Forget about the future: effects of thought suppression on memory for imaginary emotional episodes

Whether intentional suppression of an unpleasant or unwanted memory reduces the ability to recall that memory subsequently is a contested issue in contemporary memory research. Building on findings that similar processes are recruited when individuals remember the past and imagine the future, we measured the effects of thought suppression on memory for imagined future scenarios. Thought suppression reduced the ability to recall emotionally negative scenarios, but not those that were emotionally positive. This finding suggests that intentionally avoiding thoughts about emotionally negative episodes may inhibit representations of those memories, progressively reducing their availability to recall.     

Prospective memory in the rat

The content of prospective memory is comprised of representations of an action to perform in the future. When people form prospective memories, they temporarily put the memory representation in an inactive state while engaging in other activities, and then activate the representation in the future. Ultimately, successful activation of the memory representation yields an action at an appropriate, but temporally distant, time. A hallmark of prospective memory is that activation of the memory representation has a deleterious effect on current ongoing activity. Recent evidence suggests that scrub jays and non-human primates, but not other species, are capable of future planning. We hypothesized that prospective memory produces a selective deficit in performance at the time when rats access a memory representation but not when the memory representation is inactive. Rats were trained in a temporal bisection task (90 min/day). Immediately after the bisection task, half of the rats received an 8-g meal (meal group) and the other rats received no additional food (no-meal group). Sensitivity to time in the bisection task was reduced as the 90-min interval elapsed for the meal group but not for the no-meal group. This time-based prospective-memory effect was not based on response competition, an attentional limit, anticipatory contrast, or fatigue. Our results suggest that rats form prospective memories, which produces a negative side effect on ongoing activity.     

Remembering the past and imagining the future: Differences in event specificity of spontaneously generated thought

A growing interest has emerged in the role that autobiographical memory retrieval plays in simulation of future events. Cognitive explorations in this domain have generally relied on cue word paradigms with instructions to develop specific (relating to one particular day) memories or future events. However, the usefulness of this paradigm has been questioned with respect to its ability to assess habitual patterns of retrieval within autobiographical memory. The current study investigated similarities and differences in how participants spontaneously remember the past and imagine the future when the specificity constraints inherent in the cue word task are removed. A total of 93 undergraduate students completed two sentence-completion tasks, probing for past and future events. A number of differences emerged between past and future thought; in particular, they were less specific when simulating future events compared with past events. This reduction in specificity was the result of participants producing more future thoughts relating to extended lifetime periods and semantic associates. The findings are discussed in relation to the underlying cognitive processes involved in autobiographical memory retrieval and future event simulation.     

Field perspective deficit for positive memories characterizes autobiographical memory in euthymic depressed patients

Research on autobiographical memory (AM) and the ability to retrieve specific autobiographical events in euthymic depressed patients yielded divergent results. The main goal of the present study was to further explore episodic specificity of AM among fully remitted depressed patients. Twenty euthymic depressed patients and 20 matched healthy controls were given a semi-structured interview, which assesses episodic specificity of positive and negative autobiographical memories regarding event and details' specificity, autonoetic consciousness (remember/know procedure) and visual perspective (field/observer procedure). Results showed an impairment of episodic specificity of AM in euthymic depressed patients. This impairment was explained by a field perspective deficit for positive memories only. These results suggest that euthymic patients continue to exhibit discrepancy between their current self and their self for positive past behaviors, which maintains an unfavorable view of their current self. Specific cognitive interventions may improve the self-relevance of their positive memories.     

Personality and mental time travel: a differential approach to autonoetic consciousness

Recent research on autonoetic consciousness indicates that the ability to remember the past and the ability to project oneself into the future are closely related. The purpose of the present study was to confirm this proposition by examining whether the relationship observed between personality and episodic memory could be extended to episodic future thinking and, more generally, to investigate the influence of personality traits on self-information processing in the past and in the future. Results show that Neuroticism and Harm Avoidance predict more negative past memories and future projections. Other personality dimensions exhibit a more limited influence on mental time travel (MTT). Therefore, our study provide an additional evidence to the idea that MTT into the past and into the future rely on a common set of processes by which past experiences are used to envision the future.     

