Propranolol reduces emotional distraction in working memory: A partial mediating role of propranolol-induced cortisol increases?

Noradrenalin modulates prefrontal function, such as working memory (WM), and is associated with enhanced distractibility, and enhanced memory for emotional events and stimuli. The beta-blocker propranolol has been shown to reduce memory for emotional stimuli. Herein we describe investigations aimed at assessing whether the administration of propranolol would reduce the interference by emotional distractions during WM performance. In a between-subjects design, 48 young, healthy men received 80 mg propranolol (n = 25) or placebo (n = 23), before performing an “emotional Sternberg task” with neutral and negatively arousing distracters. Compared to placebo, propranolol impaired WM at low load, however, it also reduced the interference by emotional distracters at high load. Furthermore, an explorative moderated-mediation analysis indicated that the observed propranolol effects on emotional distraction were partially mediated by cortisol. In future non-clinical and clinical memory studies using propranolol administration, cortisol elevations should be monitored to further investigate the potential mediating role of cortisol.     

Brief,pre-retrieval stress differentially influences long-term memory depending on sex and corticosteroid response

Previous work has indicated that stress generally impairs memory retrieval. However, little research has addressed discrepancies that exist in this line of work and the factors that could explain why stress can exert differential effects on retrieval processes. Therefore, we examined the influence of brief, pre-retrieval stress that was administered immediately before testing on long-term memory in males and females. Participants learned a list of 42 words varying in emotional valence and arousal. Following the learning phase, participants were given an immediate free recall test. Twenty-four hours later, participants submerged their non-dominant hand in a bath of ice cold (Stress) or warm (No Stress) water for 3 min. Immediately following this manipulation, participants’ memory for the word list was assessed via free recall and recognition tests. We observed no group differences on short-term memory. However, male participants who showed a robust cortisol response to the stress exhibited enhanced long-term recognition memory, while male participants who demonstrated a blunted cortisol response to the stress exhibited impaired long-term recall and recognition memory. These findings suggest that the effects of brief, pre-retrieval stress on long-term memory are sex-specific and mediated by corticosteroid mechanisms.     

The influence of cognitive and emotional suppression on overgeneral autobiographical memory retrieval

Over-general autobiographical memory (OAM) retrieval is characterized by retrieval of categoric autobiographical memories. According to the CarFAX model, this tendency may result from avoidance which functions to protect the person against recalling details of upsetting memories. This study tested whether avoidance strategies impact on the ability to retrieve specific autobiographical memories. Healthy participants (N = 51) watched a negative video clip and were instructed to either suppress any thought (thought suppression), suppress any feeling (emotional inhibition), or think and feel naturally (controls) in response to the video. Participants then completed the Autobiographical Memory Test. Participants engaging in either thought suppression or emotional inhibition retrieved fewer categoric autobiographical memories than controls. These findings challenge the affect regulation component of the CarFAX model insofar as they suggest that regulatory strategies that aim to reduce awareness of adverse emotional memories do not necessarily lead to increased recall of categoric autobiographical memories.     

Acute effects of alcohol on memory: Impact of emotional context and serial position

Although the amnestic effects of alcohol in humans are well known, its effects on emotional memory are unclear. In this study, using a randomized double-blind placebo-controlled design, we examine narrative emotional episodic memory in healthy human female volunteers (n = 32) who received either a single dose of alcohol (0.6 g/kg), or a placebo and then viewed neutral story elements presented in either a neutral or emotional context. Memory was tested for gist and detail of the neutral elements 3 days later in a surprise recognition test. Since alcohol modulates GABAergic neurotransmission and may exert its effects on emotion through the limbic system, we predicted that acute alcohol treatment would reduce the expected emotional memory-advantage for gist, leaving detail memory relatively unaffected. Furthermore, given previous findings showing that ‘primacy’ memory is enhanced by physiological arousal, we predicted that reduced arousal produced by alcohol would have the opposite effect and impair primacy memory relative to the middle or ‘recency’ sections of the narrative. Emotional arousal was expected to oppose this effect, so impaired primacy memory following alcohol was only expected in the neutral version of the narrative. Although there was a main effect of story phase (though not of story version), contrary to expectations, alcohol impaired primacy memory for emotionally encoded neutral material. The results suggest that under certain circumstances emotional context or physiological arousal make memories labile and susceptible to disruption through pharmacological manipulation during encoding.     

