Verbal Paired-associate Learning Research Articles

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.

Supplemental Material for 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

Supplemental Material for 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

Feasibility of Remote Automated Verbal Paired Associate (VPA) Learning Over Repeated Exposure (LORE)

AbstractBackgroundLearning over repeated exposure (LORE) in periods of days or months has been shown in recent studies to be sensitive to amyloid load where short‐term learning tested in immediate recall was not (Samaroo et al., 2020). Prior LORE studies have used visual presentations of words, non‐words, and faces. We addressed the feasibility of using validated verbal paired associate (VPA) stimuli in an automated LORE task, with verbal delivery and scoring performed by our NeuroVocalix system using text‐to‐speech (TTS) and automated speech recognition (ASR). Previously we have shown that using a word‐pair memorability model based on natural language characteristics to generate sets of VPA word‐pairs of equivalent memorability allows for repeated testing with interchangeable stimulus sets. Here we explore the use of one such set in an adaptation of VPA that assesses LORE rather than immediate recall and shows promising results.MethodIn this pilot study, we assessed memory performance in 20 older adults (10m, 10f) aged 65+ years, (M = 70.7, SD = 4.65), recruited using the Prolific online platform with the test delivered using our proprietary system. The task for participants was to learn a set of eight word‐pair associations over a burst of five days. On the first day, participants heard the word‐pair set, and were immediately tested for recall of that set. On days two, three, and four of the study, participants first attempted cued recall of the eight word‐pairs, after which the set was presented again, and the session ended. On the final day, cued recall was tested for the last time.ResultOn the first day, immediate recall scores were in line with first attempt VPA scores observed in validation work. On the second day of the series, scores fell through forgetting, and then learning over three further exposures showed monotonically increasing recall scores with neither ceiling nor floor effects across the group. Adherence was excellent, with 99% of sessions successfully completed, and participants reported high enjoyment of the task and eager anticipation of sessions.ConclusionVPA‐form LORE using our validated VPA word‐pair stimuli performs well and shows promising task characteristics in a representative sample.

Feasibility of Remote Automated Verbal Paired Associate (VPA) Learning Over Repeated Exposure (LORE)

AbstractBackgroundLearning over repeated exposure (LORE) in periods of days or months has been shown in recent studies to be sensitive to amyloid load where short‐term learning tested in immediate recall was not (Samaroo et al., 2020). Prior LORE studies have used visual presentations of words, non‐words, and faces. We addressed the feasibility of using validated verbal paired associate (VPA) stimuli in an automated LORE task, with verbal delivery and scoring performed by our NeuroVocalix system using text‐to‐speech (TTS) and automated speech recognition (ASR). Previously we have shown that using a word‐pair memorability model based on natural language characteristics to generate sets of VPA word‐pairs of equivalent memorability allows for repeated testing with interchangeable stimulus sets. Here we explore the use of one such set in an adaptation of VPA that assesses LORE rather than immediate recall and shows promising results.MethodIn this pilot study, we assessed memory performance in 20 older adults (10m, 10f) aged 65+ years, (M = 70.7, SD = 4.65), recruited using the Prolific online platform with the test delivered using our proprietary system. The task for participants was to learn a set of eight word‐pair associations over a burst of five days. On the first day, participants heard the word‐pair set, and were immediately tested for recall of that set. On days two, three, and four of the study, participants first attempted cued recall of the eight word‐pairs, after which the set was presented again, and the session ended. On the final day, cued recall was tested for the last time.ResultOn the first day, immediate recall scores were in line with first attempt VPA scores observed in validation work. On the second day of the series, scores fell through forgetting, and then learning over three further exposures showed monotonically increasing recall scores with neither ceiling nor floor effects across the group. Adherence was excellent, with 99% of sessions successfully completed, and participants reported high enjoyment of the task and eager anticipation of sessions.ConclusionVPA‐form LORE using our validated VPA word‐pair stimuli performs well and shows promising task characteristics in a representative sample.

