Autobiographical Memory Retrieval Research Articles

Effects of cortisol on memory in women with borderline personality disorder: role of co-morbid post-traumatic stress disorder and major depression

Stress and cortisol administration are known to have impairing effects on memory retrieval in healthy humans. These effects are reported to be altered in patients with major depressive disorder (MDD) and post-traumatic stress disorder (PTSD) but they have not yet been investigated in borderline personality disorder (BPD). In a placebo-controlled cross-over study, 71 women with BPD and 40 healthy controls received either placebo or 10 mg of hydrocortisone orally before undertaking a declarative memory retrieval task (word list learning) and an autobiographical memory test (AMT). A working memory test was also applied. Overall, opposing effects of cortisol on memory were observed when comparing patients with controls. In controls, cortisol had impairing effects on memory retrieval whereas in BPD patients cortisol had enhancing effects on memory retrieval of words, autobiographical memory and working memory. These effects were most pronounced for specificity of autobiographical memory retrieval. Patients with BPD alone and those with co-morbid PTSD showed this effect. We also found that co-morbid MDD influenced the cortisol effects: in this subgroup (BPD + MDD) the effects of cortisol on memory were absent. The present results demonstrate beneficial effects of acute cortisol elevations on hippocampal-mediated memory processes in BPD. The absence of these effects in patients with co-morbid MDD suggests that these patients differ from other BPD patients in terms of their sensitivity to glucocorticoids (GCs).

Autobiographical memory in multiple sclerosis patients: Assessment and cognitive facilitation

The multifocal nature of lesions in multiple sclerosis hints at the occurrence of autobiographical memory (AbM) impairment. However, the dearth of studies on AbM in multiple sclerosis is noticeable, notwithstanding the importance of AbM in everyday life. In the first section of this study, 25 multiple sclerosis patients and 35 controls underwent a detailed episodic AbM assessment. Results obtained by means of ANOVA suggested an AbM retrieval deficit in every patient. That pattern of performance paved the way for the second section of the study, in which we followed up 10 out of the 25 patients. Our objective was to assess the effectiveness of a cognitive facilitation programme designed to alleviate AbM retrieval deficits, based on the key role of mental visual imagery on AbM. Statistical group analyses by means of ANOVA and individual analyses using the χ2 test showed significant differences in AbM test results, in post-facilitation relative to pre-facilitation training, in all 10 patients. Moreover, the patients' comments showed that the positive effects were transferred in their daily life functioning. We would like to suggest that the facilitation programme efficiently enhanced the process of self-centred mental visual imagery, which might have compensated for poor retrieval of personal memories by providing better access to visual details and detailed visual scenes of personal recollections.

Neural populations in human posteromedial cortex display opposing responses during memory and numerical processing

Our understanding of the human default mode network derives primarily from neuroimaging data but its electrophysiological correlates remain largely unexplored. To address this limitation, we recorded intracranially from the human posteromedial cortex (PMC), a core structure of the default mode network, during various conditions of internally directed (e.g., autobiographical memory) as opposed to externally directed focus (e.g., arithmetic calculation). We observed late-onset (>400 ms) increases in broad high γ-power (70-180 Hz) within PMC subregions during memory retrieval. High γ-power was significantly reduced or absent when subjects retrieved self-referential semantic memories or responded to self-judgment statements, respectively. Conversely, a significant deactivation of high γ-power was observed during arithmetic calculation, the duration of which correlated with reaction time at the signal-trial level. Strikingly, at each recording site, the magnitude of activation during episodic autobiographical memory retrieval predicted the degree of suppression during arithmetic calculation. These findings provide important anatomical and temporal details-at the neural population level-of PMC engagement during autobiographical memory retrieval and address how the same populations are actively suppressed during tasks, such as numerical processing, which require externally directed attention.

Executive function and emotional focus in autobiographical memory specificity in older adults

The current study examined the role of executive function in retrieval of specific autobiographical memories in older adults with regard to control of emotion during retrieval. Older and younger adults retrieved memories of specific events in response to emotionally positive, negative and neutral word cues. Contributions of inhibitory and updating elements of executive function to variance in autobiographical specificity were assessed to determine processes involved in the commonly found age-related reduction in specificity. A negative relationship between age and specificity was only found in retrieval to neutral cues. Alternative explanations of this age preservation of specificity of emotional recall are explored, within the context of control of emotion in the self-memory system and preserved emotional processing and positivity effect in older adults. The pattern of relationships suggests updating, rather than inhibition, as the source of age-related reduction in specificity, but that emotional processing (particularly of positively valenced memories) is not influenced by age-related variance in executive control. The tendency of older adults to focus on positive material may thus act as a buffer against detrimental effects of reduced executive function capacity on autobiographical retrieval, representing a possible target for interventions to improve specificity of autobiographical memory retrieval in older adults.

