Recognition memory for emotional and neutral faces: an event-related potential study

This study examined emotional influences on the hypothesized event-related potential (ERP) correlates of familiarity and recollection (Experiment 1) and the states of awareness (Experiment 2) accompanying recognition memory for faces differing in facial affect. Participants made gender judgments to positive, negative, and neutral faces at study and were in the test phase instructed to discriminate between studied and nonstudied faces. Whereas old-new discrimination was unaffected by facial expression, negative faces were recollected to a greater extent than both positive and neutral faces as reflected in the parietal ERP old-new effect and in the proportion of remember judgments. Moreover, emotion-specific modulations were observed in frontally recorded ERPs elicited by correctly rejected new faces that concurred with a more liberal response criterion for emotional as compared to neutral faces. Taken together, the results are consistent with the view that processes promoting recollection are facilitated for negative events and that emotion may affect recognition performance by influencing criterion setting mediated by the prefrontal cortex.     

Posttrial d-cycloserine enhances the emotional memory of an incentive downshift event

The present research was designed to determine whether an incentive downshift event induces an emotional memory that can be modulated by d-cycloserine (DCS), a partial agonist at the glycine site of N-methyl-d-aspartate receptor (NMDAR). DCS has been reported to have memory-enhancing properties in other training situations. Experiments 1 and 2 involved a consummatory successive negative contrast (cSNC) situation in which animals are exposed to an incentive downshift involving sucrose solutions of different concentrations. DCS administration (30 mg/kg, ip) immediately after the first 32-to-4% sucrose downshift trial (Experiment 1) retarded recovery of consummatory behavior, but immediately after the first 32-to-6% sucrose downshift trial (Experiment 2) did not affect recovery. There was no evidence that DCS affected consummatory behavior in the absence of an incentive downshift in a manner analogous to a conditioned taste aversion (Experiment 3). These results suggest that activation of NMDARs via the glycine modulatory site enhances the emotional memory triggered by exposure to an incentive downshift event.     

Language processing abnormalities in adolescents with psychotic-like experiences: an event related potential study

Language impairments are a well established finding in patients with schizophrenia and in individuals at-risk for psychosis. A growing body of research has revealed shared risk factors between individuals with psychotic-like experiences (PLEs) from the general population and patients with schizophrenia. In particular, adolescents with PLEs have been shown to be at an increased risk for later psychosis. However, to date there has been little information published on electrophysiological correlates of language comprehension in this at-risk group. A 64 channel EEG recorded electrical activity while 37 (16 At-Risk; 21 Controls) participants completed the British Picture Vocabulary Scale (BPVS-II) receptive vocabulary task. The P300 component was examined as a function of language comprehension. The at-risk group were impaired behaviourally on receptive language and were characterised by a reduction in P300 amplitude relative to the control group. The results of this study reveal electrophysiological evidence for receptive language deficits in adolescents with PLEs, suggesting that the earliest neurobiological changes underlying psychosis may be apparent in the adolescent period.     

Enhancement of declarative memory by emotional arousal and visual memory function in Alzheimer's disease

The specific effects of visual and verbal memory on the ability of emotional arousal to enhance declarative memory were examined by using multiple linear regression analysis on data from a sample of 56 patients with probable Alzheimer's disease (AD). The enhancing effect of emotion on memory was evaluated by an illustrated story paradigm, and the visual and verbal memory by a standard memory test. In AD, memory enhancement by emotion was significantly correlated with visual memory but not with verbal memory, regardless of age, sex, educational attainment, and severity of dementia, suggesting a close association between memory enhancement by emotion and visual memory.     