Effects of oral cortisol treatment in healthy young women on memory retrieval of negative and neutral words

Studies in rodents have demonstrated that glucocorticoids enhance memory consolidation but impair delayed memory retrieval. Similar findings have been reported in humans. Emotional items are better remembered than neutral items. However, it is unknown if emotional valence influences the effects of cortisol on retrieval. In this double-blind crossover study, 16 healthy women learned a wordlist containing 15 neutral and 15 negative words. Delayed recall was tested 5h later. Cortisol administered before recall testing significantly reduced retrieval (p<.01). Exploratory follow-up analysis revealed that cortisol significantly impaired retrieval of negative words (p<.01), while having no significant effect on neutral words (p=.47). The current findings could suggest that emotional material is especially sensitive to the memory modulating effects of stress hormones.     

Self-grounding visual,auditory and olfactory autobiographical memories

Given that autobiographical memory provides a cognitive foundation for the self, we investigated the relative importance of visual, auditory and olfactory autobiographical memories for the self. Thirty subjects, with a mean age of 35.4 years, participated in a study involving a three × three within-subject design containing nine different types of autobiographical memory cues: pictures, sounds and odors presented with neutral, positive and negative valences. It was shown that visual compared to auditory and olfactory autobiographical memories involved higher cognitive and emotional constituents for the self. Furthermore, there was a trend showing positive autobiographical memories to increase their proportion to both cognitive and emotional components of the self, from olfactory to auditory to visually cued autobiographical memories; but, yielding a reverse trend for negative autobiographical memories. Finally, and independently of modality, positive affective states were shown to be more involved in autobiographical memory than negative ones.     

Impaired retention is responsible for temporal order memory deficits in mild cognitive impairment

Temporal order memory, or remembering the order of events, is critical for everyday functioning and is difficult for patients with mild cognitive impairment (MCI). It is currently unclear whether these patients have difficulty acquiring and/or retaining such information and whether deficits in these patients are in excess of “normal” age-related declines. Therefore, the current study examined age and disease-related changes in temporal order memory as well as whether memory load played a role in such changes. Young controls (n = 25), older controls (n = 34), and MCI patients (n = 32) completed an experimental task that required the reconstruction of sequences that were 3, 4, or 5 items in length both immediately after presentation (i.e., immediate recall) and again after a 10-min delay (i.e., delayed recall). During the immediate recall phase, there was an effect of age largely due to reduced performance at the two longest span lengths. Older controls and MCI patients only differed during the five span (controls > MCI). During the delayed recall, however, there were significant effects of both age and MCI regardless of span length. In MCI patients, immediate recall was significantly correlated with measures of executive functioning, whereas delayed recall performance was only related to other memory tests. These findings suggest that MCI patients experience initial temporal order memory deficits at the point when information begins to exceed working memory capacity and become dependent on medial temporal lobe functioning. Longer-term deficits are due to an inability to retain information, consistent with the characteristic medial temporal lobe dysfunction in MCI.     

Relations between emotion,memory, and attention: Evidence from taboo Stroop,lexical decision,and immediate memory tasks

This article reports five experiments demonstrating theoretically coherent effects of emotion on memory and attention. Experiments 1-3 demonstrated three taboo Stroop effects that occur when people name the color of taboo words. One effect is longer color-naming times for taboo than for neutral words, an effect that diminishes with word repetition. The second effect is superior recall of taboo words in surprise memory tests following color naming. The third effect is better recognition memory for colors consistently associated with taboo words rather than with neutral words. None of these effects was due to retrieval factors, attentional disengagement processes, response inhibition, or strategic attention shifts. Experiments 4 and 5 demonstrated that taboo words impair immediate recall of the preceding and succeeding words in rapidly presented lists but do not impair lexical decision times. We argue that taboo words trigger specific emotional reactions that facilitate the binding of taboo word meaning to salient contextual aspects, such as occurrence in a task and font color in taboo Stroop tasks.     