Differential effects of arousal in positive and negative autobiographical memories

Autobiographical memories are characterised by a range of emotions and emotional reactions. Recent research has demonstrated that differences in emotional valence (positive vs. negative emotion) and arousal (the degree of emotional intensity) differentially influence the retrieved memory narrative. Although the mnemonic effects of valence and arousal have both been heavily studied, it is currently unclear whether the effects of emotional arousal are equivalent for positive and negative autobiographical events. In the current study, multilevel models were used to examine differential effects of emotional valence and arousal on the richness of autobiographical memory retrieval both between and within subjects. Thirty-four young adults were asked to retrieve personal autobiographical memories associated with popular musical cues and to rate the valence, arousal and richness of these events. The multilevel analyses identified independent influences of valence and intensity upon retrieval characteristics at the within- and between-subject levels. In addition, the within-subject interactions between valence and arousal highlighted differential effects of arousal for positive and negative memories. These findings have important implications for future studies of emotion and memory, highlighting the importance of considering both valence and arousal when examining the role emotion plays in the richness of memory representation.

Functional neuroimaging of sex differences in autobiographical memory recall.

Autobiographical memory (AM) is episodic memory for personally experienced events. The brain areas underlying AM retrieval are known to include several prefrontal cortical and medial temporal lobe regions. Sex differences in AM recall have been reported in several behavioral studies, but the functional anatomical correlates underlying such differences remain unclear. This study used fMRI to compare the neural correlates of AM recall between healthy male and female participants (n = 20 per group). AM recall in response to positive, negative, and neutral cue words was compared to a semantic memory task involving the generation of examples from a category using emotionally valenced cues. Behaviorally, females recalled more negative and fewer positive AMs compared with males, while ratings of arousal, vividness, and memory age did not differ significantly between sexes. Males and females also did not differ significantly in their performance on control tasks. Neurophysiologically, females showed increased hemodynamic activity compared to males in the dorsolateral prefrontal cortex (DLPFC), dorsal anterior insula, and precuneus while recalling specific AMs (all valences combined); increased activity in the DLPFC, transverse temporal gyrus, and precuneus while recalling positive AMs; and increased activity in the anterior cingulate cortex, precuneus, amygdala, and temporopolar cortex when recalling negative AMs. When comparing positive to negative AMs directly, males and females differed in their BOLD responses in the hippocampus and DLPFC. We propose that the differential hemodynamic changes may reflect sex-specific cognitive strategies during recall of AMs irrespective of the phenomenological properties of those memories.

Involuntary and voluntary autobiographical memory specificity as a function of depression

Background and objectivesThis study tests the hypothesis derived from the CaR-FA-X model (Capture and Rumination, Functional Avoidance and Executive Function model, Williams et al., 2007), that depressed individuals will be less specific during voluntary than involuntary autobiographical memory retrieval and looks at the relative contributions of rumination, avoidance and executive function to memory specificity. MethodsTwenty depressed and twenty never depressed individuals completed a memory diary, recording 10 involuntary and 10 voluntary autobiographical memories. Psychiatric status (assessed with the Structured Clinical Interview for DSM-IV, SCID-1), psychopathology, rumination, avoidance and executive function were assessed prior to completion of the memory diary. ResultsBoth groups were more specific during involuntary than voluntary memory retrieval. No overall group differences were identified. However, when non-remitted depressed participants were compared to partially remitted and never depressed participants the expected interaction was identified; non-remitted depressed individuals were less specific during voluntary, but not during involuntary recall. Consistent with theory, negative correlations between memory specificity, rumination and avoidance were also present. LimitationsThe study presents an important yet preliminary finding which warrants further replication with a larger sample size. ConclusionsThe findings provide support for a number of models of autobiographical memory retrieval in particular the CaR-FA-X model of memory specificity.

A longitudinal study of processes predicting the specificity of autobiographical memory in the adolescent offspring of depressed parents

Deficits in specific autobiographical memory retrieval are closely associated with depression. The ability to retrieve specific autobiographical memories develops throughout childhood and adolescence and is associated with adolescent depression within and across time. Studying young samples before they first experience depression provides an approach for testing processes that underlie reduced autobiographical memory specificity. This study is the first to examine the longitudinal association of rumination and executive function with autobiographical memory specificity in a sample of adolescents at elevated risk for future depression. A total of 259 adolescents (aged between 10 and 18 years) completed the Autobiographical Memory Test at baseline and 1-year follow-up. Measures of rumination, executive function, and depressive symptoms were obtained at baseline. The interaction between rumination and executive function predicted autobiographical memory specificity over time. Whereas rumination in the context of low executive function predicted reduced specificity, this was not the case in the context of high executive function. The interaction between rumination and executive function was independent of the effects of age, gender, IQ, baseline levels of memory specificity, and depressive symptoms.

