Purpose:　To　compare　the　blood　oxygen　level-dependent　(BOLD)　response,　measured　with　functional　magnetic　resonance　(MR)　imaging,　in　the　posterior　cingulate　cortex　(PCC)　and　adjacent　precuneus　regions　between　healthy　control　subjects　and　patients　with　amnestic　mild　cognitive　impairment　(MCI)　during　problem-solving　tasks.　Materials　and　Methods:　This　study　was　approved　by　the　institutional　review　board.　Each　subject　provided　written　informed　consent.　Thirteen　patients　with　amnestic　MCI　and　13　age-and　sex-matched　healthy　control　subjects　participated　in　the　study.　The　functional　magnetic　resonance　(MR)　imaging　tasks　were　simplified　4　x　4-grid　number　placement　puzzles　that　were　divided　into　a　simple　task　(using　the　row　rule　or　the　column　rule　to　solve　the　puzzle)　and　a　complex　task　(using　both　the　row　and　column　rules　to　solve　the　puzzle).　Behavioral　results　and　functional　imaging　results　between　the　healthy　control　group　and　the　amnestic　MCI　group　were　analyzed.　Results:　The　accuracy　for　the　complex　task　in　the　healthy　control　group　was　significantly　higher　than　that　in　the　amnestic　MCI　group　(P　＜　.05).　The　healthy　control　group　exhibited　a　deactivated　BOLD　signal　intensity　(SI)　change　in　the　bilateral　PCC　and　adjacent　precuneus　regions　during　the　complex　task,　whereas　the　amnestic　MCI　group　showed　activation.　The　positive　linear　correlations　between　the　BOLD　SI　change　in　bilateral　PCC　and　adjacent　precuneus　regions　and　in　bilateral　hippocampi　in　the　amnestic　MCI　group　were　significant　(P　＜　.001),　while　in　the　healthy　control　group,　they　were　not　(P　＞=　.23).　Conclusion:　These　findings　suggest　that　an　altered　BOLD　response　in　amnestic　MCI　patients　during　complex　tasks　might　be　related　to　a　decline　in　problem-solving　ability　and　to　memory　impairment　and,　thus,　may　indicate　a　compensatory　response　to　memory　impairment.　(C)　RSNA,　2011