Immediate recall influences the effects of pre-encoding stress on emotional episodic long-term memory consolidation in healthy young men

The stress-associated activation of the hypothalamus-pituitary-adrenal axis influences memory. Several studies have supported the notion that post-learning stress enhances memory consolidation, while pre-retrieval stress impairs retrieval. Findings regarding the effects of pre-encoding stress, in contrast, have been rather inconsistent. In the current two studies, the impact of an immediate retrieval task on these effects was explored. In the first study, 24 healthy young male participants were exposed to a psychosocial laboratory stressor (Trier Social Stress Test) or a control condition before viewing positive, negative, and neutral photographs, which were accompanied by a brief narrative. Immediate as well as delayed (24?h later) free recall was assessed. Stress was expected to enhance emotional long-term memory without affecting immediate recall performance. Stress caused a significant increase in salivary cortisol concentrations but had no significant effects on immediate or delayed retrieval performance, even though a trend toward poorer memory of the stress group was apparent. Based on these findings, the second experiment tested the hypothesis that the beneficial effects of stress on emotional long-term memory performance might be abolished by an immediate recall test. In the second study (n?=?32), the same design was used, except for the omission of the immediate retrieval test. This time stressed participants recalled significantly more negative photographs compared to the control group. The present study indicates that an immediate retrieval attempt of material studied after stress exposure can prevent or even reverse the beneficial effects of pre-encoding stress on emotional long-term memory consolidation.     

Psychosocial stress impairs working memory at high loads: an association with cortisol levels and memory retrieval

Stress and cortisol are known to impair memory retrieval of well-consolidated declarative material. The effects of cortisol on memory retrieval may in particular be due to glucocorticoid (GC) receptors in the hippocampus and prefrontal cortex (PFC). Therefore, effects of stress and cortisol should be observable on both hippocampal-dependent declarative memory retrieval and PFC-dependent working memory (WM). In the present study, it was tested whether psychosocial stress would impair both WM and memory retrieval in 20 young healthy men. In addition, the association between cortisol levels and cognitive performance was assessed. It was found that stress impaired WM at high loads, but not at low loads in a Sternberg paradigm. High cortisol levels at the time of testing were associated with slow WM performance at high loads, and with impaired recall of moderately emotional, but not of highly emotional paragraphs. Furthermore, performance at high WM loads was associated with memory retrieval. These data extend previous results of pharmacological studies in finding WM impairments after acute stress at high workloads and cortisol-related retrieval impairments.     

Tâche d’évaluation de la mémoire autobiographique (TEMA) adaptée à l’enfant

IntroductionResearch on depression in children (Vrielynck, Deplus & Philippot, 2007) has documented that an overgeneral memory in autobiographical recall constitutes a vulnerability factor for affective disorders. Until now, no valid and reliable instrument in French was available to measure this variable in school-age children.ObjectiveThe objective of the study was to develop an instrument for the evaluation of the generality of the autobiographical memory recall in French speaking school-age children (7–13 years). This instrument is based on the task generally used with adults, the Autobiographical Memory Test (AMT; Williams & Broadbent, 1986).MethodIn the first study, a corpus of cue words for the Tâche d’Evaluation de la Mémoire Autobiographique (TEMA) adapted for children was selected. Forty French words were judged by 221 children between 7 and 13 years on features which could impact on the specificity and emotional valence of the memories recalled (familiarity and comprehension of the word, visual imagineability, emotional assessment). In the second study, this tool was proposed to a sample of 149 children between 7 and 13 years.Results and conclusionThe between-judges reliability was comparable to the adult version of the test. The lack of stability of measured variables after 8 to 12 months is discussed in relationship with age-related developments in autobiographical memory. At last, norms are provided with respect to the emotional valence of the recalled memory and to age.     

