Paired-associate Learning Research Articles

Does a Polyherbal Medicine Enhance Cognition in Healthy Older Adults? An Exploratory Open-Label Study.

Objective: This 12-week open-label study evaluated a multi-herbal tablet containing Reynoutria japonica, Vitis vinifera, Silybum marianum, Ginkgo biloba, and Panax ginseng, for potential improvement of cognitive function in 25 healthy older adults (50-75 years). Methods: The primary outcome, cognition, was assessed using the Cambridge Neuropsychological Test Automated Battery. Results: Significant improvement in working memory was observed. Errors in the Paired Associate Learning (PAL) task and spatial working memory reduced by -7.9 (95%CI: -12.3, -3.5) and -3.3 (95%CI: -6.3, -0.3) respectively, while PAL memory score increased by 2.0 (95%CI: 0.9, 3.1). Conclusion: These preliminary results suggest memory improvement, but further rigorous testing is needed.

PRN: progressive reasoning network and its image completion applications

Ancient murals embody profound historical, cultural, scientific, and artistic values, yet many are afflicted with challenges such as pigment shedding or missing parts. While deep learning-based completion techniques have yielded remarkable results in restoring natural images, their application to damaged murals has been unsatisfactory due to data shifts and limited modeling efficacy. This paper proposes a novel progressive reasoning network designed specifically for mural image completion, inspired by the mural painting process. The proposed network comprises three key modules: a luminance reasoning module, a sketch reasoning module, and a color fusion module. The first two modules are based on the double-codec framework, designed to infer missing areas’ luminance and sketch information. The final module then utilizes a paired-associate learning approach to reconstruct the color image. This network utilizes two parallel, complementary pathways to estimate the luminance and sketch maps of a damaged mural. Subsequently, these two maps are combined to synthesize a complete color image. Experimental results indicate that the proposed network excels in restoring clearer structures and more vivid colors, surpassing current state-of-the-art methods in both quantitative and qualitative assessments for repairing damaged images. Our code and results will be publicly accessible at https://github.com/albestobe/PRN.

Associative Learning in Subclinical Hypothyroidism at Different Ranges of Thyroid Stimulating Hormone: A Cambridge Neuropsychological Test Automated Battery (CANTAB) Study of Visual Paired Association Learning Task.

Associative learning deficits are constantly found in subclinical hypothyroidism (SCH). Despite achieving normal thyroid stimulating hormone (TSH) levels, a considerable number of patients undergoing levothyroxine (LT-4) treatment frequently complain about memory retrieval. The Paired Association Learning (PAL) task involves computerised testing on the CANTAB- Cambridge Neuropsychological Test Automated Battery, also considered a screening tool for Alzheimer's disease (AD). This study aimed to investigate the impact of different levels of TSH on visual associative learning in SCH and determine if these impairments were reversed with LT-4. A total of 134 participants were included in this cross-sectional study. Group 1: 35 healthy controls; patients with SCH (Group 2: 33 newly identified cases; Group 3: 32 patients on LT-4 with elevated TSH; Group 4: 34 euthyroid but on LT-4). A thyroid profile and a neuropsychological clinical assessment were done. The visual PAL task was performed on CANTAB. PAL was significantly impaired (p = <0.05) in all 3 patient groups as compared to Group 1. The PAL total errors (adjusted) scores were significantly higher in Groups 2 and 3, indicating that associative learning is definitely impaired in SCH, reaching levels previously seen in patients with AD. Our findings encourage screening for visual associative learning or memory retrieval in patients with SCH. The study present has established a more reasonable threshold of TSH 2.5mIU/L to encourage examination of associative learning and the initiation of LT-4 in SCH. Poor PAL task performance in patients with SCH may have significant implications in clinical settings for suspecting AD.

Mitochondrial DNA copy number associated dementia risk by somatic mutations and frailty.

