Memory Task Performance Research Articles

Cortical α4β2-nicotinic acetylcholine receptors and cognitive decline in Parkinson's disease

Background Autopsy and in vivo molecular imaging studies suggest altered binding of the α4β2-nicotinic cholinergic receptor (α4β2-nAChR) with cognitive dysfunction in Parkinson's disease (PD). Objective To determine the relationship between cortical and hippocampal binding of the α4β2-nAChR with [18F]XTRA PET, a high-affinity radiotracer that enables quantification of α4β2-nAChR in these regions, and cognitive function in individuals with PD. Methods Individuals with PD (N = 32) and age-similar, controls without PD or dementia (N = 10) completed a cognitive assessment and one 90-min, [18F]XTRA PET scan. Metabolite-corrected arterial input function radioactivity time-activity curves were generated to obtain total distribution volume (VT) across 12 regions of interest (ROIs). [18F]XTRA binding was compared 1) between controls and people with PD and 2) between controls, persons with PD with normal cognition (PD-NC), and persons with PD with MCI (PD-MCI). Results [18F]XTRA binding was higher in the occipital cortex of the combined group of PD participants compared to age-similar controls. No regions showed lower binding in PD. VT with, but not without, partial volume correction was different between controls, PD-NC, and PD-MCI groups, and this was driven by higher binding in PD-MCI compared to controls. Regression of regional VT on cognitive domain T-scores, adjusting for age, showed that worse performance in visual-spatial memory tasks was associated with higher VT in the precuneus and the entire parietal cortex. Conclusions Higher α4β2-nAChR binding in posterior cortical regions is found in PD and associated with worse visual perception and memory, possibly due to lower receptor occupancy by endogenous acetylcholine.

Sociodemographic factors, cognitive performance and cognitive reserve in brazilian High Performance Older Adults (HPOAs)

Given the increasing aging population, investigating the cognitive functioning of older adults is crucial. Various factors are associated with both cognitive decline and preservation. High Performance Older Adults (HPOAs) are a subset of older individuals demonstrating exceptional cognitive abilities, often exhibiting phenotypic characteristics such as superior cognitive skills. This study aims to investigate the relationship between sociodemographic factors, cognitive reserve and cognitive performance in a sample of brazilian older adults identified as having high cognitive abilities. To examine this phenomenon, data were collected via a sociodemographic questionnaire and cognitive assessments. Of an initial sample of 62 participants, 54 completed the study (38.8% men, 61.1% women). Analysis revealed 12 participants (22.2%) met HPOA criteria, while 42 (77.7%) were classified as Standard Performance Older Adults (SPOAs). HPOAs demonstrated significantly better performance on the Rey Auditory Verbal Learning Test (RAVLT) in trials A1-A5, A6, A7, and Recognition Memory (p < 0.001); on the Rey Complex Figure in Immediate and Delayed Recall (p = 0.006), and on the Trail Making Test A (TMT A) (p = 0.003). Significant differences were also found in the analysis items of the Cognitive Reserve Scale (CRS) (p < 0.001; p = 0.008; p = 0.002). The findings reveal that HPOAs exhibit superior performance in episodic memory, attention and processing speed tasks. The model coefficients in logistic regression revealed a statistically significant association between Total Points in CRS and HPOA (β = 0.0508, standard error = 0.0147, z = 3.45, p < 0.001). These results emphasize the importance of cognitive reserve for preserving cognitive performance in the elderly. New research should aim to elucidate the complex interplay of markers associated with HPOAs, employing rigorous research protocols sensitive to sociocultural context.

