Investigator general objective is therefore to study and compare the benefit of several methods of management of cognitive difficulties reported by patients during treatment for breast cancer, among several treatments, offered independently in patients' homes and supervised from a distance: adapted physical activity only, cognitive stimulation only, and adapted physical activity coupled with cognitive stimulation (during separate sessions). The study will therefore be the first to include a group benefiting from these two management methods, which will make it possible to assess the individual benefit of cognitive stimulation sessions and adapted physical activity but also the benefit of combined sessions.As this type of combined management has never been the subject of a study, and previous studies relating to a single type of management having raised patient adhesion difficulties, it does not seem certain that this type of care is feasible in practice. Before studying its effectiveness, it is therefore essential to check the feasibility and acceptability of such a program combining sessions of adapted physical activity and cognitive stimulation sessions.Investigator will therefore first carry out a feasibility study, longitudinal and monocentric, which will assess the adherence of patients treated for breast cancer to the performance of cognitive stimulation sessions coupled with sessions of adapted physical activity.This feasibility study is a key stage of the Cog-Stim protocol because its results will probably highlight the obstacles to the intervention program, which will allow the investigator to propose adjustments to improve the study design for the following stages of the protocol. (design optimization).

Inclusion Criteria:

• Patient aged over 18,
• Patient with localized breast cancer, starting or receiving adjuvant radiotherapy , having or not receiving previous adjuvant chemotherapy, not yet having started hormone therapy,
• Patient with a cognitive complaint having a significant impact on her quality of life (FACT
• Cog questionnaire, QoL score ≤ percentile 10 by age),
• Absence of major cognitive impairment preventing the performance of cognitive tests (compliance with the MoCA score threshold according to the age and educational level of the patient according to GRECOGVASC standards)
• Absence of personality disorders and known progressive psychiatric pathology (e.g. schizophrenia),
• Absence of symptomatic neurological history (neurological sequelae of a head trauma, stroke with loss of consciousness> 30 min, multiple sclerosis, epilepsy, neurodegenerative pathology, etc.),
• Patient with level of education 3 "end of primary education" minimum (Barbizet scale),
• Have access to a computer (fixed or portable) equipped with a keyboard, a webcam (or the possibility of connecting one), headphones or speakers; have an internet connection and an e-mail account; be able to use these tools and Equipment,
• Mastery of the French language,
• Patient who signed the consent to participate in the study.
• Patients should start the study during radiation therapy.

Exclusion Criteria:

• Abuse of alcohol or drug use,
• Severe visual and / or hearing loss,
• Patient unable to respond to cognitive tests,
• Medical contraindication to the practice of adapted physical activity
• Cognitive management in progress,
• Patient's refusal to participate,
• Patient deprived of liberty or under guardianship,
• Patient unable to submit to study monitoring for geographic, social or psychopathological reasons.