N=800)=47.66, p<0.001, phi=0.28. Consumption (Session 3): - Experimental consumed M=291.1 ml (SD=124.7; range 138–500) vs Control M=86.1 ml (SD=71; range 0–242). Mann–Whitney U=10.00, z=−4.46, p<0.001, r=0.79. Overall: Water deprivation increased attentional duration toward water images, did not yield significant frontal asymmetry differences, and significantly increased choice of beverages and actual water consumption.

The findings support the motivating operations framework: water deprivation (EO) elevated the reinforcing value of beverages and evoked related behaviors. Attention results show that deprivation increased the depth of visual processing (longer average fixation duration) toward water, while fixation counts were higher for the salty biscuit image under time-limited viewing, suggesting metric-specific sensitivities. EEG frontal asymmetry did not differ significantly, indicating limited neural evidence of approach-related activation under these conditions and sample size, despite prior literature linking deprivation and appetitive cues to left frontal activity. Behaviorally, deprivation robustly increased selection of liquid options and actual water consumption, aligning with value- and behavior-altering effects predicted by MOs. The multi-method approach demonstrates how integrating eye-tracking, EEG, choice, and consumption can map the functional relation between antecedent states and consumer behavior, offering objective, actionable insights for consumer research and practice.

This study introduces and tests a multi-method procedure combining eye-tracking, EEG, and behavioral measures to assess motivating functions of antecedent events in consumer behavior. Using water deprivation as an EO, the approach captured changes in attention and robust effects on choice and consumption, while EEG asymmetry effects were inconclusive. The procedure provides a systematic framework for academics and practitioners to evaluate how situational factors influence consumers in-store or online. Future research should replicate with larger samples, extend to real-world retail settings, and examine additional motivating operations beyond water deprivation to test the robustness and generalizability of the approach.

Key limitations include a modest sample size (n=32), which may have limited power to detect EEG frontal asymmetry effects; laboratory setting that may reduce ecological validity compared to in-store contexts; time-limited stimulus presentation potentially influencing the relationship between fixation count and duration; and reliance on a single antecedent manipulation (water deprivation and salty food ingestion) and specific stimuli. Future studies should increase sample size, test in naturalistic environments, vary deprivation duration and stimulus characteristics (e.g., calorie content, stimulus type), and examine other motivating operations.