The role of the thalamus and hippocampus in episodic memory performance in patients with multiple sclerosis

Background: Episodic memory loss is one of the most common cognitive symptoms in patients with multiple sclerosis (MS), but the pathophysiology of this symptom remains unclear. Both the hippocampus and thalamus have been implicated in episodic memory and show regional atrophy in patients with MS. Objective: In this work, we used functional magnetic resonance imaging (fMRI) during a verbal episodic memory task, lesion load, and volumetric measures of the hippocampus and thalamus to assess the relative contributions to verbal and visual–spatial episodic memory. Methods: Functional activation, lesion load, and volumetric measures from 32 patients with MS and 16 healthy controls were used in a predictive analysis of episodic memory function. Results: After adjusting for disease duration, immediate recall performance on a visual–spatial episodic memory task was significantly predicted by hippocampal volume ( p < 0.003). Delayed recall on the same task was significantly predicted by volume of the left thalamus ( p < 0.003). For both memory measures, functional activation of the thalamus during encoding was more predictive than that of volume measures ( p < 0.002). Conclusion: Our results suggest that functional activation may be useful as a predictive measure of episodic memory loss in patients with MS.

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EXPRESS: Stimulus novelty, task demands, and strategy use in episodic memory

Quarterly Journal of Experimental Psychology ◽

10.1177/1747021820980301 ◽

2020 ◽

pp. 174702182098030

Author(s):

Otto Waris ◽

Daniel Fellman ◽

Jussi Jylkkä ◽

Matti Laine

Keyword(s):

Episodic Memory ◽

Task Performance ◽

Recall Performance ◽

Cognitive Task ◽

Memory Performance ◽

Memory Task ◽

Strategy Use ◽

Skill Learning ◽

Cognitive Task Performance ◽

And Task

Cognitive task performance is a dynamic process that evolves over time, starting from the first encounters with a task. An important aspect of these task dynamics is the employment of strategies to support successful performance and task acquisition. Focusing on episodic memory performance, we: (1) tested two hypotheses on the effects of novelty and task difficulty on strategy use; (2) replicated our previous results regarding strategy use in a novel memory task; and (3) evaluated whether repeated open-ended strategy queries affect task performance and/or strategy use. The present pre-registered online study comprised 161 adult participants who were recruited through the Prolific crowdsourcing platform. We employed two separate 5-block list learning tasks, one with 10 pseudowords and the other with 18 common nouns, and collected recall performance and strategy reports for each block. Using Bayesian linear mixed effects models, the present findings (1) provide some support for the hypothesis that task-initial strategy development is not triggered only by task novelty, but can appear also in a familiar, moderately demanding task; (2) replicate earlier findings from an adaptive working memory task indicating strategy use from the beginning of a task, associations between strategy use and objective task performance, and only modest agreement between open-ended vs. list-based strategy reports; and (3) indicate that repeated open-ended strategy reports do not affect objective recall. We conclude that strategy use is an important aspect of memory performance right from the start of a task, and it undergoes development at the initial stages depending on task characteristics. In a larger perspective, the present results concur with the views of skill learning and adaptivity in cognitive task performance.

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Memory impairment in multiple sclerosis: Relevance of hippocampal activation and hippocampal connectivity

Multiple Sclerosis Journal ◽

10.1177/1352458514567727 ◽

2015 ◽

Vol 21 (13) ◽

pp. 1705-1712 ◽

Cited By ~ 38

Author(s):

Hanneke E Hulst ◽

Menno M Schoonheim ◽

Quinten Van Geest ◽

Bernard MJ Uitdehaag ◽

Frederik Barkhof ◽

...

