The effect of headache pain on attention (encoding) and memory (recognition)

Memory is a key cognitive variable in pain management. This study examined the effect of headaches on participants' encoding of words (attention) and later memory for words. The dependent measures were response time during encoding and recognition memory; headache pain was the independent measure. Eighty participants were randomized to one of four groups: two groups had the same condition (headache pain or no headache pain) for both the encoding and memory tasks and two groups had mixed conditions (i.e. pain during encoding/no pain during recognition; no pain during encoding/pain during recognition). Participants with pain during encoding judged words significantly slower (177.53ms) than participants without pain during encoding. Participants with pain during the memory task recognized significantly fewer words (5.4%) than participants without pain during the memory task, regardless of pain condition during encoding. Results from this and other pain and memory studies conducted in this laboratory suggest that pain, as it adversely affects memory, may operate at a threshold level rather than on a dose-response continuum.     

Implicit phonological priming during visual word recognition

Phonology is a lower-level structural aspect of language involving the sounds of a language and their organization in that language. Numerous behavioral studies utilizing priming, which refers to an increased sensitivity to a stimulus following prior experience with that or a related stimulus, have provided evidence for the role of phonology in visual word recognition. However, most language studies utilizing priming in conjunction with functional magnetic resonance imaging (fMRI) have focused on lexical-semantic aspects of language processing. The aim of the present study was to investigate the neurobiological substrates of the automatic, implicit stages of phonological processing. While undergoing fMRI, eighteen individuals performed a lexical decision task (LDT) on prime-target pairs including word-word homophone and pseudoword-word pseudohomophone pairs with a prime presentation below perceptual threshold. Whole-brain analyses revealed several cortical regions exhibiting hemodynamic response suppression due to phonological priming including bilateral superior temporal gyri (STG), middle temporal gyri (MTG), and angular gyri (AG) with additional region of interest (ROI) analyses revealing response suppression in the left lateralized supramarginal gyrus (SMG). Homophone and pseudohomophone priming also resulted in different patterns of hemodynamic responses relative to one another. These results suggest that phonological processing plays a key role in visual word recognition. Furthermore, enhanced hemodynamic responses for unrelated stimuli relative to primed stimuli were observed in midline cortical regions corresponding to the default-mode network (DMN) suggesting that DMN activity can be modulated by task requirements within the context of an implicit task.     

Visual word recognition: the first half second

We used magnetoencephalography (MEG) to map the spatiotemporal evolution of cortical activity for visual word recognition. We show that for five-letter words, activity in the left hemisphere (LH) fusiform gyrus expands systematically in both the posterior-anterior and medial-lateral directions over the course of the first 500 ms after stimulus presentation. Contrary to what would be expected from cognitive models and hemodynamic studies, the component of this activity that spatially coincides with the visual word form area (VWFA) is not active until around 200 ms post-stimulus, and critically, this activity is preceded by and co-active with activity in parts of the inferior frontal gyrus (IFG, BA44/6). The spread of activity in the VWFA for words does not appear in isolation but is co-active in parallel with spread of activity in anterior middle temporal gyrus (aMTG, BA 21 and 38), posterior middle temporal gyrus (pMTG, BA37/39), and IFG.     

Spatiotemporal brain maps of delayed word repetition and recognition

Whole-head magnetoencephalography (MEG) was used to spatiotemporally map the brain response underlying episodic retrieval of words studied a single time following a long delay (approximately 40 min). Recognition following a long delay occurs as a strong, sustained, differential response, within bilateral, ventral, and lateral prefrontal cortex, anterior temporal and medial parietal regions from approximately 500 ms onward, as well as ventral occipitotemporal regions from approximately 700 ms onward. In comparison with previous tasks using multiple repetitions at short delays, these effects were centered within the same areas (anteroventral temporal and ventral prefrontal) but were shifted to longer latencies (approximately 500 ms vs. approximately 200 ms), were less left-lateralized, and appear more in anterolateral prefrontal regions and less in lateral temporal cortex. Furthermore, comparison of correctly classified words with misclassified, novel and repeated words, suggests that these frontotemporal-parietocingulate responses are sensitive to actual as well as perceived repetition. The results also suggest that lateral prefrontal regions may participate more in controlled effortful retrieval, while left ventral frontal and anterior temporal responses may support sustained lexicosemantic processing. Additionally, left ventromedial temporal sites may be relatively more involved in episodic retrieval, while lateral temporal sites may participate more in automatic priming.     