Working Memory as the Focus of the Bilingual Effect in Executive Functions

The bilingual effect on executive functions (EFs) has garnered considerable attention, with most studies focusing on the visual domain and largely overlooking the auditory domain. Furthermore, research has predominantly concentrated on specific subcomponents of executive functions, with few studies systematically examining all three key subcomponents. This raises two important questions: (a) Is the bilingual effect specific to certain modalities (modality-specific), or a more general phenomenon (modality-general)? (b) Is the bilingual effect concentrated in a specific component of executive functions (process-specific), or does it extend to all three components (process-general)? To explore these questions, this study recruited monolingual Chinese and bilingual Chinese–English participants, using matched visual and auditory Stroop, N-back, and task-switching tasks to assess inhibitory control, working memory, and cognitive flexibility in both groups. The results showed that, after controlling for variables like intelligence, socioeconomic status, and age, bilingualism significantly predicted performance in both auditory and visual working memory tasks, explaining 34% and 19% of the variance, respectively. However, no evidence was found to support a bilingual effect in inhibitory control or cognitive flexibility. In conclusion, these results suggest that bilingual effects are not only process-specific (affecting only working memory) but also modality-general (providing advantages in both visual and auditory modalities).

Early midlife ovarian removal is associated with lower posterior hippocampal function.

Women with early bilateral salpingo-oophorectomy (BSO) have greater Alzheimer's disease (AD) risk than women with spontaneous menopause (SM), but the pathway toward this risk is understudied. Considering associative memory deficits may reflect early signs of AD, we studied how BSO affected brain activity underlying associative memory. Early midlife women with BSO (with and without 17β-estradiol therapy [ET]) and age-matched controls (AMCs) with intact ovaries completed a face-name associative memory task during functional magnetic resonance imaging. Hippocampal activity along the anteroposterior axis during associative encoding and retrieval was compared among three groups (BSO [n=28], BSO+ET [n=35], AMCs [n=40]). Both BSO groups (with and without ET) showed lower posterior hippocampal activation during encoding compared to the AMC group. However, this difference in activation was not significantly correlated with associative memory task performance. Early 17β-estradiol loss may influence posterior hippocampal activity during associative encoding, possibly presaging late-life AD. After ovarian removal, changes in hippocampal function may affect dementia risk. Midlife ovarian removal is associated with less activation in the posterior hippocampus. Estradiol therapy may ameliorate alterations in brain function during learning.

Resting‐state activity across cortical hierarchies provides readiness for memorizing in aging humans

AbstractBackgroundThe neural basis of memory aging remains elusive. The default mode network (DMN) supports memory encoding and retrieval, and its connectivity decreases in aging. Young adults with larger differences in resting‐state functional connectivity (rsFC) between higher‐order DMN and lower‐order sensory/motor network (SMN) have better cognition and memory. We combined resting‐state and task‐based fMRI during an associative memory task to explore how this cross‐hierarchical contrast of rsFC is linked to memory aging.MethodWe included resting‐state prior to (an object‐scene‐pair encoding) task fMRI from 16 young adults (YA; 24.6 ± 3.6 years; 7 females) and 42 cognitively normal older adults (OA; 76.8 ± 6.9 years; 24 females) in the Berkeley Aging Cohort Study. We subtracted the averaged rsFC within lower‐order regions from higher‐order ones, and correlated the cross‐hierarchy contrast of rsFC with age and memory task performance. Brain function contrast between the higher and lower order regions may also manifest as the temporal difference/delay of cortical activation, seen in propagating waves between hierarchical cortices. The propagating number (i.e., frequency) in each direction (“High‐to‐low” or “Low‐to‐high”) was therefore also correlated with memory performance and activation in anterior‐temporal (AT), posterior‐medial (PM), and hippocampal (HPC) memory regions during task‐fMRI.ResultAmong OAs, cross‐hierarchy contrast of rsFC decreased with aging (Spearman’s ρ = ‐ 0.32, p = 0.040) and in females (p = 2.3 ×10‐3). OAs with lower rsFC contrast had worse memory during retrieval (ρ = 0.36, p = 0.019; Figure 1). Memory scores were not correlated with mean rsFC within higher‐order regions or lower‐order ones. Propagating number along the “Low‐to‐high” direction decreased in OAs. More propagation was associated with better memory and lower task‐evoked activation in AT, PM, and HPC regions (all ρ strength > 0.35, p < 0.030; Figure 2&3).ConclusionPatterns of resting‐state functional connectivity related to hierarchical cortical organization are associated with aging and memory decline. In particular, slow propagating waves of cortical activation transiting across these hierarchies may serve a preparatory function, readying the brain for memory formation, a process that is affected by aging.

