Working memory is a core cognitive function that supports goal-directed behavior and complex thought.We developed a spatial working memory and attention test on paired symbols(SWAPS)which has been proved to be a usefu...Working memory is a core cognitive function that supports goal-directed behavior and complex thought.We developed a spatial working memory and attention test on paired symbols(SWAPS)which has been proved to be a useful and valid tool for spatial working memory and attention studies in the fields of cognitive psychology,education,and psychiatry.The repeated administration of working memory capacity tests is common in clinical and research settings.Studies suggest that repeated cognitive tests may improve the performance scores also known as retest effects.The systematic investigation of retest effects in SWAPS is critical for interpreting scientific results,but it is still not fully developed.To address this,we recruited 77 college students aged 18–21 years and used SWAPS comprising 72 trials with different memory loads,learning time,and delay span.We repeated the test once a week for five weeks to investigate the retest effects of SWAPS.There were significant retest effects in the first two tests:the accuracy of the SWAPS tests significantly increased,and then stabilized.These findings provide useful information for researchers to appropriately use or interpret the repeated working memory tests.Further experiments are still needed to clarify the factors that mediate the retest effects,and find out the cognitive mechanism that influences the retest effects.展开更多
BACKGROUND Working memory serves as a fundamental cognitive function that substantially impacts performance in various cognitive tasks.Extensive neurophysiological research has established that theta oscillations(4-8 ...BACKGROUND Working memory serves as a fundamental cognitive function that substantially impacts performance in various cognitive tasks.Extensive neurophysiological research has established that theta oscillations(4-8 Hz)play an essential role in supporting working memory operations.Theta-band transcranial alternating current stimulation(tACS)offers a potential mechanism for working memory enhancement through direct modulation of these fundamental neural oscillations.Nevertheless,current empirical evidence shows substantial variability in the observed effects of theta-tACS across studies.AIM To conduct a systematic review and meta-analysis evaluating the effects of thetatACS on working memory performance in healthy adults.METHODS A systematic literature search was performed on PubMed,EMBASE,and Web of Science up to March 10,2025.Effect sizes were computed using Hedges’g with 95%confidence intervals(CIs),with separate meta-analyses for all included studies and for distinct working memory paradigms[n-back and delayed matchto-sample(DMTS)tasks]to examine potential task-specific effects.Subgroup analyses and meta-regression were performed to evaluate the influence of key moderating variables.RESULTS The systematic review included 21 studies(67 effect sizes).Initial meta-analysis showed theta-tACS moderately improved working memory(Hedges’g=0.405,95%CI:0.212-0.598).However,this effect became nonsignificant after correcting for publication bias(trim-and-fill adjusted Hedges’g=0.082,95%CI:-0.052 to 0.217).Task-specific analyses revealed significant benefits in n-back tasks(Hedges’g=0.463,95%CI:0.193-0.733)but not in DMTS tasks(Hedges’g=0.257,95%CI:-0.186 to 0.553).Moderator analyses showed that performance in n-back tasks was influenced by stimulation frequency(P=0.001),concurrent status(P=0.014),task modality(P=0.005),and duration(P=0.013),whereas only the region of targeted stimulation(P=0.012)moderated DMTS tasks.CONCLUSION Theta-tACS enhances working memory in healthy adults,with effects modulated by the task type and protocol parameters,offering dual implications for cognitive enhancement and clinical interventions.展开更多
Rhythm,as a prominent characteristic of auditory experiences such as speech and music,is known to facilitate attention,yet its contribution to working memory(WM)remains unclear.Here,human participants temporarily reta...Rhythm,as a prominent characteristic of auditory experiences such as speech and music,is known to facilitate attention,yet its contribution to working memory(WM)remains unclear.Here,human participants temporarily retained a 12-tone sequence presented rhythmically or arrhythmically in WM and performed a pitch change-detection task.Behaviorally,while having comparable accuracy,rhythmic tone sequences showed a faster response time and lower response boundaries in decision-making.Electroencephalographic recordings revealed that rhythmic sequences elicited enhanced non-phase-locked beta-band(16 Hz–33 Hz)and theta-band(3 Hz–5 Hz)neural oscillations during sensory encoding and WM retention periods,respectively.Importantly,the two-stage neural signatures were correlated with each other and contributed to behavior.As beta-band and theta-band oscillations denote the engagement of motor systems and WM maintenance,respectively,our findings imply that rhythm facilitates auditory WM through intricate oscillation-based interactions between the motor and auditory systems that facilitate predictive attention to auditory sequences.展开更多
Working memory is an executive memory process that includes encoding,maintenance,and retrieval.These processes can be modulated by transcranial alternating current stimulation(tACS)with sinusoidal waves.However,little...Working memory is an executive memory process that includes encoding,maintenance,and retrieval.These processes can be modulated by transcranial alternating current stimulation(tACS)with sinusoidal waves.However,little is known about the impact of the rate of current change on working memory.In this study,we aimed to investigate the effects of two types of tACS with different rates of current change on working memory performance and brain activity.We applied a randomized,single-blind design and divided 81 young participants who received triangular wave tACS,sinusoidal wave tACS,or sham stimulation into three groups.Participants performed n-back tasks,and electroencephalograms were recorded before,during,and after active or sham stimulation.Compared to the baseline,working memory performance(accuracy and response time)improved after stimulation under all stimulation conditions.According to drift-diffusion model analysis,triangular wave tACS significantly increased the efficiency of non-target information processing.In addition,compared with sham conditions,triangular wave tACS reduced alpha power oscillations in the occipital lobe throughout the encoding period,while sinusoidal wave tACS increased theta power in the central frontal region only during the later encoding period.The brain network connectivity results showed that triangular wave tACS improved the clustering coefficient,local efficiency,and node degree intensity in the early encoding stage,and these parameters were positively correlated with the non-target drift rate and decision starting point.Our findings on how tACS modulates working memory indicate that triangular wave tACS significantly enhances brain network connectivity during the early encoding stage,demonstrating an improvement in the efficiency of working memory processing.In contrast,sinusoidal wave tACS increased the theta power during the later encoding stage,suggesting its potential critical role in late-stage information processing.These findings provide valuable insights into the potential mechanisms by which tACS modulates working memory.展开更多
The prefrontal cortex and hippocampus may support sequential working memory beyond episodic memory and spatial navigation.This stereoelectroencephalography(SEEG)study investigated how the dorsolateral prefrontal corte...The prefrontal cortex and hippocampus may support sequential working memory beyond episodic memory and spatial navigation.This stereoelectroencephalography(SEEG)study investigated how the dorsolateral prefrontal cortex(DLPFC)interacts with the hippocampus in the online processing of sequential information.Twenty patients with epilepsy(eight women,age 27.6±8.2 years)completed a line ordering task with SEEG recordings over the DLPFC and the hippocampus.Participants showed longer thinking times and more recall errors when asked to arrange random lines clockwise(random trials)than to maintain ordered lines(ordered trials)before recalling the orientation of a particular line.First,the ordering-related increase in thinking time and recall error was associated with a transient theta power increase in the hippocampus and a sustained theta power increase in the DLPFC(3–10 Hz).In particular,the hippocampal theta power increase correlated with the memory precision of line orientation.Second,theta phase coherences between the DLPFC and hippocampus were enhanced for ordering,especially for more precisely memorized lines.Third,the theta band DLPFC→hippocampus influence was selectively enhanced for ordering,especially for more precisely memorized lines.This study suggests that theta oscillations may support DLPFC-hippocampal interactions in the online processing of sequential information.展开更多