跨记忆系统的模式识别

目的:探讨模式识别中,当模式和模板分别处于不同的记忆系统时,如何进行比较。方法:对15例2004-02/06中南民族大学学生视力(含矫正视力)正常者进行一项全部报告实验和两项抽样匹配实验。实验所用的刺激物为3类卡片,其上分别有8个汉字、1个汉字和提示符“!”,它们分别称为模式卡片、模板卡片和提示符卡片。抽样匹配实验分为两类:①抽样匹配实验1。在该实验中,模板后于模式呈现。②抽样匹配实验2。与抽样匹配实验1不同,该实验中模板先于模式呈现。结果:符合标准的13例,进入结果分析。①全部报告实验中,总平均模式转换量为3.71个,相应的总平均模式转换率为46.38%。②抽样匹配实验1中,总平均匹配模式识别量为11.13个,总平均匹配模式转换量均为11.28个,两者差异不显著(P>0.05)。③抽样匹配实验2中,总平均匹配模式识别量为19.63个,总平均匹配模式转换量为11.13个,两者差异显著[t(13)=12.879,SD=0.099,P=0.000]。结论:通过全部报告实验和抽样匹配实验1,得到一个判别模式识别时所利用信息来源的判据:如果匹配模式的识别量显著多于其转换量,模式识别需直接利用模式的感觉记忆信息;利用鉴别信息来源的判据得出,在抽样匹配实验2中,模式的感觉记忆信息被直接用于模式识别,它与只具有短时记忆信息的模板跨记忆系统直接     

Inhibition and facilitation in visual word recognition: prefrontal contribution to the orthographic neighborhood size effect

The recognition of words is a central component of language processing. A major role for visual word recognition has been attributed to the orthographic neighbors of a word, i.e., words that are orthographically similar to a target word. It has been demonstrated that the presence of orthographic neighbors facilitates the recognition of words, but hinders the rejection of nonwords. It is therefore assumed that representations of orthographic neighbors are at least partially activated during word recognition, and that they influence word recognition depending on the specific task context. In the present study, we used fMRI to examine the neural bases of the effect of orthographic neighborhood size on speeded lexical decisions to words and nonwords. Our results demonstrate lexicality x neighborhood size interactions in mid-dorsolateral and medial prefrontal cortex, suggesting the involvement of a domain-general, extra-lexical process for orthographic neighborhood effects on word and nonword processing. This result challenges computational models that offer purely lexical accounts of the orthographic neighborhood effect and suggests an important role for executive control functions during visual word recognition.     

The effect of a musical mood induction procedure on mood state-dependent word retrieval

The purpose of this experiment was to replicate and expand upon an earlier study by Thaut and de l'Etoile (1993) by examining the effect of a musical mood induction procedure on mood state-dependent word retrieval. Participants (N = 45) completed a 2-day testing procedure. On day one, participants read a list of adjectives and wrote down an antonym for each one. On day two, participants recalled as many of the antonyms as possible. During the testing procedure, participants were placed in 1 of 4 conditions: (a) mood induction at encoding, (b) mood induction at recall, (c) no mood induction, and (d) mood induction at both encoding and recall. The mood induction procedure included 3 steps. Participants first assessed their current mood state using a visual analog scale. They then listened to music for 5 minutes, determined the mood of the piece while listening, and tried to match their mood to the music. Finally, participants again used the visual analog scale to indicate their mood. Results indicated that participants who received mood induction prior to both encoding and recall were able to retrieve significantly more words than participants who did not undergo any mood induction. The results are discussed in light of the associative network theory of memory and emotions and the treatment of mood disorders.     