Acute effects of nicotine administration during prospective memory, an event related fMRI study

We previously demonstrated that stimulating neuronal nicotinic acetylcholine receptors modulates prospective memory (PM), the ability to remember and implement a prior intention. Here we used fMRI to explore the neuronal correlates of acute nicotinic (1 mg) modulation during PM, employing a double blind, valence-matched placebo-controlled design, and a solely event-related analysis. Eight healthy adults completed on two occasions (1 week washout) a simple attentional task containing infrequent PM trials. PM activated bilateral parietal, prefrontal (BA10) and anterior cingulate, and deactivated genual cingulate and medial prefrontal regions. Further, acute nicotine administration decreased activity within a largely overlapping right parietal region. This data validates a purely event-related approach to exploring PM, and suggests procholinergic modulation of PM by parietal rather than BA10/frontal regions.     

False memory and level of processing effect: an event-related potential study

Event-related potentials (ERPs) were used to determine the effects of level of processing on true and false memory, using the Deese-Roediger-McDermott (DRM) paradigm. In the DRM paradigm, lists of words highly associated to a single nonpresented word (the 'critical lure') are studied and, in a subsequent memory test, critical lures are often falsely remembered. Lists with three critical lures per list were auditorily presented here to participants who studied them with either a shallow (saying whether the word contained the letter 'o') or a deep (creating a mental image of the word) processing task. Visual presentation modality was used on a final recognition test. True recognition of studied words was significantly higher after deep encoding, whereas false recognition of nonpresented critical lures was similar in both experimental groups. At the ERP level, true and false recognition showed similar patterns: no FN400 effect was found, whereas comparable left parietal and late right frontal old/new effects were found for true and false recognition in both experimental conditions. Items studied under shallow encoding conditions elicited more positive ERP than items studied under deep encoding conditions at a 1000-1500 ms interval. These ERP results suggest that true and false recognition share some common underlying processes. Differential effects of level of processing on true and false memory were found only at the behavioral level but not at the ERP level.     

The influence of self-awareness on emotional memory formation: an fMRI study

Evidence from functional neuroimaging studies of emotional perception shows that when attention is focused on external features of emotional stimuli (external perceptual orienting—EPO), the amygdala is primarily engaged, but when attention is turned inwards towards one’s own emotional state (interoceptive self-orienting—ISO), regions of the salience network, such as the anterior insula (AI) and the dorsal anterior cingulate cortex (dACC), also play a major role. Yet, it is unknown if ISO boosts the contributions of AI and dACC not only to emotional ‘perception’ but also to emotional ‘memory’. To investigate this issue, participants were scanned with functional magnetic resonance imaging (fMRI) while viewing emotional and neutral pictures under ISO or EPO, and memory was tested several days later. The study yielded three main findings: (i) emotion boosted perception-related activity in the amygdala during both ISO and EPO and in the right AI exclusively during ISO; (ii) emotion augmented activity predicting subsequent memory in AI and dACC during ISO but not during EPO and (iii) high confidence memory was associated with increased amygdala–dACC connectivity, selectively for ISO encoding. These findings show, for the first time, that ISO promotes emotional memory formation via regions associated with interoceptive awareness of emotional experience, such as AI and dACC.     

Chronic effects of social drinking in a card-sorting task: an event related potential study.

OBJECTIVE: The Wisconsin Card Sorting Task (WCST) is one of the most widely used neuropsychological tests of frontal lobe function, which is thought to be affected by regular alcohol use. The present study used a computer-adapted version of the WCST to assess the effects of chronic alcohol consumption on the brain. METHODS: Participants (N=59) sorted cards according to an initially unknown sorting rule, which referred to shape, number, or color. The correctness of the chosen sorting rule was indicated by a feedback stimulus. This correct sorting rule had to be followed for a number of stimuli, and when it changed participants had to find out which rule had to be followed next. A distinction was made between early (correct sorting rule is unknown) and late trials (correct sorting rule is known and applied). To measure brain activity related during the task event related potentials (ERPs) were recorded to the target and feedback stimulus in light (N=14), moderate (N=16) and heavy (N=19) social drinkers and excessive alcohol users (N=10). RESULTS: No differences in number of series completed or the reaction time in each trial, were found between the four groups. In contrast, a mid-frontal N1 component in reaction to the feedback stimuli did reveal differences between the four groups. In the light and moderate drinkers, on early feedback trials the N1 was larger relative to late feedback trials, but this effect was absent in the heavy social drinkers and excessive drinkers. CONCLUSIONS: The reduced N1 effect with increasing alcohol intake could reflect abnormal allocation of attention or impaired conflict monitoring, possibly based on activity in the anterior cingulate cortex. SIGNIFICANCE: Heavy social drinking and excessive drinking leads to changes in the mid-frontal N1 during feedback trials of the WCST.     