BACKGROUND The detection rate of depression among university students has been increasing in recent years,becoming one of the main psychological diseases that endangers their physical and mental health.According to st...BACKGROUND The detection rate of depression among university students has been increasing in recent years,becoming one of the main psychological diseases that endangers their physical and mental health.According to statistics,self-harm and suicide,for which there is no effective intervention,are the second leading causes of death.AIM To explore the relationship between different elements and levels of physical activity and college students’depression-symptom-specific working memory indicators.METHODS Of 143 college students were analyzed using the Beck Depression Self-Rating Scale,the Physical Activity Rating Scale,and the Working Memory Task.RESULTS There was a significant difference between college students with depressive symptoms and healthy college students in completing verbal and spatial working memory(SWM)tasks correctly(all P<0.01).Physical Activity Scale-3 scores were significantly and positively correlated with the correct rate of the verbal working memory task(r=0.166)and the correct rate of the SWM task(r=0.210)(all P<0.05).There were significant differences in the correct rates of verbal and SWM tasks according to different exercise intensities(all P<0.05)and different exercise durations(all P<0.05),and no significant differences in the correct rates of verbal and SWM tasks by exercise frequency(all P>0.05).CONCLUSION An increase in physical exercise among college students,particularly medium-and high-intensity exercise and exercise of 30 min or more,can improve the correct rate of completing working memory tasks.展开更多
This experimental study investigated how text difficulty and different working memory capacity(WMC)affected Chinese EFL learners’reading comprehension and their tendency to engage in task-unrelated thoughts,that is,m...This experimental study investigated how text difficulty and different working memory capacity(WMC)affected Chinese EFL learners’reading comprehension and their tendency to engage in task-unrelated thoughts,that is,mind wandering(MW),in the course of reading.Sixty first-year university non-English majors participated in the study.A two-factor mixed experimental design of 2(text difficulty:difficult and simple)×2(WMC:high/large and low/small)was employed.Results revealed that 1)the main and interaction effects of WMC and text difficulty on voluntary MW were significant,whereas those on involuntary MW were not;2)while reading the easy texts,the involuntary MW of high-WMC individuals was less frequent than that of low-WMC ones,whereas while reading the difficult ones,the direct relationship between WMC and involuntary MW was not found;and that 3)high-WMC individuals had a lower overall rate of MW and better reading performance than low-WMC individuals did,but with increasing text difficulty,their rates of overall MW and voluntary MW were getting higher and higher,and the reading performance was getting lower and lower.These results lend support to WM theory and have pedagogical implications for the instruction of L2 reading.展开更多
Background: Working memory is an executive function that plays an important role in many aspects of daily life, and its impairment in patients with attention-deficit/hyperactivity disorder (ADHD) affects quality of li...Background: Working memory is an executive function that plays an important role in many aspects of daily life, and its impairment in patients with attention-deficit/hyperactivity disorder (ADHD) affects quality of life. The dorsolateral prefrontal cortex (DLPFC) has been a good target site for transcranial direct current stimulation (tDCS) due to its intense involvement in working memory. In our 2018 study, tDCS improved visual-verbal working memory in healthy subjects. Objective: This study examines the effects of tDCS on ADHD patients, particularly on verbal working memory. Methods: We conducted an experiment involving verbal working memory of two modalities, visual and auditory, and a sustained attention task that could affect working memory in 9 ADHD patients. Active or sham tDCS was applied to the left DLPFC in a single-blind crossover design. Results: tDCS significantly improved the accuracy of visual-verbal working memory. In contrast, tDCS did not affect auditory-verbal working memory and sustained attention. Conclusion: tDCS to the left DLPFC improved visual-verbal working memory in ADHD patients, with important implications for potential ADHD treatments.展开更多
The relation between evolution of spatial working memory function and of morphology of the dorsolateral prefrontal cortex among the rhesus monkey (Macaca mulatta), the slow loris (Nycticebus coucang) and the tree shre...The relation between evolution of spatial working memory function and of morphology of the dorsolateral prefrontal cortex among the rhesus monkey (Macaca mulatta), the slow loris (Nycticebus coucang) and the tree shrew (Tupaia belangen chinensis) were reported in present paper. The results read as follows: In the DR performance with training, the rhesus monkeys and slow lorises could reach a criterion of 90% correct response at 1.1 ± 3.2 seconds, and 3.8±0.4 seconds delay interval, respectively, by 1000 training trails. The tree shrews failed to reach the criterion of 90% correct response even at 0 seconds delay interval by 1000 training trails. If a delay interval was tested in one session (30 trails) only, doing the DR performamce without training, the rhesus monkeys reached a correct of 80% or higher in each session at 0, 1, 2, 3, 4, and 5 seconds delay, respectively. The percent correct in each session of the slow lorises showed no differences from the rhesus monkeys at 0, 1, 2, 3, and 4 seconds delay. However, when the delay interval was increased to 5 seconds, the percent correct of the DR performance declined to 70% or lower in the slow lorises. In the tree shrews the percent correct in each session reached to 70% or lower at 0, 1, 2, 3, 4, and 5 seconds delay interval, respectively. The morphological studies revealed that the size of the prefrontal cortex increased, and the structure got complex in the course of the evolution in primates. It is suggested that the relation of evolution between the spatial working memory function and anatomy in the prefrontal cortex might be significant among the three species, both the development of morphology and that of the spatial working memory function in the dorsolateral prefrontal cortex are later than other regions of cerebral cortex in phylogenetic evolution course.展开更多
Objective： To assess functional relationship by calculating inter- and intra-hemispheric electroencephalography （EEG） coherence at rest and during a working memory task of patients with mild cognitive impairment （...Objective： To assess functional relationship by calculating inter- and intra-hemispheric electroencephalography （EEG） coherence at rest and during a working memory task of patients with mild cognitive impairment （MCI）. Methods： The sample consisted of 69 subjects： 35 patients （n = 17 males, n = 18 females; 52-71 years old） and 34 normal controls （n = 17 males, n = 17 females; 51 -63 years old）. Mini-mental state examination （MMSE） of two groups revealed that the scores of MCI patients did not differ significantly from those of normal controls （P〉0.05）. In EEG recording, subjects were performed at rest and during working memory task. EEG signals from F3-F4, C3-C4, P3-P4, T5-T6 and O1-O2 electrode pairs are resulted from the inter-hemispheric action, and EEG signals from F3-C3, F4-C4, C3-P3, C4-P4, P3-O1, P4-O2, T5-C3, T6-C4, T5-P3 and T6-P4 electrode pairs are resulted from the intra-hemispheric action for delta （1.0-3.5 Hz）, theta （4.0-7.5 Hz）, alpha-1 （8.0-10.0 Hz）, alpha-2 （10.5-13.0 Hz）, beta-1 （13.5-18.0 Hz） and beta-2 （18.5-30.0 Hz） frequency bands. The influence of inter- and intra-hemispheric coherence on EEG activity with eyes closed was examined using fast Fourier transformation from the 16 sampled channels. Results： During working memory tasks, the inter- and intra-hemispheric EEG coherences in all bands were significantly higher in the MCI group in comparison with those in the control group （P〈0.05）. However, there was no significant difference in inter- and intra-hemispheric EEG coherences between two groups at rest. Conclusion： Experimental results comprise evidence that MCI patients have higher degree of functional connectivity between hemispheres and in hemispheres during working condition, It suggests that MCI may be associated with compensatory processes during working memory tasks between hemispheres and in hemispheres. Moreover, failure of normal cortical connections may exist in MCI patients.展开更多