Top-down modulation of ventral occipito-temporal responses during visual word recognition

Although interactivity is considered a fundamental principle of cognitive (and computational) models of reading, it has received far less attention in neural models of reading that instead focus on serial stages of feed-forward processing from visual input to orthographic processing to accessing the corresponding phonological and semantic information. In particular, the left ventral occipito-temporal (vOT) cortex is proposed to be the first stage where visual word recognition occurs prior to accessing nonvisual information such as semantics and phonology. We used functional magnetic resonance imaging (fMRI) to investigate whether there is evidence that activation in vOT is influenced top-down by the interaction of visual and nonvisual properties of the stimuli during visual word recognition tasks. Participants performed two different types of lexical decision tasks that focused on either visual or nonvisual properties of the word or word-like stimuli. The design allowed us to investigate how vOT activation during visual word recognition was influenced by a task change to the same stimuli and by a stimulus change during the same task. We found both stimulus- and task-driven modulation of vOT activation that can only be explained by top-down processing of nonvisual aspects of the task and stimuli. Our results are consistent with the hypothesis that vOT acts as an interface linking visual form with nonvisual processing in both bottom up and top down directions. Such interactive processing at the neural level is in agreement with cognitive and computational models of reading but challenges some of the assumptions made by current neuro-anatomical models of reading.     

应激对大鼠空间记忆发育的影响

目的研究应激刺激对发育期大鼠空间记忆发育的影响. 方法采用发育期 Wistar大鼠 22只,按随机抽签法分为应激 1组 (30 V)、应激 2组 (45 V)、对照组.电刺激大鼠 10次 /d,连续 1周;采用血清放免法检测生长激素含量变化;通过 Morris水迷宫检测应激对大鼠空间记忆能力的影响. 结果应激 2组水迷宫空间学习记忆逃逸时间较应激 1组 [训练第 1～ 5天应激 1, 2组分别为( 23.61± 16.06) ,(14.19± 5.01) s],较对照组 [训练第 1～ 5天为( 26.86± 9.89) s],差异有显著性意义( t=2.35～ 3.02,P< 0.05) ; 应激 2组的生长激素 [(2.24± 0.49) μ g/L]含量偏低 ,应激 1组的生长激素含量 [(3.26± 0.82) μ g/L]有明显增高趋势 (t=2.83,P< 0.05). 结论应激刺激可提高幼年大鼠空间记忆能力的发育;达到 45 V应激刺激可以影响幼年大鼠的体格发育 ,而 30 V应激刺激则不会妨碍甚至可以促进幼年大鼠的体格发育.     

Processing stages underlying word recognition in the anteroventral temporal lobe

The anteroventral temporal lobe integrates visual, lexical, semantic and mnestic aspects of word processing, through its reciprocal connections with the ventral visual stream, language areas, and the hippocampal formation. We used linear microelectrode arrays to probe population synaptic currents and neuronal firing in different cortical layers of the anteroventral temporal lobe, during semantic judgments with implicit priming and overt word recognition. Since different extrinsic and associative inputs preferentially target different cortical layers, this method can help reveal the sequence and nature of local processing stages at a higher resolution than was previously possible. The initial response in inferotemporal and perirhinal cortices is a brief current sink beginning at approximately 120 ms and peaking at approximately 170 ms. Localization of this initial sink to middle layers suggests that it represents feedforward input from lower visual areas, and simultaneously increased firing implies that it represents excitatory synaptic currents. Until approximately 800 ms, the main focus of transmembrane current sinks alternates between middle and superficial layers, with the superficial focus becoming increasingly dominant after approximately 550 ms. Since superficial layers are the target of local and feedback associative inputs, this suggests an alternation in predominant synaptic input between feedforward and feedback modes. Word repetition does not affect the initial perirhinal and inferotemporal middle layer sink but does decrease later activity. Entorhinal activity begins later (approximately 200 ms), with greater apparent excitatory post-synaptic currents and multiunit activity in neocortically projecting than hippocampal-projecting layers. In contrast to perirhinal and entorhinal responses, entorhinal responses are larger to repeated words during memory retrieval. These results identify a sequence of physiological activation, beginning with a sharp activation from lower level visual areas carrying specific information to middle layers. This is followed by feedback and associative interactions involving upper cortical layers, which are abbreviated to repeated words. Following bottom-up and associative stages, top-down recollective processes may be driven by entorhinal cortex. Word processing involves a systematic sequence of fast feedforward information transfer from visual areas to anteroventral temporal cortex followed by prolonged interactions of this feedforward information with local associations and feedback mnestic information from the medial temporal lobe.     