Detecting mild cognitive impairment remotely with the modified memory impairment screen by telephone

ABSTRACT The original Memory Impairment Screen by Telephone (MIST) was designed to identify individuals with dementia but was relatively ineffective for identification of less severe impairment observed in mild cognitive impairment (MCI). We expanded the original MIST to create a modified instrument (mMIST) with greater sensitivity to less severe memory impairment. Older men and women with subjective cognitive decline were assessed by phone with the mMIST and subsequently classified independently with MCI or non-pathological cognitive decline. Participants with MCI produced lower scores on the mMIST than did participants without MCI, 10.8 ± 2.7 vs 13.3 ± 1.3, t = 5.68, p < 0.001, and performance on the mMIST predicted performances on the California Verbal Learning Test (CVLT), Verbal Paired Associate Learning Test (VPAL), Montreal Cognitive Assessment (MoCA) total score, and MoCA memory index score, p < 0.001. Receiver operating characteristic (ROC) analyses identified the optimal cut score on the mMIST to distinguish participants with and without MCI with Sensitivity = 73.1%, Specificity = 79.1%, and AUC = 0.79. Predictive values for distinguishing the amnestic form of MCI (aMCI) from non-amnestic MCI were Sensitivity = 81.8%, Specificity = 30%, and AUC = 0.82. These findings indicate that the mMIST is a valid screening instrument for identifying MCI. It can be administered remotely at low cost and low participant burden. Also, the mMIST has potential utility for remote cross-sectional and longitudinal evaluation in research and clinical contexts. Further investigation is indicated to corroborate its utility for assessment of aging patients and research participants.

Assessing dynamic brain activity during verbal associative learning using MEG/fMRI co-processing

BackgroundThe abilities of individual neuroimaging methods to resolve spatial and temporal contributions of brain regions during cognitive processes are limited. Co-processing of functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG) may overcome some of the limitations by utilizing Multiple Sparse Priors (MSP) in a Bayesian framework that takes advantage of the temporal resolution of MEG and spatial resolution of fMRI. Methods24 healthy participants were recruited to perform a paired-associate verbal learning task during fMRI and MEG scans. FMRI data were processed within Group ICA fMRI Toolbox. Independent components (ICs) were temporally sorted by task time series (|r|>0.30 threshold identified task-related ICs). Task-positive (“generate”) ICs were retained as spatial priors for MEG analyses. MEG data were processed by an event-related potential (ERP) approach and with a theta power approach. MEG source reconstructions were constrained within the task-positive ICs for both ERP and theta-power approaches. ResultsFor fMRI, five networks were identified as task-related. Four ICs underlying active generation spanned bilateral parietal, orbitofrontal, medial frontal and superior temporal regions, and occipital lobe. FMRI-constrained MEG source reconstructions using the ERP approach yielded early visual cortex activity followed by left inferior frontal gyrus (IFG) and orbito-frontal cortex (OFC) recruitment to coalesce in the left inferior temporal lobe. For the theta approach, MEG source reconstructions showed a progression of activity from bilateral temporal areas to left OFC and middle temporal gyrus, followed by right IFG. DiscussionMSP analyses informed by fMRI produced more focused regional activity than reconstructions without priors suggesting this approach may result in identifying more relevant semantic information during active generation. Constraining MEG source reconstruction to fMRI priors during active generation indicates fronto-temporal and fronto-parietal networks are interconnected across time and space.

Automating the verbal paired associates test to assess memory remotely and at scale