The ability to recall and recognize facts we experienced in the past is based on a complex mechanism in which several cerebral regions are implicated. Neuroimaging and lesion studies agree in identifying the frontal l...The ability to recall and recognize facts we experienced in the past is based on a complex mechanism in which several cerebral regions are implicated. Neuroimaging and lesion studies agree in identifying the frontal lobe as a crucial structure for memory processes, and in particular for working memory and episodic memory and their relationships. Furthermore, with the introduction of transcranial magnetic stimulation （TMS） a new way was proposed to investigate the relationships between brain correlates, memory functions and behavior. The aim of this review is to present the main findings that have emerged from experiments which used the TMS technique for memory analysis. They mainly focused on the role of the dorsolateral prefrontal cortex in memory process. Furthermore, we present state-of-the-art evidence supporting a possible use of TMS in the clinic. Specifically we focus on the treatment of memory deficits in depression and anxiety disorders.展开更多
Objective Working memory is a key cognitive function in which the prefrontal cortex plays a crucial role. This study aimed to show the firing patterns of a neuronal population in the prefrontal cortex of the rat in a ...Objective Working memory is a key cognitive function in which the prefrontal cortex plays a crucial role. This study aimed to show the firing patterns of a neuronal population in the prefrontal cortex of the rat in a working memory task and to explore how a neuronal ensemble encodes a working memory event. Methods Sprague-Dawley rats were trained in a Y-maze until they reached an 80% correct rate in a working memory task. Then a 16-channel microelectrode array was implanted in the prefrontal cortex. After recovery, neuronal population activity was recorded during the task, using the Cerebus data-acquisition system. Spatio-temporal trains of action potentials were obtained from the original neuronal population signals. Results During the Y-maze working memory task, some neurons showed significantly in- creased firing rates and evident neuronal ensemble activity. Moreover, the anticipatory activity was associated with the delayed alternate choice of the upcoming movement. In correct trials, the averaged pre-event firing rate （10.86 ± 1.82 spikes/ bin） was higher than the post-event rate （8.17 ± 1.15 spikes/bin） （P 〈0.05）. However, in incorrect trials, the rates did not differ. Conclusion The results indicate that the anticipatory activity of a neuronal ensemble in the prefrontal cortex may play a role in encoding working memory events.展开更多
BACKGROUND： In patients with depression, as well as in patients with schizophrenia, both mood and working memory performance are often impaired. Both issues can only be addressed and improved with medication to some ...BACKGROUND： In patients with depression, as well as in patients with schizophrenia, both mood and working memory performance are often impaired. Both issues can only be addressed and improved with medication to some extent. OBJECTIVE： This study investigates the mood and the working memory performance in patients with depression or schizophrenia and whether acupuncture can improve these. DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS： A pragmatic clinical trial design was used The study was conducted in a psychiatric clinic. Fifty patients with depression and 50 with schizophrenia were randomly divided into an experimental and a waiting-list group. Additionally, 25 healthy control participants were included. Twelve weeks of individualized acupuncture treatment was used as the clinical intervention. MAIN OUTCOME MEASURES： All patients were tested before （T1） and after （T2） acupuncture treatment on a mood scale （Beck Depression Inventory-II, BDI-II）, a simple working memory task （digit span）, and a complex working memory task （letter-number sequencing）; the healthy controls were tested at T1 only. RESULTS： Patients with depression scored worse than the others on the BDI-II, and patients with schizophrenia scored worse than the healthy controls. On the digit span, patients with schizophrenia did not differ from healthy controls whereas they scored worse of all on the letter-number sequencing. With respect to the acupuncture findings, first, the present study showed that the use of acupuncture to treat patients with schizophrenia was both practical and safe. Moreover, acupuncture had a positive effect on the BDI-II for the depression group, but acupuncture had no effect on the digit span and on the letter- number sequencing performance for the two clinical groups. CONCLUSION： The clinical improvement in patients with depression after acupuncture treatment was not accompanied by any significant change in a simple working memory task or in a more complex working memory task; the same was true for the patients with schizophrenia.展开更多
The activity in sensory cortices and the prefrontal cortex （PFC） throughout the delay interval of working memory （WM） tasks reflect two aspects of WM-quality and quantity, respectively. The delay activity in senso...The activity in sensory cortices and the prefrontal cortex （PFC） throughout the delay interval of working memory （WM） tasks reflect two aspects of WM-quality and quantity, respectively. The delay activity in sensory cortices is fine-tuned to sensory information and forms the neural basis of the precision of WM storage, while the delay activity in the PFC appears to represent behavioral goals and filters out irrelevant distractions, forming the neural basis of the quantity of task-relevant information in WM. The PFC and sensory cortices interact through different frequency bands of neuronal oscillation （theta, alpha, and gamma） to fulfill goal-directed behaviors.展开更多
In this study, we used functional magnetic resonance imaging(fMRI) to investigate longitudinal changes in brain activation during a verbal working memory(VWM) task performed by patients who had experienced a transient...In this study, we used functional magnetic resonance imaging(fMRI) to investigate longitudinal changes in brain activation during a verbal working memory(VWM) task performed by patients who had experienced a transient ischemic attack(TIA). Twenty-five first-ever TIA patients without visible lesions in conventional MRI and 25 healthy volunteers were enrolled. VWM task-related fMRI was conducted 1 week and 3 months post-TIA. The brain activity evoked by the task and changes over time were assessed. We found that, compared with controls, patients exhibited an increased activation in the bilateral inferior frontal gyrus(IFG), right dorsolateral prefrontal cortex(DLPFC), insula, inferior parietal lobe(IPL), and cerebellum during the task performed 1 week post-TIA. But only the right IFG still exhibited an increased activation at 3 months post-TIA. A direct comparison of fMRI data between 1 week and 3 months post-TIA showed greater activation in the bilateral middle temporal gyrus, right DLPFC, IPL, cerebellum, and left IFG in patients at 1 week post-TIA. We conclude that brain activity patterns induced by a VWM task remain dynamic for a period of time after a TIA, despite the cessation of clinical symptoms. Normalization of the VWM activation pattern may be progressively achieved after transient episodes of ischemia in TIA patients.展开更多
To investigate the features of electroencephalography （EEG） power and coherence at rest and during a working memory task of patients with mild cognitive impairment （MCI）. Thirty-five patients （17 males, 18 female...To investigate the features of electroencephalography （EEG） power and coherence at rest and during a working memory task of patients with mild cognitive impairment （MCI）. Thirty-five patients （17 males, 18 females; 52-71 years old） and 34 sex- and age-matched controls （17 males, 17 females; 51-63 years old） were recruited in the present study. Mini-Mental State Examination （MMSE） of 35 patients with MCI and 34 normal controls revealed that the scores of MCI patients did not differ significantly from those of normal controls （P〉0.05）. Then, EEGs at rest and during working memory task with three levels of working memory load were recorded. The EEG power was computed over 10 channels： fight and left frontal （F3, F4）, central （C3, C4）, parietal （P3, P4）, temporal （T5, T6） and occipital （O1, O2）; inter-hemispheric coherences were computed from five electrode pairs of F3-F4, C3-C4, P3-P4, T5-T6 and O1-O2 for delta （1.0-3.5 Hz）, theta （4.0-7.5 Hz）, alpha-1 （8.0-10.0 Hz）, alpha-2 （10.5-13.0 Hz）, beta-1 （13.5-18.0 Hz） and beta-2 （18.5-30.0 Hz） frequency bands. All values of the EEG power of MCI patients were found to be higher than those of normal controls at rest and during working memory tasks. Furthermore, the values of EEG power in the theta, alpha-1, alpha-2 and beta-1 bands of patients with MCI were significantly high （P〈0.05） in comparison with those of normal controls. Correlation analysis indicated a significant negative correlation between the EEG powers and MMSE scores. In addition, during working memory tasks, the EEG coherences in all bands were significantly higher in the MCI group in comparison with those in the control group （P〈0.05）. However, there was no significant difference in EEG coherences between two groups at rest. These findings comprise evidence that MCI patients have higher EEG power at rest, and higher EEG power and coherence during working conditions. It suggests that MCI may be associated with compensatory processes at rest and during working memory tasks. Moreover, failure of normal cortical connections may be exist in MCI patients.展开更多
