Could chatting with AI keep aging brains sharp?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria Stage 1: Feasibility Study Participants must belong to one of the following groups: Healthy younger adults aged 18 to 40 years. Older adults with normal cognitive function aged 65 years or older and a Montreal Cognitive Assessment score of 24 or higher. Older adults with cognitive impairment aged 65 years or older and a Montreal Cognitive Assessment score of 18 to 23. Participants must have completed at least elementary school, corresponding to 6 or more years of education. Participants must be able to read and write Chinese, communicate in Chinese, and understand the study content. Participants must be able to use a tablet or smartphone independently or with assistance from a family member. Participants must have sufficient hearing and vision, with usual corrective devices if needed, to complete the study tasks. Stage 2: Preliminary Efficacy Study Participants must be aged 65 years or older. Participants must be considered at high risk of dementia by meeting at least one of the following conditions: 1. Subjective cognitive decline: A Subjective Cognitive Decline Questionnaire score greater than 7 out of 24. A response of yes to both of the following questions: Compared with your previous usual condition, do you have memory problems? Have your family members or close contacts noticed memory problems compared with your previous condition? Performance within the normal range on standardized cognitive tests, defined as scores no more than 1.5 standard deviations below age- and education-adjusted norms on the Color Trails Test and memory-related assessments. 2. Mild cognitive impairment: A diagnosis of mild cognitive impairment made by a neurologist or psychiatrist according to accepted diagnostic criteria. Evidence of memory performance at least 1.5 standard deviations below age- and education-adjusted normative values on at least one subtest of the Wechsler Memory Scale, Third Edition. 3. Limited social interaction: Living alone, living with a person who cannot provide care, or living with a person who is absent for at least 3 days per week; or A score below 12 on the 6-item Lubben Social Network Scale. 4. Chronic disease: A physician diagnosis of hypertension or diabetes for at least 1 year; and A need for ongoing medication or lifestyle management. Participants must have completed at least elementary school, corresponding to 6 or more years of education. Participants must be able to read and write Chinese, communicate in Chinese, and understand news and study-related content. Participants must be able to use a tablet or smartphone independently or with assistance from a family member. Participants must have sufficient hearing and vision, with usual corrective devices if needed, to complete the conversation and reading tasks. Exclusion Criteria A diagnosis of dementia or a severe neurodegenerative disorder, such as moderate-to-advanced Parkinson disease or Huntington disease. A history of a severe psychiatric disorder, such as schizophrenia or severe bipolar disorder, or current acute psychiatric symptoms that may interfere with understanding or responding during conversations. A major neurological event within the previous 6 months, such as stroke or severe traumatic brain injury, that may substantially affect cognitive or language function. Severe hearing, speech, or language impairment that prevents basic verbal communication, even when assistive devices are used. An acute medical illness, active infection, or any condition considered by a physician to make study participation inappropriate. Inability to complete a 20-minute conversation task or unwillingness to allow collection of interaction data.