AbstractBackgroundVerbal neuropsychological tests are sensitive to the early signs of neurodegeneration in older adults. However, their dependence on in‐person testing and manual scoring make them unsuitable for large‐scale screening and home‐based monitoring. To address this, we have developed a fully automated verbal paired associate learning (VPA) test. Here we describe the program of work to refine and validate this task, and ensure suitability of the test for remote, repeat administration.MethodsTwo phases of data collection were carried out. In the first, data was collected from 3,264 participants aged 17–86 years (M = 34.5, SD = 12.32) at home and on their own devices. The automated VPA task comprises eight word‐pairs, learned over three attempts. Automatic speech recognition (ASR) scores responses in real‐time, using the Neurovocalix platform. Following this phase, the task was refined to better enable repeat testing. This included producing a large corpus of algorithmically generated pairs, controlling for important linguistic features (e.g. frequency and concreteness), and adding brief familiarisation to the first visit to increase reliability and stability. We assessed: 1) the accuracy of automated scoring 2) the impact of participant characteristics and task design on performance and consistency 3) participant feedback.ResultsData from the first phase showed excellent correspondence between human and automated scoring of VPA, with a correlation .93 (p &lt; 0.001), and the expected sensitivity to ageing number of task performance. Participant demographics and technology choice did not impact correspondence between ASR scoring and manual scoring. In the second phase data collection, we compared VPA performance in participants with (N = 190) and without (N = 186) prior familiarisation. Familiarisation dramatically improved consistency of participant performance, eliminating the significant effect of task order on performance (F &gt; 100, p &lt; 0.001). Participants reported that they found the task engaging and easy to understand, and repeated testing over five sessions in older adults was well tolerated.ConclusionsTogether, these results demonstrate that remote, automated, voice‐based, cognitive assessments are feasible and acceptable. These methods may therefore be useful in the context of home‐based screening or monitoring in remote clinical trials, enabling longitudinal assessment of memory in AD.

Relationship between neuropsychological test scores and hippocampal atrophy in non-demented Japanese older adults

BackgroundIt is essential to detect morphological changes in the brain prior to the onset of cognitive decline. Although hippocampal volumes have been reported to be correlated with scores on neuropsychological tests, this relationship is still unclear among Japanese non-demented older adults. Thus, this exploratory retrospective study aimed to identify neuropsychological tests that correlate with the degree of hippocampal atrophy in Japanese non-demented older adults. MethodsThirteen non-demented Japanese older adults aged 71.2 ± 5.2 years were included. Hippocampal atrophy was evaluated by assessing the participants’ MRI scans using the voxel-based specific regional analysis system for Alzheimer’s disease (VSRAD) software. Spearman’s partial correlation analyses were conducted to reveal relationships between VSRAD scores and neuropsychological test scores, including Raven’s Colored Progressive Matrices test (RCPM), the Standard Verbal Paired Associate Learning test (SP-A), and the Trail Making Test (TMT) scores by controlling for age, sex, and years of education. ResultsThe Spearman’s partial correlation analysis results revealed that there were significant correlations between the degree of hippocampal atrophy and RCPM (rho = -0.691, p = 0.027), TMT part B (rho = 0.823, p = 0.003), and the related SP-A test scores (rho = -0.663, p = 0.027). ConclusionsOur results indicate that neuropsychological tests, particularly the TMT part B, might be used in assessing the degree of hippocampal atrophy in non-demented Japanese elderly individuals and should be studied further in the future to develop screening methods to detect brain atrophy.

Changes in cognitive function after carotid artery revascularization: Clinical significance of Standard Verbal Paired-Associate Learning Test (S-PA)

Changes in cognitive function after carotid artery revascularization: Clinical significance of Standard Verbal Paired-Associate Learning Test (S-PA)

Supplementation with Matured Hop Bitter Acids Improves Cognitive Performance and Mood State in Healthy Older Adults with Subjective Cognitive Decline.

Background:Prevention of age-related cognitive decline and depression is becoming urgent because of rapid growing aging populations. Effects of vagal nerve activation on brain function by food ingredients are inadequately investigated; matured hop bitter acid (MHBA) administration reportedly improves cognitive function and depression via vagal nerve activation in model mice.Objective:We investigated the effects of MHBA supplementation on cognitive function and mood state in healthy older adults with perceived subjective cognitive decline.Methods:Using a randomized double-blind placebo-controlled trial design, 100 subjects (aged 45–69 years) were randomly assigned into placebo (n = 50) and MHBA (n = 50) groups, and received placebo or MHBA capsules daily for 12 weeks.Results:Symbol Digit Modalities Test (SDMT) score assessing divided attention at week 12 was significantly higher (p = 0.045) and β-endorphin at week 12 was significantly lower (p = 0.043) in the subjects receiving MHBA. Transthyretin in serum, a putative mild cognitive impairment marker, was significantly higher at week 12 in the MHBA group than in the placebo group (p = 0.048). Subgroup analysis classified by the subjective cognitive decline questionnaire revealed that in addition to improved SDMT scores, memory retrieval assessed using the standard verbal paired-associate learning tests and the Ray Verbal Learning Test at week 12 had significantly improved in the subgroup with perceived subjective cognitive decline and without requirement for medical assistance in the MHBA group compared with that in the placebo group.Conclusion:This study suggested that MHBA intake improves cognitive function, attention, and mood state in older adults.

