Age Deficits in Associative Memory are not Alleviated by Multisensory Paradigms

OBJECTIVES

Age deficits in memory are widespread, this impacts individuals at a personal level, and investigating memory has been a key focus in cognitive ageing research. Age deficits occur in memory for an episode, where information from the environment is integrated through the senses into an episodic event via associative memory. Associating items in memory has been shown to be particularly difficult for older adults but can often be alleviated by providing support from the external environment. The current investigation explored the potential for increased sensory input (multimodal stimuli) to alleviate age deficits in associative memory. Here, we present compelling evidence, supported by Bayesian analysis, for a null age-by-modality interaction.

METHODS

Across three pre-registered studies, young and older adults (n = 860) completed associative memory tasks either in single modalities or in multimodal formats. Study 1 used either visual text (unimodal) or video introductions (multimodal) to test memory for name-face associations. Studies 2 and 3 tested memory for paired associates. Study 2 used unimodal visual presentation or cross modal visual-auditory word pairs in a cued recall paradigm. Study 3 presented word pairs as visual only, auditory only or audiovisual and tested memory separately for items (individual words) or associations (word pairings).

RESULTS

Typical age deficits in associative memory emerged, but these were not alleviated by multimodal presentation.

DISCUSSION

The lack of multimodal support for associative memory indicates that perceptual manipulations are less effective than other forms of environmental support at alleviating age deficits in associative memory.

Episodic Memory formation: A review of complex Hippocampus input pathways

Memories of everyday experiences involve the encoding of a rich and dynamic representation of present objects and their contextual features. Traditionally, the resulting mnemonic trace is referred to as Episodic Memory, i.e. the "what", "where" and "when" of a lived episode. The journey for such memory trace encoding begins with the perceptual data of an experienced episode handled in sensory brain regions. The information is then streamed to cortical areas located in the ventral Medio Temporal Lobe, which produces multi-modal representations concerning either the objects (in the Perirhinal cortex) or the spatial and contextual features (in the parahippocampal region) of the episode. Then, this high-level data is gated through the Entorhinal Cortex and forwarded to the Hippocampal Formation, where all the pieces get bound together. Eventually, the resulting encoded neural pattern is relayed back to the Neocortex for a stable consolidation. This review will detail these different stages and provide a systematic overview of the major cortical streams toward the Hippocampus relevant for Episodic Memory encoding.

Evaluating the Feasibility of The NIH Toolbox Cognition Battery for Autistic Children and Adolescents

This study evaluates the feasibility of the NIH Toolbox Cognition Battery (NIH-TCB) for use in autism spectrum disorder (ASD). 116 autistic children and adolescents and 80 typically developing (TD) controls, ages 3-17 years, completed four NIH-TCB tasks related to inhibitory control, cognitive flexibility, processing speed, and episodic memory. While the majority of autistic and TD children completed all four tasks, autistic children experienced greater difficulties with task completion. Across autistic and TD children, performance on NIH-TCB tasks was highly dependent on IQ, but significant performance differences related to ASD diagnosis were found for two of four tasks. These findings highlight the potential strengths and limitations of the NIH-TCB for use with autistic children.

Emotional state alters encoding of long-term spatial episodic memory

The neurobiology of emotion and episodic memory are well-researched subjects, as is their intersection: memory of emotional events (i.e. emotional memory). We and others have previously demonstrated that the emotional valence of stimuli is encoded in the dorsal hippocampus, a structure integral to the acquisition, consolidation and retrieval of long-term episodic memories. Such findings are consistent with the idea that the emotional valence of stimuli contributes to the "what" component of episodic memories ("where" and "when" being the other components). We hypothesized that being in a heightened emotional state by itself does not contribute to the "what" component of episodic memories. We tested an inference of this hypothesis - that negative emotional state does not alter re-encoding of a spatial episodic event. Rats from the experimental group explored a novel place at their baseline emotional state (Event 1) and 20 min later re-explored the same place (Event 2) in a negative emotional state induced by a state-altering event prior to Event 2. We examined neuronal ensembles that induced expression of Arc and Homer1a, two immediate-early genes (IEGs) necessary for synaptic plasticity and consolidation of long-term memories, during both events. We found that in dorsal CA1 and dorsal CA3, Event 1 and Event 2 induced IEG expression in different neuronal ensembles. This finding was reflected in a low Fidelity score, which assesses the percentage of the Event 1 IEG-expressing ensemble re-activated during Event 2. The Fidelity score was significantly higher in a control group which was at a baseline emotional state during Event 2. Groups which were matched for non-specific disruptions from the state-altering event had intermediate Fidelity scores in dorsal CA1. The Fidelity scores of the dorsal CA3 in the latter groups were similar to those of the control group. Combined, the findings reject the tested hypothesis and suggest that a negative emotional state is encoded in the hippocampus as part of the long-term memory of episodic events that lack explicit emotion-inducing stimuli. These findings also suggest that individuals who often experience strong negative emotional states incorporate these states into ongoing non-emotional episodic memories.