The Influence of Music Reading on Spatial Working Memory and Self-Assessment Accuracy.

Previous research has suggested that Western musicians, who generally demonstrate proficiency in reading musical scores, exhibit superior performance in visuospatial working memory tasks compared to non-musicians. Evidence indicates brain activation in regions such as the left inferior parietal lobe and the right posterior fusiform gyrus during music reading, which are associated with visuospatial processing. This study aimed to explore how musical training influences spatial working memory and to examine the relationship between self-assessment accuracy and cognitive performance. A visuospatial working memory test, the Corsi block-tapping test (CBT), was administered to 70 participants, including 35 musicians with experience in music reading and 35 non-musicians. CBT performances were compared between groups, controlling for sex and age differences using analysis of covariance. Participants were also asked to self-assess their visuospatial capabilities. Musicians performed significantly better than non-musicians in the CBT and demonstrated greater metacognitive accuracy in evaluating their visuospatial memory capacities. A total of 46.34% of musicians who claimed good performance on the CBT did in fact perform well, in comparison with 14.63% of non-musicians. Sex influenced the outcomes of spatial working memory, while age did not significantly affect performance. This self-awareness of visuospatial capabilities reflects a form of metacompetence, encompassing reflective thinking and the ability to assess one's cognitive skills. Furthermore, while differences in spatial working memory between musicians and non-musicians appear to be related to executive functions associated with general music practice, further investigation is needed to explore other potential influences beyond musical experience.

Does background sound impact cognitive performance and relaxation states in enclosed office?

Does background sound impact cognitive performance and relaxation states in enclosed office?

Machine learning diagnosis of schizophrenia using structural and functional images of the brain

Abstract. This study aims to provide earlier, and faster schizophrenia diagnosis based on neurocognitive, structural, and behavioral measures using machine learning. This is because current ways of diagnosis, while accurate, delay patients ability to seek medical care before observable, lasting symptoms develop and are prone to error and discrimination. To provide diagnosis, we used Linear Support Vector Machine (linear SVM), Random Forest (RF), Multilayer Perceptron (MLP), and k-Nearest Neighbor (kNN), all trained with neurocognitive and behavioral measures combined with either structural or functional MRI data or both of 99 subjects from the OpenNeuro public dataset. 100 iterations of classification were run, and results showed a higher-than-average accuracy for all classifiers using all combinations of parameters, with a highest accuracy of 0.75 using linear SVM trained with behavioral and neurocognitive measures and fMRI data. We found correlations between structural changes in AAL3 brain regions and n-back working memory task performance, noting that the inferior parietal gyrus, right precuneus, supplementary motor area, and the central lateral thalamic nucleus have the highest feature importance. This means that future studies can select these features for further clinical examination or for machine learning diagnosis. We conclude that linear SVM provides the highest average diagnostic accuracy, and that fMRI data often leads to more accurate algorithmic decisions than sMRI data and thus should be weighed more in future studies.

A novel phosphodiesterase 5 inhibitor, RF26, improves memory impairment and ameliorates tau aggregation and neuroinflammation in the P301S tauopathy mouse model of Alzheimer's disease

Phosphodiesterase-5 (PDE5) inhibitors are primarily used in the treatment of erectile dysfunction and pulmonary hypertension, but have also been reported to have a potential therapeutic effect for the treatment of Alzheimer's disease (AD). This is likely to be through stimulation of nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) signaling by elevating cGMP, a secondary messenger involved in processes of neuroplasticity. In the present study, we evaluated the efficacy of a novel PDE5 inhibitor, RF26, using P301S tauopathy mice model. A body of experimental evidence suggests that the development of tau inclusions leads to the neurodegeneration observed in tauopathies, including AD, Frontotemporal dementia (FTD), Supranuclear palsy and others. RF26 successfully targeted NO/cGMP signaling pathway and showed a significant improvement of spatial memory task performance of P301S mice using Morris Water Maze and T-maze. Furthermore, RF26 -treated mice showed a significant reduction of phosphorylated tau load, gliosis and downregulated pro-inflammatory cytokines. The presented data support the efficacy of RF26 as a potent PDE5 inhibitor and calls for further investigation as a potential therapeutic drug for Alzheimer's and other tauopathy related neurological disorders.

