The Effects of Multi-Modal Intervention Protocols on Verbal Intelligence Domains in Pakistani School Students: A Randomized Crossover Trial

Abstract

Background: The extent to which intellectual performance can be modulated remains a central debate in cognitive psychology. This study investigated the efficacy of longitudinal intervention protocols combining cognitive load (Dual n-back), physiological arousal (Aerobic Physical Exercise; APE), and sensory consolidation (Wakeful Rest) to determine the optimal sequence for enhancing verbal intelligence domains in adolescents.

Method: A 6-week, double-blind, randomized crossover trial was conducted with school-aged students (N=25, M=12.98). Using a within-subjects design, participants were exposed to six counterbalanced intervention sequences (e.g., N-R-E, E-N-R). Verbal Intelligence (VI) and its constituent indices the Working Memory Index (WMI) and Verbal Comprehension Index (VCI) were psychometrically evaluated weekly using the Wechsler Intelligence Scale for Children (WISC-IV).

Results: Repeated-measures ANOVA revealed significant main effects for both intervention condition and time across all measured domains (F (1, 24) = 170.31, p < .001). While isolated Dual n-back training showed strong independent effects, the data identified superior synergistic protocols. Post-hoc Bonferroni analysis confirmed that the N-R-E (Dual n-back -Wakeful Rest -Aerobic Exercise) and N-E-R (Dual n-back - Aerobic Exercise -Wakeful Rest) sequences yielded the highest significant improvements in verbal comprehension, digit span, and short-term memory (p < .05). The results demonstrated a significant ascent from a baseline mean of 94.85 (SD = 25.48) to a peak performance of 152.90 (SD = 8.45) by the final experimental trial. This substantial increase in primary scores was accompanied by a marked reduction in variance, suggesting that the N-R-E and N-E-R sequences effectively homogenized high-level cognitive performance across the cohort.

Conclusions: This study’s findings suggest that verbal intelligence domains are highly plastic and responsive to specific behavioral sequencing. The results indicate that "cognitive priming" via n-back training, when followed by physiological stimulation or consolidation periods, maximizes neural receptivity and information retention. This provides a scalable framework for educational interventions aimed at optimizing cognitive development.