Being the agent: memory for action events

Whoever paid the bill at the restaurant last night, will clearly remember doing it. Independently from the type of action, it is a common experience that being the agent provides a special strength to our memories. Even if it is generally agreed that personal memories (episodic memory) rely on separate neural substrates with respect to general knowledge (semantic memory), little is known on the nature of the link between memory and the sense of agency. In the present paper, we review results from two experiments investigating the effects of agency on both explicit and implicit memory traces. Performance of normal subjects is compared to that of schizophrenic patients in order to explore the role of awareness of action on memory. It is proposed that reliable first-person information is necessary to create a stable and coherent motor memory trace.     

Episodic recollection in animals: “If it walks like a duck and quacks like a duck…”

In humans, episodic memory is most commonly defined as the subjective experience of recollection, presenting a major challenge to the identification of episodic memory in animals. Here we take the position that episodic memory also has several other distinctive qualities that can be assessed objectively in animals, as well as humans, and the examination of these properties provides insights into underlying mechanisms of episodic memory. We focus on recent evidence accumulated in this laboratory indicating that recognition in rats involves a threshold retrieval process, similar to that observed in human episodic recall. Also, rats can remember the temporal order of unique events, characteristic of the replay of vivid episodic memories in humans. Furthermore, rats combine elements of “when” and “where” events occur, as well as the flow of events within a memory, to distinguish memories that share overlapping features, also characteristic of human episodic memory. Finally, all of these capacities are dependent on the hippocampus, which also plays a critical role in human episodic memory. This combination of findings strongly suggests that animals have the same fundamental information processing functions that underlie episodic recall in humans.     

Autobiographical memory, autonoetic consciousness, and self-perspective in aging

In this study, the authors examined the effects of aging on autobiographical memory in 180 participants by means of a new method designed to assess across 5 lifetime periods the nature of memories-that is, specificity and spontaneity--and the phenomenal experience of remembering--that is, self-perspective and autonoetic consciousness--via the field/observer and remember/know paradigms respectively. Age-related differences were found for the specificity and spontaneity of memories and the phenomenal experience of remembering. There was an increase in observer and know responses with age, but a decrease in field and remember responses and in the ability to justify them by recalling sensory-perceptive, affective, or spatiotemporal specific details. This pattern confirms the existence of a semantic-episodic dissociation in autobiographical memory in aging. Moreover, the data support the view that older participants can subjectively "travel back in time" to relive personal events in the most distant past better than those in the recent past.     

错误记忆的来源：编码阶段／保持阶段

错误记忆是人们对未经验过事件或未学过单词的记忆。研究表明,不同实验室研究范式下引发的错误记忆在来源阶段上存在差异。本研究通过同时操纵预警提示和时间间隔两个因素来探讨错误记忆的来源问题。结果发现:关联性错误记忆出现预警效应,但不具有时间效应;误导性错误记忆则恰好相反。可见,关联性错误记忆可能主要发生在编码阶段,而误导性错误记忆则可能主要发生在保持阶段。     

Animals may not be stuck in time

Humans have the ability to mentally travel forward and back in time. They can retrieve vivid memories of past events (episodic memories) and can imagine the future (planning). Although it has been suggested that this is a uniquely human ability, the evidence for subjective time travel in humans is typically based on verbal report and elaboration. Such evidence cannot be obtained from animals. However, we may have indirect evidence for episodic memory and planning. For example, we can show that animals can ‘report’ about their recent past experience when they are unexpectedly asked to do so—performance that is analogous to episodic memory. We can also show that animals use the anticipation of a future event as the basis for a present action—analogous to planning. Thus, we have suggestive evidence that animals may not be stuck in time.     

Bias in memory predicts bias in estimation of future task duration

Both anecdotal accounts and experimental evidence suggest that people underestimate how long it will take them to complete future tasks. A possible reason for this tendency is that people remember tasks as taking less time than they actually did, with these biased memories causing a corresponding bias in prediction. Two experiments were performed to determine whether or not a systematic bias in memory could explain a similar systematic bias in prediction. In support, it was found that (1) the tendency to underestimate future duration disappears when the task is novel, (2) there is similar bias in estimation of both past and future durations, and (3) variables that affect memory of duration, such as level of experience with the task and duration of delay before estimation, affect prediction of duration in the same way. It appears that, at least in part, people underestimate future event duration because they underestimate past event duration.     