Mitochondrial dysfunction is linked to physical impairment and dementia. Mitochondrial DNA copy number (mtDNAcn) from blood may predict cognitive decline and dementia risk, but the effect of somatic mutations or frailty is unknown. We estimated mtDNAcn using fastMitoCalc and microheteroplasmies using mitoCaller, from Whole Genome Sequencing (WGS) data. In 189,566 participants free of dementia at study entry (mean age = 56 ± 8), we examined the association between mtDNAcn and subsequent dementia diagnosis using Cox regression. Cognition was assessed in a subset on average 8.9years later. We examined the associations between mtDNAcn and cognitive measures using multivariable linear regression, adjusted for demographic factors, mtDNAcn-related parameters, and apolipoprotein E ε4 status. We further stratified by frailty and microheteroplasmies. Over an average follow-up of 13.2years, 3533 participants developed dementia. Each SD higher mtDNAcn (16) was associated with 4.2% lower all-cause dementia hazard (HR = 0.958, p = 0.030), 6% lower non-AD dementia hazard (HR = 0.933, p = 0.022), and not-AD dementia hazard. The associations between mtDNAcn and all-cause dementia and non-AD dementia were stronger among those who were pre-frail or frail or with higher microheteroplasmies. Higher mtDNAcn was associated with higher DSST scores (p = 0.036) and significant only among those with higher microheteroplasmies or frailty (p = 0.029 and 0.048, respectively). mtDNAcn was also associated with delta TMT and paired associate learning only in pre-frail/frail participants (p = 0.007 and 0.045, respectively). Higher WGS-based mtDNAcn in human blood is associated with lower dementia risk, specifically non-AD dementia, and specific cognitive function. The relationships appear stronger in high somatic mutations or frailty. Future studies are warranted to investigate biological underpinnings.

Vagus nerve stimulation during training fails to improve learning in healthy rats

Learning new skills requires neuroplasticity. Vagus nerve stimulation (VNS) during sensory and motor events can increase neuroplasticity in networks related to these events and might therefore serve to facilitate learning on sensory and motor tasks. We tested if VNS could broadly improve learning on a wide variety of tasks across different skill domains in healthy, female adult rats. VNS was paired with presentation of stimuli or on successful trials during training, strategies known to facilitate plasticity and improve recovery in models of neurological disorders. VNS failed to improve either rate of learning or performance for any of the tested tasks, which included skilled forelimb motor control, speech sound discrimination, and paired-associates learning. These results contrast recent findings from multiple labs which found VNS pairing during training produced learning enhancements across motor, auditory, and cognitive domains. We speculate that these contrasting results may be explained by key differences in task designs, training timelines and animal handling approaches, and that while VNS may be able to facilitate rapid and early learning processes in healthy subjects, it does not broadly enhance learning for difficult tasks.

Effects of pair work and individual work on paired‐associate vocabulary learning in an EFL context

AbstractThis study investigates how different modes of a memorization activity in paired‐associate learning (PAL), namely pair work and individual work, can affect learners’ short‐ and long‐term retention of newly learned vocabulary items. In the aforementioned activity, two groups of Japanese college students studying English as a foreign language (EFL) learned 20 novel English vocabulary items using a second language–first language (L2–L1) list. First, the pair group worked in pairs; one member asked the other to state the L1 equivalent of the target items aloud for 2.5 min, and vice versa. Second, the members of the individual group memorized the L1 meanings of the target words for 5 minutes using their own methods. Subsequently, an immediate posttest and questionnaire survey regarding their preferred learning styles and strategies were conducted after the study session. Furthermore, a surprise delayed posttest was administered 3 weeks after the session. The results revealed that the individual group outperformed in the immediate posttest. However, the pair group scored significantly better in the delayed posttest. These results suggest that individual work is superior for memorizing a larger number of words in a short time but that memory can decay relatively quickly. Conversely, pair work may be superior for long‐term retention.

Dentate gyrus ensembles gate context-dependent neural states and memory retrieval.

Memories of events are linked to the contexts in which they were encoded. This contextual linking ensures enhanced access to those memories that are most relevant to the context at hand, including specific associations that were previously learned in that context. This principle, referred to as encoding specificity, predicts that context-specific neural states should bias retrieval of particular associations over others, potentially allowing for the disambiguation of retrieval cues that may have multiple associations or meanings. Using a context-odor paired associate learning paradigm in mice, here, we show that chemogenetic manipulation of dentate gyrus ensembles corresponding to specific contexts reinstates context-specific neural states in downstream CA1 and biases retrieval toward context-specific associations.

Bypassing Striatal Learning Mechanisms Using Delayed Feedback to Circumvent Learning Deficits in Traumatic Brain Injury.