Setting sample size using cost efficiency in fMRI studies

Background: Sample size calculations are rarely performed for functional magnetic resonance imaging studies involving clinical populations. This may be due to uncertainty as to the size of expected effect and the variance of the blood oxygenation level dependent response. Moreover, existing sample size methods ignore the costs associated with performing the proposed study. The current paper describes how cost efficiency, a recently proposed method, can be used in conjunction with existing methods to address these issues. Methods: Cost efficiency is the ratio of a study’s value to its cost, and sample size is chosen to maximize cost efficiency (ie, to maximize return on investment). It is suggested that sample size calculations begin by calculating the sample sizes required to achieve a given power, through varying the input parameters to the calculation over their plausible ranges. Cost efficiency can then help narrow the resulting range of sample sizes and help choose one sample size. The approach is illustrated through a recent functional magnetic resonance imaging study of autobiographical memory retrieval in patients with major depressive disorder. An example: Setting power to 80% and type 1 error rate to 5%, the method of Mumford and Nichols was used to calculate sample size. There were no reported effect sizes for similar studies in the literature; consequently, this parameter was varied over its plausible range (Cohen’s d varying from 0.2 to 0.8). This yielded sample sizes ranging from 50 to 800. Within these, cost efficiency gave a sample size of 88. Conclusion: Poor reporting of the input parameters to power-based methods of sample size determination results in a wide range of candidate sample sizes. The cost efficiency approach supplies a way of narrowing this range and choosing a sample size from that.

A case of hyperthymesia: rethinking the role of the amygdala in autobiographical memory

Much controversy has been focused on the extent to which the amygdala belongs to the autobiographical memory (AM) core network. Early evidence suggested the amygdala played a vital role in emotional processing, likely helping to encode emotionally charged stimuli. However, recent work has highlighted the amygdala's role in social and self-referential processing, leading to speculation that the amygdala likely supports the encoding and retrieval of AM. Here, cognitive as well as structural and functional magnetic resonance imaging data was collected from an extremely rare individual with near-perfect AM, or hyperthymesia. Right amygdala hypertrophy (approximately 20%) and enhanced amygdala-to-hippocampus connectivity (>10 SDs) was observed in this volunteer relative to controls. Based on these findings and previous literature, we speculate that the amygdala likely charges AMs with emotional, social, and self-relevance. In heightened memory, this system may be hyperactive, allowing for many types of autobiographical information, including emotionally benign, to be more efficiently processed as self-relevant for encoding and storage.

Episodic autobiographical memory in amnestic mild cognitive impairment: What are the neural correlates?

Autobiographical memory in amnestic Mild Cognitive Impairment (aMCI) is characterized by impaired retrieval of episodic memories, but relatively preserved personal semantic knowledge. This study aimed to identify (via FDG-PET) the neural substrates of impaired episodic specificity of autobiographical memories in 35 aMCI patients compared with 24 healthy elderly controls. Significant correlations between regional cerebral activity and the proportion of episodic details in autobiographical memories from two life periods were found in specific regions of an autobiographical brain network. In aMCI patients, more than in controls, specifically episodic memories from early adulthood were associated with metabolic activity in the cuneus and in parietal regions. We hypothesized that variable retrieval of episodic autobiographical memories in our aMCI patients would be related to their variable capacity to reactivate specific sensory-perceptual and contextual details of early adulthood events linked to reduced (occipito-parietal) visual imagery and less efficient (parietal) attentional processes. For recent memories (last year), a correlation emerged between the proportion of episodic details and activity in lateral temporal regions and the temporo-parietal junction. Accordingly, variable episodic memory for recent events may be related to the efficiency of controlled search through general events likely to provide cues for the retrieval of episodic details and to the ability to establish a self perspective favouring recollection.