Objective： The functional relationship between calculated alpha band spectral power and inter-/intra-hemispheric coherence during a three-level working memory task of patients with mild cognitive impairment （MCI） w...Objective： The functional relationship between calculated alpha band spectral power and inter-/intra-hemispheric coherence during a three-level working memory task of patients with mild cognitive impairment （MCI） was investigated. Methods：Subjects included 35 MCI patients according to the DSM-Ⅳ criteria （mean age： 62.3, SD： 6.5） and 34 healthy controls （mean age：57.4, SD： 4.0） were selected from the community at large. All subjects performed a simple calculation and recall task with three levels of working memory load while electroencephalograph （EEG） signal was recorded. The spectral EEG power was computed over alphal （8.0～10.0 Hz） and alpha2 （10.5～13.0 Hz） frequency bands and was compared between rest stage and working memory processing stage by two-way ANOVA. Post hoc testing analyzed the differences between each two levels of working memory load during task processing. The inter-hemisphere EEG coherence of frontal （F3-F4）, central （C3-C4）, parietal （P3-P4）, temporal （T5-T6） as well as occipital （O1-O2） was compared between MCI patients and normal controls. The EEG signals from F3-C3,F4-C4, C3-P3, C4-P4, P3-O1, P4-O2, T5-C3, T6-C4, T5-P3 and T6-P4 electrode pairs resulted from the intra-hemispheric action for alphal and alpha2 frequency bands. Result： There was significantly higher EEG power from MCI patients than from normal controls both at rest and during working memory processing. Significant differences existed between rest condition and three-level working memory tasks （P〈0.001）. The inter- and intra-hemispheric coherence during working memory tasks showed a ＂drop to rise＂ tendency compared to that at rest condition. There was significantly higher coherence in MCI patients than in the controls.When task difficulties increased, the cortical connectivity of intra-hemispheric diminished while the inter-hemispheric connectivity dominantly maintained the cognitive processing in MCI patients. Conclusion： The results of the present study indicate that the alpha frequency band may be the characteristic band in distinguishing MCI patients from normal controls during working memory tasks. MCI patients exhibit greater inter-hemispheric connectivity than intra-hemispheric connectivity when memory demands increase. MCI patients mobilize a compensatory mechanism to maintain the processing effectiveness while the processing efficiency is reduced.展开更多
Due to the critical roles of emotion and working memory in our daily activities,a great deal of attention has been given to how emotion influences working memory performance.Although the association between emotion an...Due to the critical roles of emotion and working memory in our daily activities,a great deal of attention has been given to how emotion influences working memory performance.Although the association between emotion and working memory is relatively well established,whether mood enhances or impairs working memory performance remains controversial.The present review provides a relatively representative overview of the research on the effect of different dimensions of emotion on working memory among healthy adults spanning a 30-year period.The findings show that the valence,arousal and motivational dimensions of emotion could all exert an impact on working memory performance.The impact of emotion on working memory might be modulated by task relevance,emotion type,working memory paradigms and individual differences.The vast majority of the studies regarding the effect of emotion on working memory performance focused on the impact of negatively valenced affect and yielded highly contradictory findings.The impacts of arousal and motivation on working memory have been less explored,and inconsistent findings have also been reported.Possible explanations are discussed.Considerable research on the effect of certain dimensions of emotion on working memory has suffered from a lack of control of other emotional dimensions,and different aspects of working memory have been investigated by various paradigms.Directions for further studies should include the exploration of specific dimensions of emotion on different aspects of working memory,with the other dimensions being well controlled.展开更多
The deficiency theories of dyslexia are quite contradictory and the cross-cultural studies in recent years mainly focused on whether the dyslexics among cultures shared the same cognitive profile or just based on the ...The deficiency theories of dyslexia are quite contradictory and the cross-cultural studies in recent years mainly focused on whether the dyslexics among cultures shared the same cognitive profile or just based on the language.This study used Near-Infrared Spectroscopy (NIRS) imaging to measure the regional cerebral blood volume (BV) and the changes of cerebral activation in the left prefrontal cortex of 12 Chinese dyslexic children and their 12 age-matched normal controls during the Paced Vis-ual Serial Addition Test (PVSAT).Results showed that the scores of PVSAT of dyslexic children were significantly lower than those of the normal children (t=3.33,P<0.01).The activations of the left pre-frontal cortex in the normal group were significantly greater than those of dyslexic children (all P<0.01).Our results indicated that Chinese dyslexia had a general deficiency in working memory and this may be caused by the abnormal metabolic activity of brain blood volume in the left prefrontal cortex and the deficits in brain function might be the basis of neuropathology of Chinese dyslexia.Present study sup-ports the difference on brain activation of dyslexics from different languages may be caused by the same cognitive system related to reading.展开更多
Astrocytes are increasingly recognized to play an active role in learning and memory,but whether neural inputs can trigger event-specific astrocytic Ca^(2+)dynamics in real time to participate in working memory remain...Astrocytes are increasingly recognized to play an active role in learning and memory,but whether neural inputs can trigger event-specific astrocytic Ca^(2+)dynamics in real time to participate in working memory remains unclear due to the difficulties in directly monitoring astrocytic Ca^(2+)dynamics in animals performing tasks.Here,using fiber photometry,we showed that population astrocytic Ca^(2+)dynamics in the hippocampus were gated by sensory inputs(centered at the turning point of the T-maze)and modified by the reward delivery during the encoding and retrieval phases.Notably,there was a strong inter-locked and antagonistic relationship between the astrocytic and neuronal Ca^(2+)dynamics with a 3-s phase difference.Furthermore,there was a robust synchronization of astrocytic Ca^(2+)at the population level among the hippocampus,medial prefrontal cortex,and striatum.The inter-locked,bidirectional communication between astrocytes and neurons at the population level may contribute to the modulation of information processing in working memory.展开更多
基金the National Natural Science Foundation of China(No.91632103)the Shanghai Education Commission Research and Innovation Program(No.2019-01-07-00-02-E00037)+2 种基金the Program of Shanghai Subject Chief Scientist(No.17XD1401700)the Higher Education Disciplinary Innovation Programthe“Eastern Scholar”Project。
文摘Working memory is a core cognitive function that supports goal-directed behavior and complex thought.We developed a spatial working memory and attention test on paired symbols(SWAPS)which has been proved to be a useful and valid tool for spatial working memory and attention studies in the fields of cognitive psychology,education,and psychiatry.The repeated administration of working memory capacity tests is common in clinical and research settings.Studies suggest that repeated cognitive tests may improve the performance scores also known as retest effects.The systematic investigation of retest effects in SWAPS is critical for interpreting scientific results,but it is still not fully developed.To address this,we recruited 77 college students aged 18–21 years and used SWAPS comprising 72 trials with different memory loads,learning time,and delay span.We repeated the test once a week for five weeks to investigate the retest effects of SWAPS.There were significant retest effects in the first two tests:the accuracy of the SWAPS tests significantly increased,and then stabilized.These findings provide useful information for researchers to appropriately use or interpret the repeated working memory tests.Further experiments are still needed to clarify the factors that mediate the retest effects,and find out the cognitive mechanism that influences the retest effects.
