Long-term Memory Retrieval Research Articles

Memory Aids as a Disability-Related Accommodation? Let’s Remember to Recommend Them Appropriately

Memory aids are now frequently provided to elementary and secondary school students to increase their success in achieving provincial curriculum standards. While such an accommodation may meet the immediate goal of improved academic performance it may not be warranted based on an actual long-term memory retrieval impairment and may therefore be inequitable, providing an unfair academic advantage relative to non-disabled students. Furthermore, providing memory aid accommodations inappropriately may rob students of the opportunity to learn effective study and retrieval strategies, leading instead to dependence on an accommodation that may not be continued once they enter post-secondary education. An appropriate accommodation at the post-secondary level of education removes a disability-related barrier (functional impairment) and assists only those facing such barriers; under human rights legislation, accommodations are not implemented to guarantee success, reduce anxiety, or provide unequal access to material. Memory aids improve the retrieval of information from long-term storage for everyone. As such, the current widespread provision of this accommodation prior to post-secondary studies must be evaluated critically, with such supports offered only when justified. A six-step process for determining when memory aids are an appropriate accommodation within the post-secondary setting is provided and discussed.

Hemispheric Asymmetries in Electroencephalogram Oscillations for Long-Term Memory Retrieval in Healthy Individuals.

The hemispherical encoding retrieval asymmetry (HERA) model, established in 1991, suggests that the involvement of the right prefrontal cortex (PFC) in the encoding process is less than that of the left PFC. The HERA model was previously validated for episodic memory in subjects with brain traumas or injuries. In this study, a revised HERA model is used to investigate long-term memory retrieval from newly learned video-based content for healthy individuals using electroencephalography. The model was tested for long-term memory retrieval in two retrieval sessions: (1) recent long-term memory (recorded 30 min after learning) and (2) remote long-term memory (recorded two months after learning). The results show that long-term memory retrieval in healthy individuals for the frontal region (theta and delta band) satisfies the revised HERA asymmetry model.

Working memory limits severely constrain long-term retention

There has been considerable controversy in recent years as to whether information held in working memory (WM) is rapidly forgotten or automatically transferred to long-term memory (LTM). Although visual WM capacity is very limited, we appear able to store a virtually infinite amount of information in visual LTM. Still, LTM retrieval often fails. Some view visual WM as a mental sketchpad that is wiped clean when new information enters, but not a consistent precursor of LTM. Others view the WM and LTM systems as inherently linked. Distinguishing between these possibilities has been difficult, as attempts to directly manipulate the active holding of information in visual WM has typically introduced various confounds. Here, we capitalized on the WM system's capacity limitation to control the likelihood that visual information was actively held in WM. Our young-adult participants (N = 103) performed a WM task with unique everyday items, presented in groups of two, four, six, or eight items. Presentation time was adjusted according to the number of items. Subsequently, we tested participants' LTM for items from the WM task. LTM was better for items presented originally within smaller WM set sizes, indicating that WM limitations contribute to subsequent LTM failures, and that holding items in WM enhances LTM encoding. Our results suggest that a limit in WM capacity contributes to an LTM encoding bottleneck for trial-unique familiar objects, with a relatively large effect size.

AMPA Receptor Expression Requirement During Long-Term Memory Retrieval and Its Association with mTORC1 Signaling.

