Retrieving autobiographical memories in autobiographical contexts: are age-related differences in narrated episodic specificity present outside of the laboratory?

The Autobiographical Interview, a method for evaluating detailed memory of real-world events, reliably detects differences in episodic specificity at retrieval between young and older adults in the laboratory. Whether this age-associated reduction in episodic specificity for autobiographical event retrieval is present outside of the laboratory remains poorly understood. We used a videoconference format to administer the Autobiographical Interview to cognitively unimpaired older adults (N = 49, M = 69.5, SD = 5.94) and young adults (N = 54, M = 22.5, SD = 4.19) who were in their homes at the time of retrieval. Relative to young adults, older adults showed reduced episodic specificity in their home environment, as reflected by fewer episodic or "internal" details (t (101) = 3.23, p = 0.009) and more "external" details (i.e., semantic, language-based details) (t (101) = 3.60, p = 0.003). These findings, along with detail subtype profiles in the narratives, bolster the ecological validity of the Autobiographical Interview and add promise to the use of virtual cognitive testing to improve the accessibility, participant diversity, scalability, and ecological validity of memory research.

Hippocampal Functions Modulate Transfer-Appropriate Cortical Representations Supporting Subsequent Memory.

The hippocampus plays a central role as a coordinate system or index of information stored in neocortical loci. Nonetheless, it remains unclear how hippocampal processes integrate with cortical information to facilitate successful memory encoding. Thus, the goal of the current study was to identify specific hippocampal-cortical interactions that support object encoding. We collected fMRI data while 19 human participants (7 female and 12 male) encoded images of real-world objects and tested their memory for object concepts and image exemplars (i.e., conceptual and perceptual memory). Representational similarity analysis revealed robust representations of visual and semantic information in canonical visual (e.g., occipital cortex) and semantic (e.g., angular gyrus) regions in the cortex, but not in the hippocampus. Critically, hippocampal functions modulated the mnemonic impact of cortical representations that are most pertinent to future memory demands, or transfer-appropriate representations Subsequent perceptual memory was best predicted by the strength of visual representations in ventromedial occipital cortex in coordination with hippocampal activity and pattern information during encoding. In parallel, subsequent conceptual memory was best predicted by the strength of semantic representations in left inferior frontal gyrus and angular gyrus in coordination with either hippocampal activity or semantic representational strength during encoding. We found no evidence for transfer-incongruent hippocampal-cortical interactions supporting subsequent memory (i.e., no hippocampal interactions with cortical visual/semantic representations supported conceptual/perceptual memory). Collectively, these results suggest that diverse hippocampal functions flexibly modulate cortical representations of object properties to satisfy distinct future memory demands.Significance Statement The hippocampus is theorized to index pieces of information stored throughout the cortex to support episodic memory. Yet how hippocampal processes integrate with cortical representation of stimulus information remains unclear. Using fMRI, we examined various forms of hippocampal-cortical interactions during object encoding in relation to subsequent performance on conceptual and perceptual memory tests. Our results revealed novel hippocampal-cortical interactions that utilize semantic and visual representations in transfer-appropriate manners: conceptual memory supported by hippocampal modulation of frontoparietal semantic representations, and perceptual memory supported by hippocampal modulation of occipital visual representations. These findings provide important insights into the neural mechanisms underlying the formation of information-rich episodic memory and underscore the value of studying the flexible interplay between brain regions for complex cognition.

Episodic Past, Future, and counterfactual thinking in Relapsing-Remitting Multiple sclerosis.