基金Supported by Shanghai Municipal Health Commission’s Special Clinical Research Project for the Hygiene Industry,No.20244Y0041Youth Initiation Fund of Naval Medical University,No.2023QN028 and No.2023QN030。
文摘BACKGROUND Working memory serves as a fundamental cognitive function that substantially impacts performance in various cognitive tasks.Extensive neurophysiological research has established that theta oscillations(4-8 Hz)play an essential role in supporting working memory operations.Theta-band transcranial alternating current stimulation(tACS)offers a potential mechanism for working memory enhancement through direct modulation of these fundamental neural oscillations.Nevertheless,current empirical evidence shows substantial variability in the observed effects of theta-tACS across studies.AIM To conduct a systematic review and meta-analysis evaluating the effects of thetatACS on working memory performance in healthy adults.METHODS A systematic literature search was performed on PubMed,EMBASE,and Web of Science up to March 10,2025.Effect sizes were computed using Hedges’g with 95%confidence intervals(CIs),with separate meta-analyses for all included studies and for distinct working memory paradigms[n-back and delayed matchto-sample(DMTS)tasks]to examine potential task-specific effects.Subgroup analyses and meta-regression were performed to evaluate the influence of key moderating variables.RESULTS The systematic review included 21 studies(67 effect sizes).Initial meta-analysis showed theta-tACS moderately improved working memory(Hedges’g=0.405,95%CI:0.212-0.598).However,this effect became nonsignificant after correcting for publication bias(trim-and-fill adjusted Hedges’g=0.082,95%CI:-0.052 to 0.217).Task-specific analyses revealed significant benefits in n-back tasks(Hedges’g=0.463,95%CI:0.193-0.733)but not in DMTS tasks(Hedges’g=0.257,95%CI:-0.186 to 0.553).Moderator analyses showed that performance in n-back tasks was influenced by stimulation frequency(P=0.001),concurrent status(P=0.014),task modality(P=0.005),and duration(P=0.013),whereas only the region of targeted stimulation(P=0.012)moderated DMTS tasks.CONCLUSION Theta-tACS enhances working memory in healthy adults,with effects modulated by the task type and protocol parameters,offering dual implications for cognitive enhancement and clinical interventions.
基金supported by the National Natural Science Foundation of China(12171373)supported by the Fundamental Research Funds for the Central Universities of China(GK202207018).
文摘Rhythm,as a prominent characteristic of auditory experiences such as speech and music,is known to facilitate attention,yet its contribution to working memory(WM)remains unclear.Here,human participants temporarily retained a 12-tone sequence presented rhythmically or arrhythmically in WM and performed a pitch change-detection task.Behaviorally,while having comparable accuracy,rhythmic tone sequences showed a faster response time and lower response boundaries in decision-making.Electroencephalographic recordings revealed that rhythmic sequences elicited enhanced non-phase-locked beta-band(16 Hz–33 Hz)and theta-band(3 Hz–5 Hz)neural oscillations during sensory encoding and WM retention periods,respectively.Importantly,the two-stage neural signatures were correlated with each other and contributed to behavior.As beta-band and theta-band oscillations denote the engagement of motor systems and WM maintenance,respectively,our findings imply that rhythm facilitates auditory WM through intricate oscillation-based interactions between the motor and auditory systems that facilitate predictive attention to auditory sequences.
基金supported by the Key-Area Research and Development Program of Guangdong Province(2023B0303030002)the Beijing Natural Science Foundation(IS23114,7242274)+4 种基金the China Postdoctoral Science Foundation(2023TQ0027 and 2024M754099)the STI 2030-Major Projects(2022ZD0208500)the National Natural Science Foundation of China(62336002,82071912,62406025,82202291,62373056,62306035)the Beijing Nova Program(20230484465)the Shenzhen Basic Research Program(JCYJ20241202124804007).
文摘Working memory is an executive memory process that includes encoding,maintenance,and retrieval.These processes can be modulated by transcranial alternating current stimulation(tACS)with sinusoidal waves.However,little is known about the impact of the rate of current change on working memory.In this study,we aimed to investigate the effects of two types of tACS with different rates of current change on working memory performance and brain activity.We applied a randomized,single-blind design and divided 81 young participants who received triangular wave tACS,sinusoidal wave tACS,or sham stimulation into three groups.Participants performed n-back tasks,and electroencephalograms were recorded before,during,and after active or sham stimulation.Compared to the baseline,working memory performance(accuracy and response time)improved after stimulation under all stimulation conditions.According to drift-diffusion model analysis,triangular wave tACS significantly increased the efficiency of non-target information processing.In addition,compared with sham conditions,triangular wave tACS reduced alpha power oscillations in the occipital lobe throughout the encoding period,while sinusoidal wave tACS increased theta power in the central frontal region only during the later encoding period.The brain network connectivity results showed that triangular wave tACS improved the clustering coefficient,local efficiency,and node degree intensity in the early encoding stage,and these parameters were positively correlated with the non-target drift rate and decision starting point.Our findings on how tACS modulates working memory indicate that triangular wave tACS significantly enhances brain network connectivity during the early encoding stage,demonstrating an improvement in the efficiency of working memory processing.In contrast,sinusoidal wave tACS increased the theta power during the later encoding stage,suggesting its potential critical role in late-stage information processing.These findings provide valuable insights into the potential mechanisms by which tACS modulates working memory.
基金supported by the STI2030-Major Project(2021ZD0203600)with additional support from the Shanghai Municipal Science and Technology Commission(2018SHZDZX05 and 2018ZR1406500)+3 种基金the Shanghai Pujiang Program(19PJ1407500)the Shanghai Jiao Tong University Medical and Engineering Cross Research Fund(YG2019QNA31)the Shanghai Municipal Health Commission Clinical Study Special Fund(20194Y0067)the Ruijin Hospital Guangci Excellence Youth Training Program(GCQN-2019-B10).