The relation between event related potential and working memory in healthy subjects

In numerous investigations the P300-component of the event related potential has proved a valid indicator of memory activities. The present study explores the amplitude and latency of the components of event-related potential regarding short-term memory task. Event related potentials, elicited by auditory stimuli, were recorded in 40 healthy subjects. For evaluating short term memory capacity of a subject, software in Delphi for Windows language was written. Algorithm of the software was the presentation of randomly selected four different digits for 4 seconds, removing it and waiting for subject's response, adding one digit, if response was true, otherwise decreased by one. After 20 trials, mean of recall time for true answers was computed. The subjects with high recall time showed prolonged latency of P300. A positive correlation was found between P300 latency and recall time. No correlation was found between N1, P2 and N2 latency or amplitude and recall time. These results suggest that memory problems are well correlated with the abnormalities of P300.     

Replication of an evoked potential study of lateralized hemispheric dysfunction in schizophrenics

Visual (VEP) and auditory (AEP) evoked potentials (EPs) were measured to replicate previous findings concerning lateralized hemispheric dysfunction in chronic schizophrenic patients in a new sample. Measures of EP waveform stability (Zr') showed greater hemispheric asymmetry in 26 unmedicated chronic schizophrenics than in 26 matched nonpatients, and relatively lower left and right hemisphere values in schizophrenics. Similar hemispheric differences were not found between medicated patients and matched nonpatients; medication was associated with higher left and lower right hemisphere stability. EP amplitudes were lower with medications, the lowest amplitudes found in patients receiving nonphenothiazine or nonpiperazines as opposed to phenothiazine-piperazine drugs. Medications were associated with amplitude asymmetries not observed in unmedicated patients. This study confirms greater than normal hemispheric asymmetry of VEP and AEP waveshape stability measures in chronic schizophrenics, and lower left than right hemisphere stability suggesting left hemisphere dysfunction. Alteration of EP asymmetries by antipsychotic medications suggests that medication effects may obscure evidence of lateralized dysfunction in schizophrenics.     

缺血性白质脑病患者事件相关电位研究

目的探讨缺血性白质脑病患者认知障碍、情感障碍的特点及规律,及对事件相关电位进行研究。方法收集缺血性白质脑病患者480例和正常对照86例,分别应用MMSE和Hamilton焦虑量表和24项版本抑郁量表进行测评,并进行事件相关电位P300、N400检测。结果缺血性白质脑病不同分级认知障碍、情感障碍差异有统计学意义,随着脑白质损害加重、分级增高,认知障碍和情感障碍加重,事件相关电位P300和N400潜伏期明显延长,波幅明显降低。结论缺血性白质脑病可造成患者严重认知、情感障碍,事件相关电位P300、N400可作为早期诊断缺血性白质脑病认知障碍的客观指标。     