Towards theoretically understanding how long-term memory semantics can support working memory performance.

Working memory is the system that supports the temporary storage and processing of information. It is generally agreed that working memory is a mental workspace, with a combination of resources operating together to maintain information in mind for potential use in thought and action. Theories typically acknowledge the contributions of long-term memory to this system. One particular aspect of long-term memory, namely semantic long-term memory, can effectively supplement or "boost" working memory performance. This may be a relatively automatic process via the semantic properties of the stimuli or more active via strategy development and implementation. However, the precise mechanisms require greater theoretical understanding. In this review of the literature, we critically discuss theoretical models of working memory and their proposed links with long-term memory. We also explore empirical research that contributes to our understanding of the ways in which semantics can support performance of both verbal and visuospatial working memory tasks, with a view to potential intervention development. This includes the possibility of training people with lower performance (e.g., older adults) to use semantics during working memory tasks. We conclude that semantics may offer an opportunity to maximise working memory performance. However, to realise this potential, more research is needed, particularly in the visuospatial domain.

Ginger Extract Improves Cognitive Dysfunction via Modulation of Gut Microbiota-Derived Short-Chain Fatty Acids in D-Galactose/Ovariectomy-Induced Alzheimer-Like Disease.

Alzheimer's disease (AD) is the most common form of dementia with complex causes and limited treatment options. Recent research has suggested a connection between the progression of AD and the activity of gut microbiota. Ginger, a plant known for its anti-inflammatory, antioxidant, and neuroprotective properties, has gained attention as a potential treatment for alleviating AD symptoms. In this study, we induced an AD model in female rats through ovariectomy and D-galactose injection and then investigated the protective effects of oral administration of ginger ethanolic extract. We assessed changes in short-chain fatty acids (SCFAs), learning and memory abilities, neuroinflammatory markers in plasma, and the hippocampus, as well as histological changes in the intestine and hippocampus in sham-operated, diseased, and treatment groups. Oral administration of ginger ethanolic extract improved gut microbiota activity, increased SCFA levels, and enhanced the expression of tight junction proteins. Additionally, ginger extract reduced the concentrations of TNF-α and IL-1β in both plasma and the hippocampus. Furthermore, it significantly reduced cell death and amyloid plaque deposition in the hippocampal tissue. These physiological changes resulted in improved performance in learning and memory tasks in rats treated with ginger compared with the disease group. These findings provide compelling evidence for the beneficial effects of ginger on the gut-brain axis, leading to improvements in learning and memory through the reduction of neuroinflammation.

Motor-related oscillations reveal the involvement of sensorimotor processes during recognition memory

Certain object properties may render an item as more memorable than others. One such property is manipulability, or the extent to which an object can be interacted with using our hands. This study sought to determine if the manipulability of an item modulates memory task performance on both a behavioural and neural level. We recorded electroencephalography (EEG) from a large sample of right-handed individuals (N=53) during a visual item recognition memory task. The task contained stimuli of both high and low manipulability. Analysis focused on activity in the theta rhythm (3.5-7Hz), which has been implicated in sensorimotor integration, and the mu rhythm (8-14Hz), the primary oscillation associated with sensorimotor related behaviours. At both encoding and retrieval, theta oscillations were greater over the left motor region for high manipulability stimuli, suggesting that an item's sensorimotor properties are assessed immediately upon presentation. Manipulability did not affect activity in the mu rhythm. However, mu oscillations over the left motor region were lower during the retrieval of old versus new items and response time was faster for old items, aligning with the cortical reinstatement hypothesis. These results collectively reveal an association between motor oscillations and memory processes, highlight the involvement of sensorimotor processing at both encoding and retrieval.