Neuropsychological profile of amyloid‐positive versus amyloid‐negative amnestic Mild Cognitive Impairment

Patients diagnosed with amnestic mild cognitive impairment (aMCI) are at high risk of progressing to dementia. It became possible, through the use of biomarkers, to diagnose those patients with aMCI who have Alzheimer's disease. However, it is presently unfeasible that all patients undergo biomarker testing. Since neuropsychological testing is required to make a formal diagnosis of aMCI, it would be interesting if it could be used to predict the amyloid status of patients with aMCI. Participants with aMCI, known amyloid status (Aβ+ or Aβ-) and a comprehensive neuropsychological evaluation, were selected from the Cognitive Complaints Cohort database for this study. Neuropsychological tests were compared in Aβ+ and Aβ- aMCI patients. A binary logistic regression analysis was conducted to model the probability of being amyloid positive. Of the 216 aMCI patients studied, 117 were Aβ+ and 99 were Aβ-. Aβ+ aMCI patients performed worse on several memory tests, namely Word Total Recall, Logical Memory Immediate and Delayed Free Recall, and Verbal Paired Associate Learning, as well as on Trail Making Test B, an executive function test. In a binary logistic regression model, only Logical Memory Delayed Free Recall retained significance, so that for each additional score point in this test, the probability of being amyloid positive decreased by 30.6%. The resulting model correctly classified 64.6% of the aMCI cases regarding their amyloid status. The neuropsychological assessment remains an essential step to diagnose and characterize patients with aMCI; however, neuropsychological tests have limited value to distinguish the aMCI patients who have amyloid pathology from those who might suffer from other clinical conditions.

Normalization of mediotemporal and prefrontal activity, and mediotemporal-striatal connectivity, may underlie antipsychotic effects of cannabidiol in psychosis.

Recent evidence suggests that cannabidiol (CBD), a non-intoxicating ingredient present in cannabis extract, has an antipsychotic effect in people with established psychosis. However, the effect of CBD on the neurocognitive mechanisms underlying psychosis is unknown. Patients with established psychosis on standard antipsychotic treatment were studied on separate days at least one week apart, to investigate the effects of a single dose of orally administered CBD (600 mg) compared to a matched placebo (PLB), using a double-blind, randomized, PLB-controlled, repeated-measures, within-subject cross-over design. Three hours after taking the study drug participants were scanned using a block design functional magnetic resonance imaging (fMRI) paradigm, while performing a verbal paired associate learning task. Fifteen psychosis patients completed both study days, 13 completed both scanning sessions. Nineteen healthy controls (HC) were also scanned using the same fMRI paradigm under identical conditions, but without any drug administration. Effects of CBD on brain activation measured using the blood oxygen level-dependent hemodynamic response fMRI signal were studied in the mediotemporal, prefrontal, and striatal regions of interest. Compared to HC, psychosis patients under PLB had altered prefrontal activation during verbal encoding, as well as altered mediotemporal and prefrontal activation and greater mediotemporal-striatal functional connectivity during verbal recall. CBD attenuated dysfunction in these regions such that activation under its influence was intermediate between the PLB condition and HC. CBD also attenuated hippocampal-striatal functional connectivity and caused trend-level symptom reduction in psychosis patients. This suggests that normalization of mediotemporal and prefrontal dysfunction and mediotemporal-striatal functional connectivity may underlie the antipsychotic effects of CBD.

