Parkinson's disease is the second most common neurodegenerative disease after Alzheimer's disease. It is mostly characterized by the presence of motor difficulties. However, it can also be accompanied by cognitive disorders which have an equally significant impact on the quality of life of patients and which are not relieved by any treatment. Among the functions affected by Parkinson's disease, inhibition is an essential process for adapting our behaviors in daily life. Inhibition allows us to stop an action that is no longer required or appropriate to the situation in which we find ourselves in. For example, it comes into play when we have to stop at a stop sign while driving. Recent studies suggest that it could be possible to improve the functioning of these processes by using non-invasive brain stimulation tools. Transcranial alternating current electrical stimulation has thus showed promising results in improving functions such as working memory. This technique is completely painless and non-invasive and consists in applying an electric current of very low intensity (barely perceptible) at the level of the scalp, using electrodes. The investigators are conducting a study to test whether transcranial alternating current electrical stimulation could improve the functioning of the inhibition process which is altered in patients. For this, the investigators will measure this process using a task performed on a computer (the Stop Signal Reaction Time Task), as well as brain activity using a method called electroencephalography, before and after stimulation. For this study, the investigators will include 50 patients and 40 healthy participants to investigate the effect of the stimulation on inhibition.