Feedback facilitates learning by guiding and modifying behaviors through an action-outcome contingency. As the majority of existing studies have focused on the immediate presentation of feedback, the impact of delayed feedback on learning is understudied. Prior work demonstrated that learning from immediate and delayed feedback employed distinct brain regions in healthy individuals, and compared to healthy individuals, individuals with traumatic brain injury (TBI) are impaired in learning from immediate feedback. The goal of the current investigation was to assess the effects of delayed vs immediate feedback on learning in individuals with TBI and examine brain networks associated with delayed and immediate feedback processing. Nonprofit research organization. Twenty-eight individuals with moderate-to-severe TBI. Participants completed a paired-associate word learning task while undergoing magnetic resonance imaging. During the task, feedback was presented either immediately, after a delay, or not at all (control condition). Learning performance accuracy, confidence ratings, post-task questionnaire, and blood oxygen level-dependent signal. Behavioral data showed that delayed feedback resulted in better learning performance than immediate feedback and no feedback. In addition, participants reported higher confidence in their performance during delayed feedback trials. During delayed vs immediate feedback processing, greater activation was observed in the superior parietal and angular gyrus. Activation in these areas has been previously associated with successful retrieval and greater memory confidence. The observed results might be explained by delayed feedback processing circumventing the striatal dopaminergic regions responsible for learning from immediate feedback that are impaired in TBI. In addition, delayed feedback evokes less of an affective reaction than immediate feedback, which likely benefited memory performance. Indeed, compared to delayed feedback, positive or negative immediate feedback was more likely to be rated as rewarding or punishing, respectively. The findings have significant implications for TBI rehabilitation and suggest that delaying feedback during rehabilitation might recruit brain regions that lead to better functional outcomes.

The relationship between metacognitive monitoring, non-verbal intellectual ability, and memory performance in kindergarten children

When assessing their certainty, children are often poor at accurately monitoring their level of learning. The study examined the relationships between memory performance, intellectual ability, and metacognitive monitoring accuracy in kindergarten children. We also explored whether specific thresholds in memory performance and non-verbal intellectual ability influence metacognitive monitoring accuracy to identify group-specific patterns that might be masked by an overall linear analysis. We assessed the monitoring discrimination of 290 kindergarteners (Mage 6 years) using a paired-associates learning task. Results showed small correlations between task performance, intellectual ability, and metacognitive monitoring. Non-verbal intellectual ability provided explanatory value for monitoring accuracy beyond memory performance. We observed group-specific results consistent with the unskilled-and-unaware effect; children with the highest memory skills were more effective at discriminating between correct and incorrect answers than their peers with the lowest memory skills. However, kindergarteners with the highest non-verbal intellectual abilities did not demonstrate greater cognitive adaptability in novel tasks, as their monitoring accuracy was comparable to that of peers with average or lower intellectual abilities. Findings indicate that both task performance and non-verbal intellectual ability are relevant for monitoring accuracy, but the impact of non-verbal intellectual ability was less significant than anticipated. The modest correlation suggests that kindergarteners' non-verbal intellectual ability and metacognitive monitoring abilities operate relatively independently.

Visual–verbal paired-associate learning: An investigation of the role of verbal and crossmodal associative learning in reading skills in French first- and second-grade children.

Visual–verbal paired-associate learning: An investigation of the role of verbal and crossmodal associative learning in reading skills in French first- and second-grade children.

The Granular Retrosplenial Cortex Is Necessary in Male Rats for Object-Location Associative Learning and Memory, But Not Spatial Working Memory or Visual Discrimination and Reversal, in the Touchscreen Operant Chamber.

The retrosplenial cortex (RSC) is a hub of diverse afferent and efferent projections thought to be involved in associative learning. RSC shows early pathology in mild cognitive impairment and Alzheimer's disease (AD), which impairs associative learning. To understand and develop therapies for diseases such as AD, animal models are essential. Given the importance of human RSC in object-location associative learning and the success of object-location associative paradigms in human studies and in the clinic, it would be of considerable value to establish a translational model of object-location learning for the rodent. For this reason, we sought to test the role of RSC in object-location learning in male rats using the object-location paired-associates learning (PAL) touchscreen task. First, increased cFos immunoreactivity was observed in granular RSC following PAL training when compared with extended pretraining controls. Following this, RSC lesions following PAL acquisition were used to explore the necessity of the RSC in object-location associative learning and memory and two tasks involving only one modality: trial-unique nonmatching-to-location for spatial working memory and pairwise visual discrimination/reversal. RSC lesions impaired both memory for learned paired-associates and learning of new object-location associations but did not affect performance in either the spatial or visual single-modality tasks. These findings provide evidence that RSC is necessary for object-location learning and less so for learning and memory involving the individual modalities therein.