A dual-subsystem model of the brain's default network: Self-referential processing, memory retrieval processes, and autobiographical memory retrieval

Most internally oriented mental activities are known to strongly activate the default network, which includes remembering the past, future thinking and social cognition, and are heavily self-referential, and demanding of memory retrieval processes. Based on these observations and building on related findings from the literature, the present article proposed a simple, dual-subsystem model of the default network. The ability of the model to estimate brain activity during autobiographical memory (AM) retrieval and related reference conditions was then tested by performing a quantitative meta-analysis of relevant literature. The model divided the default network into two subsystems. The first, called the 'cortical midline subsystem (CMS)', was comprised of the anteromedial prefrontal cortex and posterior cingulate cortex, and primarily mediates self-referential processing. The other, termed the 'parieto-temporal subsystem (PTS)', included the inferior parietal lobule, medial temporal lobe and lateral temporal cortex, and mainly supports memory retrieval processes. The meta-analysis of AM retrieval contrasts yielded a double dissociation that was consistent with this model. First, CMS regions associated more with an AM>laboratory-based memory (LM) contrast than with an AM>rest contrast, confirming that these regions play more critical roles in self-referential processing than memory retrieval processes. Second, all three PTS regions showed a greater association with an AM>rest contrast than with an AM>LM contrast, confirming that their role in memory retrieval processes is greater than in self-referential processing. Although the present model is limited in scope, both in terms of anatomical and functional specifications, it integrates diverse processes such as self-referential processing, episodic and semantic memory and subsystem interface, and provides useful heuristics that can guide further research on fractionation of the default network.

Patterns of Autobiographical Memory in Adults with Autism Spectrum Disorder

Two studies are presented that explored the effects of experimental manipulations on the quality and accessibility of autobiographical memories in adults with autism spectrum disorder (ASD), relative to a typical comparison group matched for age, gender and IQ. Both studies found that the adults with ASD generated fewer specific memories than the comparison group, and took significantly longer to do so. Despite this, experimental manipulations affected two indices of autobiographical memory (specificity and retrieval latency) similarly in both groups. These results suggest that adults with ASD experience a quantitative reduction in the speed and specificity of autobiographical memory retrieval, but that when they do retrieve these memories, they do so in a way that is qualitatively similar to that of typical adults.

Autobiographical memory in depression: An fMRI study

Depression is associated with three distinct alterations in memory functioning: mood-congruent recall, overgenerality, and intrusive memories. These concern the autobiographical memory system, yet no previous studies have examined the neural correlates of autobiographical memory function in depression. In the present study we used functional magnetic resonance imaging (fMRI) to assess depressed and control participants during an autobiographical memory task. In their first visit to the laboratory, participants wrote a narrative account of a distressing event. Participants were scanned during the second visit while they viewed old items from their narrative and new words or phrases in a recognition memory task. Activity common to both groups during the successful identification of personal emotional memories was observed in regions previously associated with autobiographical memory retrieval. Reduced activity in the depressed group was observed in three regions of the prefrontal cortex associated with cognitive, emotional, and memory inhibition. These results are consistent with a failure by depressed individuals to inhibit task-irrelevant information during an autobiographical memory task.

Neural correlates of autobiographical memory in amnestic Mild Cognitive Impairment

Episodic memory dysfunction, commonly assessed with word list recall, is the main characteristic of amnestic Mild Cognitive Impairment (aMCI). While brain pathology underlying this kind of memory impairment is well established in aMCI, little is known about the effect of neurodegeneration on autobiographical memory. The present study investigated neuronal correlates of autobiographical memory in aMCI patients (n=12) and healthy elderly controls (n=13) using functional magnetic resonance imaging (fMRI). Additionally, voxel-based morphometry (VBM) was employed to reveal brain pathology in aMCI patients. Neuropsychological assessment showed significant impairment in episodic memory tasks (immediate and delayed word list recall) in aMCI patients. Moreover, VBM revealed significantly reduced gray matter concentration, which was most pronounced in the temporal lobes of aMCI patients. Despite episodic memory impairment and atrophy in areas that are associated with encoding and recall of episodic memories, aMCI patients showed no alterations in brain activation associated with autobiographical memory retrieval. These findings could suggest that autobiographical memory is subserved by a different neuronal network than episodic memory and that the two memory systems are differently affected by aMCI.

Slow Breathing and Emotions Associated with Odor-Induced Autobiographical Memories

An important feature of olfactory perception is its dependence on respiratory activity. By inspiration, olfactory information ascends directly to olfactory-related limbic structures. Therefore, every breath with odor molecules activates these limbic areas associated with emotional experience and memory retrieval. We tested whether odors associated with autobiographical memories can trigger pleasant emotional experiences and whether respiration changes during stimulation with these odors. During presentation of odors related to autobiographical memories and control odors, we measured minute ventilation, tidal volume, respiratory frequency, O2 consumption, and end tidal CO2 concentration. Findings showed that autobiographical memory retrieval was associated with increasing tidal volume and decreasing respiratory frequency more than during presentation of control odors. Subjective feelings such as emotional arousal during retrieval of the memory, arousal level of the memory itself, or pleasantness and familiarity toward the odor evoked by autobiographical memory were more specific emotional responses compared with those related to control odors. In addition, high trait anxiety subjects responded with a stronger feeling of being taken back in time and had high arousal levels with tidal volume increases. We discussed assumptions regarding how deep and slow breathing is related to pleasantness and comfortableness of an autobiographical memory.