Recently, it was reported that mechanistic/mammalian target of rapamycin complex 1 (mTORC1) activity during memory retrieval is required for normal expression of aversive and non-aversive long-term memories. Here we used inhibitory-avoidance task to evaluate the potential mechanisms by which mTORC1 signaling pathway participates in memory retrieval. First, we studied the role of GluA-subunit trafficking during memory recall and its relationship with mTORC1 pathway. We found that pretest intrahippocampal infusion of GluR23ɣ, a peptide that selectively blocks GluA2-containing AMPA receptor (AMPAR) endocytosis, prevented the amnesia induced by the inhibition of mTORC1 during retrieval. Additionally, we found that GluA1 levels decreased and GluA2 levels increased at the hippocampal postsynaptic density subcellular fraction of rapamycin-infused animals during memory retrieval. GluA2 levels remained intact while GluA1 decreased at the synaptic plasma membrane fraction. Then, we evaluated the requirement of AMPAR subunit expression during memory retrieval. Intrahippocampal infusion of GluA1 or GluA2 antisense oligonucleotides (ASO) 3 h before testing impaired memory retention. The memory impairment induced by GluA2 ASO before retrieval was reverted by GluA23ɣ infusion 1 h before testing. However, AMPAR endocytosis blockade was not sufficient to compensate GluA1 synthesis inhibition. Our work indicates that de novo GluA1 and GluA2 AMPAR subunit expression is required for memory retrieval with potential different roles for each subunit and suggests that mTORC1 might regulate AMPAR trafficking during retrieval. Our present results highlight the role of mTORC1 as a key determinant of memory retrieval that impacts the recruitment of different AMPAR subunits.

Auditory processing in children: Role of working memory and lexical ability in auditory closure.

We examined the relationship between cognitive-linguistic mechanisms and auditory closure ability in children. Sixty-seven school-age children recognized isolated words and keywords in sentences that were interrupted at a rate of 2.5 Hz and 5 Hz. In essence, children were given only 50% of speech information and asked to repeat the complete word or sentence. Children’s working memory capacity (WMC), attention, lexical knowledge, and retrieval from long-term memory (LTM) abilities were also measured to model their role in auditory closure ability. Overall, recognition of monosyllabic words and lexically easy multisyllabic words was significantly better at 2.5 Hz interruption rate than 5 Hz. Recognition of lexically hard multisyllabic words and keywords in sentences was better at 5 Hz relative to 2.5 Hz. Based on the best fit generalized “logistic” linear mixed effects models, there was a significant interaction between WMC and lexical difficulty of words. WMC was positively related only to recognition of lexically easy words. Lexical knowledge was found to be crucial for recognition of words and sentences, regardless of interruption rate. In addition, LTM retrieval ability was significantly associated with sentence recognition. These results suggest that lexical knowledge and the ability to retrieve information from LTM is crucial for children’s speech recognition in adverse listening situations. Study findings make a compelling case for the assessment and intervention of lexical knowledge and retrieval abilities in children with listening difficulties.

Unwanted Memory Intrusions Recruit Broad Motor Suppression.

Quickly preventing the retrieval of (inappropriate) long-term memories might recruit a similar control mechanism as rapid action-stopping. A very specific characteristic of rapid action-stopping is "global motor suppression": When a single response is rapidly stopped, there is a broad skeletomotor suppression. This is shown by the technique of TMS placed over a task-irrelevant part of the primary motor cortex (M1) to measure motor-evoked potentials. Here, we used this same TMS method to test if rapidly preventing long-term memory retrieval also shows this broad skeletomotor suppression effect. Twenty human participants underwent a Think/No-Think task. In the first phase, they learned word pairs. In the second phase, they received the left-hand word as a cue and had to either retrieve the associated right-hand word ("Think") or stop retrieval ("No-Think"). At the end of each trial, they reported whether they had experienced an intrusion of the associated memory. Behaviorally, on No-Think trials, they reported fewer intrusions than Think trials, and the reporting of intrusions decreased with practice. Physiologically, we observed that the motor-evoked potential, measured from the hand (which was irrelevant to the task), was reduced on No-Think trials in the time frame of 300-500 msec, especially on trials where they did report an intrusion. This unexpected result contradicted our preregistered prediction that we would find such a decrease on No-Think trials where the intrusion was not reported. These data suggest that one form of executive control over (inappropriate) long-term memory retrieval is a rapid and broad stop, akin to action-stopping, that is triggered by the intrusion itself.

Age-Related Changes in Listening Effort for Children and Teenagers With Normal Hearing and Cochlear Implants.