文摘The prefrontal cortex and hippocampus may support sequential working memory beyond episodic memory and spatial navigation.This stereoelectroencephalography(SEEG)study investigated how the dorsolateral prefrontal cortex(DLPFC)interacts with the hippocampus in the online processing of sequential information.Twenty patients with epilepsy(eight women,age 27.6±8.2 years)completed a line ordering task with SEEG recordings over the DLPFC and the hippocampus.Participants showed longer thinking times and more recall errors when asked to arrange random lines clockwise(random trials)than to maintain ordered lines(ordered trials)before recalling the orientation of a particular line.First,the ordering-related increase in thinking time and recall error was associated with a transient theta power increase in the hippocampus and a sustained theta power increase in the DLPFC(3–10 Hz).In particular,the hippocampal theta power increase correlated with the memory precision of line orientation.Second,theta phase coherences between the DLPFC and hippocampus were enhanced for ordering,especially for more precisely memorized lines.Third,the theta band DLPFC→hippocampus influence was selectively enhanced for ordering,especially for more precisely memorized lines.This study suggests that theta oscillations may support DLPFC-hippocampal interactions in the online processing of sequential information.
文摘BACKGROUND The detection rate of depression among university students has been increasing in recent years,becoming one of the main psychological diseases that endangers their physical and mental health.According to statistics,self-harm and suicide,for which there is no effective intervention,are the second leading causes of death.AIM To explore the relationship between different elements and levels of physical activity and college students’depression-symptom-specific working memory indicators.METHODS Of 143 college students were analyzed using the Beck Depression Self-Rating Scale,the Physical Activity Rating Scale,and the Working Memory Task.RESULTS There was a significant difference between college students with depressive symptoms and healthy college students in completing verbal and spatial working memory(SWM)tasks correctly(all P<0.01).Physical Activity Scale-3 scores were significantly and positively correlated with the correct rate of the verbal working memory task(r=0.166)and the correct rate of the SWM task(r=0.210)(all P<0.05).There were significant differences in the correct rates of verbal and SWM tasks according to different exercise intensities(all P<0.05)and different exercise durations(all P<0.05),and no significant differences in the correct rates of verbal and SWM tasks by exercise frequency(all P>0.05).CONCLUSION An increase in physical exercise among college students,particularly medium-and high-intensity exercise and exercise of 30 min or more,can improve the correct rate of completing working memory tasks.
文摘This experimental study investigated how text difficulty and different working memory capacity(WMC)affected Chinese EFL learners’reading comprehension and their tendency to engage in task-unrelated thoughts,that is,mind wandering(MW),in the course of reading.Sixty first-year university non-English majors participated in the study.A two-factor mixed experimental design of 2(text difficulty:difficult and simple)×2(WMC:high/large and low/small)was employed.Results revealed that 1)the main and interaction effects of WMC and text difficulty on voluntary MW were significant,whereas those on involuntary MW were not;2)while reading the easy texts,the involuntary MW of high-WMC individuals was less frequent than that of low-WMC ones,whereas while reading the difficult ones,the direct relationship between WMC and involuntary MW was not found;and that 3)high-WMC individuals had a lower overall rate of MW and better reading performance than low-WMC individuals did,but with increasing text difficulty,their rates of overall MW and voluntary MW were getting higher and higher,and the reading performance was getting lower and lower.These results lend support to WM theory and have pedagogical implications for the instruction of L2 reading.
文摘Background: Working memory is an executive function that plays an important role in many aspects of daily life, and its impairment in patients with attention-deficit/hyperactivity disorder (ADHD) affects quality of life. The dorsolateral prefrontal cortex (DLPFC) has been a good target site for transcranial direct current stimulation (tDCS) due to its intense involvement in working memory. In our 2018 study, tDCS improved visual-verbal working memory in healthy subjects. Objective: This study examines the effects of tDCS on ADHD patients, particularly on verbal working memory. Methods: We conducted an experiment involving verbal working memory of two modalities, visual and auditory, and a sustained attention task that could affect working memory in 9 ADHD patients. Active or sham tDCS was applied to the left DLPFC in a single-blind crossover design. Results: tDCS significantly improved the accuracy of visual-verbal working memory. In contrast, tDCS did not affect auditory-verbal working memory and sustained attention. Conclusion: tDCS to the left DLPFC improved visual-verbal working memory in ADHD patients, with important implications for potential ADHD treatments.
文摘The relation between evolution of spatial working memory function and of morphology of the dorsolateral prefrontal cortex among the rhesus monkey (Macaca mulatta), the slow loris (Nycticebus coucang) and the tree shrew (Tupaia belangen chinensis) were reported in present paper. The results read as follows: In the DR performance with training, the rhesus monkeys and slow lorises could reach a criterion of 90% correct response at 1.1 ± 3.2 seconds, and 3.8±0.4 seconds delay interval, respectively, by 1000 training trails. The tree shrews failed to reach the criterion of 90% correct response even at 0 seconds delay interval by 1000 training trails. If a delay interval was tested in one session (30 trails) only, doing the DR performamce without training, the rhesus monkeys reached a correct of 80% or higher in each session at 0, 1, 2, 3, 4, and 5 seconds delay, respectively. The percent correct in each session of the slow lorises showed no differences from the rhesus monkeys at 0, 1, 2, 3, and 4 seconds delay. However, when the delay interval was increased to 5 seconds, the percent correct of the DR performance declined to 70% or lower in the slow lorises. In the tree shrews the percent correct in each session reached to 70% or lower at 0, 1, 2, 3, 4, and 5 seconds delay interval, respectively. The morphological studies revealed that the size of the prefrontal cortex increased, and the structure got complex in the course of the evolution in primates. It is suggested that the relation of evolution between the spatial working memory function and anatomy in the prefrontal cortex might be significant among the three species, both the development of morphology and that of the spatial working memory function in the dorsolateral prefrontal cortex are later than other regions of cerebral cortex in phylogenetic evolution course.
基金Project (No. 2003B070) supported by the Science and TechnologyProgram of Zhejiang Province, China
文摘Objective： To assess functional relationship by calculating inter- and intra-hemispheric electroencephalography （EEG） coherence at rest and during a working memory task of patients with mild cognitive impairment （MCI）. Methods： The sample consisted of 69 subjects： 35 patients （n = 17 males, n = 18 females; 52-71 years old） and 34 normal controls （n = 17 males, n = 17 females; 51 -63 years old）. Mini-mental state examination （MMSE） of two groups revealed that the scores of MCI patients did not differ significantly from those of normal controls （P〉0.05）. In EEG recording, subjects were performed at rest and during working memory task. EEG signals from F3-F4, C3-C4, P3-P4, T5-T6 and O1-O2 electrode pairs are resulted from the inter-hemispheric action, and EEG signals from F3-C3, F4-C4, C3-P3, C4-P4, P3-O1, P4-O2, T5-C3, T6-C4, T5-P3 and T6-P4 electrode pairs are resulted from the intra-hemispheric action for delta （1.0-3.5 Hz）, theta （4.0-7.5 Hz）, alpha-1 （8.0-10.0 Hz）, alpha-2 （10.5-13.0 Hz）, beta-1 （13.5-18.0 Hz） and beta-2 （18.5-30.0 Hz） frequency bands. The influence of inter- and intra-hemispheric coherence on EEG activity with eyes closed was examined using fast Fourier transformation from the 16 sampled channels. Results： During working memory tasks, the inter- and intra-hemispheric EEG coherences in all bands were significantly higher in the MCI group in comparison with those in the control group （P〈0.05）. However, there was no significant difference in inter- and intra-hemispheric EEG coherences between two groups at rest. Conclusion： Experimental results comprise evidence that MCI patients have higher degree of functional connectivity between hemispheres and in hemispheres during working condition, It suggests that MCI may be associated with compensatory processes during working memory tasks between hemispheres and in hemispheres. Moreover, failure of normal cortical connections may exist in MCI patients.