Multiple sclerosis (MS) is a progressive disease characterized by widespread white matter lesions in the brain and spinal cord. In addition to well-characterized motor deficits, MS results in cognitive impairments in several domains, notably in episodic autobiographical memory. Recent studies have also revealed that patients with MS exhibit deficits in episodic future thinking, i.e., our capacity to imagine possible events that may occur in our personal future. Both episodic memory and episodic future thinking have been shown to share cognitive and neural mechanisms with a related kind of hypothetical simulation known as episodic counterfactual thinking: our capacity to imagine alternative ways in which past personal events could have occurred but did not. However, the extent to which episodic counterfactual thinking is affected in MS is still unknown. The current study sought to explore this issue by comparing performance in mental simulation tasks involving either past, future or counterfactual thoughts in relapsing-remitting MS. Diffusion weighted imaging (DWI) measures were also extracted to determine whether changes in structural pathways connecting the brain's default mode network (DMN) would be associated with group differences in task performance. Relative to controls, patients showed marked reductions in the number of internal details across all mental simulations, but no differences in the number of external and semantic-based details. It was also found that, relative to controls, patients with relapsing-remitting MS reported reduced composition ratings for episodic simulations depicting counterfactual events, but not so for actual past or possible future episodes. Additionally, three DWI measures of white matter integrity-fractional anisotropy, radial diffusivity and streamline counts-showed reliable differences between patients with relapsing-remitting MS and matched healthy controls. Importantly, DWI measures associated with reduced white matter integrity in three association tracts on the DMN-the right superior longitudinal fasciculus, the left hippocampal portion of the cingulum and the left inferior longitudinal fasciculus-predicted reductions in the number of internal details during episodic counterfactual simulations. Taken together, these results help to illuminate impairments in episodic simulation in relapsing-remitting MS and show, for the first time, a differential association between white matter integrity and deficits in episodic counterfactual thinking in individuals with relapsing-remitting MS.

Reduction of Hospitalization and Mortality by Echocardiography-Guided Treatment in Advanced Heart Failure.

In advanced heart failure (AHF) clinical evaluation fails to detect subclinical HF deterioration in outpatient settings. The aim of the study was to determine whether the strategy of intensive outpatient echocardiographic monitoring, followed by treatment modification, reduces mortality and re-hospitalizations at 12 months. Methods: 214 patients with ejection fraction < 30% and >1 hospitalization during the last year underwent clinical evaluation and echocardiography at discharge and were divided into intensive (IMG; N = 143) or standard monitoring group (SMG; N = 71). In IMG, volemic status and left ventricular filling pressure were assessed 14, 30, 90, 180 and 365 days after discharge. HF treatment, particularly diuretic therapy, was temporarily intensified when HF deterioration signs and E/e' > 15 were detected. In SMG, standard outpatient monitoring without obligatory echocardiography at outpatient visits was performed. Results: We observed lower hospitalization (absolute risk reduction [ARR]-0.343, CI-95%: 0.287−0.434, p < 0.05; number needed to treat [NNT]-2.91) and mortality (ARR-0.159, CI 95%: 0.127−0.224, p < 0.05; NNT-6.29) in IMG at 12 months. One-year survival was 88.8% in IMG and 71.8% in SMG (p < 0.05). Conclusion: In AHF, outpatient monitoring of volemic status and intracardiac filling pressures to individualize treatment may potentially reduce hospitalizations and mortality at 12 months follow-up. Echocardiography-guided outpatient therapy is feasible and clinically beneficial, providing evidence for the larger application of this approach.

Asymptomatic COVID-19 and ST-elevation myocardial infarction in young adults: lessons learned from two similar cases.

We present two cases of acute myocardial infarction in young patients with asymptomatic COVID-19 infection and ST-elevation myocardial infarction (STEMI), complicated by severe acute heart failure and ventricular fibrillation, resulting cardiopulmonary resuscitation and mechanical ventilatory support. Urgent primary percutaneous coronary intervention with further complex treatment was effective in both cases with critical cardiovascular state and co-morbid COVID-19 infection. This report illustrates the challenges in clinical severity of STEMI with COVID-19 infection, despite of young age and absence of clinical symptoms and chronic co-morbidities. STEMI patients with even asymptomatic COVID-19 infection may be presented with significantly higher rates of severe acute heart failure.

Characteristics of stroke service implementation in Armenia.

Background: Acute stroke care service in Armenia was established in 2019 after the implementation of the National Stroke Program (NSP). This study aimed to provide an up-to-date account of the current image and clinical characteristics of acute stroke service implementation at a tertiary hospital in Armenia by analyzing the quality of care and identifying the areas that need improvement. Methods: We analyzed patient data from a single hospital in 1 year after the establishment of acute stroke care service (February 2021-January 2022). We selected patients who were within 0-24 h from symptom onset at admission and included patients who benefited from reperfusion therapies (intravenous thrombolysis (IVT) and/or endovascular thrombectomy (EVT)). A favorable outcome was defined as a drop in the National Institutes of Health Stroke Scale (NIHSS) by more than four points at discharge and a modified Rankin score (mRS) of 0-2 at 90 days. Results: Of the total 385 patients, 155 underwent reperfusion therapies, 91% of patients (141/155) arrived by ambulance, 79.2% (122/155) had neurological improvement at discharge, and 60.6% (94/155) had an mRS of 0-2 at 3 months. Less than 5% of patients had early direct access to the rehabilitation center. Conclusion: Our study demonstrated that the implementation of NSP with organized protocol-driven inpatient care led to significant advancement in acute stroke service performance. We believe that our report will serve as a model for achieving advanced and structured stroke care in a resource-limited context and contribute to the future development of the healthcare system in our country.