A clinically viable measure of listening effort is crucial in safeguarding the educational success of hard-of-hearing students enrolled in mainstream schools. To this end, a novel behavioral paradigm of listening effort targeting school-age children has been designed and reported in Hsu et al. (2017). The current article consists of two follow-up experiments investigating the effects of noise, processing depth, and age in a similar paradigm, first in a group of participants with normal hearing (NH) followed by a sample of school-age cochlear implant (CI) users. Research objectives include the construction of normative values of listening effort and comparing outcomes between age-matched NH and CI participants. In Experiment 1, the listening effort dual-task paradigm was evaluated in a group of 90 NH participants with roughly even age distribution between 6 and 26 years. The primary task asked a participant to verbally repeat each of the target words presented in either quiet or noise, while the secondary task consisted of categorization true-or-false questions "animal" and "dangerous," representing two levels of semantic processing depth. Two outcome measures were obtained for each condition: a classic word recognition score (WRS) and an average response time (RT) measured during the secondary task. The RT was defined as the main listening effort metric throughout the study. Each NH participant's long-term memory retrieval speed and working memory capacity were also assessed through standardized tests. It was hypothesized that adding noise would negatively affect both WRS and RT, whereas an increase in age would see significant improvement in both measures. A subsequent Experiment 2 administered a shortened version of the paradigm to 14 school-age CI users between 5 and 14 years old at a university clinic. The patterns of results from the CI group were expected to approximate those of the NH group, except with larger between-subject variability. For NH participants, while WRS was significantly affected by age and noise levels, RT was significantly affected by age, noise levels, and depth of processing. RT was significantly correlated with long-term memory retrieval speed but not with working memory capacity. There was also a significant interaction effect between age and noise levels for both WRS and RT. The RT data set from the NH group served as a basis to establish age-dependent 95% prediction intervals for expected future observations. For CI participants, the effect of age on the two outcome measures was more visible when target words were presented in quiet. Depending on the condition, between 35.7% and 72.7% of the children with CI exhibited higher-than-norms listening effort as measured by categorization processing times. Listening effort appears to decrease with age from early school-age years to late teenage years. The effects of background noise and processing depth are comparable with those reported in Hsu et al. (2017). Future studies interested in expanding the paradigm's clinical viability should focus on the reduction of testing time while maintaining or increasing the sensitivity and external validity of its outcome measures.

Activation of 5-HT1A and 5-HT7 receptors enhanced a positively reinforced long-term memory

Memory is one of the most important capabilities of our mind since it determines our individuality. Memory formation involves different stages: acquisition, consolidation and retrieval. There are many studies about early stages, however little is known about memory retrieval. Retrieval is the use of learned information and represents a big problem in patients with memory deficits where the main issue is that they can learn but cannot remember. Previous findings have demonstrated that 5-hydroxytryptamine (5-HT) is a neurotransmitter involved in memory process. Hence, here we are exploring the role of 5-HT in memory retrieval by using its metabolic precursor l-tryptophan and several ligands at 5-HT1A and 5-HT7 receptors. Experimental protocol consisted of evaluating conditioned responses (%CR) after one week of interruption following autoshaping sessions for memory formation; a decrease of %CR was interpreted as memory decay. Systemic administration of: (1) l-tryptophan (50 and 100 mg/kg), (2) 5-HT1A receptor agonist 8-OH-DPAT (0.031 and 0.062 mg/kg), (3) the selective antagonist 5-HT1A receptor WAY 100635 (0.3 and 0.6 mg/kg), (4) the 5-HT7 receptor agonist, LP 211, in a dose-dependent manner (1, 2.5, 5.0 and 10.0 mg/kg) enhanced memory retrieval. Further, the 5-HT7 receptor antagonist, SB 269970 (10.0 mg/kg), had no effect. Finally, SB 269970 (10.0 mg/kg) significantly blocked memory retrieval enhancement produced by 10.0 mg/kg LP 211, but not that induced by 2.5 mg/kg LP 211.These results, taken together, suggest that activation of 5-HT1A and 5-HT7 receptors enhanced memory retrieval and these receptors may be therapeutic targets to improve long-term memory retrieval.