Association of obesity to reaction time and visual memory in schizophrenia

BackgroundBoth overweight and cognitive deficits are common among people with schizophrenia (SZ) and schizoaffective disorder. The results in earlier studies have been inconsistent on whether overweight is associated with cognitive deficits in psychotic disorders. AimsOur aim in this study was to detect possible associations between obesity and cognitive deficits among study participants with SZ and schizoaffective disorder. MethodsThe study sample included 5382 participants with a clinical diagnosis of SZ or schizoaffective disorder selected from the Finnish SUPER study. Obesity was measured both with body-mass index and waist circumference. The cognitive performance was evaluated with two tests from the Cambridge automated neuropsychological test battery: Reaction time was evaluated with the 5-choice serial reaction time task. Visual memory was evaluated with the paired associative learning test. The final analysis included a total sample of 4498 participants applicable for the analysis of the reaction time and 3967 participants for the analysis of the visual memory. ResultsObesity measured with body-mass index was associated with better performance in reaction time task among both female and male participants. Among male participants, overweight was associated with better performance in the visual memory test. The waist circumference was not associated with cognitive measures. ConclusionsThe results suggest that obesity in people with SZ or schizoaffective disorder might not be associated with cognitive deficits but instead with better cognitive performance. The results were opposite from earlier literature on the general population. More research is required to better understand whether the results might be partly caused by the differences in the etiology of obesity between the general population and people with SZ.

Quantifying Prefrontal-Hippocampal Circuit Engagement Using Scalp EEG and the Paired Associates Learning Task

The hippocampus (HPC)-prefrontal cortical (PFC) circuit, critical for affective processing and cognition, is vulnerable in mental health disorders. Although disrupted HPC-PFC functional connectivity is a common feature of anxiety, schizophrenia, and autism, how local cellular interactions within this circuit manifest as large-scale temporal coordination remains unknown. The objective of this project is to provide novel mechanistic insights into disrupted neural coordination in mental illness by examining the relationship between invasive local field potential (LFP) recordings from the HPC and PFC, and scalp electroencephalogram (EEG) during the Paired Associates Learning (PAL) task. The PAL task measures visuospatial associative memory by requiring animals to learn the stimulus-location pairing of different images on a touchscreen. We have previously shown that manipulations that disrupt HPC-PFC coordination, such as traumatic brain injury and advanced age, lead to PAL performance impairments. Importantly, EEG recordings during PAL performance in human study participants have shown associations between behavioral deficits and altered neural dynamics in schizophrenia and anxiety. We hypothesize that simultaneous LFP and EEG recordings from rats performing the PAL task will reveal highly correlated theta power across brain regions, as well as significant phase relationships among frequencies when compared to rest periods. Preliminary data show correlated increases in theta power in both the LFP and EEG from HPC as well as PFC, and higher power in the theta frequency band during PAL compared to rest periods. Future analyses will determine phase coherence between frequencies within a signal as well as brain regions. Exploring the relationship between invasive neurophysiological measures of the LFP and non-invasive surface EEG signals in the context of a translatable behavioral paradigm could provide new physiological and behavioral biomarkers that may be capable of predicting HPC-PFC coordination and aid the development of therapies for treating mental health disorders. The Evelyn F. McKnight Brain Research Foundation and the NIH/NIMH (grant R01MH126236). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Association between arterial health and cognition in adolescents: The PANIC study.

We investigated the associations of the measures of arterial health with cognition in adolescents and whether physical activity (PA) or sedentary time (ST) confounds these associations. One hundred sixteen adolescents (71 boys) aged 15.9 ± 0.4 participated in the study. PA and ST were assessed using a combined accelerometer/heart rate monitor. Overall cognition was computed from the results of psychomotor function, attention, working memory, and paired-associate learning tests. Pulse wave velocity was measured by impedance cardiography, carotid intima-media thickness, and carotid artery distensibility by carotid ultrasonography. Systolic and diastolic blood pressure (SBP and DBP) were measured using an aneroid sphygmomanometer. SBP was inversely associated with overall cognition (standardized regression coefficient [β] = -0.216, 95% confidence interval (CI) -0.406 to -0.027, p = 0.025). Pulse wave velocity (β = -0.199, 95% CI -0.382 to -0.017, p = 0.033) was inversely associated with working memory task accuracy. SBP was directly associated with reaction time in the attention (β = 0.256, 95% CI 0.069 to 0.443, p = 0.008) and errors in the paired-associate learning tasks (β = 0.308, 95% CI 0.126 to 0.489, p = 0.001). Blood pressure was inversely associated with overall cognition. PA or ST did not confound the associations. Results suggest that preventing high blood pressure is important for promoting cognition in adolescents.