Exercising with virtual reality is potentially better for the working memory and positive mood than cycling alone

Exercising with virtual reality is potentially better for the working memory and positive mood than cycling alone

Subjective cognitive decline is associated with altered patterns of brain activity and connectivity during performance of an old/new recognition memory task

Subjective Cognitive Decline (SCD) is considered a preclinical stage within the AD continuum. Knowledge about the functional changes in the brain associated with episodic memory retrieval and novelty recognition in people with SCD is currently very limited. The study aimed to evaluate behavioural and neurofunctional changes in individuals with SCD, measured relative to a control group, during successful episodic memory retrieval and novelty recognition, as well as to compare the functional connectivity patterns related to these cognitive processes within the Default Mode Network (DMN) in both groups. Participants performed an old/new recognition memory task with words while the BOLD signal was acquired. No between-group differences were observed in the performance of the episodic memory task. However, during the successful recognition of old words, the SCD group showed brain hypoactivity in the right rolandic operculum and reduced functional connectivity between the DMN and the fronto-parietal control network (FPCN). During the correct identification of new words, the SCD group also showed reduced connectivity between the DMN and the FPCN, and lower connectivity within the DMN. Despite the absence of objective evidence of cognitive impairment, people with SCD display several changes in brain activity and connectivity associated with episodic memory retrieval and novelty recognition.

The role of articulatory rehearsal in short-term false memories during ageing.

Recent studies have shown that articulatory rehearsal prevents false memories in working memory tasks in young adults. During ageing, a substantial increase in false memories has been documented in numerous studies. The aim of this study was to investigate the role of rehearsal in the increase of false memories with age. In two experiments, we manipulated the opportunity to use rehearsal in a Brown-Peterson task in which younger (n = 80) and older (n = 70) adults maintained semantically related word lists and reported their maintenance strategies. Both experiments showed that reducing the opportunity to use rehearsal increased false memories and decreased correct recall in both groups. Furthermore, older adults made more false memories and less correct recall than younger adults, and these effects were partially mediated by the number of times participants reported using rehearsal (Experiment 2). These findings suggest that age-related differences in rehearsal use explain differences in working memory task performance.

Introducing ART: A new method for testing auditory memory with circular reproduction tasks.

Theories of visual working memory have seen significant progress through the use of continuous reproduction tasks. However, these tasks have mainly focused on studying visual features, with limited examples existing in the auditory domain. Therefore, it is unknown to what extent newly developed memory models reflect domain-general limitations or are specific to the visual domain. To address this gap, we developed a novel methodology: the Auditory Reproduction Task (ART). This task utilizes Shepard tones, which create an infinite rising or falling tone illusion by dissecting pitch chroma and height, to create a 1-360° auditory circular space. In Experiment 1, we validated the perceptual circularity and uniformity of this auditory stimulus space. In Experiment 2, we demonstrated that auditory working memory shows similar set size effects to visual working memory-report error increased at a set size of 2 relative to 1, caused by swap errors. In Experiment 3, we tested the validity of ART by correlating reproduction errors with commonly used auditory and visual working memory tasks. Analyses revealed that ART errors were significantly correlated with performance in both auditory and visual working memory tasks, albeit with a stronger correlation observed with auditory working memory. While these experiments have only scratched the surface of the theoretical and computational constraints on auditory working memory, they provide a valuable proof of concept for ART. Further research with ART has the potential to deepen our understanding of auditory working memory, as well as to explore the extent to which existing models are tapping into domain-general constraints.

Examining the Effects of Embodiment on Working Memory Performance in VR

This study investigates the impact of immersive virtual reality (VR) environments on working memory task performance and the role of embodiment in VR. Sixteen participants engaged in N-back tasks presented either on a computer screen or in VR. Participants were assigned to one of four conditions: non-VR, VR without mimicking, VR with mimicking, or VR with mimicking and virtual mirror. Statistical analyses revealed no significant differences in sense of embodiment or task performance among the VR conditions. Additionally, there were no significant changes in working memory performance across conditions. While the findings suggest that variations in VR setups may not affect embodiment or task performance, the study’s preliminary nature emphasizes the need for larger sample sizes for more conclusive results. Further research is warranted to validate these findings and explore the effects of VR interventions on cognitive outcomes.

Dose Response of Transcranial Photobiomodulation on Cognitive Efficiency in Healthy Older Adults: A Task-Related Functional Near-Infrared Spectroscopy Study.

