This chapter provides an interdisciplinary exploration of the neural foundations underlying cognitive processes. It begins by outlining how different brain regions support key cognitive functions—such as the occipital lobe for visual perception, temporal and parietal lobes for auditory and somatosensory processing, the hippocampus for memory, and various prefrontal regions for attention and decision-making. This chapter details the roles of neurotransmitters (e.g., glutamate, GABA, dopamine, and serotonin), hormones (e.g., cortisol and oxytocin), and growth factors (e.g., BDNF, NGF, and IGF-1) in modulating brain activity and behavior. It reviews key methodologies in cognitive neuroscience, including EEG, fMRI, MEG, TMS, and lesion studies, which have advanced our understanding of connectome and neural network dynamics. Additionally, the chapter discusses neuropsychological disorders such as Alzheimer’s disease, Parkinson’s disease, traumatic brain injury, and stroke, highlighting their cognitive impacts and rehabilitation strategies. Finally, the findings emphasize the critical role of sleep in memory consolidation, neuroplasticity, and overall cognitive function.