Stress and long-term memory retrieval: a systematic review.

Introduction The experience of stressful events can alter brain structures involved in memory encoding, storage and retrieval. Here we review experimental research assessing the impact of the stress-related hormone cortisol on long-term memory retrieval.Method A comprehensive literature search was conducted on PubMed, Web of Science and PsycNet databases with the following terms: “stress,” “long-term memory,” and “retrieval.” Studies were included in the review if they tested samples of healthy human participants, with at least one control group, and with the onset of the stress intervention occurring after the encoding phase and shortly (up to one hour) before the final memory test.Results Thirteen studies were included in the qualitative synthesis (N = 962) and were classified according to the time elapsed between stress induction and memory retrieval (stress-retrieval delay), the stress-inducing protocol (stressor), the time of day in which stress induction took place, sex, and age of participants. Most studies induced stress with the Trier Social Stress Test (TSST) between 15 and 25 minutes before the final memory (mostly recall) test and showed significant increases in cortisol levels and memory impairment.Discussion The reviewed studies indicate that stress does impair retrieval, particularly when induced with the TSST, in the afternoon, up to 45 minutes before the onset of the final memory test, in healthy young men. These results may inform future research on the impact of stress-induced cortisol surges on memory retrieval.

Aging and associative binding in contingency learning

ABSTRACT Cue competition effects are pervasive in young adults’ learning, but evidence for these effects in older adults’ learning is mixed. For example, although older adults show strong forward blocking, they do not show recovery from overshadowing. We examined whether this could be due to problems with associative binding using a rapid, streamed trial contingency learning task to minimize long-term memory retrieval demands. In a forward blocking paradigm , target cues gained less predictive value when the competing companion cues had high predictive value and this forward blocking effect was similar for younger and older adults. In a backward blocking paradigm, target cues lost more predictive value when the competing companion cues had high predictive value, but this backward blocking effect was greater for younger than older adults. These findings, together with evidence that within-compound associations for companion and target cues mediate backward, but not forward cue competition effects, suggest that a decline in associative binding may be responsible for the absence of backward cue competition effects in older adults’ contingency learning .

Training and transfer effects of long-term memory retrieval training

ABSTRACT Long-term memory retrieval ability and working memory can share attention control ability. Based on cognitive plasticity, a hypothesis that cognitive training could improve long-term memory retrieval efficiency and that this could transfer to retrieval involving working memory was proposed. 60 undergraduates were randomly assigned to a group of training and an active control group; all the participants completed the same tasks in the same order before and after the training, the tasks included a long-term memory retrieval access task, a intelligence test, a switching task, a working memory updating task, a response inhibition task and an interference control task. The statistics results indicate that cognitive training can improve long-term memory retrieval efficiency and has a transfer effect on working memory updating, interference control and switching ability, but not on response inhibition or intelligence. This reveal the plasticity of long-term memory retrieval and its influence on working memory.

Structure-activity relationship study of tryptophan-based butyrylcholinesterase inhibitors.

A series of tryptophan-based selective nanomolar butyrylcholinesterase (BChE) inhibitors was designed and synthesized. Compounds were optimized in terms of potency, selectivity, and synthetic accessibility. The crystal structure of the inhibitor 18 in complex with BChE revealed the molecular basis for its low nanomolar inhibition (IC50=2.8nM). The favourable invitro results enabled a first-in-animal invivo efficacy and safety trial, which demonstrated a positive impact on fear-motivated and spatial long-term memory retrieval without any concomitant adverse motor effects. Altogether, this research culminated in a handful of new lead compounds with promising potential for symptomatic treatment of patients with Alzheimer's disease.

