Previous studies about cognitive intervention targeting older adults revealed that cognitive training had effects on the improvement of cognitive function.However, researches are rare that investigated direct changes of brain structures after cognitive training.

The advanced scientific technique allowed us to develop service robots designed to assist human work, which can be important with an increase in the aging population and high costs of elderly care. In this regard, the investigators considered robots for elderly's cognitive training and developed 17 cognitive programs in collaboration with Center for Intelligent Robotics at Korea Institute of Science and Technology.

The purposes of this study were to demonstrate the effects of the investigators newly developed robot assisted group cognitive training programs on the brain in older adults and to identify whether they can help to improve cognitive function or mood in the elderly compared to the conventional cognitive training or control group that were not involved in any cognitive training.

Primary outcome The primary outcome of this study was the change in cortical thickness between the baseline and the post-intervention assessment.

Secondary outcomes Change in the brain functional network from the baseline to the postintervention assessment was also assessed as a secondary outcome ascertained by the analysis of resting state fMRI, which has been used to show correlated spontaneous activity within cortical and subcortical regions that are functionally related.

Further secondary outcomes were changes between the baseline and the post-intervention assessment on cognitive function measured by validated neuropsychological tests such as SNSB and CANTAB on participants' depressive and anxiety symptoms scored by Geriatric Depression Scale and Geriatric Anxiety Inventory respectively, on self reported memory problems measured by Korean Dementia Screenng Questionnaire, Multifactorial Memory Questionnaire and Prospective and Retrospective Memory Questionnaire, on functions of daily living acitivity measured by Bayer ADL, on quality of life measuared by WHOQOL-bref.

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.