Striatum and Hippocampus on Different Time Scales (e-Time)

Inclusion Criteria: Huntington's disease gene carriers Patient included in the BioHD protocol Age from 18 to 90 years old Symptomatic patient TFC ≥ 11 UHDRS motor> 5 Native language: French Affiliation to a social security or to another social protection Signature of informed consent • Patients with Alzheimer's disease MMS from 20 to 26 (included) Age: from 60 to 90 years old Native language: French Progressive deterioration of memory reported by patient or caregiver for more than 6 months Profile at RL /RI 16: no significant improvement with indexing Episodic memory disorder isolated or associated with other cognitive disorders MRI: Atrophy of the median temporal lobe Affiliation to a social security or to another social protection Signature of informed consent • Healthy subjects Healthy subject included in the BioHD protocol MMS ≥ 26 Age from 18 to 90 years old Native language: French Affiliation to a social security or to another social protection Signature of informed consent Exclusion Criteria: Huntington's disease gene carriers Intellectual deterioration preventing understanding of the protocol Other dementia than Huntington's disease Patient living alone at home Major depression Patient under legal protection Patient deprived of liberty Pregnant or breastfeeding woman, situation known to the investigator Inability to handle an electronic tablet Patients with Alzheimer's disease Intellectual deterioration preventing understanding of the protocol Patient living alone at home Sudden onset of memory impairment Early onset of the following symptoms: difficulty in walking, convulsions, changes in behavior Focal neurological characteristics including hemiparesis, sensory loss, visual field deficit Early extrapyramidal sign Other dementia than Alzheimer's disease Major depression Cerebrovascular disease Toxic, metabolic or infectious anomaly Patient under legal protection Patient deprived of liberty Pregnant or breastfeeding woman, situation known to the investigator Inability to handle an electronic tablet Healthy subjects Intellectual deterioration preventing understanding of the protocol Known neurological or psychiatric illness Patient under legal protection Subject deprived of liberty Pregnant or breastfeeding woman, situation known to the investigator Inability to handle an electronic tablet