The study examines the impact of generative artificial intelligence (GAI) on the motivation, autonomy, competence, and well-being of undergraduate marketing students when addressing case studies under three conditions: traditional resolution (human only), collaborative resolution (human + AI), and automatic resolution (AI only). Grounded in Self-Determination Theory and Cognitive Evaluation Theory, a quasi-experimental design was applied with 80 students, assessing the dependent variables through adapted Likert-type scales and objective rubrics. The findings reveal significant differences across the three dimensions analyzed (ANOVA, p < 0.001): competence and autonomy are higher when students engage actively, particularly in the collaborative condition, while emotional well-being increases in contexts supported by technology. However, satisfaction with one’s own performance declines when AI entirely replaces human execution. The observed motivational pattern supports the hypothesis that the degree of agency and control in the task mediates the psychological effects of GAI, suggesting hybrid models in which technology serves as informational scaffolding rather than as a substitute for students’ judgment.