Are there sex differences in brain activity during long-term memory? A systematic review and fMRI activation likelihood estimation meta-analysis

ABSTRACT The degree to which sex differences exist in the brain is a current topic of debate. In the present discussion paper, we reviewed eight functional magnetic resonance imaging (fMRI) papers to determine whether there are sex differences in brain activity during long-term memory retrieval. The objectives were: 1) to compare the experimental parameters in studies reporting significant versus null long-term memory sex differences, and 2) to identify whether specific brain regions were associated with sex differences during long-term memory. The following experimental parameters were extracted from each paper: the number of participants, the average age of participants, stimulus type(s), whether or not performance was matched, whether or not sex differences were reported, the type of between-subject statistical test used, and the contrast(s) employed. The particular experimental parameters employed in each study did not appear to determine whether sex differences were observed, as there were sex differences in all eight studies. An activation likelihood estimation (ALE) meta-analysis was conducted to identify brain regions activated to a greater degree by females than males or males than females. This ALE meta-analysis revealed sex differences (male > female) in the lateral prefrontal cortex, visual processing regions, parahippocampal cortex, and the cerebellum. This constitutes compelling evidence that there are substantial sex differences in brain activity during long-term memory retrieval. More broadly, the present findings question the widespread practice of collapsing across sex in the field of cognitive neuroscience.

Modulation of cortical activity in response to learning and long-term memory retrieval of 2D verses stereoscopic 3D educational contents: Evidence from an EEG study

Stereoscopic 3D (S3D) displays provide a very realistic visualization experience to the viewers through a sensation of depth perception. Despite the rapid growth of S3D technology (S3D) in education, very little has been known about the effects of S3D on human behavior and the corresponding brain's responses over traditional 2D display during conscious learning and Long-Term Memory (LTM) recall process. The present study aims to explore the effects of S3D technology on human behavior and the brain responses during learning and memory using an electroencephalography (EEG) technique. A sample of 68 participants between 18 and 30 years of age was recruited to perform three tasks: (1) Raven's Advanced Progressive Matrices (RAPM) test to assess the fluid intelligence ability; (2) learning task to study the S3D or 2D based contents for learning; and (3) memory recall task to assess the memory recall and retention performance. The participants were randomly assigned to two groups―2D group and S3D group, in such a way that their fluid intelligence ability, age, and background knowledge about the learning material are controlled. The analysis of behavioral data suggested that responses of both groups in terms of reaction time after two months of retention were statistically significantly different, F(2.66,125.09) = 4.47, p = .007, ηp2 = 0.087. The differences between the S3D and 2D groups were identified by EEG analysis, i.e., the classifier correctly discriminated the EEG signals of both groups with more than 90% accuracy rate. The EEG source analysis showed statistically significant differences between the groups in the brain regions of BA 7, BA 10, BA 11, and BA 25, reflecting widespread neuronal networks involved in the S3D group as compared to the 2D group in the LTM recollection. In conclusion, it was experimentally showed that the human brain processed the S3D contents differently by utilizing more cortical regions and neuronal networks than the traditional 2D contents, which modulates the behavior of the participants by recollecting the LTM faster in the recall task.

Impact of GRIK4 gene polymorphisms on cognitive dysfunction in patients with major depression

An increasing body of research has focused on the functions of the glutamate receptor ionotropic kainate 4 (GRIK4) gene in treatment for depression, memory, as well as neurodegenerative diseases. It is widely recognized that major depressive disorder (MDD) patients often display cognitive dysfunctions, which do not strictly correlate with the severity of depressive symptoms, and in some individuals persist after clinical remission. However, little is known regarding the particular role of GRIK4 in cognitive functions of patients suffering from a MDD. The current study therefore sought to examine the impact of GRIK4 polymorphism on cognitive functions in MDD patients. A total of 217 MDD patients participated in this study. Their depressive severity was determined with the 17-item Hamilton Depression Rating Scale, and cognitive functions were evaluated using the Stroop Neuropsychological Screening Test, tests of visual reproduction and immediate logical memory, and the verbal fluency test (VFT). All patients were genotyped to determine GRIK4 polymorphisms. Results of VFT revealed statistical differences among all single-nucleotide polymorphism (SNP) genotypes. In the Stroop-color-word test, only rs6589847 was discovered to be statistically different. No significant difference was found in the Stroop-color task scores, the visual reproduction test, or the immediate logical memory test. GRIK4 polymorphism exerted a significant effect on long-term memory retrieval and selective attention, but did not affect immediate memory.