Changes in brain electrical activity during extended continuous word recognition

Twenty healthy subjects (10 men, 10 women) participated in an EEG study with an extended continuous recognition memory task, in which each of 30 words was randomly shown 10 times and subjects were required to make old vs. new decisions. Both event-related brain potentials (ERPs) and induced band power (IBP) were investigated. We hypothesized that repeated presentations affect recollection rather than familiarity. For the 300- to 500-ms time window, an 'old/new' ERP effect was found for the first vs. second word presentations. The correct recognition of an 'old' word was associated with a more positive waveform than the correct identification of a new word. The old/new effect was most pronounced at and around the midline parietal electrode position. For the 500- to 800-ms time window, a linear repetition effect was found for multiple word repetitions. Correct recognition after an increasing number of repetitions was associated with increasing positivity. The multiple repetitions effect was most pronounced at the midline central (Cz) and fronto-central (FCz) electrode positions and reflects a graded recollection process: the stronger the memory trace grows, the more positive the ERP in the 500- to 800-ms time window. The ERP results support a dual-processing model, with familiarity being discernable from a more graded recollection state that depends on memory strengths. For IBP, we found 'old/new' effects for the lower-2 alpha, theta, and delta bands, with higher bandpower during 'old' words. The lower-2 alpha 'old/new' effect most probably reflects attentional processes, whereas the theta and delta effects reflect encoding and retrieval processes. Upon repeated word presentations, the magnitude of induced delta power in the 375- to 750-ms time window diminished linearly. Correlation analysis suggests that decreased delta power is moderately associated with faster decision speed and higher accuracy.     

咪达唑仑对全麻术中知晓显性记忆的影响

目的全麻过程中患者常出现深痛觉与浅镇静现象,而麻醉医生又难以监测,从而导致术后知晓率日益增多。探讨静脉全麻中小剂量咪达唑仑对术中知晓显性记忆的影响及对术中患者的心理护理。方法腹腔镜胆囊切除术患者323例,随机数字法分组为对照组159例,咪达唑仑组164例,全麻术中所有患者均聆听强度大小和内容相同的音乐片段,术后24h调查患者对术中的知晓情况。结果对照组插管前平均动脉压(MAP)为(14.8±1.3)kPa,插管后(14.4±1.9)kPa,插管前后比较t=1.74,P>0.05。咪达唑仑组插管前MAP(15.0±1.2)kPa,插管后(11.7±1.1)kPa,插管前后比较t=1.72,P>0.05。对照组插管前心率(HR)为(84±10)次/min,插管后(84±10)次/min,插管前后比较t=1.83,P>0.05。咪达唑仑组插管前HR(84±10)次/min,插管后(84±12)次/min,插管前后比较t=1.64,P>0.05对照组有36例患者能回忆起术中曾听到音乐的部分内容,咪达唑仑组无一例患者回忆起听过音乐片段。结论全麻术中应用咪达唑仑能明显抑制术中患者的外显性记忆力,有效地防止术中知晓给患者带来不应有的心理上的不良影响。     

The time course of visual word recognition as revealed by linear regression analysis of ERP data