Keyword(s):

Multiple Sclerosis ◽

Memory Impairment ◽

Memory Performance ◽

Memory Function ◽

Neuropsychological Test ◽

Memory Task ◽

Hippocampal Volume ◽

Male Gender ◽

Imaging Data ◽

The Right

Background: Memory impairment is frequent in multiple sclerosis (MS), but it is unclear what functional brain changes underlie this cognitive deterioration. Objective: To investigate functional hippocampal activation and connectivity, in relation to memory performance in MS. Methods: Structural and functional magnetic resonance imaging data were acquired for 57 MS patients and 28 healthy controls (HCs), yielding hippocampal measures of volume, lesions, functional activation during a memory task and functional connectivity at rest. Memory function was based on two subtests of a larger neuropsychological test battery and related to hippocampal neuroimaging measures, using linear regression. Results: Hippocampal volume was lower in MS patients, as compared to HCs. In MS, hippocampal activation during the task was increased in cognitively preserved, but decreased in cognitively impaired, patients. Increased hippocampal connectivity was detected in MS patients, as compared to HCs, between the left hippocampus and the right posterior cingulate. Memory impairment in MS was explained (adjusted R2 = 0.27) by male gender, decreased hippocampal activation and increased hippocampal connectivity ( p = 0.001). Conclusions: Decreased activation of the hippocampus, increased connectivity and male gender were associated with worse memory performance in MS. These results indicate that increased activation and increased connectivity do not always coincide, and relate differently to cognitive dysfunction in MS.

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Maintained Frontal Activity Underlies High Memory Function Over 8 Years in Aging

Cerebral Cortex ◽

10.1093/cercor/bhy177 ◽

2018 ◽

Vol 29 (7) ◽

pp. 3111-3123 ◽

Cited By ~ 8

Author(s):

Didac Vidal-Piñeiro ◽

Markus H Sneve ◽

Lars H Nyberg ◽

Athanasia M Mowinckel ◽

Donatas Sederevicius ◽

...

Keyword(s):

Older Adults ◽

Episodic Memory ◽

Memory Performance ◽

Memory Function ◽

Memory Task ◽

Cortical Atrophy ◽

High Performing ◽

Adult Participants ◽

Memory Experiment ◽

Frontal Activity

AbstractAging is characterized by substantial average decline in memory performance. Yet contradictory explanations have been given for how the brains of high-performing older adults work: either by engagement of compensatory processes such as recruitment of additional networks or by maintaining young adults’ patterns of activity. Distinguishing these components requires large experimental samples and longitudinal follow-up. Here, we investigate which features are key to high memory in aging, directly testing these hypotheses by studying a large sample of adult participants (n > 300) with fMRI during an episodic memory experiment where item-context relationships were implicitly encoded. The analyses revealed that low levels of activity in frontal networks—known to be involved in memory encoding—were associated with low memory performance in the older adults only. Importantly, older participants with low memory performance and low frontal activity exhibited a strong longitudinal memory decline in an independent verbal episodic memory task spanning 8 years back (n = 52). These participants were also characterized by lower hippocampal volumes and steeper rates of cortical atrophy. Altogether, maintenance of frontal brain function during encoding seems to be a primary characteristic of preservation of memory function in aging, likely reflecting intact ability to integrate information.

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Exercise and Episodic Specificity Induction on Episodic Memory Function

Medicina ◽

10.3390/medicina55080422 ◽

2019 ◽

Vol 55 (8) ◽

pp. 422

Author(s):

Loprinzi ◽

McRaney ◽

Luca ◽

McDonald

Keyword(s):

