The nature of time-based forgetting in immediate memory

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] The existence of time-based forgetting has been a controversial topic almost as long as memory has been investigated. In recent years there have been strong claims that time-based forgetting does not exist or is only a mediating factor in determining forgetting from other sources. This dissertation investigates these claims. In Chapters 1 and 2 I investigate whether time per se causes forgetting or whether time is a mediating factor for proactive interference. In Chapter 3 I investigate why some researchers do not find an effect of absolute duration of memory retention, given that the passage of time clearly lead to forgetting in Chapters 1 and 2, as well as in earlier work. I find that time per se does lead to forgetting in immediate memory and that some researchers do not observe this forgetting because the method of investigation they use allows long periods of consolidation which protect against time-based loss