Alzheimer's disease has become increasingly prevalent among the older population, leading to significant social and economic burdens. Transcranial photobiomodulation (tPBM) has shown promise as a cognitive intervention for enhancing cognitive efficiency in healthy older adults, and individuals with mild cognitive impairment and Alzheimer's disease. However, determining the optimal tPBM dosage is crucial for ensuring effective and efficient intervention. This study aimed to compare the effects of different dosages in a single tPBM session on cognitive efficiency in healthy older adults. In this randomized controlled trial, 88 healthy older participants were assigned to either a single dose (irradiance = 30 mW/cm2, fluence = 10.8 J/cm2; n = 44) or a double dose (irradiance = 30 mW/cm2, fluence = 21.6 J/cm2; n = 44) tPBM session. Cognitive efficiency was assessed using functional near-infrared spectroscopy during a visual working memory span task. The single dose group exhibited significantly greater cognitive efficiency enhancement, indicated by a more pronounced reduction in oxygenated hemoglobin during a challenging task level (span level 9) (p = 0.021, d = 0.50), and better working memory task performance (p = 0.045, d = 0.31). Furthermore, participants with better visuospatial abilities demonstrated greater improvement after a single dose (r = -0.42, p = 0.004). In contrast, participants with varying cognitive function did not exhibit additional benefits from a double dose (r = -0.22-0.15, p = 0.16-0.95). These findings suggest that higher tPBM dosages may not necessarily result in superior cognitive improvement in older adults.

The effects of moderate prenatal alcohol exposure on performance in hippocampal-sensitive spatial memory and anxiety tasks by adult male and female rat offspring

Moderate prenatal alcohol exposure (mPAE) results in structural alterations to the hippocampus. Previous studies have reported impairments in hippocampal-sensitive tasks, but have not compared performance between male and female animals. In the present study, performance in hippocampal-sensitive spatial memory and anxiety behavior tests were compared across adult male and female saccharin (SACC) control mPAE Long-Evans rat offspring. Two tests of spatial memory were conducted that were aimed at assessing memory for recently acquired spatial information: A delayed spatial alternation task using an M-shaped maze and a delayed match-to-place task in the Morris water task. In both tasks, rats in SACC and mPAE groups showed similar learning and retention of a spatial location even after a 2-h interval between encoding and retention. A separate group of adult male and female SACC and mPAE rat offspring were tested for anxiety-like behaviors in the elevated plus-maze paradigm. In this test, both male and female mPAE rats exhibited a significantly greater amount of time and a greater number of head dips in the open arms, while locomotion and open arm entries did not differ between groups. The results suggest that mPAE produces a reduction in anxiety-like behaviors in both male and female rats in the elevated plus-maze.

Grapheme-Color Synesthesia and Its Connection to Memory.

Synesthesia is the involuntary association of different senses, where individuals experience one sensory modality in response to the stimulation of another. For example, a synesthete may perceive colors when reading certain numbers or associate specific tastes with particular words. Synesthesia manifests differently for individuals grouping the condition in subcategories such as grapheme-color, sound-to-color, lexical-gustatory, mirror-touch, and much more. This review covers grapheme-color synesthesia, described as the involuntary perception of specific colors or color associations when seeing or thinking about certain letters, numbers, or symbols. This review explores the performance of declarative memory tasks in individuals with grapheme-color synesthesia. A comprehensive search of controlled trials published between 2014 to 2024 was conducted through PubMed and Google Scholar databases. In Google Scholar, the search terms grapheme-color synesthesia, grapheme-color synaesthesia, and memory were used. In PubMed, additional MeSH (Medical Subject Headings) terms were used which included grapheme-color synesthesia and memory. Studies that measured declarative memory and grapheme-color synesthesia were included yielding a total of seven controlled trials. Grapheme-color synesthetes demonstrated advanced performance in declarative memory tasks; however, this may not have any clinical significance. Grapheme-color synesthetes demonstrated a better performance in their ability to recall colors, but not as much recalling words. Synesthetes were shown to outperform non-synesthetes in visual memory tasks. Synesthetes showed better recall of paired patterns, shape-color associations, and visual grids compared to control groups, but the influence of synesthesia on word memory remains unclear. Future research should consider adding control for confounding factors, collaborating with other institutions, and increasing sample size.