Why Am I Remembering This Now? Predicting the Occurrence of Involuntary (Spontaneous) Episodic Memories.
ABSTRACT Involuntary episodic memories are memories of events that come to mind spontaneously, that is, with no preceding retrieval attempts. They are common in daily life and observed in a range of clinical disorders in the form of negative, intrusive recollections or flashbacks. However, little is known about their underlying mechanisms. Here we report a series of experiments in which-for the first time-the activation of involuntary memories is controlled and predicted on the basis of manipulations done at encoding. During encoding, participants were presented with pictures of scenes paired with sounds. Both scene and sound could be either unique (derived from a category that was presented only once) or repeated (derived from a category that was presented several times). During retrieval, the participants conducted an attention-demanding sound location task employing sounds from the encoding phase. In addition to the sound location task, they were asked to record all memories that might spontaneously arise during this task. Unique sounds generated most involuntary memories, consistent with the notion of cue overload. Repeated sounds rarely generated involuntary memories, but often yielded memories of repeated scenes in a voluntary (strategic) recall condition. Retrieval times were lower for involuntary than for comparable samples of strategically retrieved memories, suggesting less executive control involved in involuntary recall. Our findings show that it is possible to control the activation of involuntary episodic memories of daily scenes on the basis of well-known mechanisms of associative memory. (PsycINFO Database Record (c) 2012 APA, all rights reserved).
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ABSTRACT: Determining the memory systems that support nonhuman animals' capacity to remember distant past events is currently the focus an intense research effort and a lively debate [1-3]. Comparative psychology has largely adopted Tulving's framework by focusing on whether animals remember what-where-when something happened (i.e., episodic-like memory) [4-6]. However, apes have also been reported to recall other episodic components  after single-trial exposures [8, 9]. Using a new experimental paradigm we show that chimpanzees and orangutans recalled a tool-finding event that happened four times 3 years earlier (experiment 1) and a tool-finding unique event that happened once 2 weeks earlier (experiment 2). Subjects were able to distinguish these events from other tool-finding events, which indicates binding of relevant temporal-spatial components. Like in human involuntary autobiographical memory, a cued, associative retrieval process triggered apes' memories: when presented with a particular setup, subjects instantaneously remembered not only where to search for the tools (experiment 1), but also the location of the tool seen only once (experiment 2). The complex nature of the events retrieved, the unexpected and fast retrieval, the long retention intervals involved, and the detection of binding strongly suggest that chimpanzees and orangutans' memories for past events mirror some of the features of human autobiographical memory.Current biology: CB 07/2013; · 10.99 Impact Factor