Psychological and Neurocognitive Impact of Behcet’s Disease

Behcet’s disease is a vasculitis, causing multisystem inflammation and resulting in oral and genital ulcers and eye and skin lesions. A proportion of suffers also have neurological involvement, termed neuro-Behcet’s disease. The purpose of this review was to investigate the psychological and neurocognitive sequelae associated with Behcet’s and neuro-Behcet’s disease and provide directions for future research. Depression and anxiety are the most researched psychological conditions in Behcet’s disease and appear to be the most consistently observed disorders across studies. Depression and anxiety severity is significantly higher relative to controls, and rates are similar across Behcet’s and neuro-Behcet’s cohorts. A systematic review would be helpful to fully determine the magnitude of these psychological disorders in Behcet’s disease and elucidate correlated clinical, regional and demographic factors. Further research is also needed into somatic and psychotic conditions as existing studies have yielded inconsistent results. Attenuations in neurocognitive functioning appear to be on a continuum. Reduced cognitive functioning is observed in Behcet’s disease relative to healthy controls; however, it is observed more frequently in neuro-Behcet’s disease, and in a broader range of neurocognitive domains (visual-spatial abilities, working memory, acquired knowledge, processing speed, long-term memory encoding and retrieval). Methodological limitations in existing studies, thus far, have not allowed for further synthesis of the data, such as through meta-analysis, and the field would benefit from several large-sample, multi-site studies using broad cognitive assessment batteries. Assessments of psychological functioning should be included as part of routine practice in clinics treating patients for Behcet’s disease. The potential for neurocognitive impairment should also be considered, particularly in those with neuro-Behcet’s. Appropriate referral pathways for psychiatric, psychological or neuropsychological intervention and treatment can then be offered, so that the psychological and neurocognitive needs in this patient cohort can be appropriately met.

Frontal lobe and long-term memory retrieval analysis during pre-learning stress using EEG signals

This paper uses the EEG analysis to investigate the relationship between pre-learning stress, frontal lope and long-term memory in the brain. The stress on learning stage is a challenge, especially in academic life. Stress also on learning stage affects the retrieval or recall from the memory. Nowadays; there are many recent works have discovered the relationship between stress, learning and memory performance based on different techniques. Some of these techniques are biological methods. Moreover, these methods have discovered the effect of stress based on hormones levels such as cortisol, or based on physiological effects such as blood pressure. However, these techniques have given conflicting discoveries because of the instability of hormones and an extensive number of related elements. The main aim of this research is to discover the relationship between Pre-learning stress, frontal lope, and long-term memory retrieval using EEG signals. The experimental results indicate that there is a relationship between theta rhythm in the frontal lobe and long-term memory retrieval during Pre-learning stress.

Proofreading by students: implications of executive and non-executive components of working memory in the detection of phonological, orthographical, and grammatical errors

The present research studied the role of the nonexecutive and executive components of working memory in the detection of typographical, lexical, and grammatical errors. Before performing the error detection tasks, undergraduate participants completed a battery of tasks that evaluated nonexecutive functions (verbal and visuospatial storage) and executive functions (coordination of verbal and visuospatial storage and processing, strategic retrieval from long-term memory, effortful shifting) as support working memory. The analyses found that typographical errors were better detected than grammatical errors, followed by lexical errors. Visuospatial storage and coordination of verbal storage and processing were significant predictors of detection of typographical and lexical errors. Effortful shifting was a significant predictor only of detection of lexical errors, while strategic retrieval in long-term memory was the only predictor of detection of grammatical errors. Globally, in the verbal domain, the executive component of working memory appeared more involved than the nonexecutive component whereas, in the visuospatial domain, the nonexecutive component seems more involved than the executive component.

