Hadis Imani

• This Ph.D. dissertation investigates the neurobehavioral, psychological, and cognitive factors influencing postural control and its age-related changes through four studies. Postural control is essential for daily activities, and its decline with age increases fall risk, leading to autonomy loss and reduced quality of life. The first study (Imani & Godde, 2021) explores how self-efficacy mediates the relationship between falls and autonomy in older adults. While falls negatively impact autonomy, higher self-efficacy reduces this effect. Cognitive function predicts autonomy but does not moderate the relationship between falls and autonomy. The second study examines the bidirectional link between cognitive and physical function. Results show that cognitive decline affects physical abilities over time and vice versa, highlighting the strong connection between executive function and motor control. This reinforces how cognitive decline, falls, and depressive mood contribute to reduced social participation. The third study investigates the effects of transcranial direct current stimulation (tDCS) combined with balance training in younger adults. Targeting the sensorimotor cortex and dorsolateral prefrontal cortex (DLPFC), the study assesses how anodal tDCS enhances balance. Resting-state EEG is also explored as a predictor of training effects. The fourth study extends this research to older adults, revealing age-related differences in neural activation during balance training. Results suggest individualized stimulation protocols may improve balance outcomes. Overall, these studies emphasize the cognitive-motor link in postural control and propose targeted interventions to enhance balance and autonomy, particularly in older adults at risk of falls.