Remembering events related to close relationships,self-growth,and helping others: Intrinsic autobiographical memories,need satisfaction,and well-being

The present research examined the relationships between memories with intrinsic versus non-intrinsic themes, need satisfaction, and well-being. In Study 1, participants (n = 244) who included intrinsic themes when asked to describe an autobiographical memory reported greater well-being than participants who did not. The degree of need satisfaction characterizing these memories mediated the relationship between intrinsic memories and well-being. In Study 2, participants (n = 126) were assigned to describe a memory characterized by intrinsic (e.g., helping others) or extrinsic (e.g., popularity) values. Need satisfaction characterizing the intrinsic, but not extrinsic, memories, was associated with well-being. Describing an intrinsic (but not an extrinsic) memory positively increased situational well-being. Need satisfaction in the intrinsic memories predicted the subsequent increase in well-being.     

Dissociating the two faces of selective memory retrieval

Research in the past four decades has repeatedly shown that selective retrieval of some (non-target) memories can impair subsequent retrieval of other (target) information, a finding known as retrieval-induced forgetting. More recently, however, there is evidence that selective retrieval can both impair and enhance recall of related memories (K-H. T. Bäuml & Samenieh, 2010). To identify possible experimental dissociations between the detrimental and the beneficial effects of memory retrieval, we examined retrieval dynamics in listwise directed forgetting, varying the delay between preceding non-target and subsequent target recall. When target recall immediately followed non-target recall, we replicated the prior work and found detrimental effects of memory retrieval on to-be-remembered items but beneficial effects on to-be-forgotten items. In contrast, when a delay was introduced between non-target and target recall, the detrimental effects were present but the beneficial effects were absent. The results demonstrate a first experimental dissociation between the two effects of memory retrieval. They are consistent with a recent two-factor account of the two faces of selective memory retrieval.     

Stress administered prior to encoding impairs neutral but enhances emotional long-term episodic memories

Stressful events frequently comprise both neutral and emotionally arousing information, yet the impact of stress on emotional and neutral events is still not fully understood. The hippocampus and frontal cortex have dense concentrations of receptors for stress hormones, such as cortisol, which at high levels can impair performance on hippocampally dependent memory tasks. Yet, the same stress hormones can facilitate memory for emotional information, which involves interactions between the hippocampus and amygdala. Here, we induced psychosocial stress prior to encoding and examined its long-term effects on memory for emotional and neutral episodes. The stress manipulation disrupted long-term memory for a neutral episode, but facilitated long-term memory for an equivalent emotional episode compared with a control condition. The stress manipulation also increased salivary cortisol, catecholamines as indicated by the presence of alpha-amylase, heart rate, and subjectively reported stress. Stressed subjects reported more false memories than nonstressed control subjects, and these false memories correlated positively with cortisol levels, providing evidence for a relationship between stress and false memory formation. Our results demonstrate that stress, when administered prior to encoding, produces different patterns of long-term remembering for neutral and emotional episodes. These differences likely emerge from differential actions of stress hormones on memory-relevant regions of the brain.     

Dissociating the two faces of selective memory retrieval

Research in the past four decades has repeatedly shown that selective retrieval of some (non-target) memories can impair subsequent retrieval of other (target) information, a finding known as retrieval-induced forgetting. More recently, however, there is evidence that selective retrieval can both impair and enhance recall of related memories (K-H. T. B?uml & Samenieh, 2010). To identify possible experimental dissociations between the detrimental and the beneficial effects of memory retrieval, we examined retrieval dynamics in listwise directed forgetting, varying the delay between preceding non-target and subsequent target recall. When target recall immediately followed non-target recall, we replicated the prior work and found detrimental effects of memory retrieval on to-be-remembered items but beneficial effects on to-be-forgotten items. In contrast, when a delay was introduced between non-target and target recall, the detrimental effects were present but the beneficial effects were absent. The results demonstrate a first experimental dissociation between the two effects of memory retrieval. They are consistent with a recent two-factor account of the two faces of selective memory retrieval.     

