Neural correlates of age-related verbal episodic memory decline: A PET study with combined subtraction/correlation analysis

摘要: Using PET, we have determined the neural substrates of age-related verbal episodic memory decline. Twelve young and twelve older healthy volunteers (mean age; 22 59 years, respectively) were scanned while performing encoding retrieval tasks. Retrieval performance was lower in old than subjects. The PET data analyzed using a combined subtraction/correlation approach. Classic subtraction disclosed prefrontal rCBF increases common to both groups, distributed bilaterally during exclusively right-sided retrieval, without between-group differences. correlation analysis between activity subsequent revealed significant correlations for left hippocampal region but right inferior frontal gyrus subjects only. Thus, an task may reflect combination (i) subtle dysfunction, evidenced by more widespread activity-performance (ii) less efficient as unaltered activation pattern (as classic method) despite reduced performance. These exploratory findings suggest aged brain be unable compensate efficiency cortex additional activation.