Effects of Collagen Hydrolysates on Human Brain Structure and Cognitive Function: A Pilot Clinical Study

This study investigated the effects of collagen hydrolysates (CH) on language cognitive function and brain structure. In this open-label study, 5 g CH was administered once a day for 4 weeks to 30 healthy participants aged 49–63 years. The primary outcome measures were the brain healthcare quotients based on gray matter volume (GM-BHQ) and fractional anisotropy (FA-BHQ). The secondary outcome measures were changes in scores between week 0 and week 4 for word list memory (WLM) and standard verbal paired associate learning (S-PA) tests as well as changes in the physical, mental, and role/social component summary scores of the Short Form-36(SF-36) quality of life instrument. CH ingestion resulted in significant improvements in FA-BHQ (p = 0.0095), a measure of brain structure, as well in scores for the WLM (p = 0.0046) and S-PA (p = 0.0007) tests, which measure cognitive function. There were moderate correlations between the change in WLM score and the change in GM-BHQ (r = 0.4448; Spearman’s rank correlation) and between the change in S-PA score and the change in FA-BHQ (r = 0.4645). Daily ingestion of CH changed brain structure and improved language cognitive function.

Disrupted parahippocampal and midbrain function underlie slower verbal learning in adolescent-onset regular cannabis use

RationaleProlonged use of cannabis, the most widely used illicit drug worldwide, has been consistently associated with impairment in memory and verbal learning. Although the neurophysiological underpinnings of these impairments have been investigated previously using functional magnetic resonance imaging (fMRI), while performing memory tasks, the results of these studies have been inconsistent and no clear picture has emerged yet. Furthermore, no previous studies have investigated trial-by-trial learning.ObjectivesWe aimed to investigate the neural underpinnings of impaired verbal learning in cannabis users as estimated over repeated learning trials.MethodsWe studied 21 adolescent-onset regular cannabis users and 21 non-users using fMRI performed at least 12 h after last cannabis use, while they performed a paired associate verbal learning task that allowed us to examine trial-by-trial learning. Brain activation during repeated verbal encoding and recall conditions of the task was indexed using the blood oxygen level-dependent haemodynamic response fMRI signal.ResultsThere was a significant improvement in recall score over repeated trials indicating learning occurring across the two groups of participants. However, learning was significantly slower in cannabis users compared to non-users (p = 0.032, partial eta-squared = 0.108). While learning verbal stimuli over repeated encoding blocks, non-users displayed progressive increase in recruitment of the midbrain, parahippocampal gyrus and thalamus (p = 0.00939, partial eta-squared = 0.180). In contrast, cannabis users displayed a greater but disrupted activation pattern in these regions, which showed a stronger correlation with new word-pairs learnt over the same blocks in cannabis users than in non-users.ConclusionsThese results suggest that disrupted medial temporal and midbrain function underlie slower learning in adolescent-onset cannabis users.

Sex, Age, and Handedness Modulate the Neural Correlates of Active Learning.

BackgroundSelf-generation of material compared to passive learning results in mproved memory performance; this may be related to recruitment of a fronto-temporal encoding network. Using a verbal paired-associate learning fMRI task, we examined the effects of sex, age, and handedness on the neural correlates of self-generation.MethodsData from 174 healthy English-speaking participants (78M, 56 atypically handed; ages 19–76) were preprocessed using AFNI and FSL. Independent component analysis was conducted using GIFT (Group ICA fMRI Toolbox). Forty-one independent components were temporally sorted by task time series. Retaining correlations (r > 0.25) resulted in three task-positive (“generate”) and three task-negative (“read”) components. Using participants’ back-projected components, we evaluated the effects of sex, handedness, and aging on activation lateralization and localization in task-relevant networks with two-sample t-tests. Further, we examined the linear relationship between sex and neuroimaging data with multiple regression, covarying for scanner, age, and handedness.ResultsTask-positive components identified using ICA revealed a fronto-parietal network involved with self-generation, while task-negative components reflecting passive reading showed temporo-occipital involvement. Compared to older adults, younger adults exhibited greater task-positive involvement of the left inferior frontal gyrus and insula, whereas older adults exhibited reduced prefrontal lateralization. Greater involvement of the left angular gyrus in task-positive encoding networks among right-handed individuals suggests the reliance on left dominant semantic processing areas may be modulated by handedness. Sex effects on task-related encoding networks while controlling for age and handedness suggest increased right hemisphere recruitment among males compared to females, specifically in the paracentral lobe during self-generation and the suparmarginal gyrus during passive reading.ImplicationsIdentified neuroimaging differences suggest that sex, age, and handedness are factors in the differential recruitment of encoding network regions for both passive and active learning.