Mental time travel after trauma: the specificity and temporal distribution of autobiographical memories and future-directed thoughts

The present study investigated the relationship between trauma exposure and specificity and temporal distribution of autobiographical memories and future-directed thoughts. A group of sexual assault victims were compared with women without previous trauma exposure in relation to specificity of autobiographical memories, as measured by the Autobiographical Memory Task (AMT) and specificity of future-directed thoughts as measured by the Future Cueing Task (FCT). The temporal distribution of future-directed thoughts and autobiographical memories was studied by asking the participants to estimate when each memory reported on the AMT had occurred and when each future event reported on the FCT would occur. The results showed no difference between the trauma group and the controls on specificity of autobiographical memories and future-directed thoughts. In line with a review of Moore and Zoellner (2007), PTSD symptoms as measured by the Impact of Event Scale (IES) correlated negatively with specificity. Furthermore, we observed no difference in temporal distribution of future-directed thoughts or autobiographical memories between trauma exposed participants and controls.     

How we have fallen: implicit trajectories in collective temporal thought

ABSTRACT

Memory may play a critical role in the ability to imagine events in the future. While most work on this relation has concerned episodic memory and simulated episodic events in the future, the current study examines how collective memories relate to imagination for the collective future. Two thousand American participants provided events for (1) America’s origins, (2) normative events that all Americans should remember, and (3) events in America’s future. Each event was rated for emotional valence. Whereas collective memories – particularly origin events – showed pronounced positivity biases, there was a negativity bias in collective future thought, indicating an implicit trajectory of decline in Americans’ representations of their nation across time. Imagination for the social future may not be simulated based on the template of collective memories, but may rather relate to the past in a way that is mediated by cultural narrative schemata.     

Mental time travel after trauma: The specificity and temporal distribution of autobiographical memories and future-directed thoughts

The present study investigated the relationship between trauma exposure and specificity and temporal distribution of autobiographical memories and future-directed thoughts. A group of sexual assault victims were compared with women without previous trauma exposure in relation to specificity of autobiographical memories, as measured by the Autobiographical Memory Task (AMT) and specificity of future-directed thoughts as measured by the Future Cueing Task (FCT). The temporal distribution of future-directed thoughts and autobiographical memories was studied by asking the participants to estimate when each memory reported on the AMT had occurred and when each future event reported on the FCT would occur. The results showed no difference between the trauma group and the controls on specificity of autobiographical memories and future-directed thoughts. In line with a review of Moore and Zoellner (2007), PTSD symptoms as measured by the Impact of Event Scale (IES) correlated negatively with specificity. Furthermore, we observed no difference in temporal distribution of future-directed thoughts or autobiographical memories between trauma exposed participants and controls.     

A sham drug improves a demanding prospective memory task

Every day, people rely on prospective memory—our ability to remember to perform a future action—to carry out myriad tasks. We examined how a sham cognitive enhancing drug might improve people's performance on a prospective memory task. We gave some people (but not others) the sham drug, and asked everyone to perform a high-effort prospective memory task. People who received the sham drug performed better on the prospective memory task. They also took longer to perform their ongoing task, suggesting that they increased their effortful monitoring. These results fit with research showing that suggestions can lead people to increase cognitive effort and increase memory performance.     