Effects of age on working memory: an event-related potential study

The effects of age on behavioural performance and event-related potentials recorded during a working memory task using digits presented either acoustically or visually, were studied in 37 healthy subjects with an age range from 19 to 71 years. With increasing age, psychological tests showed a progressive decline in visuo-spatial performance and both auditory and visual reaction times (RT) increased. There were multiple and varying effects of age on both early and late ERP components. For both auditory and visual responses, increasing age was associated with an increased amplitude of early positive waves (auditory P100 and visual P145) and, in the oldest subjects, significant delays of the major late positive waves. Other changes were modality-specific with a progressive shift of amplitude maxima in the early negative waves of the visual ERPs (from an N190 peak maximal at Pz in the young, to an N270 peak maximal at Cz in the older subjects) and an altered amplitude distribution of late potentials (after the P250 wave) in the auditory responses. The age at which ERP changes occurred varied—significant latency prolongations and increases in the amplitude of the major frontal positive waves occurred only in the oldest subjects, whereas a redistribution of late auditory ERPs also occurred in the intermediate age group. There was no interaction between age and increasing memory load, suggesting that there is no specific effect of age on memory scanning in this age range for these levels of task difficulty. Thus, although performance in working memory was apparently unaffected by age, as judged by behavioural parameters (apart from slowing of the reaction times), ERPs revealed significant changes in both early and late electrical brain processes associated with working memory as age increases. These changes which were not symptomatically manifest and only revealed by sensitive tests, may represent subtle dysfunction of working memory (or associated processes) which does not prevent the successful completion of our task, compensatory mechanisms (which are essential to successfully complete the task), or a combination of both age-induced dysfunction and compensatory mechanisms.     

Cognition in epilepsy: a multichannel event related potential (P300) study

Auditory event-related potentials (AERP) were elicited in 68 epileptic patients and 30 age-matched controls. Epileptic patients had significantly prolonged N2 and P300 (P3) latencies compared with controls. Seven patients were above the range of 3 standard deviations from the control mean values. Amongst epileptics, patients with temporal lobe epilepsy had significantly prolonged P3 latencies compared to patients with idiopathic generalized epilepsy. Patients with abnormal EEGs had significantly prolonged P3 latencies compared to those with normal EEGs. Patients on anticonvulsant monotherapy had shorter P3 latencies, compared to patients taking a combination of two or more anticonvulsants. Patients on shorter duration of treatment had less prolonged P3 latencies compared to those on longer anticonvulsant treatment.     

Visual processing in the inferior temporal cortex: An intracranial event related potential study

ObjectiveTo investigate visual processing over the inferior temporal cortex (ITC) by recording intracranial event-related potentials (IERPs), and correlating the results with those of electrocortical stimulation mapping (ESM).MethodsIERPs to word, non-word, and non-letter visual stimuli were recorded over the ITC in 6 patients with intractable epilepsy. Two patients underwent ESM of the same contacts.ResultsIERPs were observed at 18 electrodes in 4 out of 6 patients. Nine electrodes showed early IERPs (peak latency ? 200 ms) over the posterior and middle ITC and 7 of them showed a following late ERP component, “early + late IERPs”. Nine electrodes showed late IERPs (peak latency > 200 ms) over the middle and anterior ITC. Among four electrodes showing language or visual phenomena by ESM, one electrode showed a short latency IERP, another electrode showed a late IERP, and the remaining two electrodes showed no IERPs.ConclusionsOur findings further support that the visual recognition occurred sequentially from posterior to anterior ITC. Dissociation of IERPs and ESM may be explained by the methodological difference.SignificanceIERP study disclosed that visual recognition occurred sequentially from posterior to anterior ITC.     

Facial emotion processing and language during early-to-middle childhood development: An event related potential study

Facial emotion processing (FEP) is critical to social cognitive ability. Developmentally, FEP rapidly improves in early childhood and continues to be fine-tuned throughout middle childhood and into adolescence. Previous research has suggested that language plays a role in the development of social cognitive skills, including non-verbal emotion recognition tasks. Here we investigated whether language is associated with specific neurophysiological indicators of FEP. One hundred and fourteen children (4–12 years) completed a language assessment and a FEP task including stimuli depicting anger, happiness, fear, and neutrality. EEG was used to record key event related potentials (ERPs; P100, N170, LPP at occipital and parietal sites separately) previously shown to be sensitive to faces and facial emotion. While there were no main effects of language, the P100 latency to negative expressions appeared to increase with language, while LPP amplitude increased with language for negative and neutral expressions. These findings suggest that language is linked to some early physiological indicators of FEP, but this is dependent on the facial expression. Future studies should explore the role of language in later stages of neural processing, with a focus on processes localised to ventromedial prefrontal regions.     