Supplementation With Whey Peptide Rich in β-Lactolin Improves Cognitive Performance in Healthy Older Adults: A Randomized, Double-Blind, Placebo-Controlled Study.

Epidemiological reports showed that consumptions of fermented dairy products are beneficial for cognitive decline in elderly. Our previous preclinical studies have demonstrated that intakes of whey peptide rich in the β-lactolin [β-lactopeptide of glycine-thereonine-tryptophan-tyrosine (GTWY)] improve memory and attention by regulating monoamine system, and clinical study using neuropsychological test suggested that consumptions with GTWY-rich whey peptide enhance cognitive performance associated with the frontal cortex activity. However, corresponding interventional studies in humans are limited. Objectives: to evaluate the effects of the whey peptide on cognitive functions in healthy older adults using a randomized, double-blinded, placebo-controlled trial design. 114 healthy subjects aged 50–75 were supplemented with the whey peptide or placebo for 12 weeks, and changes in cognitive function were assessed using neuropsychological tests at weeks 0, 6, and 12 of the intervention. Neuropsychological tests included assessments for memory functions (subtests from Wechsler memory scale-revised, standard verbal paired-associate learning test, and recognition memory test for faces), assessments for attention (cancelation and detection tests), and assessments for general cognitive functions (repeatable battery for assessments of neuropsychological status). Cerebral blood flow was also assessed using near-infrared spectroscopy (NIRS) after 6 weeks of intervention. This study was registered on the 19 November, 2017 in the database of the University Hospital Medical Information Network (UMIN) prior to enrollment of subjects (Registration No. UMIN000030461: https://www.umin.ac.jp/ctr/index-j.htm). In the whey peptide group, visual paired-associates I and visual cancelation tests were significantly improved compared with those in the placebo group at weeks 6 and 12 of the intervention, respectively. Visuospatial and constructional scores of the repeatable battery for assessments of neuropsychological status and standard verbal paired-associate learning tests (S-PA) also tended to be improved by the intervention at week 12. Daily intakes of GTWY-rich whey peptide show beneficial effects on cognitive performance, especially associative learning memory and control of attention, in healthy older adults and might prevent age-related cognitive declines.

A Key Role for Subiculum-Fornix Connectivity in Recollection in Older Age.

Individual differences in memory during aging are associated with the microstructure of the fornix, a bidirectional tract connecting the hippocampus with the diencephalon, basal forebrain and cortex. To investigate the origin of alterations in fornix microstructure, measurement of hippocampal subfield volumes was combined with diffusion MRI and cognitive evaluation in a new sample of 31 healthy human participants aged 50–89 years. The fornix, uncinate and parahippocampal cingulum were reconstructed using diffusion MRI tractography. Episodic memory was assessed with free and cued verbal recall, visual recognition and paired associate learning tests. Recall performance was associated with fornix microstructure and hippocampal subfield volumes. Subiculum and CA1 volumes remained positively associated with fornix microstructure when controlling for other volumes. Subiculum volume was also associated with fornix microstructure independent of age. Regression analyses showed that subiculum-fornix associations explained more variation in recall than that of CA1-fornix associations. In a multivariable regression model, age and subiculum volume were independent predictors of free recall whilst fornix microstructure and CA1 volume were not. These results suggest that age-related changes in a network that includes the subiculum and fornix are important in cognitive change in healthy aging. These results match anatomical predictions concerning the importance of hippocampal – diencephalic projections for memory.

Orthographic Learning in Children Who Are Deaf or Hard of Hearing.

