scholarly journals Enhanced brain activity associated with memory access in highly superior autobiographical memory

2018 ◽  
Vol 115 (30) ◽  
pp. 7795-7800 ◽  
Author(s):  
Valerio Santangelo ◽  
Clarissa Cavallina ◽  
Paola Colucci ◽  
Alessia Santori ◽  
Simone Macrì ◽  
...  
Keyword(s):  
Autobiographical Memory ◽  
Brain Activity ◽  
Memory Function ◽  
Human Memory ◽  
Functional Coupling ◽  
Temporoparietal Junction ◽  
Memory Impairments ◽  
Efficient Access ◽  
Sensory Cortices ◽  
Past Experiences

Brain systems underlying human memory function have been classically investigated studying patients with selective memory impairments. The discovery of rare individuals who have highly superior autobiographical memory (HSAM) provides, instead, an opportunity to investigate the brain systems underlying enhanced memory. Here, we carried out an fMRI investigation of a group of subjects identified as having HSAM. During fMRI scanning, eight subjects with HSAM and 21 control subjects were asked to retrieve autobiographical memories (AMs) as well as non-AMs (e.g., examples of animals). Subjects were instructed to signal the “access” to an AM by a key press and to continue “reliving” it immediately after. Compared with controls, individuals with HSAM provided a richer AM recollection and were faster in accessing AMs. The access to AMs was associated with enhanced prefrontal/hippocampal functional connectivity. AM access also induced increased activity in the left temporoparietal junction and enhanced functional coupling with sensory cortices in subjects with HSAM compared with controls. In contrast, subjects with HSAM did not differ from controls in functional activity during the reliving phase. These findings, based on fMRI assessment, provide evidence of interaction of brain systems engaged in memory retrieval and suggest that enhanced activity of these systems is selectively involved in enabling more efficient access to past experiences in HSAM.

scholarly journals Evidence for a pervasive autobiographical memory impairment in Logopenic Progressive Aphasia: clinical and neural correlates

2020 ◽  
Author(s):  
Siddharth Ramanan ◽  
David Foxe ◽  
Hashim El-Omar ◽  
Rebekah M. Ahmed ◽  
John R. Hodges ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Autobiographical Memory ◽  
Memory Impairment ◽  
Language Disorder ◽  
Memory Performance ◽  
Memory Function ◽  
Structured Interview ◽  
Progressive Aphasia ◽  
Memory Impairments

ABSTRACTLogopenic Progressive Aphasia is a rare language disorder characterised by repetition and naming difficulties, reflecting the progressive degeneration of left-lateralized peri-sylvian temporal and inferior parietal regions. Mounting evidence suggests that cognitive impairments in this syndrome extend beyond the language domain to include episodic encoding and retrieval disturbances. To date, it remains unknown whether autobiographical memories from across the lifespan are also subject to decline, yet this information is critical to arrive at a comprehensive understanding of the Logopenic syndrome. The objective of this study was to provide the first in depth examination of autobiographical memory function in Logopenic Progressive Aphasia using the Autobiographical Interview, a validated semi-structured interview which assesses recollection of the past under free and probed recall conditions. Autobiographical memory performance in 10 well-characterised Logopenic Progressive Aphasia patients was contrasted with that of 18 typical amnestic Alzheimer’s disease and 16 healthy Control participants. Relative to Controls, Logopenic Progressive Aphasia cases showed marked impairment in the free recall of episodic details, scoring comparably to disease-matched cases of Alzheimer’s disease. This impairment was evident across all time periods and persisted even when formal structured probing was provided. Importantly, controlling for overall level of language disruption failed to ameliorate the autobiographical memory impairment in the Logopenic Progressive Aphasia group, suggesting a genuine amnesia spanning recent and remote memories. Whole-brain voxel-based morphometry analyses revealed that total episodic information retrieved in Logopenic Progressive Aphasia was associated with decreased grey matter intensity predominantly in a bilateral posterior parietal network. Taken together, our findings reveal for the first time the presence of marked remote and recent autobiographical memory impairments in Logopenic Progressive Aphasia, that cannot be explained solely due to their language difficulties or disease staging. Our findings hold important clinical implications for the accurate characterization of Logopenic Progressive Aphasia, and suggest that episodic memory difficulties should be considered as one of the core clinical features of this syndrome.

scholarly journals Neural signatures of compression in the retelling of past events

2021 ◽  
Author(s):  
Elizabeth Musz ◽  
Janice Chen
Keyword(s):  
Brain Activity ◽  
Human Memory ◽  
Universal Form ◽  
Neural Representations ◽  
Brain Pattern ◽  
Temporal Compression ◽  
Past Experiences ◽  
Systematic Encoding ◽  
Neural Signatures

