This study aimed to evaluate and compare the cognitive and spatial learning outcomes of two instructional modalities, traditional 2D atlas-based learning and 3D atlas-based visualization, in the teaching of human embryology. Conducted as a cross-over experimental study at Khyber Medical University, the research involved thirty-four postgraduate students equally divided into Group A and Group B. In Phase 1, Group A received 2D instruction while Group B received 3D instruction. Each participant completed a pretest, a two-hour instructional session on heart development, a post-test immediately after, and a delayed post-test two weeks later. Cognitive understanding was assessed using a structured questionnaire, while spatial ability was evaluated using the Visualization of Rotation (ROT) test. After Phase 1, the instructional methods were flipped between the groups, and the assessments were repeated.
Before flipping, a significant difference was observed in pretest cognitive scores between the groups (F = 5.405, p = 0.026), with the Group B (3D in Phase 1) scoring higher; however, this difference did not persist in post-test or delayed post-test results. Spatial scores also showed a clear advantage for the Group B before the flip, with significantly higher post-test (F = 27.781, p < 0.05) and delayed post-test scores (F = 55.07, p < 0.05). After flipping, the group receiving 3D instruction achieved higher spatial scores at both the post-test and delayed post-test stages confirming the consistent advantage of 3D visualization across both phases. Within-group analysis revealed modest improvements after instruction for both groups, followed by a normal decline at delayed testing.
Overall, the findings suggest that 3D atlas-based learning enhances spatial reasoning and visualization skills, while traditional 2D learning remains effective for factual content mastery. The cross-over design minimized the influence of baseline differences and allowed direct comparison of both modalities within the same participants. These results support an integrated pedagogical approach where 3D visualization tools are introduced early to build spatial frameworks, followed by 2D resources to reinforce conceptual understanding and retention.