Purpose The purpose of the current study was to investigate the relationship between orthographic learning and language, reading, and cognitive skills in 9-year-old children who are deaf or hard of hearing (DHH) and to compare their performance to age-matched typically hearing (TH) controls. Method Eighteen children diagnosed with moderate-to-profound hearing loss who use hearing aids and/or cochlear implants participated. Their performance was compared with 35 age-matched controls with typical hearing. Orthographic learning was evaluated using a spelling task and a recognition task. The children were assessed on measures of reading ability, language, working memory, and paired-associate learning. Results On average, the DHH group performed more poorly than the TH controls on the spelling measure of orthographic learning, but not on the recognition measure. For both groups of children, there were significant correlations between orthographic learning and phonological decoding and between visual-verbal paired-associate learning and orthographic learning. Conclusions Although the children who are DHH had lower scores in the spelling test of orthographic learning than their TH peers, measures of their reading ability revealed that they acquired orthographic representations successfully. The results are consistent with the self-teaching hypothesis in suggesting that phonological decoding is important for orthographic learning.

Examining the direct and indirect effects of visual–verbal paired associate learning on Chinese word reading

Associative learning, traditionally measured with paired associate learning (PAL) tasks, has been found to predict reading ability in several languages. However, it remains unclear whether it also predicts word reading in Chinese, which is known for its ambiguous print–sound correspondences, and whether its effects are direct or indirect through the effects of other reading-related skills such as phonological awareness and rapid naming. Thus, the purpose of this study was to examine the direct and indirect effects of visual–verbal PAL on word reading in an unselected sample of Chinese children followed from the second to the third kindergarten year. A sample of 141 second-year kindergarten children (71 girls and 70 boys; mean age=58.99months, SD=3.17) were followed for a year and were assessed at both times on measures of visual–verbal PAL, rapid naming, and phonological awareness. In the third kindergarten year, they were also assessed on word reading. The results of path analysis showed that visual–verbal PAL exerted a significant direct effect on word reading that was independent of the effects of phonological awareness and rapid naming. However, it also exerted significant indirect effects through phonological awareness. Taken together, these findings suggest that variations in cross-modal associative learning (as measured by visual–verbal PAL) place constraints on the development of word recognition skills irrespective of the characteristics of the orthography children are learning to read.

P207 Affecting declarative long-term memory with transcranial alternating current stimulation (tACS)

Introduction and objective Previous studies imply that tACS can entrain the ongoing physiological neuronal oscillations depending on the targeted function and the parameters (frequency, intensity and phase) of the stimulation. The aim of the present study was to clarify if tACScould influence the performance of healthy subjects on a verbal paired-associate learning paradigm. Methods For that, we conducted three different crossover, randomized, single-blind, placebo-controlled studies, using a battery-driven Starstim stimulator system (Neuroelectrics, Barcelona, Spain). In the first study ( n = 6), we applied 100 Hz tACS with 1.5 mA (active electrode T7, return Fpz and T8); in the second one ( n = 6), 1.0 mA, 6 Hz (3 s) followed by 80 Hz (5 s) tACS during ISI and Stimulus presentation using the same electrodes configuration; in the third one ( n = 15), we combined a temporal- and pre-frontal stimulation using 7 electrodes. Here the stimulation intensity was 1 mA at 6 Hz (temporal) and 80 Hz (pre-frontal) combined stimulation. For all the studies, we used 8 cm 2 round rubber electrodes inside a saline-soaked sponge pocket, applying 10 min stimulation during the word-pairs learning phase. After the learning phase, the subjects had a 10 min pause, followed by a test phase with a cued recall. The subjects returned after 24 h for a second cued-recall test. All subjects receivedactive and sham tACS in a counterbalanced, randomized-manner. Results In the first two studies, no significant difference were found in the accuracy performance between days across conditions, as well as between days within conditions; in the third study, we found no significant difference between days across conditions, but significant difference between days in the active ( t = 2.98, p = 0.010) and sham ( t = 2.52, p = 0.024) stimulation. Conclusion The stimulation parameters tested could not influence the memory performance assessed by this memory task with the present number of subjects in the first two studies. Further variations of waveforms, intensity and stimulation parameters should be tested with the same task in order to probe the possible influence of tACS on episodic long-term memory. The final results will be presented in the conference.