When we retell our past experiences, we aim to reproduce some version of the original events; this reproduced version is often temporally compressed relative to the original. How does such compression of memories manifest in brain activity? One possibility is that a compressed retrieved memory manifests as a neural pattern which is more dissimilar to the original, relative to a more detailed or vivid memory. However, we argue that measuring raw dissimilarity alone is insufficient, as it confuses a variety of interesting and uninteresting changes. To address this problem, we examine brain pattern changes that are consistent across people. We show that temporal compression in individuals' retelling of past events predicts systematic encoding-to-recall transformations in a number of higher associative regions. These findings elucidate how neural representations are not simply reactivated, but can also be transformed due to temporal compression during a universal form of human memory expression: verbal retelling.

Emotional Reactivity to Visual Content as Revealed by ERP Component Clustering

2015 ◽  
Vol 29 (4) ◽  
pp. 135-146 ◽  
Author(s):  
Miroslaw Wyczesany ◽  
Szczepan J. Grzybowski ◽  
Jan Kaiser
Keyword(s):  
Emotional Reactivity ◽  
Brain Activity ◽  
Affective State ◽  
Occipital Lobe ◽  
Stimulus Onset ◽  
Emotional States ◽  
Neural Basis ◽  
Temporoparietal Junction ◽  
The Right ◽  
The Impact

Abstract. In the study, the neural basis of emotional reactivity was investigated. Reactivity was operationalized as the impact of emotional pictures on the self-reported ongoing affective state. It was used to divide the subjects into high- and low-responders groups. Independent sources of brain activity were identified, localized with the DIPFIT method, and clustered across subjects to analyse the visual evoked potentials to affective pictures. Four of the identified clusters revealed effects of reactivity. The earliest two started about 120 ms from the stimulus onset and were located in the occipital lobe and the right temporoparietal junction. Another two with a latency of 200 ms were found in the orbitofrontal and the right dorsolateral cortices. Additionally, differences in pre-stimulus alpha level over the visual cortex were observed between the groups. The attentional modulation of perceptual processes is proposed as an early source of emotional reactivity, which forms an automatic mechanism of affective control. The role of top-down processes in affective appraisal and, finally, the experience of ongoing emotional states is also discussed.

Do People’s Motives Influence Their Susceptibility to Imagination Inflation?

2010 ◽  
Vol 57 (1) ◽  
pp. 77-82 ◽  
Author(s):  
Stefanie J. Sharman ◽  
Samantha Calacouris
Keyword(s):  
Autobiographical Memory ◽  
Source Monitoring ◽  
False Beliefs ◽  
Explicit Motives ◽  
Imagination Inflation ◽  
Motivational Model ◽  
Past Experiences ◽  
Implicit And Explicit ◽  
Affiliation Motives

People are motivated to remember past autobiographical experiences related to their current goals; we investigated whether people are also motivated to remember false past experiences related to those goals. In Session 1, we measured subjects’ implicit and explicit achievement and affiliation motives. Subjects then rated their confidence about, and memory for, childhood events containing achievement and affiliation themes. Two weeks later in Session 2, subjects received a “computer-generated profile” based on their Session 1 ratings. This profile suggested that one false achievement event and one false affiliation event had happened in childhood. After imagining and describing the suggested false events, subjects made confidence and memory ratings a second time. For achievement events, subjects’ explicit motives predicted their false beliefs and memories. The results are explained using source monitoring and a motivational model of autobiographical memory.

Autobiographical Memory Impairments as a Transdiagnostic Feature of Mental Illness: A meta-analysis of autobiographical memory specificity and overgenerality amongst people with psychiatric diagnoses

2020 ◽  
Author(s):  
Tom Joseph Barry ◽  
David John Hallford ◽  
Keisuke Takano
Keyword(s):  
Autobiographical Memory ◽  
Memory Retrieval ◽  
Keyword Search ◽  
Meta Analysis ◽  
Future Research ◽  
Psychiatric Diagnoses ◽  
Schizophrenia Spectrum Disorders ◽  
Memory Impairments ◽  
Memory Specificity ◽  
Causal Mechanisms

