Idiopathic nondementing Parkinson’s disease (PD) is marked by progressive loss of dopaminergic neurons in the substantia nigra pars compacta and ventral tegmental area. Recent brain imaging work implicates these stru...Idiopathic nondementing Parkinson’s disease (PD) is marked by progressive loss of dopaminergic neurons in the substantia nigra pars compacta and ventral tegmental area. Recent brain imaging work implicates these structures in dopamine modulated networks subserving episodic memory. These findings are of relevance to PD because they suggest that dopamine depletion contributes to the disease-dependent decline in episodic memory, and therefore, this decline should, at least partially, be remediated by dopaminergic medication. Recognition memory (RM), recollection and familiarity during recognition was examined in 17 PD patients, 12 of whom were medicated with a D2 dopamine agonist (pramipexole or ropinirole) and l-dopa, with a further 5 PD control patients on l-dopa but no D2 agonist. Memory was tested “ON” and, following a period of medication withdrawal, “OFF” and compared to a group of 14 matched healthy volunteers (HV). The HVs were also tested twice in the absence of medication. The patients on the agonists PD showed significant impairments in recollection ON- and OFF-medication, whereas the l-dopa control patients exhibited a decline in OFF-recollection only. RM and familiarity were spared in both groups ON- and OFF-medication. These findings suggest that D2 dopamine agonists (combined with l-dopa) contribute to disease-dependent episodic memory impairment.展开更多
Several investigations have shown that emotional events show superior recall than non-emotional ones. However, the cortical mechanisms underlying the episodic recall of emotional scenes are still poorly understood. Ou...Several investigations have shown that emotional events show superior recall than non-emotional ones. However, the cortical mechanisms underlying the episodic recall of emotional scenes are still poorly understood. Our main aim was to compare the magnitude of the Event-Related brain Potentials (ERP) old-new effect related to emotionally unpleasant, pleasant and neutral photographic images. As expected, correct recognition of all types of images elicited three topographically distinct ERP components sensitive to the classical old-new recognition effect. The results revealed that the behavioral performances were mainly sensitive to arousal, while the ERP old/new effect over posterior regions (300 - 1000 ms) was exclusively affected by unpleasantness. A later component (1000 - 1400 ms) showed an inverted old/ new effect at parietal sites, which was also sensitive to unpleasantness. These results imply that ERP reflecting episodic conscious recollection and post-retrieval monitoring are clearly affected both by valence and arousal.展开更多
Objective:To investigate gender difference in the effects of daytime sleep on item and source memories,which are dissociable elements of declarative memory,and the effects of sleep on recollection and familiarity,whic...Objective:To investigate gender difference in the effects of daytime sleep on item and source memories,which are dissociable elements of declarative memory,and the effects of sleep on recollection and familiarity,which are two processes underlying recognition. Methods:Participants saw a series of pictures with either blue or red background,and were then given a pretest for item and source memories. Then males and females respectively were randomly assigned either to a wake or a sleep condition. In the wake condition,participants remained awake until the posttest;in the sleep condition,participants slept for 1 h until awakened and asked to remain awake until the posttest. Results:Daytime sleep contributed to retention of source memory rather than item memory in females,whereas males undergoing daytime sleep had a trend towards increased familiarity. For females,however,neither recollection nor familiarity appeared to be influenced by daytime sleep. Conclusion:The mechanism underlying gender difference may be linked with different memory traces resulting from different encoding strategies,as well as with different electrophysiological changes during daytime sleep.展开更多
文摘Idiopathic nondementing Parkinson’s disease (PD) is marked by progressive loss of dopaminergic neurons in the substantia nigra pars compacta and ventral tegmental area. Recent brain imaging work implicates these structures in dopamine modulated networks subserving episodic memory. These findings are of relevance to PD because they suggest that dopamine depletion contributes to the disease-dependent decline in episodic memory, and therefore, this decline should, at least partially, be remediated by dopaminergic medication. Recognition memory (RM), recollection and familiarity during recognition was examined in 17 PD patients, 12 of whom were medicated with a D2 dopamine agonist (pramipexole or ropinirole) and l-dopa, with a further 5 PD control patients on l-dopa but no D2 agonist. Memory was tested “ON” and, following a period of medication withdrawal, “OFF” and compared to a group of 14 matched healthy volunteers (HV). The HVs were also tested twice in the absence of medication. The patients on the agonists PD showed significant impairments in recollection ON- and OFF-medication, whereas the l-dopa control patients exhibited a decline in OFF-recollection only. RM and familiarity were spared in both groups ON- and OFF-medication. These findings suggest that D2 dopamine agonists (combined with l-dopa) contribute to disease-dependent episodic memory impairment.
文摘Several investigations have shown that emotional events show superior recall than non-emotional ones. However, the cortical mechanisms underlying the episodic recall of emotional scenes are still poorly understood. Our main aim was to compare the magnitude of the Event-Related brain Potentials (ERP) old-new effect related to emotionally unpleasant, pleasant and neutral photographic images. As expected, correct recognition of all types of images elicited three topographically distinct ERP components sensitive to the classical old-new recognition effect. The results revealed that the behavioral performances were mainly sensitive to arousal, while the ERP old/new effect over posterior regions (300 - 1000 ms) was exclusively affected by unpleasantness. A later component (1000 - 1400 ms) showed an inverted old/ new effect at parietal sites, which was also sensitive to unpleasantness. These results imply that ERP reflecting episodic conscious recollection and post-retrieval monitoring are clearly affected both by valence and arousal.
基金supported partially by the National Basic Research Program (973) of China (No. 2006CB303101)the National Natural Science Foundation of China (No. 90820305)
文摘Objective:To investigate gender difference in the effects of daytime sleep on item and source memories,which are dissociable elements of declarative memory,and the effects of sleep on recollection and familiarity,which are two processes underlying recognition. Methods:Participants saw a series of pictures with either blue or red background,and were then given a pretest for item and source memories. Then males and females respectively were randomly assigned either to a wake or a sleep condition. In the wake condition,participants remained awake until the posttest;in the sleep condition,participants slept for 1 h until awakened and asked to remain awake until the posttest. Results:Daytime sleep contributed to retention of source memory rather than item memory in females,whereas males undergoing daytime sleep had a trend towards increased familiarity. For females,however,neither recollection nor familiarity appeared to be influenced by daytime sleep. Conclusion:The mechanism underlying gender difference may be linked with different memory traces resulting from different encoding strategies,as well as with different electrophysiological changes during daytime sleep.