文摘The ability to recall and recognize facts we experienced in the past is based on a complex mechanism in which several cerebral regions are implicated. Neuroimaging and lesion studies agree in identifying the frontal lobe as a crucial structure for memory processes, and in particular for working memory and episodic memory and their relationships. Furthermore, with the introduction of transcranial magnetic stimulation （TMS） a new way was proposed to investigate the relationships between brain correlates, memory functions and behavior. The aim of this review is to present the main findings that have emerged from experiments which used the TMS technique for memory analysis. They mainly focused on the role of the dorsolateral prefrontal cortex in memory process. Furthermore, we present state-of-the-art evidence supporting a possible use of TMS in the clinic. Specifically we focus on the treatment of memory deficits in depression and anxiety disorders.
基金supported by the National Natural Science Foundation of China(61074131,91132722)the Doctoral Fund of the Ministry of Education of China(20101202110007)
文摘Objective Working memory is a key cognitive function in which the prefrontal cortex plays a crucial role. This study aimed to show the firing patterns of a neuronal population in the prefrontal cortex of the rat in a working memory task and to explore how a neuronal ensemble encodes a working memory event. Methods Sprague-Dawley rats were trained in a Y-maze until they reached an 80% correct rate in a working memory task. Then a 16-channel microelectrode array was implanted in the prefrontal cortex. After recovery, neuronal population activity was recorded during the task, using the Cerebus data-acquisition system. Spatio-temporal trains of action potentials were obtained from the original neuronal population signals. Results During the Y-maze working memory task, some neurons showed significantly in- creased firing rates and evident neuronal ensemble activity. Moreover, the anticipatory activity was associated with the delayed alternate choice of the upcoming movement. In correct trials, the averaged pre-event firing rate （10.86 ± 1.82 spikes/ bin） was higher than the post-event rate （8.17 ± 1.15 spikes/bin） （P 〈0.05）. However, in incorrect trials, the rates did not differ. Conclusion The results indicate that the anticipatory activity of a neuronal ensemble in the prefrontal cortex may play a role in encoding working memory events.
文摘BACKGROUND： In patients with depression, as well as in patients with schizophrenia, both mood and working memory performance are often impaired. Both issues can only be addressed and improved with medication to some extent. OBJECTIVE： This study investigates the mood and the working memory performance in patients with depression or schizophrenia and whether acupuncture can improve these. DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS： A pragmatic clinical trial design was used The study was conducted in a psychiatric clinic. Fifty patients with depression and 50 with schizophrenia were randomly divided into an experimental and a waiting-list group. Additionally, 25 healthy control participants were included. Twelve weeks of individualized acupuncture treatment was used as the clinical intervention. MAIN OUTCOME MEASURES： All patients were tested before （T1） and after （T2） acupuncture treatment on a mood scale （Beck Depression Inventory-II, BDI-II）, a simple working memory task （digit span）, and a complex working memory task （letter-number sequencing）; the healthy controls were tested at T1 only. RESULTS： Patients with depression scored worse than the others on the BDI-II, and patients with schizophrenia scored worse than the healthy controls. On the digit span, patients with schizophrenia did not differ from healthy controls whereas they scored worse of all on the letter-number sequencing. With respect to the acupuncture findings, first, the present study showed that the use of acupuncture to treat patients with schizophrenia was both practical and safe. Moreover, acupuncture had a positive effect on the BDI-II for the depression group, but acupuncture had no effect on the digit span and on the letter- number sequencing performance for the two clinical groups. CONCLUSION： The clinical improvement in patients with depression after acupuncture treatment was not accompanied by any significant change in a simple working memory task or in a more complex working memory task; the same was true for the patients with schizophrenia.
基金supported by the National Basic Research Development Program (973 Program) of China (2013CB329501)a Scientific Project of the Science and Technology Commission of Shanghai Municipality, China (11140900600)+2 种基金the Shanghai Committee of Science and Technology (15ZR1410600)the National Natural Science Foundation of China (31100742)funds from the MIND Research Institute, Irvine, CA, USA
文摘The activity in sensory cortices and the prefrontal cortex （PFC） throughout the delay interval of working memory （WM） tasks reflect two aspects of WM-quality and quantity, respectively. The delay activity in sensory cortices is fine-tuned to sensory information and forms the neural basis of the precision of WM storage, while the delay activity in the PFC appears to represent behavioral goals and filters out irrelevant distractions, forming the neural basis of the quantity of task-relevant information in WM. The PFC and sensory cortices interact through different frequency bands of neuronal oscillation （theta, alpha, and gamma） to fulfill goal-directed behaviors.
基金supported by the National Natural Science Foundation of China (81300943 and 81472162)the Postdoctoral Science Special Foundation of China (2014T70867)
文摘In this study, we used functional magnetic resonance imaging(fMRI) to investigate longitudinal changes in brain activation during a verbal working memory(VWM) task performed by patients who had experienced a transient ischemic attack(TIA). Twenty-five first-ever TIA patients without visible lesions in conventional MRI and 25 healthy volunteers were enrolled. VWM task-related fMRI was conducted 1 week and 3 months post-TIA. The brain activity evoked by the task and changes over time were assessed. We found that, compared with controls, patients exhibited an increased activation in the bilateral inferior frontal gyrus(IFG), right dorsolateral prefrontal cortex(DLPFC), insula, inferior parietal lobe(IPL), and cerebellum during the task performed 1 week post-TIA. But only the right IFG still exhibited an increased activation at 3 months post-TIA. A direct comparison of fMRI data between 1 week and 3 months post-TIA showed greater activation in the bilateral middle temporal gyrus, right DLPFC, IPL, cerebellum, and left IFG in patients at 1 week post-TIA. We conclude that brain activity patterns induced by a VWM task remain dynamic for a period of time after a TIA, despite the cessation of clinical symptoms. Normalization of the VWM activation pattern may be progressively achieved after transient episodes of ischemia in TIA patients.
