OBJECTIVE:Although visual memory has been shown to be impaired in amnestic mild cognitive impairment (aMCI), the differences between MCI subtypes are not well defined. The current study attempted to investigate visual memory profiles in different MCI subtypes.
METHODS:One hundred and seventy volunteers aged older than 50 years performed several visual memory tests included in the CANTAB battery. Participants were classified into four groups: (1) multiple domain aMCI (mda-MCI) (32 subjects); (2) single domain aMCI (sda-MCI)(57 subjects); (3) multiple domain non amnestic MCI (mdna-MCI) (32 subjects); and (4) controls (54 healthy individuals without cognitive impairment). Parametric and non parametric analyses were performed to compare the groups and to obtain their corresponding memory profiles.
RESULTS:The mda-MCI group exhibited impairments in both dimensions of episodic memory (recognition and recollection/recall), and also in learning and working memory, whereas the sda-MCI only showed impairment in recollection-delayed recall and learning. The mdna-MCI group displayed impairment in working memory but good preservation of learning and episodic memory.
CONCLUSION:The CANTAB visual memory profiles may contribute to better cognitive characterization of patients with different MCI subtypes, allowing comparison across several processes involved in visual memory such as attention, recognition, recollection and working memory.