Decades of research has examined the difficulty that people with psychiatric diagnoses, such as Major Depressive Disorder, Schizophrenia Spectrum Disorders, and Posttraumatic Stress Disorder, have in recalling specific autobiographical memories from events that lasted less than a day. Instead, they seem to retrieve general events that have occurred many times or which occurred over longer periods of time, termed overgeneral memory. We present the first transdiagnostic meta-analysis of memory specificity/overgenerality, and the first meta-regression of proposed causal mechanisms. A keyword search of Embase, PsycARTICLES and PsycINFO databases yielded 74 studies that compared people with and without psychiatric diagnoses on the retrieval of specific (k = 85) or general memories (k = 56). Multi-level meta-analysis confirmed that people with psychiatric diagnoses typically recall fewer specific (g = -0.864, 95% CI[-1.030, -0.698]) and more general (g = .712, 95% CI[0.524, 0.900]) memories than diagnoses-free people. The size of these effects did not differ between diagnostic groups. There were no consistent moderators; effect sizes were not explained by methodological factors such as cue valence, or demographic variables such as participants’ age. There was also no support for the contribution of underlying processes that are thought to be involved in specific/general memory retrieval (e.g., rumination). Our findings confirm that deficits in autobiographical memory retrieval are a transdiagnostic factor associated with a broad range of psychiatric problems, but future research should explore novel causal mechanisms such as encoding deficits and the social processes involved in memory sharing and rehearsal.

Introduction to the cognitive abilities account for the reminiscence bump in the temporal distribution of autobiographical memory

2019 ◽  
Author(s):  
Steve M. J. Janssen
Keyword(s):  
Autobiographical Memory ◽  
Cognitive Abilities ◽  
Memory Performance ◽  
Memory Function ◽  
Early Adulthood ◽  
Temporal Distribution ◽  
Alternative Account ◽  
Reminiscence Bump ◽  
Significant Events ◽  
Cue Words

People tend to recall more specific personal events from adolescence and early adulthood than from other lifetime periods, a finding known as the reminiscence bump. Several explanations have suggested that events from the reminiscence bump are especially emotional, important, or positive, but studies using cue words have not found support for these claims. An alternative account postulates that cognitive abilities function optimally in adolescence and early adulthood, which may cause more memories to be stored in those lifetime periods. Although other studies have previously discussed the cognitive abilities account as a possible explanation for the reminiscence bump, it was only recently shown that cognitive abilities are indeed related to autobiographical memory performance. When this recent finding is combined with previous findings that cognitive abilities as well as autobiographical memory function optimally in adolescence and early adulthood, they suggest that the cognitive abilities account is a promising explanation for the reminiscence bump in the temporal distribution of word-cued memories. However, because the account does not aim to explain the reminiscence bump in the distribution of highly significant events, it should be regarded as complementary to the existing accounts.

scholarly journals Neural Basis of Visually Guided Head Movements Studied With fMRI

2003 ◽  
Vol 89 (5) ◽  
pp. 2516-2527 ◽  
Author(s):  
Laurent Petit ◽  
Michael S. Beauchamp
Keyword(s):  
Eye Movements ◽  
Head Movement ◽  
Brain Activity ◽  
Posterior Part ◽  
Vestibular Stimulation ◽  
Head Movements ◽  
Oculomotor Control ◽  
Imaging Studies ◽  
Neural Basis ◽  
Temporoparietal Junction

We used event-related fMRI to measure brain activity while subjects performed saccadic eye, head, and gaze movements to visually presented targets. Two distinct patterns of response were observed. One set of areas was equally active during eye, head, and gaze movements and consisted of the superior and inferior subdivisions of the frontal eye fields, the supplementary eye field, the intraparietal sulcus, the precuneus, area MT in the lateral occipital sulcus and subcortically in basal ganglia, thalamus, and the superior colliculus. These areas have been previously observed in functional imaging studies of human eye movements, suggesting that a common set of brain areas subserves both oculomotor and head movement control in humans, consistent with data from single-unit recording and microstimulation studies in nonhuman primates that have described overlapping eye- and head-movement representations in oculomotor control areas. A second set of areas was active during head and gaze movements but not during eye movements. This set of areas included the posterior part of the planum temporale and the cortex at the temporoparietal junction, known as the parieto-insular vestibular cortex (PIVC). Activity in PIVC has been observed during imaging studies of invasive vestibular stimulation, and we confirm its role in processing the vestibular cues accompanying natural head movements. Our findings demonstrate that fMRI can be used to study the neural basis of head movements and show that areas that control eye movements also control head movements. In addition, we provide the first evidence for brain activity associated with vestibular input produced by natural head movements as opposed to invasive caloric or galvanic vestibular stimulation.