Episodic Memory ◽

Acute Exercise ◽

Memory Performance ◽

Memory Function ◽

Memory Task ◽

Exercise Group ◽

Acute Bout ◽

Short Video ◽

Two Parameters ◽

Main Effects

Background and objectives: Episodic specific induction (ESI) is a manipulation shown to enhance episodic memory function. Episodic specificity induction involves thoroughly unpacking a recently encoded memory, with this enhanced retrieval-induced process helping to facilitate subsequent cognitions. In addition to ESI, emerging work suggests that acute exercise may also help to facilitate episodic memory function. The purpose of this study was to evaluate the potential individual and combined effects of acute exercise and ESI on subsequent episodic memory performance. Materials and Methods: Participants (n = 120) were randomly assigned into one of four groups, (1) ESI and exercise (ESI + E), (2) ESI only (ESI), (3) exercise only (E), and (4) no ESI and no exercise (Control; C). The ESI protocol involved watching a short video and then recalling details about the setting, people, and actions in the video. The exercise protocol involved an acute bout (15 min) of treadmill exercise. After these tasks, episodic memory function was evaluated with an autobiographical interview assessment and a computerized episodic memory task involving what–where–when integration. Results: We did not observe significant main effects for exercise or ESI on memory function but did observe some suggestive evidence of an interaction effect of these two parameters on episodic memory. That is, for the exercise group, memory performance was higher when combined with ESI as opposed to without ESI. Conclusions: Acute exercise and ESI may interact to influence episodic memory function.

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Impact of Comorbid Depression on Serial Position Effects in Alzheimer’s Disease

GeroPsych ◽

10.1024/1662-9647/a000115 ◽

2014 ◽

Vol 27 (4) ◽

pp. 161-169 ◽

Cited By ~ 1

Author(s):

Nienke A. Hofrichter ◽

Sandra Dick ◽

Thomas G. Riemer ◽

Carsten Schleussner ◽

Monique Goerke ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Serial Position ◽

Episodic Memory ◽

Memory Performance ◽

Memory Function ◽

Word List ◽

Position Effects ◽

Serial Position Effects ◽

List Memory

Hippocampal dysfunction and deficits in episodic memory have been reported for both Alzheimer’s disease (AD) and major depressive disorder (MDD). Primacy performance has been associated with hippocampus-dependent episodic memory, while recency may reflect working memory performance. In this study, serial position profiles were examined in a total of 73 patients with MDD, AD, both AD and MDD, and healthy controls (HC) by means of CERAD-NP word list memory. Primacy performance was most impaired in AD with comorbid MDD, followed by AD, MDD, and HC. Recency performance, on the other hand, was comparable across groups. These findings indicate that primacy in AD is impaired in the presence of comorbid MDD, suggesting additive performance decrements in this specific episodic memory function.

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The Effect of Divided Attention on Encoding and Retrieval in Episodic Memory Revealed by Positron Emission Tomography

Journal of Cognitive Neuroscience ◽

10.1162/089892900562093 ◽

2000 ◽

Vol 12 (2) ◽

pp. 267-280 ◽

Cited By ~ 89

Author(s):

Tetsuya Iidaka ◽

Nicole D. Anderson ◽

Shitij Kapur ◽

Roberto Cabez ◽

Fergus I. M. Craik

Keyword(s):

Positron Emission Tomography ◽

Prefrontal Cortex ◽

Episodic Memory ◽

Divided Attention ◽

Memory Performance ◽

Memory Task ◽

Anterior Cingulate ◽

Emission Tomography ◽

Positron Emission ◽

Encoding And Retrieval

The effects of divided attention (DA) on episodic memory encoding and retrieval were investigated in 12 normal young subjects by positron emission tomography (PET). Cerebral blood flow was measured while subjects were concurrently performing a memory task (encoding and retrieval of visually presented word pairs) and an auditory tone-discrimination task. The PET data were analyzed using multivariate Partial Least Squares (PLS), and the results revealed three sets of neural correlates related to specific task contrasts. Brain activity, relatively greater under conditions of full attention (FA) than DA, was identified in the occipital-temporal, medial, and ventral-frontal areas, whereas areas showing relatively more activity under DA than FA were found in the cerebellum, temporo-parietal, left anterior-cingulate gyrus, and bilateral dorsolateral-prefrontal areas. Regions more active during encoding than during retrieval were located in the hippocampus, temporal and the prefrontal cortex of the left hemisphere, and regions more active during retrieval than during encoding included areas in the medial and right-prefrontal cortex, basal ganglia, thalamus, and cuneus. DA at encoding was associated with specific decreases in rCBF in the left-prefrontal areas, whereas DA at retrieval was associated with decreased rCBF in a relatively small region in the right-prefrontal cortex. These different patterns of activity are related to the behavioral results, which showed a substantial decrease in memory performance when the DA task was performed at encoding, but no change in memory levels when the DA task was performed at retrieval.