EEG correlates of a range of psycholinguistic word properties were used to investigate the time course of access to psycholinguistic information during visual word recognition. Neurophysiological responses recorded in a visual lexical decision task were submitted to linear regression analysis. First, 10 psycholinguistic features of each of 300 stimulus words were submitted to a principal component analysis, which yielded four orthogonal variables likely to reflect separable processes in visual word recognition: Word length, Letter n-gram frequency, Lexical frequency and Semantic coherence of a word's morphological family. Since the lexical decision task required subjects to distinguish between words and pseudowords, the binary variable Lexicality was also investigated using a factorial design. Word-pseudoword differences in the event-related potential first appeared at 160 ms after word onset. However, regression analysis of EEG data documented a much earlier effect of both Word length and Letter n-gram frequency around 90 ms. Lexical frequency showed its earliest effect slightly later, at 110 ms, and Semantic coherence significantly correlated with neurophysiological measures around 160 ms, simultaneously with the lexicality effect. Source estimates indicated parieto-temporo-occipital generators for the factors Length, Letter n-gram frequency and Word frequency, but widespread activation with foci in left anterior temporal lobe and inferior frontal cortex related to Semantic coherence. At later stages (>200 ms), all variables exhibited simultaneous EEG correlates. These results indicate that information about surface form and meaning of a lexical item is first accessed at different times in different brain systems and then processed simultaneously, thus supporting cascaded interactive processing models.     

The role of the prefrontal cortex in recognition memory and memory for source: an fMRI study.

We employed fMRI to index neural activity in prefrontal cortex during tests of recognition and source memory. At study, subjects were presented with words displayed either to the left or right of fixation, and, depending on the side, performed one of two orienting tasks. The test phase consisted of a sequence of three 10-word blocks, displayed in central vision. For one block, subjects performed recognition judgements on a mixture of two old and eight new words (low density recognition). For another block, recognition judgements were performed on a mixture of eight old and two new words (high density recognition). In the remaining block, also consisting of eight old and two new items, the requirement was to judge whether each word had been presented at study on the left or the right. Relative to the low density condition, high density recognition was associated with increased activity in right and, to a lesser extent, left, anterior prefrontal cortex (BA 10), replicating the findings of two previous PET studies. Right anterior prefrontal activity did not show any further increase during the source task. Instead, greater activity was found, relative to high density recognition, in left BA 10, left inferior frontal gyrus (BA 45/47), and bilateral opercular cortices (BA 45/47). The findings are inconsistent with the proposal that activation of right anterior prefrontal cortex during memory retrieval reflects "postretrieval" processing demands, such demands being considerably greater for judgments of source than recognition. The findings provide further evidence that the left prefrontal cortex plays a role in episodic memory retrieval when the task explicitly requires recovery of contextual as well as item information.     

Contextual interference in recognition memory with age

Previous behavioral research suggests that although elderly adults' memory benefits from supportive context, misleading or irrelevant contexts produce greater interference. In the present study, we use event-related fMRI to investigate age differences when processing contextual information to make recognition judgments. Twenty-one young and twenty elderly incidentally encoded pictures of objects presented in meaningful contexts, and completed a memory test for the objects presented in identical or novel contexts. Elderly committed more false alarms than young when novel objects were presented in familiar, but task-irrelevant, contexts. Elderly showed reduced engagement of bilateral dorsolateral prefrontal cortex and anterior cingulate relative to young, reflecting disruption of a cognitive control network for processing context with age. Disruption occurred for both high and low-performing elderly, suggesting that cognitive control deficits are pervasive with age. Despite showing disruption of the cognitive control network, high-performing elderly recruited additional middle and medial frontal regions that were not recruited by either low-performing elderly or young adults. This suggests that high-performing elderly may compensate for the disruption of the cognitive control network by recruiting additional frontal resources to overcome cognitive control deficits that affect recognition memory.     

