Cross-Enhanced Multimodal Fusion of Eye-Tracking and Facial Features for Alzheimer's Disease Diagnosis

Accurate diagnosis of Alzheimer's disease (AD) is essential for enabling timely intervention and slowing disease progression. Multimodal diagnostic approaches offer considerable promise by integrating complementary information across behavioral and perceptual domains. Eye-tracking and facial features, in particular, are important indicators of cognitive function, reflecting attentional distribution and neurocognitive state. However, few studies have explored their joint integration for auxiliary AD diagnosis. In this study, we propose a multimodal cross-enhanced fusion framework that synergistically leverages eye-tracking and facial features for AD detection. The framework incorporates two key modules: (a) a Cross-Enhanced Fusion Attention Module (CEF AM), which models inter-modal interactions through cross-attention and global enhancement, and (b) a Direction-Aware Convolution Module (DACM), which captures fine-grained directional facial features via horizontal-vertical receptive fields. To support this work, we constructed a synchronized multimodal dataset, including 25 patients with AD and 25 healthy controls (HC), by recording aligned facial video and eye-tracking sequences during a visual memory-search paradigm, providing an ecologically valid resource for evaluating integration strategies. Extensive experiments on this dataset demonstrate that our framework outperforms traditional late fusion and feature concatenation methods, achieving a classification accuracy of 95.11% in distinguishing AD from HC, highlighting superior robustness and diagnostic performance by explicitly modeling inter-modal dependencies and modality-specific contributions. Introduction Alzheimer's disease (AD), a progressive and irreversible neurodegenera-tive disorder, represents the primary cause of dementia in older adults [1]. It typically begins with mild memory loss and gradually progresses to severe impairments in executive and cognitive functions [2]. Within the global aging population, more than 150 million people worldwide will be affected by AD or other forms of dementia [3], imposing a substantial burden on both families and healthcare systems. Early and accurate identification of Alzheimer's disease is vital to initiate interventions that may slow progression and improve quality of life. Clinically, the diagnosis of AD primarily relies on biomarker analysis, neu-roimaging techniques, and neuropsychological assessments.