Effects of a Targeted Nutritional Intervention on Auditory–Visual Event-Related Potentials in South-Indian Infants: An Exploratory Analysis of a Cluster Randomized Trial

Background/Objectives: Inadequate macronutrient intake may affect neurodevelopment in early infancy. In India, government-supplied take-home rations (THRs) attempt to meet this gap but lack adequate fat and protein. This study evaluated the impact of a 3-month macronutrient modified-THR intervention on infant neurodevelopment using event-related potentials (ERPs). Methods: A two-group cluster randomized controlled trial (village clusters = 12/group; N = 67/group) enrolled healthy breastfed infants (6–9 months) in Karnataka, India. The intervention group received a milk–legume-based THR providing ~200 kcal/day (ML-THR, estimated protein:energy (PE) and fat:energy (FE) ratios: 12% and 45%) with the standard government THR (SG-THR, estimated PE and FE ratios: 7% and 4%), while controls received SG-THRs only. All mothers received education on infant and young child feeding practices, water sanitation and hygiene. Auditory, visual and attention processing ERPs were measured using a short, culturally adapted, infant-friendly paradigm. Linear mixed models evaluated intervention effects over time. Results: The intervention was associated with region-specific visual ERP changes: increased fractional latencies in anterior regions for face, nonface (500–750 ms); decreased fractional latencies in the central region for frequent (10–250 ms) and face (500–750 ms) and in the posterior region for frequent–rare difference (250–500 ms). The intervention group also demonstrated a reduced area under the curve for nonface stimuli (250–500 ms). No significant auditory or visual hemifield effects were observed. None of the observed effects remained significant after false discovery rate (FDR) correction. Conclusions: The findings are exploratory and suggest the need to examine the effects of improved protein quality and fat content in THRs on visual–cortical processing in larger samples.