应用事件相关电位技术研究词汇识别中汉字正字法的作用

目的:使用事件相关电位技术考察人脑在视觉通道下汉语词汇识别中汉字正字法的作用。方法:实验于2004-04/07在徐州师范大学语言研究所事件相关电位实验室完成。①实验对象及分组:选择16名大学生(8女,8男,18～22岁)经书面同意后进行词汇判断实验。单音节词汇判断为测试组,双音节词汇判断为对照组。②实验语料:选自1986年北京语言学院出版社出版的《现代汉语频率词典》日常生活常用语部分,选词包括单音节词和双音节词。单音节假词通过调换真字相应位置的一个部件得到,双音节假词通过调换真词中一个音节得到。真词和假词的笔划数无显著差异。刺激词共264个,每个刺激呈现时间为200ms,刺激间隔在2.0￣2.5s。③实验过程:分两个序列,受试者被要求在保证反应正确的前提下尽可能迅速地进行按键操作。④实验评估:采用NeuroScan公司64导电极帽10/20系统记录脑电,离线分析处理事件相关电位数据。结果:名受试者进入结果分析。①行为学数据结果:真词的反应时均显著短于假词(P<0.05),真词的正确率均显著高于假14词(P<0.05)。②脑电数据结果:N400的波峰值假词显著低于真词(P<0.05),但只有测试组中N400的波峰单音节假词迟于真词出现;测试组中,560～660ms时间窗口内P600的平均幅值单音节假词显著高于真词(P<0.05),对照组中600～700ms时间窗口内P600的平均幅值双音节假词显著高于真词(P<0.05)。③假词减真词的差异波分析结果:测试组和对照组中均出现Nd400,Pd600,但Pd250却只在前者出现,且主要在额中央区、中央顶区分布;对照组中Nd400波幅值较小,脑区分布范围也较大,主要分布在双侧顶中央区、右半球颞顶区,测试组的Nd400主要在右半球颞顶枕区分布;测试组Pd600波幅值较大,脑区分布范围较广,主要分布于右半球中央及顶枕区,对照组则主要在右半球顶枕区分布。结论:①在视觉通道的汉语词汇判断实验中,差异波分析可观察人脑在词汇识别中正字法的作用。②Pd250是视觉词汇识别中汉字正字法作用的特异性成分,表明汉字正字法作用在刺激词呈现约250ms后开始体现,该成分可能反映了视觉词汇识别中人脑对汉字部件组合规则和汉字拼读规则的加工过程。③双音节词汇判断中Nd400可能反映了视觉词汇识别中人脑对汉字部件语义组配的加工过程;Pd600则可能反映了人脑重新分析汉字部件语义组配的加工过程。     

Different strategies for auditory word recognition in healthy versus normal aging

To explore the effects of commonly encountered pathology on auditory recognition strategies in elderly participants, magnetoencephalographic (MEG) brain activation patterns and performance were examined in 30 elderly [18 controls and 12 elderly with mild cognitive impairment (MCI) or probable Alzheimer's disease (AD)]. It was predicted that participants with known pathology would reveal different networks of brain activation, compared to healthy elderly, which should correlate with poorer performance. Participants heard a list of words representing common objects, twice. After 20 minutes a list of new and old words was presented and participants judged whether each word was heard earlier. MEG responses were analyzed using a semiautomated source modeling procedure. A cluster analysis using all subjects' MEG sources revealed three dominant patterns of activity which correlated with IQ and task performance. The highest performing group revealed activity in premotor, anterior temporal, and superior parietal lobes with little contribution from prefrontal cortex. Performance and brain activation patterns were also compared for individuals with or without abnormalities such as white matter hyperintensities and/or volume reduction evidenced on their MRIs. Memory performance and activation patterns for individuals with white matter hyperintensities resembled the group of MCI/AD patients. These results emphasize the following: (1) general pathology correlates with cognitive decline and (2) full characterization of the health of elderly participants is important in studies of normal aging since random samples from the elderly population are apt to include individuals with subclinical pathology that can affect cognitive performance.