Episodic memory

Overall, ZT-1 reduced the cognitive impairments produced by scopolamine on tasks measuring attention, working memory, episodic secondary memory, and eye-hand coordination. These findings suggest that ZT-1 may be an effective symptomatic treatment for the cognitive deficits associated with AD. 

Long-term memory then stores and operates on very diverse types of information, and there are many theories as to how the different types of information are represented and organized within it. Research shows that long-term memory operates according to a number of different systems, and researchers disagree as to exactly how it should be divided up. Yet there are some very influential theoretical divisions of long-term memory that are now widely accepted. These are the divisions between procedural memory, episodic memory, and semantic memory. 

Tulving, E., What is episodic memory Current Directions in Psychological Science 2(3), 67-70, 1993. 

Dere, E., Souza-Silva, M. A., Topic, B., Spieler, R. E., Haas, H. L. and Huston, J. P. Histidine-decarboxylase knockout mice show deficient nonreinforced episodic object memory, improved negatively reinforced water-maze performance, and increased neo- and ventro-striatal dopamine turnover. Learn. Mem. 10 510-519, 2003. 

Non-participants, by contrast, made more use of inference about affect or intent for example, that was a play fight because it probably didn t hurt him. In effect, the non-participants more often fall back on general statements about emotion or intention, in place of giving more objective or specific reasons. We also found that the long-term (one week later) interviews with participants shifted them somewhat to the non-participants perspective, presumably as their memories of the specific episode faded. 

Memory deficits are typically the first to appear in Alzheimer s disease. There is a pronounced impairment of explicit long-term memory. This involves subjective memory for events (episodic) and for factual information (semantic). Remote memories are impaired, but less so than recent ones. 

However, another controlled study in Alzheimer s disease patients found only marginal improvements in picture recognition and ratings of word-finding ability (Tariot et al. 1988). No benefits were seen in semantic or episodic memory. Biphasic effects were found on psychomotor activation, with improvements at lower doses and impairments at higher doses. 

Odors are not easily forgotten. The recognition of an odor depends on the original coding activity. When trying to recall an odor, life episodes related to that odor and the ability to label and define the odor enhance odor memory. Visual imagery, by comparison, did not enhance odor memory (Lyman and McDaniel, 1986). 

Episodic memory Inability to recall recent events... 

Tryptophan depletion in healthy volunteers impairs the retrieval of learnt material (Park et al., 1994), an effect probably mediated through a selective impairment of episodic memory consolidation (Riedel et al., 1999 Schmitt et al., 2000). However, tryptophan depletion appears to have no effect on working memory (Riedel et al., 1999) and either no effect or an enhancement of tests of executive function (Park et al., 1994 Schmitt et al., 2000). Thus the abnormality in episodic memory in mood disorders could conceivably be related to an impairment in the 5-HT system, but such an impairment is unlikely to account for the abnormalities in working memory and executive function. Clearly then, changes in consciousness occurring in affective disorders are unlikely to be explainable on the basis of an abnormality in a single neurochemical system. 

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