Does Episodic Retrieval Contribute to Creative Writing? An Exploratory Study

Previous research indicates that episodic retrieval contributes to divergent creative thinking. However, this research has relied on standard laboratory tests of divergent creative thinking, such as generating creative uses for objects; it is unknown whether episodic retrieval also contributes to domain-specific forms of creativity. Here we start to explore whether episodic retrieval contributes to content generation on one such domain-specific task: creative writing. In two experiments, we use an episodic specificity induction (ESI) that selectively impacts tasks that draw on episodic retrieval. If episodic retrieval contributes to content generation during creative writing, then ESI should selectively increase the number of episodic details that people subsequently generate on a creative writing task. In our first experiment, we found evidence that ESI increased the number of episodic details participants generated. We observed a similar, though non-significant, trend in the second experiment. These findings constitute a starting point for examining the contribution of episodic retrieval to creative writing, but additional studies will be needed to more definitively characterize the nature and extent of these contributions.

Evolution, Emotion, and Episodic Engagement

Although rodent research provides important insights into neural correlates of human psychology, new cortical areas, connections, and cognitive abilities emerged during primate evolution, including human evolution. Comparison of human brains with those of nonhuman primates reveals two aspects of human brain evolution particularly relevant to emotional disorders: expansion of homotypical association areas and expansion of the hippocampus. Two uniquely human cognitive capacities link these phylogenetic developments with emotion: a subjective sense of participating in and reexperiencing remembered events and a limitless capacity to imagine details of future events. These abilities provided evolving humans with selective advantages, but they also created proclivities for emotional problems. The first capacity evokes the "reliving" of past events in the "here-and-now," accompanied by emotional responses that occurred during memory encoding. It contributes to risk for stress-related syndromes, such as posttraumatic stress disorder. The second capacity, an ability to imagine future events without temporal limitations, facilitates flexible, goal-related behavior by drawing on and creating a uniquely rich array of mental representations. It promotes goal achievement and reduces errors, but the mental construction of future events also contributes to developmental aspects of anxiety and mood disorders. With maturation of homotypical association areas, the concrete concerns of childhood expand to encompass the abstract apprehensions of adolescence and adulthood. These cognitive capacities and their dysfunction are amenable to a research agenda that melds experimental therapeutic interventions, cognitive neuropsychology, and developmental psychology in both humans and nonhuman primates.

Stimulus valence, episodic memory, and the priming of brain activation profiles in borderline personality disorder

BACKGROUND

Borderline personality disorder (BPD) is characterized by instability in affective regulation that can result in a loss of cognitive control. Triggers may be neuronal responses to emotionally valenced context and/or stimuli. 'Neuronal priming' indexes the familiarity of stimuli, and may capture the obligatory effects of affective valence on the brain's processing system, and how such valence mediates responses to the repeated presentation of stimuli. We investigated the effects of affective valence of stimuli on neuronal priming (i.e. changes in activation to repeated presentation of stimuli), and if these effects distinguished BPD patients from controls.

METHODS

Forty BPD subjects and 25 control subjects (age range: 18-44) participated in an episodic memory task during fMRI. Stimuli were presented in alternating epochs of encoding (six images of positive, negative, and neutral valence) and recognition (six images for 'old' v. 'new' recognition). Analyses focused on inter-group differences in the change in activation to repeated stimuli (presented during Encoding and Recognition).

RESULTS

Relative to controls, BPD showed greater priming (generally greater decrease from encoding to recognition) for negatively valenced stimuli. Conversely, BPD showed less priming for positively valenced stimuli (generally greater increase from encoding to recognition).

CONCLUSION

Plausibly, the relative familiarity of negative valence to patients with BPD exerts an influence on obligatory responses to repeated stimuli leading to repetition priming of neuronal profiles. The specific effects of valence on memory and/or attention, and consequently on priming can inform the understanding of mechanisms of altered salience for affective stimuli in BPD.

