Please select the eligibility criteria that correspond to the clinical trial below.
Title: N/A
Brief Summary: A recent meta-analysis that included over 29.000 individuals found that the odds ratio (OR) of individuals with high brain reserve compared to low was 0.54 (p \< 0.0001), a risk decrease of 46%. Among the factors that influence cognitive reserve, mentally stimulating activities was the most robust factor after controlling for education, age, occupation and other potential confounds. The brain reserve effect was sustained over a median longitudinal follow-up of 7 years. It would be interesting to detect whether a complex cognitive training could show similar effects on the cognitive abilities of patients with mild Alzheimer's disease (AD) and mild cognitive impairment (MCI) as it has been reported in previous studies based on mentally stimulating activities analysis.

The hypothesis is that a complex cognitive training alters the neural networks in both subject groups and this alteration is associated with improvement or stabilization of cognitive and non-cognitive function.

The investigator will perform a complex cognitive training program. Twenty patients with mild AD and twenty four patients with MCI will be recruited in this study. The patients will be randomised in control- and treatment groups.Additionally indirect effects on non-cognitive functions will be evaluated in caregivers of the patients.

The investigators expect that the cognitive and non-cognitive abilities will be changed during the cognitive training. The investigators also expect differences between treatment and control groups.


Options:
A: Inclusion Criteria:

* community-dwelling volunteers aged 60 years or older
* without dementia
* MMSE=26 or above

Exclusion Criteria:

* if they had known dementia or significant cognitive impairment accompanied by dysfunction of daily living activities;
* had 6 years of education or under;
* were illiterate
* were unavailable during the testing and intervention periods of the study;
* had severe losses in vision or hearing; had major neurological or psychiatric illness history including any history of stroke, transient ischemic attack or traumatic brain injury;
* had a medication history which might affect on cognitive function such as acetylcholinesterase inhibitor or memantine
* had medical problems such as thyroid, liver and renal disease;
* had a significan structural abnormalities on their baseline brain MRI.
B: Inclusion Criteria:

1. At least 60 years of age
2. Self-reported levels of proficiency in English (French for Montreal site only) for speaking and understanding spoken language.
3. Able to comply with scheduled visits, treatment plan, and other trial procedures
4. Able to ambulate at least 10 meters independently
5. Having MCI operationalized using Albert et al. criteria as:

   * objective cognitive impairment in one of the following four cognitive domains: memory, executive function, attention, and language evaluated by the Montreal Cognitive Assessment (MoCA) test with scores ranging from 13-24/30.
   * Preserved activities of daily living on the disability scale confirmed by clinician interview
6. Having normal or corrected to normal vision in at least one eye so that they can identify symbols and stimuli presented on a computer screen in front of them.
7. Must be in sufficient health to participate in the study's aerobic-based exercise training program, based on medical history, vital signs, physical examination by study physicians, or written recommendation by family physician indicating one's appropriateness to participate in aerobic-based exercise training program.

Exclusion Criteria:

1. Serious underlying disease (such as active cancer, or recent heart attack) which, in the opinion of the investigator, may preclude engagement in interventions or may interfere with the participant's ability to participate fully in the study.
2. Diagnosis of dementia using criteria from the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition.
3. Participant with uncontrolled major depression, schizophrenia, severe anxiety and substance abuse.
4. Current parkinsonism or any neurological disorder with residual motor deficits (e.g. stroke with motor deficit), active musculo-skeletal disorders (e.g. severe osteoarthritis of lower limbs) or history of knee/hip replacement affecting gait performance at clinical evaluation.
5. Intention to enroll in other clinical trials during the same time period
6. Pre-existing exercise structured training program involving aerobic or resistance training in previous 6 months.
7. Taking cognitive enhancers, neuroleptics, anticholinergics or Vitamin D3 in doses more than 1000IU/day or equivalent.
C: Inclusion Criteria:

* Mini-Mental State Examination (MMSE) score 26 or greater
* Global Deterioration Scale (GDS) score less than 5
* Independent living
* Normal or correct to normal vision and hearing

Exclusion Criteria:

* Diagnosis of dementia
* Planned move from study area
* Inability to complete study activities
* Scores lower than inclusion criteria requirements
* Communication problems.
D: Inclusion Criteria:

* Male or female patients aged ≥ 55 years, fulfilling criteria of the National Institute of Neurological and Communicative Disease and Stroke (NINCDS) and the Alzheimer's Disease and Related Disorders Association (ADRDA) for the diagnosis of clinically probable AD or Petersen's criteria of mild cognitive impairment (MCI)
* No evidence for other psychiatric axis I disorders according to DSM-IV criteria
* No uncontrolled arterial hypertension or diabetes mellitus
* No history of drug/alcohol abuse
* Cholinesterase inhibitors or Memantine must have been in a stabile doses at least 2 moths in AD subject group prior to the Baseline
* The patient is able to provide written informed consent to participate in the study. If, at investigator's discretion, a patient is considered not to be capable to give legal consent, then written consent must also be obtained from the patient's legally acceptable representative.

Exclusion Criteria:

* Evidence for other psychiatric axis I disorders according to DSM-IV criteria
* Uncontrolled arterial hypertension or diabetes mellitus
* History of drug/alcohol abuse
* No ability to participate and no willing to give informed consent and comply with the study restrictions

Answer: D