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Effects of amnesia on processing in the hippocampus and default mode network during a naturalistic memory task: a case study

10.31234/osf.io/e9n8c ◽

2018 ◽

Author(s):

Christiane Oedekoven ◽

James L. Keidel ◽

Stuart Anderson ◽

Angus Nisbet ◽

Chris Bird

Keyword(s):

Functional Connectivity ◽

Episodic Memory ◽

Memory Performance ◽

Memory Task ◽

Structural Mri ◽

Brain Regions ◽

Left Hippocampus ◽

Cortical Regions ◽

The Right ◽

Encoding And Retrieval

Despite their severely impaired episodic memory, individuals with amnesia are able to comprehend ongoing events. Online representations of a current event are thought to be supported by a network of regions centred on the posterior midline cortex (PMC). By contrast, episodic memory is widely believed to be supported by interactions between the hippocampus and these cortical regions. In this MRI study, we investigated the encoding and retrieval of lifelike events (video clips) in a patient with severe amnesia likely resulting from a stroke to the right thalamus, and a group of 20 age-matched controls. Structural MRI revealed grey matter reductions in left hippocampus and left thalamus in comparison to controls. We first characterised the regions activated in the controls while they watched and retrieved the videos. There were no differences in activation between the patient and controls in any of the regions. We then identified a widespread network of brain regions, including the hippocampus, that were functionally connected with the PMC in controls. However, in the patient there was a specific reduction in functional connectivity between the PMC and a region of left hippocampus when both watching and attempting to retrieve the videos. A follow up analysis revealed that in controls the functional connectivity between these regions when watching the videos was correlated with memory performance. Taken together, these findings support the view that the interactions between the PMC and the hippocampus enable the encoding and retrieval of multimodal representations of the contents of an event.

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The effects of acute exercise on episodic memory function among young university students: moderation considerations by biological sex

Health Promotion Perspectives ◽

10.15171/hpp.2019.14 ◽

2019 ◽

Vol 9 (2) ◽

pp. 99-104 ◽

Cited By ~ 6

Author(s):

Lauren Johnson ◽

Paul D. Loprinzi

Keyword(s):

Episodic Memory ◽

University Students ◽

Verbal Memory ◽

Acute Exercise ◽

Memory Function ◽

Verbal Learning ◽

Memory Task ◽

Moderate Intensity ◽

Term Memory ◽

Main Effect

Background: The objective of this study was to evaluate potential sex-specific differences on episodic memory function and determine whether sex moderates the effects of acute exercise on episodic memory.Methods: A randomized controlled intervention was employed. This experiment was conducted among young University students (mean age = 21 years). Both males (n=20) and females (n=20)completed two counterbalanced laboratory visits, with one visit involving a 15-minute bout of moderate-intensity exercise prior to the memory task. The control visit engaged in a time matched seated task. Memory function (including short-term memory, learning, and long-term memory) was assessed from the RAVLT (Rey Auditory Verbal Learning Test).Results: We observed a significant main effect for time (P<0.001, ƞ2p= 0.77) and a marginally significant main effect for sex (P=0.06, ƞ2p= 0.09), but no time by sex by condition interaction(P=0.91, ƞ2p= 0.01). We also observed some suggestive evidence of a more beneficial effect of acute exercise on memory for females. Conclusion: In conclusion, females outperformed males in verbal memory function. Additional research is needed to further evaluate whether sex moderates the effects of acute exercise on memory function.

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Not Just a Pot: Visual Episodic Memory in Cannabis Users and Polydrug Cannabis Users: ROC and ERP Preliminary Investigation

Frontiers in Human Neuroscience ◽

10.3389/fnhum.2021.677793 ◽

2021 ◽

Vol 15 ◽

Author(s):

Alicja Anna Binkowska ◽

Natalia Jakubowska ◽

Maciej Gaca ◽

Natalia Galant ◽

Agnieszka Piotrowska-Cyplik ◽

...