Reversible Verbal Memory Integration Deficits in Obstructive Sleep Apnoea

When presented with novel but semantically related elements after learning verbal material, healthy participants tend to endorse these items as previously learned. This reflects the normal integration and association of novel verbal information into long-term memory. How obstructive sleep apnoea (OSA) negatively impacts verbal memory performance, and whether deficits are reversible following positive airway pressure (PAP) treatment, remain elusive. We investigated immediate and delayed OSA- and PAP treatment-related effects on verbal memory integration, using a false memory paradigm. Twenty-three patients with OSA learned lists of words semantically related to target non-presented words (1) at baseline after a polysomnography diagnosis night, (2) after a consecutive polysomnography night under PAP titration, and (3) after three months of compliant PAP treatment. At each session, participants learned 10 different lists of words, each list comprising 15 semantically related items. They had then to recognize 15 minutes later (after an intermediate vigilance task) previously learned words within a list including studied words (learned), unstudied but semantically related items (lures), and non-related unstudied items (controls). Sleep quality and fatigue questionnaires, and psychomotor vigilance tests (PVT) were administered at each session. PAP treatment led to OSA remission and improvement in objective and subjective sleep quality. Crucially, recognition of learned and lure words increased after the first night under treatment and remained stable three months later, suggesting successful memory integration and restoration of semantic processes. No treatment-related outcome was found on PVT performance. OSA exerts a detrimental but PAP-reversible effect on verbal learning and semantic memory integration mechanisms underlying the acquisition of novel memory representations.

Interactive Effects of Chronic Health Conditions and Financial Hardship on Episodic Memory among Older Blacks: Findings from the Health and Retirement Study

Previous research links chronic health conditions and financial hardship to cognitive outcomes among older Blacks. However, few studies have explored the moderating effect of financial hardship on chronic disease burden and specific cognitive domains. This study examined whether financial hardship (as measured by difficulty paying monthly bills) modifies the impact of self-reported chronic health conditions (e.g., diabetes, stroke) on episodic memory among 871 older Blacks (50+ years) in the Health and Retirement Study (2006). Financial hardship modified the association between chronic disease burden and episodic memory performance such that individuals who reported very little difficulty paying their monthly bills had significantly lower memory scores at high levels of disease burden compared to those reporting high financial difficulty after controlling for age, gender and education (F 2, 49 = 5.03, p= 0.010). This cross-sectional study suggests that both financial and physical wellbeing may have joint effects on cognitive health in older Blacks.

Staging the cognitive continuum in prodromal Alzheimer's disease with episodic memory

It is unclear whether episodic memory is an appropriate descriptor of the cognitive continuum in mild cognitive impairment (MCI). Here, we investigated the ability of episodic memory to track cognitive changes in patients with MCI with biomarker evidence of Alzheimer's disease (AD). We examined 387 MCI amyloid-positive subjects, cognitively staged as "early" or "late" on the basis of episodic memory impairment. Cross-sectional and longitudinal comparisons between these 2 groups were performed for each amyloid, tau, and neurodegeneration (AT(N)) profile. Cross-sectional analyses indicate that "early" MCI represents a transitional phase between normal cognition and "late" MCI in the AD biomarker pathway. After adjusting by confounders and levels of A, T, and (N), "late" MCI progressed significantly faster than "early" MCI only in profiles with both abnormal amyloid and tau markers (A+T+(N)- p < 0.05, A+T+(N)+ p < 0.001). Episodic memory staging is useful for describing symptoms in prodromal AD and complements the AT(N) profiles. Our findings might have implications for the Numeric Clinical staging scheme of the National Institute on Aging and Alzheimer's Association research framework.

Pain and Cognition in Multiple Sclerosis

Objective

The goal of the present study was to examine the relationship between pain and cognition in patients with multiple sclerosis.

Design

Cross-sectional.

Setting

Nursing home and personal environment of the investigators.

Subjects

Two groups of participants were included: 91 patients with multiple sclerosis and 80 matched control participants.

Methods

The level of pain was measured by the following pain scales: Number of Words Chosen-Affective, Colored Analogue Scale for pain intensity and suffering from pain, and the Faces Pain Scale. Mood was tested by administering the Beck Depression Inventory and the Symptom Check List-90 anxiety and depression subscale. Global cognitive functioning was assessed by the Mini Mental State Examination. Memory and executive functions were assessed by several neuropsychological tests.

Results

Multiple sclerosis (MS) patients scored significantly lower than control participants on the majority of the neuropsychological tests. The MS patients experienced more pain compared with control participants, despite the fact that they were taking significantly more pain medication. No significant correlation was observed between cognition and pain in MS patients. Verbal working memory explained 10% of pain intensity (trend). Mood appeared to be a significant predictor of pain in patients with multiple sclerosis.