文摘To investigate the features of electroencephalography （EEG） power and coherence at rest and during a working memory task of patients with mild cognitive impairment （MCI）. Thirty-five patients （17 males, 18 females; 52-71 years old） and 34 sex- and age-matched controls （17 males, 17 females; 51-63 years old） were recruited in the present study. Mini-Mental State Examination （MMSE） of 35 patients with MCI and 34 normal controls revealed that the scores of MCI patients did not differ significantly from those of normal controls （P〉0.05）. Then, EEGs at rest and during working memory task with three levels of working memory load were recorded. The EEG power was computed over 10 channels： fight and left frontal （F3, F4）, central （C3, C4）, parietal （P3, P4）, temporal （T5, T6） and occipital （O1, O2）; inter-hemispheric coherences were computed from five electrode pairs of F3-F4, C3-C4, P3-P4, T5-T6 and O1-O2 for delta （1.0-3.5 Hz）, theta （4.0-7.5 Hz）, alpha-1 （8.0-10.0 Hz）, alpha-2 （10.5-13.0 Hz）, beta-1 （13.5-18.0 Hz） and beta-2 （18.5-30.0 Hz） frequency bands. All values of the EEG power of MCI patients were found to be higher than those of normal controls at rest and during working memory tasks. Furthermore, the values of EEG power in the theta, alpha-1, alpha-2 and beta-1 bands of patients with MCI were significantly high （P〈0.05） in comparison with those of normal controls. Correlation analysis indicated a significant negative correlation between the EEG powers and MMSE scores. In addition, during working memory tasks, the EEG coherences in all bands were significantly higher in the MCI group in comparison with those in the control group （P〈0.05）. However, there was no significant difference in EEG coherences between two groups at rest. These findings comprise evidence that MCI patients have higher EEG power at rest, and higher EEG power and coherence during working conditions. It suggests that MCI may be associated with compensatory processes at rest and during working memory tasks. Moreover, failure of normal cortical connections may be exist in MCI patients.
基金Project (No.2003B070) supported by the Science and TechnologyProgram of Zhejiang Province, China
文摘Objective： The functional relationship between calculated alpha band spectral power and inter-/intra-hemispheric coherence during a three-level working memory task of patients with mild cognitive impairment （MCI） was investigated. Methods：Subjects included 35 MCI patients according to the DSM-Ⅳ criteria （mean age： 62.3, SD： 6.5） and 34 healthy controls （mean age：57.4, SD： 4.0） were selected from the community at large. All subjects performed a simple calculation and recall task with three levels of working memory load while electroencephalograph （EEG） signal was recorded. The spectral EEG power was computed over alphal （8.0～10.0 Hz） and alpha2 （10.5～13.0 Hz） frequency bands and was compared between rest stage and working memory processing stage by two-way ANOVA. Post hoc testing analyzed the differences between each two levels of working memory load during task processing. The inter-hemisphere EEG coherence of frontal （F3-F4）, central （C3-C4）, parietal （P3-P4）, temporal （T5-T6） as well as occipital （O1-O2） was compared between MCI patients and normal controls. The EEG signals from F3-C3,F4-C4, C3-P3, C4-P4, P3-O1, P4-O2, T5-C3, T6-C4, T5-P3 and T6-P4 electrode pairs resulted from the intra-hemispheric action for alphal and alpha2 frequency bands. Result： There was significantly higher EEG power from MCI patients than from normal controls both at rest and during working memory processing. Significant differences existed between rest condition and three-level working memory tasks （P〈0.001）. The inter- and intra-hemispheric coherence during working memory tasks showed a ＂drop to rise＂ tendency compared to that at rest condition. There was significantly higher coherence in MCI patients than in the controls.When task difficulties increased, the cortical connectivity of intra-hemispheric diminished while the inter-hemispheric connectivity dominantly maintained the cognitive processing in MCI patients. Conclusion： The results of the present study indicate that the alpha frequency band may be the characteristic band in distinguishing MCI patients from normal controls during working memory tasks. MCI patients exhibit greater inter-hemispheric connectivity than intra-hemispheric connectivity when memory demands increase. MCI patients mobilize a compensatory mechanism to maintain the processing effectiveness while the processing efficiency is reduced.
基金Supported by Shanghai Pujiang Program,No.2020PJC115.
文摘Due to the critical roles of emotion and working memory in our daily activities,a great deal of attention has been given to how emotion influences working memory performance.Although the association between emotion and working memory is relatively well established,whether mood enhances or impairs working memory performance remains controversial.The present review provides a relatively representative overview of the research on the effect of different dimensions of emotion on working memory among healthy adults spanning a 30-year period.The findings show that the valence,arousal and motivational dimensions of emotion could all exert an impact on working memory performance.The impact of emotion on working memory might be modulated by task relevance,emotion type,working memory paradigms and individual differences.The vast majority of the studies regarding the effect of emotion on working memory performance focused on the impact of negatively valenced affect and yielded highly contradictory findings.The impacts of arousal and motivation on working memory have been less explored,and inconsistent findings have also been reported.Possible explanations are discussed.Considerable research on the effect of certain dimensions of emotion on working memory has suffered from a lack of control of other emotional dimensions,and different aspects of working memory have been investigated by various paradigms.Directions for further studies should include the exploration of specific dimensions of emotion on different aspects of working memory,with the other dimensions being well controlled.
基金supported by a grant from National Natural Science Foundation of China (No. 30872132)
文摘The deficiency theories of dyslexia are quite contradictory and the cross-cultural studies in recent years mainly focused on whether the dyslexics among cultures shared the same cognitive profile or just based on the language.This study used Near-Infrared Spectroscopy (NIRS) imaging to measure the regional cerebral blood volume (BV) and the changes of cerebral activation in the left prefrontal cortex of 12 Chinese dyslexic children and their 12 age-matched normal controls during the Paced Vis-ual Serial Addition Test (PVSAT).Results showed that the scores of PVSAT of dyslexic children were significantly lower than those of the normal children (t=3.33,P<0.01).The activations of the left pre-frontal cortex in the normal group were significantly greater than those of dyslexic children (all P<0.01).Our results indicated that Chinese dyslexia had a general deficiency in working memory and this may be caused by the abnormal metabolic activity of brain blood volume in the left prefrontal cortex and the deficits in brain function might be the basis of neuropathology of Chinese dyslexia.Present study sup-ports the difference on brain activation of dyslexics from different languages may be caused by the same cognitive system related to reading.
基金This work was supported by Start-up Funds from Wenzhou Medical University(89211010 and 89212012)the National Natural Science Foundation of China(81630040,31771178,and 81600991)the Natural Science Foundation of Zhejiang Province of China(LY21H090014 and LQ18C090002).
文摘Astrocytes are increasingly recognized to play an active role in learning and memory,but whether neural inputs can trigger event-specific astrocytic Ca^(2+)dynamics in real time to participate in working memory remains unclear due to the difficulties in directly monitoring astrocytic Ca^(2+)dynamics in animals performing tasks.Here,using fiber photometry,we showed that population astrocytic Ca^(2+)dynamics in the hippocampus were gated by sensory inputs(centered at the turning point of the T-maze)and modified by the reward delivery during the encoding and retrieval phases.Notably,there was a strong inter-locked and antagonistic relationship between the astrocytic and neuronal Ca^(2+)dynamics with a 3-s phase difference.Furthermore,there was a robust synchronization of astrocytic Ca^(2+)at the population level among the hippocampus,medial prefrontal cortex,and striatum.The inter-locked,bidirectional communication between astrocytes and neurons at the population level may contribute to the modulation of information processing in working memory.