Effect of Supplementation of a Whey Peptide Rich in β-Lactolin on Cognitive Performance in Healthy Adults: Randomized, Double-Blind, Placebo-Controlled Study

IntroductionWith rapid increase of aging worldwide, the number of people suffering from cognitive decline and dementia has been rapidly increasing. Numerous epidemiological and clinical studies have shown that consumption of dairy products have beneficial effects on cognitive decline and dementia in elderly. Our previous demonstration using pharmacologically-induced amnesia model mice identified tryptophan-tyrosine-related peptides, especially glycine-threonine-tryptophan-tyrosine (GTWY) of lactotetrapeptide, b-lactolin, as responsible agents improving cognitive decline in whey digestions, and we have originally developed GTWY-rich whey peptide by a specific enzymatic digestion. However, the effect of GTWY-rich whey peptide on cognitive functions in human has not been investigated. The present study is the first clinical trial evaluating the effects of GTWY-rich whey peptide on cognitive functions in a randomized, double-blind, placebo-controlled design.MethodsHealthy middle to older adults, aged from 45 to 64 years, with a self-awareness of cognitive decline were recruited. 101 eligible subjects received either whey peptide tablets containing 1 g of the GTWY-rich whey peptide per day, which included 1.6 mg of GTWY, (N = 50) or placebo containing the same amount of maltodextrin (N = 51) for 12 weeks. Changes of cognitive functions from 0 week of the intervention were assessed using neuropsychological tests assessing memory functions (word recall, story recall and verbal fluency test) and attention and executive functions (stroop test, digit span, and paced auditory serial addition test) at 6 and 12 weeks.ResultsThe change of verbal fluency test (VFT) score evaluating long-term memory retrieval at 12 weeks in whey peptide group tended to be higher than that in placebo group. Subgroup analysis showed that in the subjects with high-level of subjective fatigue measured by visual-analog scale, the changes of VFT, stroop test evaluating inhibition of executive functions and subjective memory function test at 6 weeks in whey peptide group were significantly higher than those in placebo group. The change of VFT score was also significantly higher in subjects with high fatigue measured by profile of mood status.Discussion and ConclusionsThe present study suggests that consumption of GTWY-rich whey peptide improve cognitive functions, especially memory retrieval and executive function, in healthy middle to older adults, with high subjective fatigue. It is also suggested that prefrontal cortex functions, especially dorsolateral prefrontal cortex is associated with the effects of the whey peptide. Consumptions of 1 g GTWY-rich whey peptide in daily life are safe and easy, which might be a practical approach to support cognitive function.

The Latent-Variable Structure of the Addenbrooke's Cognitive Examination-Revised.

To establish a theoretically justified factor structure for the Addenbrooke's Cognitive Examination-Revised (ACE-R). Our sample comprised 288 patients with Parkinson's disease (179 men and 109 women). The mean age of participants was 66.66 (SD=8.93). Confirmatory factor analysis (CFA) was used to evaluate the test developers' five-factor model of the ACE-R, and alternative models as guided by the Cattell-Horn-Carroll (CHC) theory. Exploratory structural equation modeling (ESEM) was also employed to examine alternative factor structures to ensure that a good candidate model was not overlooked. A three-factor CHC-guided CFA and a similar three-factor ESEM model both showed acceptable overall fit, and interpretable factor structures. The three-factor CFA model showed two factors of pure CHC constructs: acquired knowledge (Gc), and visuospatial ability (Gv), and one combined factor, namely, long-term memory retrieval, fluency, and working memory (Glr-Gsm). The three-factor ESEM model showed three factors essentially in line with the CFA results. The three-factor CHC-guided CFA model was selected as the best model to guide clinical interpretation of cognitive variables underlying ACE-R scores.