Conclusion

The lack of a relationship between cognition and pain might be explained by the fact that, compared with control participants, patients with multiple sclerosis activate other non-pain-related areas to perform executive functions and memory tasks.

Obesity and insulin resistance are associated with reduced activity in core memory regions of the brain

Increasing research in animals and humans suggests that obesity may be associated with learning and memory deficits, and in particular with reductions in episodic memory. Rodent models have implicated the hippocampus in obesity-related memory impairments, but the neural mechanisms underlying episodic memory deficits in obese humans remain undetermined. In the present study, lean and obese human participants were scanned using fMRI while completing a What-Where-When episodic memory test (the “Treasure-Hunt Task”) that assessed the ability to remember integrated item, spatial, and temporal details of previously encoded complex events. In lean participants, the Treasure-Hunt task elicited significant activity in regions of the brain known to be important for recollecting episodic memories, such as the hippocampus, angular gyrus, and dorsolateral prefrontal cortex. Both obesity and insulin resistance were associated with significantly reduced functional activity throughout the core recollection network. These findings indicate that obesity is associated with reduced functional activity in core brain areas supporting episodic memory and that insulin resistance may be a key player in this association.

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Obesity associated with reduced activity in core recollection network during episodic memory.

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Insulin resistance associated with reduced activity in core recollection network during episodic memory.

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Insulin resistance, but not obesity, associated with poorer memory performance.

Impairments in Component Processes of Executive Function and Episodic Memory in Alcoholism, HIV Infection, and HIV Infection with Alcoholism Comorbidity

BACKGROUND

Executive functioning and episodic memory impairment occur in HIV infection (HIV) and chronic alcoholism (ALC). Comorbidity of these conditions (HIV + ALC) is prevalent and heightens risk of vulnerability to separate and compounded deficits. Age and disease-related variables can also serve as mediators of cognitive impairment and should be considered, given the extended longevity of HIV-infected individuals in this era of improved pharmacological therapy.

METHODS

HIV, ALC, HIV + ALC, and normal controls (NC) were administered traditional and computerized tests of executive function and episodic memory. Test scores were expressed as age- and education-corrected Z-scores; selective tests were averaged to compute Executive Function and Episodic Memory Composite scores. Efficiency scores were calculated for tests with accuracy and response times.

RESULTS

HIV, ALC, and HIV + ALC had lower scores than NC on Executive Function and Episodic Memory Composites, with HIV + ALC even lower than ALC and HIV on the Episodic Memory Composite. Impairments in planning and free recall of visuospatial material were observed in ALC, whereas impairments in psychomotor speed, sequencing, narrative free recall, and pattern recognition were observed in HIV. Lower decision-making efficiency scores than NC occurred in all 3 clinical groups. In ALC, age and lifetime alcohol consumption were each unique predictors of Executive Function and Episodic Memory Composite scores. In HIV + ALC, age was a unique predictor of Episodic Memory Composite score.

CONCLUSIONS

Disease-specific and disease-overlapping patterns of impairment in HIV, ALC, and HIV + ALC have implications regarding brain systems disrupted by each disease and clinical ramifications regarding the complexities and compounded damping of cognitive functioning associated with dual diagnosis that may be exacerbated with aging.

Comparison of "Word" vs. "Picture" Version of the Free and Cued Selective Reminding Test (FCSRT) in Older Adults

Background

This study examined the psychometric relationship between the Word and Picture versions of the Free and Cued Selective Reminding Test (FCSRT) and developed an equation for score conversion.

Methods

One hundred and eight-seven participants were administered the FCSRT-Picture and FCSRT-Word on two visits using a randomized counterbalanced design.

Results

Participants had a mean age of 82.1 (standard deviation or SD = 5.4) and mean education of 14.5 (SD = 3.3) years. Mean FCSRT-Picture Free Recall score (mean 33.0 years, range: 17–44 years) was 7.9 points higher than the Word score (mean 25.1 years, range: 3–43 years). The Picture and Word FCSRT correlations for Free Recall and Total Recall were r = 0.56, P < .01 and r = 0.46, P < .01, respectively.

Discussion

The Picture and Word versions of the FCSRT were moderately associated in a sample of cognitively normal older adults. The score mean differences and variability between FCSRT-Picture and FCSRT-Word indicate that their scores should not be considered equivalent.