The visual and semantic features that predict object memory: Concept property norms for 1,000 object images.

Humans have a remarkable fidelity for visual long-term memory, and yet the composition of these memories is a longstanding debate in cognitive psychology. While much of the work on long-term memory has focused on processes associated with successful encoding and retrieval, more recent work on visual object recognition has developed a focus on the memorability of specific visual stimuli. Such work is engendering a view of object representation as a hierarchical movement from low-level visual representations to higher level categorical organization of conceptual representations. However, studies on object recognition often fail to account for how these high- and low-level features interact to promote distinct forms of memory. Here, we use both visual and semantic factors to investigate their relative contributions to two different forms of memory of everyday objects. We first collected normative visual and semantic feature information on 1,000 object images. We then conducted a memory study where we presented these same images during encoding (picture target) on Day 1, and then either a Lexical (lexical cue) or Visual (picture cue) memory test on Day 2. Our findings indicate that: (1) higher level visual factors (via DNNs) and semantic factors (via feature-based statistics) make independent contributions to object memory, (2) semantic information contributes to both true and false memory performance, and (3) factors that predict object memory depend on the type of memory being tested. These findings help to provide a more complete picture of what factors influence object memorability. These data are available online upon publication as a public resource.

Visual and Semantic Representations Predict Subsequent Memory in Perceptual and Conceptual Memory Tests.

It is generally assumed that the encoding of a single event generates multiple memory representations, which contribute differently to subsequent episodic memory. We used functional magnetic resonance imaging (fMRI) and representational similarity analysis to examine how visual and semantic representations predicted subsequent memory for single item encoding (e.g., seeing an orange). Three levels of visual representations corresponding to early, middle, and late visual processing stages were based on a deep neural network. Three levels of semantic representations were based on normative observed ("is round"), taxonomic ("is a fruit"), and encyclopedic features ("is sweet"). We identified brain regions where each representation type predicted later perceptual memory, conceptual memory, or both (general memory). Participants encoded objects during fMRI, and then completed both a word-based conceptual and picture-based perceptual memory test. Visual representations predicted subsequent perceptual memory in visual cortices, but also facilitated conceptual and general memory in more anterior regions. Semantic representations, in turn, predicted perceptual memory in visual cortex, conceptual memory in the perirhinal and inferior prefrontal cortex, and general memory in the angular gyrus. These results suggest that the contribution of visual and semantic representations to subsequent memory effects depends on a complex interaction between representation, test type, and storage location.

Free recall test experience potentiates strategy-driven effects of value on memory.

People tend to show better memory for information that is deemed valuable or important. By one mechanism, individuals selectively engage deeper, semantic encoding strategies for high value items (Cohen, Rissman, Suthana, Castel, & Knowlton, 2014). By another mechanism, information paired with value or reward is automatically strengthened in memory via dopaminergic projections from midbrain to hippocampus (Shohamy & Adcock, 2010). We hypothesized that the latter mechanism would primarily enhance recollection-based memory, while the former mechanism would strengthen both recollection and familiarity. We also hypothesized that providing interspersed tests during study is a key to encouraging selective engagement of strategies. To test these hypotheses, we presented participants with sets of words, and each word was associated with a high or low point value. In some experiments, free recall tests were given after each list. In all experiments, a recognition test was administered 5 minutes after the final word list. Process dissociation was accomplished via remember/know judgments at recognition, a recall test probing both item memory and memory for a contextual detail (word plurality), and a task dissociation combining a recognition test for plurality (intended to probe recollection) with a speeded item recognition test (to probe familiarity). When recall tests were administered after study lists, high value strengthened both recollection and familiarity. When memory was not tested after each study list, but rather only at the end, value increased recollection but not familiarity. These dual process dissociations suggest that interspersed recall tests guide learners' use of metacognitive control to selectively apply effective encoding strategies. (PsycINFO Database Record