Block of glucocorticoid synthesis during re-activation inhibits extinction of an established fear memory

BackgroundThe pharmacology of traumatic memory extinction has not been fully characterized despite its potential as a therapeutic target for established, acquired anxiety disorders, including post-traumatic stress disorder (PTSD). Here we examine the role of endogenous glucocorticoids in traumatic memory extinction.MethodsMale C57BL/6J mice were injected with corticosterone (10 mg/kg, i.p.) or metyrapone (50 mg/kg, s.c.) during re-activation of a contextual fear memory, and compared to vehicle groups (N = 10–12 per group). To ensure that metyrapone was blocking corticosterone synthesis, we measured corticosterone levels following re-activation of a fear memory in metyrapone- and vehicle-treated animals.ResultsCorticosterone administration following extinction trials caused a long-lasting inhibition of the original fear memory trace. In contrast, blockade of corticosteroid synthesis with metyrapone prior to extinction trials enhanced retrieval and prevented extinction of context-dependent fear responses in mice. Further behavioral analysis suggested that the metyrapone enhancement of retrieval and prevention of extinction were not due to non-specific alterations in locomotor or anxiety-like behavior. In addition, the inhibition of extinction by metyrapone was rescued by exogenous administration of corticosterone following extinction trials. Finally, we confirmed that the rise in corticosterone during re-activation of a contextual fear memory was blocked by metyrapone.ConclusionsWe demonstrate that extinction of a classical contextual fear memory is dependent on endogenous glucocorticoid synthesis during re-activation of a fear memory. Our data suggest that decreased glucocorticoids during fear memory re-activation may contribute to the inability to extinguish a fear memory, thus contributing to one of the core symptoms of PTSD.     

The effects of cortisol increase on long-term memory retrieval during and after acute psychosocial stress

In this study the effects of stress-induced cortisol increases on long-term memory retrieval during and after acute psychosocial stress were examined. Seventy male students were exposed to either a psychosocial stress task or to a non-stressful control task. During and after this task, retrieval was tested for idiosyncratic emotionally negative and neutral word pair associations that were learned 1 day or 5 weeks earlier. Within the stress condition, retrieval of negative words, 5 weeks after learning, was impaired both during and after the stress task compared to the control group. Further, during the stress task, when sympathetic activity was enhanced, impaired retrieval of both neutral and emotional words was significantly related to enhanced cortisol response. In contrast, after the stress task, when cortisol levels were still increased but sympathetic activity was low again, no association was found between cortisol increase and retrieval of either neutral or emotional material. These results are in line with the previous animal research showing that when arousal is high, cortisol increase can impair memory retrieval.     

Negative emotion elicited in high school students enhances consolidation of item memory,but not source memory

The study examined the effect of negative emotion on consolidation of both item and source memory. Participants learned words read by either a male or female. Then they watched either a negative or a neutral video clip. Memory tests were carried out either 25 min or 24 h after learning. The study yielded the following findings. First, negative emotion enhanced consolidation of item memory as measured by recognition memory in the 25-min delay, and enhanced consolidation of item memory as measured by free recall in both the 25-min and the 24-h delay. Second, negative emotion had little effect on consolidation of source memory, either in the 25-min or the 24-h delay. These findings provide evidence for the differential effects of negative emotion on item memory and source memory and have implications for using emotion as a strategy to intervene memory consolidation.     

Origins of adolescents’ autobiographical memories

Adolescents (N = 46; M = 12.46 years) who had previously participated in a longitudinal study of autobiographical memory development narrated their early childhood memories, interpreted life events, and completed a family history questionnaire and language assessment. Three distinct components of adolescent memory emerged: (1) age of earliest memory and insight into life events; (2) volume of early memories; and (3) density of specific memories from early childhood. Children's language, self-awareness, and theory of mind during early childhood (19–51 months) all contributed to their memories as adolescents. However, adolescents’ early reminiscing environment was the best single predictor of the age and volume of their early memories and their insight into life events. In contrast, adolescents’ delayed self-recognition and reminiscing in early childhood predicted the density of their early memories. These findings provide partial support for theories of autobiographical memory development.