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 are 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 functions 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. Keywords: Involuntary episodic memories, intrusive memories, autobiographical memories 2 This article may not exactly replicate the final version published in the APA journal. It is not the copy of record. A definitive version was subsequently published in Journal ofExperimental Psychology: General, 142, 426-444. DOI: 10.1037/a0029128 Why am I Remembering This Now? Predicting the Occurrence of Involuntary (Spontaneous) Episodic MemoriesI was running in the Botanical Garden, while thinking of something I had just read for my psychology class. It was a beautiful spring day with singing of birds,and not many other people out. I ran per routine -and suddenly got a side stitch (which is unusual for me). I then suddenly remembered a day in Hungary, where I was running with my friend from England. I got a severe side stitch, and, through his years in the military, he had learnt some breathing techniques against side stitches, which he then taught me.Most people frequently experience involuntary episodic memories -that is, memories of personal experiences that come to mind with no preceding retrieval attempts, as illustrated by the example of the runner (derived from Berntsen, 2001). During the past 10-15 years an increasing number of studies have examined characteristics of such memories (e.g., Ball & Little, 2006;Berntsen, 1996Berntsen, , 2001Berntsen & Hall, 2004;Kvavilashvili & Mandler, 2004;Mace, 2004;Rubin, Bo...

A threatening facial expression is a potent social sign of hostility or dominance. During the past 20 years, photographs of threatening faces have been increasingly included as stimuli in studies with socially anxious participants, based on the hypothesis that a threatening face is especially salient to people with fears of social interaction or negative evaluation. The purpose of this literature review is to systematically evaluate the accumulated research and suggest possible avenues for further research. The main conclusion is that photographs of threatening faces engage a broad range of perceptual processes in socially anxious participants, particularly when exposure times are very short.

Theories of autobiographical memory distinguish between involuntary and voluntary retrieval as a consequence of conscious intention (i.e., wanting to remember). Another distinction can be made between direct and generative retrieval, which reflects the effort involved (i.e., trying to remember). However, it is unclear how intention and effort interacts. For example, involuntary memories and directly retrieved memories have been used interchangeably in the literature to refer to the same phenomenon of effortless, non-strategic retrieval. More recent theoretical advances suggest that they are separate types of retrieval, one unintentional (involuntary), another intentional and effortless (direct voluntary retrieval), and a third intentional and effortful (generative voluntary retrieval). Whether this also entails differing phenomenological characteristics, such as vividness, rehearsal, or emotional valence, has not been previously investigated. In the current study, participants reported memories in an experimental paradigm designed to elicit voluntary and involuntary memories and rated them on a number of characteristics. If intention affects the retrieval process, then we should expect differences between the characteristics of involuntary and directly retrieved memories. The results imply that retrieval intention seems to differentiate how a memory appears in a person's mind. Furthermore, we argue that these differences in part could result from differences in encoding and consolidation.

Involuntary episodic memories come to mind spontaneously--that is, with no preceding retrieval attempts. Such memories are frequent in daily life, in which they are predominantly positive and often triggered by situational features matching distinctive parts of the memory. However, individuals suffering from psychological disorders, such as posttraumatic stress disorder, have stressful, repetitive, and unwanted involuntary memories about negative events in their past. These unwanted recollections are disturbing and debilitating. Although such intrusive involuntary memories are observed across a range of clinical disorders, there is no broadly agreed upon explanation of their underlying mechanisms and no successful experimental simulations of their retrieval. In a series of experiments, we experimentally manipulated the activation of involuntary episodic memories for emotional and neutral scenes and predicted their activation on the basis of manipulations carried out at encoding and retrieval. Our findings suggest that the interplay between cue discriminability at the time of retrieval and emotional arousal at the time of encoding are crucial for explaining intrusive memories following negative events. While cue distinctiveness is important directly following encoding of the scenes, emotional intensity influences retrieval after delays of 24 hr and 1 week. Voluntary remembering follows the same pattern as involuntary remembering. Our results suggest an explanatory model of intrusive involuntary memory for emotional events in clinical disorders.

Involuntary autobiographical memories come to mind effortlessly and unintended, but the mechanisms of their retrieval are not fully understood. We hypothesize that involuntary retrieval depends on memories that are highly accessible (e.g., intense, unusual, recent, rehearsed), while the elaborate search that characterizes voluntary retrieval also produces memories that are mundane, repeated or distant - memories with low accessibility. Previous research provides some evidence for this 'threshold hypothesis'. However, in almost every prior study, participants have been instructed to report only memories while ignoring other thoughts. It is possible that such an instruction can modify the phenomenological characteristics of involuntary memories. This study aimed to investigate the effects of retrieval intentionality (i.e., wanting to retrieve a memory) and selective monitoring (i.e., instructions to report only memories) on the phenomenology of autobiographical memories. Participants were instructed to (1) intentionally retrieve autobiographical memories, (2) intentionally retrieve any type of thought (3) wait for an autobiographical memory to spontaneously appear, or (4) wait for any type of thought to spontaneously appear. They rated the mental content on a number of phenomenological characteristics both during retrieval and retrospectively following retrieval. The results support the prediction that highly accessible memories mostly enter awareness unintended and without selective monitoring, while memories with low accessibility rely on intention and selective monitoring. We discuss the implications of these effects.