The effectiveness of computerized cognitive training on cognitive functions and mental health in people with schizophrenia

IntroductionPeople with schizophrenia have multiple and persistent cognitive deficits. These defects have a deep impact on people’s psycho-social functions. Although computerized cognitive training has positive results in some people, the effect of these treatment programs in schizophrenia is not clear.ObjectivesThe purpose of this study was to investigate the effectiveness of computerized cognitive exercises on the components affecting the mental health and cognitive functions of schizophrenic patients.MethodsFifty-four adults with schizophrenia were randomly divided into two intervention and control groups. Participants in the intervention group received 30 sessions of 5-45 minutes of computerized cognitive training in addition to the usual treatment programs. While the control group only received their usual rehabilitation programs (Pharmacotherapy, psychotherapy and occupational therapy).Mental health was evaluated with Warwick-Edinburgh Mental Well-Being Scale and Depression-Anxiety-Stress Scale (DASS), and cognitive functions with CANTAB tests Batteries before the intervention, after and two months after the intervention (follow up). The set of CANTAB tests used in this study included the following tests: Spatial Recognition Memory (SRM), Paired Associates Learning (PAL), Stockings of Cambridge(SOC), Spatial Working Memory (SWM), and Spatial Span (SSP).ResultsThe analysis of the findings showed that the patients’ performance in the cognitive tests related to memory and executive functions improved significantly in the intervention group after the intervention. In problem solving skills, despite the better performance in the intervention group, the difference between the two groups was not significant. Also, the intervention was able to significantly improve mental health and reduce stress. But no significant difference was observed in reducing anxiety and depression.ConclusionsAs a result, the study showed that 30 sessions of computerized cognitive training can have a positive effect on overall mental health and some cognitive functions.Disclosure of InterestNone Declared

Visual memory and alcohol use in a middle-aged birth cohort

Light and moderate alcohol use has been reported to be associated with both impaired and enhanced cognition. The purpose of this study was to explore whether there was a linear relationship between visual memory and alcohol consumption in males and females in a large middle-aged birth cohort population in cross-sectional and longitudinal settings. Data were collected from 5585 participants completing 31-year (1997–1998) and 46-year (2012–2014) follow-ups including Paired Associate Learning (PAL) test at 46-years follow-up. The participants were originally from 12,231 study population of the Northern Finland Birth Cohort 1966 (NFBC1966). The PAL test was conducted to assess visual memory. Reported alcohol use was measured as total daily use of alcohol, beer, wine, and spirits converted into grams and as frequency and amount of use of beer, wine, and spirits. The total daily alcohol use was not associated with reduced visual memory. The frequency of use of beer and wine in males was associated with better visual memory in cross-sectional and longitudinal settings. Using six or more servings of spirits was associated with worse visual memory in males in cross-sectional and longitudinal settings. The study suggested a lack of a linear association between drinking and visual memory in the middle-aged population.

Bilingual proficiency effects in paired-associate learning of vocabulary in an unfamiliar language

Abstract We investigated three aspects of paired associate learning of vocabulary in an unfamiliar language: monolingual-bilingual differences, effects of dominance and language proficiency, and the possible role of associative strategies. Spanish–English bilinguals (48 English-dominant and 48 Spanish-dominant) and English-speaking monolinguals (n = 48) learned Swahili–English and Swahili-Spanish word pairs. Learning was assessed using cued recall (Swahili cue or Swahili response) and associative recognition tests. English-dominant bilinguals did not outperform English monolinguals on any learning measure. Cued recall accuracy was higher when learning through the dominant language than through the non-dominant language, whether the Swahili words were cues or responses. Proficiency scores in the known language were positively correlated with cued recall accuracy, whether the cue or the response was in Swahili, indicating that proficiency effects occurred not in retrievability of known words but in learning of associations. Bilingual and monolingual participants did not differ in their reported use of associative strategies.