Cannabidiol Has a Unique Effect on Global Brain Activity: A Pharmacological, Functional MRI Study in Awake Mice 

2021 ◽  
Author(s):  
Aymen Sadaka ◽  
Ana Ozuna ◽  
Richard Ortiz ◽  
Praveen Kulkarni ◽  
Clare Johnson ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Brain Activity ◽  
Stress Disorders ◽  
Functional Coupling ◽  
Specific Information ◽  
Imaging Data ◽  
Post Traumatic Stress ◽  
Brain Areas ◽  
Dose Dependent ◽  
The Brain

Abstract Background: The phytocannabinoid cannabidiol (CBD) is a potential treatment for post-traumatic stress disorders. How does CBD interact with the brain to alter behavior? We hypothesized that CBD would produce a dose-dependent reduction in brain activity and functional coupling in neural circuitry associated with fear and defense. Methods: During the scanning session awake mice were given vehicle or CBD (3, 10, or 30 mg/kg I.P.) and imaged for 10 min post treatment. Mice were also treated with the 10 mg/kg dose of CBD and imaged one hr later for resting state BOLD functional connectivity (rsFC). Imaging data were registered to a 3D MRI mouse atlas providing site-specific information on 138 different brain areas. Blood samples were collected for CBD measurements.Results: CBD produced a dose-dependent polarization of activation along the rostral-caudal axis of the brain. The olfactory bulb and prefrontal cortex showed an increase in positive BOLD whereas the brainstem and cerebellum showed a decrease in BOLD signal. This negative BOLD affected many areas connected to the ascending reticular activating system (ARAS). The ARAS was decoupled to much of the brain but was hyperconnected to the olfactory system and prefrontal cortex. The pattern of ARAS connectivity closely overlapped with brain areas showing high levels N-acyl-phosphatidylethanolamines-specific phospholipase D (NAPE-PLD) messenger RNA.Conclusion: The CBD-induced decrease in ARAS activity is consistent with an emerging literature suggesting that CBD reduces autonomic arousal under conditions of emotional and physical stress. The putative target and mechanism of action is NAPE-PLD the enzyme responsible for the biosynthesis of lipid signaling molecules like anandamide.

scholarly journals Mental travel in the social domain

2019 ◽  
Author(s):  
Mordechai Hayman ◽  
Shahar Arzy
Keyword(s):  
Social Network ◽  
Anterior Cingulate Cortex ◽  
Brain Activity ◽  
Cingulate Cortex ◽  
Retrosplenial Cortex ◽  
Anterior Cingulate ◽  
Significant Other ◽  
Temporoparietal Junction ◽  
The Social ◽  
Famous Person

“Mental travel” is the ability to imagine oneself in different places and times and to adopt other people’s point of view (POV), also termed “Theory of Mind (ToM)”. While ToM has been extensively investigated, self-projection with respect to ones’ own and others’ social networks has yet to be systematically studied.Here we asked participants to “project” themselves to four different POVs: a significant other, a non-significant other, a famous-person, and their own-self. From each POV they were asked to rate the level of affiliation (closeness) to different individuals in the respective social network while undergoing functional MRI.Participants were always faster making judgments from their own POV compared to other POVs (self-projection effect) and for people who were personally closer to their adopted POV (self-reference effect). Brain activity at the medial prefrontal and anterior cingulate cortex in the self POV condition was found to be higher compared to all other conditions. Activity at the right temporoparietal junction and medial parietal cortex was found to distinguish between the personally related (self, significant- and non-significant others) and unrelated (famous-person) individuals within the social network. Regardless of the POV, the precuneus, anterior cingulate cortex, prefrontal cortex, and temporoparietal junction distinguished between relatively closer and distant people. Representational similarity analysis (RSA) implicated the left retrosplenial cortex as crucial for social distance processing across all POVs.

scholarly journals Autobiographical Memory and End-of-Life Treatment Preferences in China

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 606-606
Author(s):  
Yao Fu ◽  
Ellen Idler
Keyword(s):  
Autobiographical Memory ◽  
End Of Life ◽  
Terminal Illness ◽  
Cultural Beliefs ◽  
Feeding Tube ◽  
Treatment Preferences ◽  
Mainland Chinese ◽  
Gastric Feeding ◽  
Past Experiences ◽  
End Of Life Treatment

Abstract In this mixed-methods study of religious/cultural beliefs and end-of-life treatment preferences in China, we surveyed 1,085 mainland Chinese people aged 18 or above online. We assessed the effects of past experience with dying people they have known and their own end-of-life treatment preferences in two hypothetical terminal illness vignettes. We found that respondents who knew or visited someone at the end of their lives were somewhat less likely to choose aggressive treatment for themselves in a lung cancer scenario (25% compared to 33%, p=.013). However, there was less difference in an Alzheimer’s disease scenario, with a choice to use a gastric feeding tube or not (39% compared to 42%, p=.262). Open-ended responses indicate that people refer to these past experiences as a reference in making end-of-life decisions for themselves. This study provides empirical evidence that autobiographical memory has a directive function that individuals call on to inform future behaviors.

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