How Body Balance Influences Political Party Evaluations: A Wii Balance Board Study

Embodied cognition research has shown how actions or body positions may affect cognitive processes, such as autobiographical memory retrieval or judgments. The present study examined the role of body balance (to the left or the right) in participants on their attributions to political parties. Participants thought they stood upright on a Wii™ Balance Board, while they were actually slightly tilted to the left or the right. Participants then ascribed fairly general political statements to one of 10 political parties that are represented in the Dutch House of Representatives. Results showed a significant interaction of congruent leaning direction with left- or right-wing party attribution. When the same analyses were performed with the political parties being divided into affiliations to the right, center, and left based on participants’ personal opinions rather than a ruling classification, no effects were found. The study provides evidence that conceptual metaphors are activated by manipulating body balance implicitly. Moreover, people’s judgments may be colored by seemingly trivial circumstances such as standing slightly out of balance.

Reliving emotional personal memories: Affective biases linked to personality and sex-related differences.

Although available evidence suggests that the emotional valence and recollective properties of autobiographical memories (AMs) may be influenced by personality- and sex-related differences, overall these relationships remain poorly understood. The present study investigated these issues by comparing the effect of general personality traits (extraversion and neuroticism) and specific traits linked to emotion regulation (ER) strategies (reappraisal and suppression) on the retrieval of emotional AMs and on the associated postretrieval emotional states, in men and women. First, extraversion predicted recollection of positive AMs in both men and women, whereas neuroticism predicted the proportion of negative AMs in men and the frequency of rehearsing negative AMs in women. Second, reappraisal predicted positive AMs in men, and suppression predicted negative AMs in women. Third, while reliving of positive memories had an overall indirect effect on postretrieval positive mood through extraversion, reliving of negative AMs had a direct effect on postretrieval negative mood, which was linked to inefficient engagement of suppression in women. Our findings suggest that personality traits associated with positive affect predict recollection of positive AMs and maintenance of a positive mood, whereas personality traits associated with negative affect, along with differential engagement of habitual ER strategies in men and women, predict sex-related differences in the recollection and experiencing of negative AMs. These findings provide insight into the factors that influence affective biases in reliving AMs, and into their possible link to sex-related differences in the susceptibility to affective disorders.

Effect of self-discrepancy on specificity of autobiographical memory retrieval

Research using a cue word paradigm has consistently shown that depression, in both adults and adolescents, is associated with difficulties in retrieving specific autobiographical memories. Inspired by previous work stating that depressed feelings are related to a perceived discrepancy between attributes of the actual and the ideal self, the present study aimed to investigate the hypothesis that cues bringing discrepancies between the actual and ideal selves to the foreground might promote or facilitate the recall of overgeneral (instead of specific) autobiographical memories. In two studies adolescents provided autobiographical memories in response to 10 high-discrepant and 10 low-discrepant words. As predicted, results in both studies showed an effect of cue word discrepancy on the specificity of autobiographical memories such that participants retrieved a smaller proportion of specific and a greater proportion of overgeneral memories in response to high-discrepant words as compared to low-discrepant words. The findings are discussed in terms of the self-memory system (SMS) as a conceptual framework of autobiographical memory (Conway & Pleydell-Pearce, 2000).

On the prevalence of directly retrieved autobiographical memories.

In this study, we used process measures to understand how people recall autobiographical memories in response to different word cues. In Experiment 1, participants provided verbal protocols when cued by object and emotion words. Participants also reported whether memories had come directly to mind. The self-reports and independent ratings of the verbal protocols indicated that directly recalled memories are much faster and more frequent than generated memories and are more prevalent when cued by objects than emotions. Experiment 2 replicated these results without protocols to eliminate any demand characteristics or output interference associated with the protocol method. In Experiment 3, we obtained converging results using a different method for assessing retrieval strategies by asking participants to assess the amount of information required to retrieve memories. The greater proportion of fast direct retrievals when memories are cued by objects accounts for reaction time differences between object and emotion cues, and not the commonly accepted explanation based on ease of retrieval. We argue for a dual-strategies approach that disputes generation as the canonical form of autobiographical memory retrieval and discuss the implication of these findings for the representation of personal events in autobiographical memory.