Cognitive function and quantitative electroencephalogram analysis in subjects recovered from COVID-19 infection

Background & ObjectivesObjective assessment of post-COVID-19 cognitive dysfunction is highly warranted. This study aimed to evaluate the cognitive dysfunction of COVID-19 survivors with cognitive complaints, both clinically and neurophysiologically, using Quantitative Electroencephalogram (QEEG).MethodsThis case–control study was conducted on 50 recovered subjects from COVID-19 infection with cognitive complaints and 50 age, sex, and educational-matched healthy controls. Both groups were subjected to the following neurocognitive tests: Paired associate learning Test (PALT) and Paced Auditory Serial Addition Test (PASAT). The neurophysiological assessment was also done for both groups using QEEG.ResultsCOVID-19 survivors had significantly lower PALT scores than controls (P < 0.001). QEEG analysis found significantly higher levels of Theta / Beta ratio in both central and parietal areas in patients than in the controls (P < 0.001 for each). The interhemispheric coherence for the frontal, central, and parietal regions was also significantly lower in patients than in the control group regarding alpha and beta bands. There were statistically significant lower scores of PALT and PASAT among cases with severe COVID-19 infection (P = 0.011, 0.005, respectively) and those who needed oxygen support (P = 0.04, 0.01, respectively). On the other hand, a statistically significantly lower mean of frontal alpha inter-hemispheric coherence among patients with severe COVID-19 infection (P = 0.01) and those needing mechanical ventilation support (P = 0.04).ConclusionEpisodic memory deficit is evident in COVID-19 survivors with subjective cognitive complaints accompanied by lower inter-hemispheric coherence in frontal regions. These clinical and neurophysiological changes are associated with hypoxia and COVID-19 severity.

A visual paired associate learning (vPAL) paradigm to study memory consolidation during sleep.

Sleep improves the consolidation and long-term stability of newly formed memories and associations. Most research on human declarative memory and its consolidation during sleep uses word-pair associations requiring exhaustive learning. In the present study, we present the visual paired association learning (vPAL) paradigm, in which participants learn new associations between images of celebrities and animals. The vPAL is based on a one-shot exposure that resembles learning in natural conditions. We tested if vPAL can reveal a role for sleep in memory consolidation by assessing the specificity of memory recognition, and the cued recall performance, before and after sleep. We found that a daytime nap improved the stability of recognition memory and discrimination abilities compared to identical intervals of wakefulness. By contrast, cued recall of associations did not exhibit significant sleep-dependent effects. High-density electroencephalography during naps further revealed an association between sleep spindle density and stability of recognition memory. Thus, the vPAL paradigm opens new avenues for future research on sleep and memory consolidation across ages and heterogeneous populations in health and disease.

Diet patterns and cognitive performance in a UK Female Twin Registry (TwinsUK)

BackgroundPlant-based diets may provide protection against cognitive decline and Alzheimer’s disease, but observational data have not been consistent. Previous studies include early life confounding from socioeconomic conditions and genetics that are known to influence both cognitive performance and diet behaviour. This study investigated associations between Mediterranean (MED) diet and MIND diets and cognitive performance accounting for shared genotype and early-life environmental exposures in female twins.MethodsDiet scores were examined in 509 female twins enrolled in TwinsUK study. The Cambridge Neuropsychological Test Automated Battery was used to assess cognition at baseline and 10 years later (in n = 275). A co-twin case–control study for discordant monozygotic (MZ) twins examined effects of diet on cognitive performance independent of genetic factors. Differences in relative abundance of taxa at 10-year follow-up were explored in subsamples.ResultsEach 1-point increase in MIND or MED diet score was associated with 1.75 (95% CI: − 2.96, − 0.54, p = 0.005 and q = 0.11) and 1.67 (95% CI: − 2.71, − 0.65, p = 0.002 and q = 0.02) fewer respective errors in paired-associates learning. Within each MZ pair, the twin with the high diet score had better preservation in spatial span especially for MED diet (p = 0.02). There were no differences between diet scores and 10-year change in the other cognitive tests. MIND diet adherence was associated with higher relative abundance of Ruminococcaceae UCG-010 (0.30% (95% CI 0.17, 0.62), q = 0.05) which was also associated with less decline in global cognition over 10 years (0.22 (95% CI 0.06, 0.39), p = 0.01).ConclusionsMIND or MED diets could help to preserve some cognitive abilities in midlife, particularly episodic and visuospatial working memory. Effects may be mediated by high dietary fibre content and increased abundance of short-chain fatty acid producing gut bacteria. Longer follow-up with repeated measures of cognition will determine whether diet can influence changes in cognition occurring in older age.