An analysis of rat prefrontal cortex in mediating executive function

While it is acknowledged that species specific differences are an implicit condition of comparative studies, rodent models of prefrontal function serve a significant role in the acquisition of converging evidence on prefrontal function across levels of analysis and research techniques. The purpose of the present review is to examine whether the prefrontal cortex (PFC) in rats supports a variety of processes associated with executive function including working memory, temporal processing, planning (prospective coding), flexibility, rule learning, and decision making. Therefore, in this review we examined changes associated with working memory processes for spatial locations, visual objects, odors, tastes, and response domains or attributes, temporal processes including temporal order, sequence learning, prospective coding, behavioral flexibility associated with reversal learning and set shifting, paired associate learning, and decision making based on effort, time discounting, and uncertainty following damage to the PFC in rats. In addition, potential parallel processes of executive function in monkeys and humans based on several theories of subregional differentiation within the PFC will be presented. Specifically, theories based on domain or attribute specificity (Goldman-Rakic, 1996), level of processing (Petrides, 1996), rule learning based on complexity (Wise, Murray, & Gerfen, 1996), executive functions based on connectivity with other brain regions associated with top-down control (Miller & Cohen, 2001), are presented and applied to PFC function in rats with the aim of understanding subregional specificity in the rat PFC. The data suggest that there is subregional specificity within the PFC of rats, monkey and humans and there are parallel cognitive functions of the different subregions of the PFC in rats, monkeys and humans.     

Cognitive avoidance of intrusive memories and autobiographical memory: specificity, autonoetic consciousness, and self-perspective

Autobiographical memory (AM) specificity is impaired in depression and post-traumatic stress disorder. Previous studies emphasised the role of cognitive avoidance of intrusive memories in this impairment. This study aimed to examine the association of cognitive avoidance of intrusive memories with specificity, autonoetic consciousness, and self-perspective. A total of 38 healthy participants were given the revised Impact of Event Scale (IES-R) and an AM task designed to assess positive and negative memories regarding specificity, autonoetic consciousness (remember/know procedure), and self-perspective (field/observer procedure). Taking into account age, verbal IQ, mood, harm avoidance, and executive resources, the IES-R avoidance subscale was negatively correlated with specificity and remember responses for positive memories, and with remember and field responses for negative memories. These findings suggest that cognitive avoidance of intrusive memories is associated with a decrease of the episodic components of AM retrieval.     

Memories from the cradle

How far back can we, as adults, remember details of our life experiences? Current popular and scientific beliefs are contradictory, with the latter stipulating that personal memories do not begin until the late preschool years (age 4–5 years) and the former claiming that we not only remember being born, but can also remember in utero experiences. In this review, these beliefs are examined in a scientific context and evaluated in terms of empirical data about the development of early memory. The theory proposed here is that memories for personal experiences are not possible until the advent of the cognitive self, around the age of 18 to 24 months. This age is much earlier than that proposed as the age of the earliest memories in other scientific accounts and much later than that proposed in popular beliefs about early memory. New data from a cross-sectional and longitudinal study of early memory development and the emergence of the self clearly show the origins of personal memory coincide with the emergence of the early self.     

The Role of Language in Temporal Cognition in 6- to 10-Year-Old Children

The ability to recognize temporal patterns and position events in time emerges during the preschool years and is refined in middle childhood. This study explored individual differences in temporal cognition in relation to verbal and nonverbal abilities. Children (30 boys, 32 girls; M_age = 8;2, age range = 6;0?10;8) completed 3 temporal-cognition tasks measuring estimation of temporal distance (how far events are from the present), knowledge of conventional times of events (specific days or months of events), and flexibility in using the calendar system (arranging nonconsecutive months in order), along with assessments of nonverbal intelligence, verbal short-term memory, visual-spatial working memory, receptive vocabulary, receptive grammar, and reading mastery. Controlling for age, performance across temporal-cognition tasks correlated with language abilities; nonverbal abilities accounted for little to no additional variance. The findings link language skills with the acquisition of conventional time patterns; such patterns developed alongside the ability to gauge distances of events in the past or future and form an organized timeline.     

Sources of Bias in Memory for Emotions

How accurately can people remember how they felt in the past? Although some investigators hold that emotional memories are resistant to change, we review evidence that current emotions, appraisals, and coping efforts, as well as personality traits, are all associated with bias in recalling past emotions. Bias occurs as memories of emotional states are updated in light of subsequent experience and goals. Biased memories in turn influence future plans and emotions, and may contribute to the formation of enduring personality traits. People's memories for emotions provide highly condensed and accessible summaries of the relevance of past experiences to current goals.