Influence of reward motivation on human declarative memory

Motivational relevance can prioritize information for memory encoding and consolidation based on reward value. In this review, we pinpoint the possible psychological and neural mechanisms by which reward promotes learning, from guiding attention to enhancing memory consolidation. We then discuss how reward value can spill-over from one conditioned stimulus to a non-conditioned stimulus. Such generalization can occur across perceptually similar items or through more complex relations, such as associative or logical inferences. Existing evidence suggests that the neurotransmitter dopamine boosts the formation of declarative memory for rewarded information and may also control the generalization of reward values. In particular, temporally-correlated activity in the hippocampus and in regions of the dopaminergic circuit may mediate value-based decisions and facilitate cross-item integration. Given the importance of generalization in learning, our review points to the need to study not only how reward affects later memory but how learned reward values may generalize to related representations and ultimately alter memory structure.     

事件相关电位（P300）的临床应用

20世纪90年代逐渐形成、发展了事件相关电位，这一诱发电位为描述心理活动、评价认知功能提供了一种客观、可行的手段，并逐渐成为精神科、神经科、老年科、心理学科等的研究热点。事件相关电位在评价和鉴别各种认知障碍中具有重要的临床应用，文章就事件相关电位P300的临床应用研究进行总结分析。     

The effects of perceived memory ability on memory conformity for an event

The present study investigated the impact of false feedback about individual memory performance relative to a co-witness on susceptibility to misinformation. Pairs of participants (n?=?130; 65 pairs) completed a visual memory test and received false feedback on their performance indicating that the memory ability of one participant in the pair was stronger relative to the other participant. The participants then viewed a crime video (either the same video or one slightly different to their partner) and discussed their memories for this video with their co-witness. Participants completed a semi-cued recall task and a recognition test about the video. False memory feedback indicating lower relative performance was associated with significant increases in sensitivity to misinformation. The results are discussed in reference to the potential contributions that co-witnesses' perceptions of both their partner's reliability and their own reliability have on event memory.     

脑梗塞的听觉事件相关电位P300初步研究

目的 分析脑梗塞患者与正常老人的听觉事件相关电位P300构成的特点.方法 使用J-1ERP仪器和听觉oddball范式,记录了31例脑梗塞患者和40例正常老人在Oz、Cz、Pz新组合三个记录点上P300,并分析其P3亚成份.结果 P3是一个复合波,对照组波形分化好,P3a、P3b双峰明显,稳定.在Oz、Cz、Pz点双峰波出现率分别为42.5%、55.0%和52.5%.在Pz点,脑梗塞组P3双峰波出现率低于对照组,有统计学差异(χ2=8.14,P=0.004).在Oz点P3a潜伏期,P3a、P3b波幅上,脑梗塞组表现为同一趋势,即潜伏期延迟和波幅低于对照组,有统计学差异.结论 P300对判断脑梗塞患者的认知状况有一定临床价值.     

精神分裂症患者事件相关电位P300的对照研究

目的:探讨精神分裂症患者听觉诱发电位P300的特征及病程对P300的影响。方法:对68例精神分裂症患者(研究组)和30名正常对照(正常对照组)进行事件相关电位P300的检测,并分析比较不同病程对P300的影响。结果:研究组Fz、Cz、FC1的P300潜伏期较对照组明显延迟(t分别=2.67,3.48,3.36;P均<0.01);Fz、Cz、FC1、FC2的波幅较对照组显著降低(t分别=5.97,2.54,4.57,3.80;P均<0.01)。对研究组中病程<6个月组和病程>5年组的患者比较发现,病程>5年组的患者Fz、Cz潜伏期延迟(t=9.23,7.63;P均<0.01),波幅降低(t=11.97,6.66;P均<0.01)。结论:精神分裂症患者认知功能受损,病程越长,受损越重。