ISSN: 2167-0277
Yi-jun Ge, Lan Xia, Fang Wang and Gui-hai Chen
Objective: To explore changes of procedural memory in the patients with primary insomnia (PI) and itscharacteristics.
Methods: Thirty-six PI patients and 36 controls were enrolled. The procedural memory was respectivelydetected by category exemplar generation and motor sequence tasks respectively, and the declarative memory wasassessed by free word task.
Results: Compared to the controls, the PI patients showed few correct numbers in the category exemplargeneration (7.7 ± 2.1 vs. 9.9 ± 1.0, z = 5.247, P<0.001), motion sequence task (8.1 ± 3.3 vs 12.0 ± 3.0, z = 4.676, P<0.001) and the phases of immediate recall (3.3 ± 1.1 vs 6.0 ± 1.2, z=6.634, P<0.001), delayed recall (9.0 ± 2.2 vs. 11.2 ± 1.1, z=4.718, P<0.001) and delayed recognition (14.2 ± 1.0 vs. 15.0 ±0.0, z = 4.637, P<0.001) of the free word task. For the different subtypes of PI, the early morning awakening group had significantly worse performance in the motor sequence task compared to the difficulty initiating sleep (z=–2.768, P=0.006) and difficulty maintaining sleep (z=–2.502, P=0.012) groups, and less correct numbers of the word-delayed recognition compared to the difficulty maintaining sleep group too (z=–2.707, P=0.007).
Conclusion: The procedural and declarative memories are impaired in the PI patients, especially the early morning awakening insomniacs.