Keyword(s):

Episodic Memory ◽

Receiver Operating Characteristic ◽

Operating Characteristic ◽

Memory Performance ◽

Visual Learning ◽

Linear Regression Analysis ◽

Memory Task ◽

Event Related Potentials ◽

Related Potentials ◽

Receiver Operating

Background While research has consistently identified an association between long-term cannabis use and memory impairments, few studies have examined this relationship in a polydrug context (i.e., when combining cannabis with other substances).Aims: In this preliminary study, we used event-related potentials to examine the recognition process in a visual episodic memory task in cannabis users (CU) and cannabis polydrug users (PU). We hypothesized that CU and PU will have both–behavioral and psychophysiological–indicators of memory processes affected, compared to matched non-using controls with the PU expressing more severe changes.Methods 29 non-using controls (CG), 24 CU and 27 PU were enrolled into the study. All participants completed a visual learning recognition task while brain electrical activity was recorded. Event-related potentials were calculated for familiar (old) and new images from a signal recorded during a subsequent recognition test. We used receiver operating characteristic curves for behavioral data analysis.Results The groups did not differ in memory performance based on receiver operating characteristic method in accuracy and discriminability indicators nor mean reaction times for old/new images. The frontal old/new effect expected from prior research was observed for all participants, while a parietal old/new effect was not observed. While, the significant differences in the late parietal component (LPC) amplitude was observed between CG and PU but not between CG and CU nor CU and PU. Linear regression analysis was used to examine the mean amplitude of the LPC component as a predictor of memory performance accuracy indicator. LPC amplitude predicts recognition accuracy only in the CG.Conclusion The results showed alterations in recognition memory processing in CU and PU groups compared to CG, which were not manifested on the behavioral level, and were the most prominent in cannabis polydrug users. We interpret it as a manifestation of the cumulative effect of multiple drug usage in the PU group.

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Hippocampal-related memory network in multiple sclerosis: A structural connectivity analysis

Multiple Sclerosis Journal ◽

10.1177/1352458518771838 ◽

2018 ◽

Vol 25 (6) ◽

pp. 801-810 ◽

Cited By ~ 3

Author(s):

Sara Llufriu ◽

Maria A Rocca ◽

Elisabetta Pagani ◽

Gianna C Riccitelli ◽

Elisabeth Solana ◽

...

Keyword(s):

Multiple Sclerosis ◽

Episodic Memory ◽

Medial Temporal Lobe ◽

Structural Integrity ◽

Memory Performance ◽

Structural Connectivity ◽

Occipital Cortex ◽

Network Efficiency ◽

Edge Graph ◽

Memory Network

Background: We used graph theoretical analysis to quantify structural connectivity of the hippocampal-related episodic memory network and its association with memory performance in multiple sclerosis (MS) patients. Methods: Brain diffusion and T1-weighted sequences were obtained from 71 MS patients and 50 healthy controls (HCs). A total of 30 gray matter regions (selected a priori) were used as seeds to perform probabilistic tractography and create connectivity matrices. Global, nodal, and edge graph theoretical properties were calculated. In patients, verbal and visuospatial memory was assessed. Results: MS patients showed decreased network strength, assortativity, transitivity, global efficiency, and increased average path length. Several nodes had decreased strength and communicability in patients, whereas insula and left temporo-occipital cortex increased communicability. Patients had widespread decreased streamline count (SC) and communicability of edges, although a few ones increased their connectivity. Worse memory performance was associated with reduced network efficiency, decreased right hippocampus strength, and reduced SC and communicability of edges related to medial temporal lobe, thalamus, insula, and occipital cortex. Conclusion: Impaired structural connectivity occurs in the hippocampal-related memory network, decreasing the efficiency of information transmission. Network connectivity measures correlate with episodic memory, supporting the relevance of structural integrity in preserving memory processes in MS.

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