MEHJABIN SHIRIN¹, Dr Shivaram Male Male², Dr. P Phani Krishna Krishna³; ¹University of Hyderabad, ²University of Hyderabad, ³Delhi University

Color remains one of the most resilient perceptual and affective modalities of the human brain, supported by distributed neural systems that often remain functional even as higher cognitive processes deteriorate. This project introduces the NeuroColor Atlas, a real-time psychophysiological framework designed to characterise how ageing and early-stage dementia alter the brain’s emotional responses to color. The study investigates whether affective color signatures neural–physiological patterns linking emotion and perception remain stable or exhibit measurable reorganisation during cognitive decline. A total of N = 10 older adults participated, comprising healthy individuals and early-stage dementia patients. Participants viewed a standardised set of chromatic stimuli while multiple physiological indices linked to autonomic and neurocognitive processing skin conductance, heart-rate variability, pupil dilation (LC–NE system activity), and gaze dynamics (oculomotor–attentional control) were recorded. These streams were temporally aligned and processed using a custom algorithm designed to extract neural-affective indicators embedded in dynamic physiological patterns. Resulting signatures were mapped into CIELAB and HSL color spaces to generate individualised chromatic profiles forming the core of the NeuroColor Atlas. Findings revealed distinct neurophysiological shifts in emotional color processing across ageing and dementia. Healthy older adults showed relatively coherent affective profiles with moderate variability in arousal responses to saturation and luminance, consistent with expected age-related changes in autonomic regulation. In contrast, dementia participants displayed diminished hue differentiation, disrupted pupil-based arousal modulation, and broader gaze dispersion patterns suggestive of altered locus coeruleus-amygdala interactions and reduced attentional stability. Notably, warm, high-saturation colors continued to evoke preserved emotional resonance, indicating that certain affective pathways may remain intact despite cortical–cognitive decline. These findings highlight real-time color–emotion mapping as a promising neurometric tool for detecting subtle affective–perceptual alterations in early dementia. The NeuroColor Atlas provides a foundational step toward developing neuroscience-informed visual environments, emotion-supportive therapeutic strategies, and biomarker-driven assessments of cognitive ageing.

Acknowledgements: I gratefully acknowledges the support of the International Society of Color Council (ISCC) Student Support Award, which contributed to the development and dissemination of this research.