Remembering or knowing: electrophysiological evidence for an episodic memory deficit in schizophrenia

2002 ◽  
Vol 32 (7) ◽  
pp. 1261-1271 ◽  
Author(s):  
I. TENDOLKAR ◽  
S. RUHRMANN ◽  
A. BROCKHAUS ◽  
R. PUKROP ◽  
J. KLOSTERKÖTTER
Keyword(s):  
Episodic Memory ◽  
Semantic Memory ◽  
Time Course ◽  
Cognitive Deficit ◽  
Declarative Memory ◽  
Event Related Potentials ◽  
New Words ◽  
Frontal Electrode ◽  
Schizophrenic Patients ◽  
Related Potentials

Background. In schizophrenia, impaired conscious retrieval of past events and facts may represent a selective cognitive deficit of declarative memory against a background of a generalized neuropsychological impairment. We aimed to disentangle the neural subprocesses leading to this deficit applying the ‘Remember/Know procedure’.Method. Event-related potentials (ERPs) were recorded as 14 schizophrenic patients and 14 controls recognized an equal mixture of previously presented old and new words. For recognized old words, participants were required to judge whether recognition was associated with recollection (‘Remember’) or familiarity (‘Know’), either reflecting episodic or semantic memory.Results. Patients showed a lack of ‘Remember responses’, which led to more opportunities to make ‘Know responses’. ERPs for ‘Remember’ compared to ‘New responses’ differed consistently in controls over left temporo-parietal and right frontal electrode sites. Although schizophrenic patients showed the same topography for this Remember old/new effect, it was apparent over temporo-parietal sites for only 800 ms and over right frontal sites for 1100 ms post-stimulus. For controls, the Know old/new effect was elicited over temporo-parietal sites between 500 and 800 ms. For patients, it showed a widespread maximum over frontal sites between 500 and 1100 ms.Conclusions. The shorter time course of the left temporo-parietal Remember old/new effect suggests that the patients' episodic memory impairment was possibly mediated by a dysfunction of the mediotemporal regions. The more widespread frontal Know old/new effect in the patients suggests that the prefrontly mediated processes associated with retrieval of semantic memory may be enhanced compensatorily.

scholarly journals Event Related Potentials and Serial List Picture Memory in Parkinson’s Patients

1996 ◽  
Vol 9 (2) ◽  
pp. 69-79
Author(s):  
M. S. Korsnes ◽  
I. Reinvang
Keyword(s):  
Cognitive Deficit ◽  
Short Term Memory ◽  
Event Related Potentials ◽  
Control Group ◽  
Serial List ◽  
Short Term ◽  
Picture Memory ◽  
Frontal Electrode ◽  
Related Potentials ◽  
Memory For Order

Two experiments examined short-term memory for order information in six patients diagnosed with Parkinson's disease (PD) and six control subjects while event related potentials (ERPs) were recorded. The subjects were tested for recognition of abstract spatial designs and words after a 5 s retention interval. The PD patients failed to respond in 29% of all trials, but the overall accuracy was similar to that in the control group when these trials were excluded. The corresponding ERP results show serial position variations both after presentation of the probe items, and after presentation of the memory set items. The amplitudes were generally lower at all positions for the PD patients at the parietal midline electrode, and the amplitudes were similar for both groups at the frontal electrode. Also, the ERP latencies were significantly slower for the PD patients than for the control group at all conditions. Indirectly the data are consistent with an interpretation of cognitive deficit in PD stressing attention resources.

An ERP Investigation of Semantic Priming, Repetition Priming, and Negative Priming in Schizophrenic Patients

2006 ◽  
Vol 20 (3) ◽  
pp. 195-211 ◽  
Author(s):  
Michael Wagner ◽  
Lioba Baving ◽  
Patrick Berg ◽  
Rudolf Cohen ◽  
Brigitte Rockstroh
Keyword(s):  
Negative Priming ◽  
Repetition Priming ◽  
Event Related Potentials ◽  
Decision Task ◽  
Positive Priming ◽  
Retrieval Processes ◽  
Schizophrenic Patients ◽  
Related Potentials ◽  
Late Positive Complex ◽  
Automatic Memory

The processing of attended and nonattended stimuli in schizophrenic patients was examined with event-related potentials (ERPs) in a lexical decision task. In positive semantic and repetition priming the N400 amplitude did not differ between a group of 17 medicated schizophrenic patients and a group of 20 matched healthy controls. However, negative priming affected the N400 only in controls. Reaction time effects were dissociated from these ERP effects, with patients showing stronger positive priming than controls but identical negative priming. The semantic processes related to the N400 appear to be intact in schizophrenic patients, but patients seem to incorporate less context information (about the nonattended prime) in their episodic memory traces. A stronger increase of the posterior late positive complex in parallel to the stronger positive priming in schizophrenic patients may reflect relatively stronger automatic memory retrieval processes in patients.

scholarly journals Not Just a Pot: Visual Episodic Memory in Cannabis Users and Polydrug Cannabis Users: ROC and ERP Preliminary Investigation

2021 ◽  
Vol 15 ◽  
Author(s):  
Alicja Anna Binkowska ◽  
Natalia Jakubowska ◽  
Maciej Gaca ◽  
Natalia Galant ◽  
Agnieszka Piotrowska-Cyplik ◽  
...  
Keyword(s):  
Episodic Memory ◽  
Receiver Operating Characteristic ◽  
Operating Characteristic ◽  
Memory Performance ◽  
Visual Learning ◽  
Linear Regression Analysis ◽  
Memory Task ◽  
Event Related Potentials ◽  
Related Potentials ◽  
Receiver Operating

Background While research has consistently identified an association between long-term cannabis use and memory impairments, few studies have examined this relationship in a polydrug context (i.e., when combining cannabis with other substances).Aims: In this preliminary study, we used event-related potentials to examine the recognition process in a visual episodic memory task in cannabis users (CU) and cannabis polydrug users (PU). We hypothesized that CU and PU will have both–behavioral and psychophysiological–indicators of memory processes affected, compared to matched non-using controls with the PU expressing more severe changes.Methods 29 non-using controls (CG), 24 CU and 27 PU were enrolled into the study. All participants completed a visual learning recognition task while brain electrical activity was recorded. Event-related potentials were calculated for familiar (old) and new images from a signal recorded during a subsequent recognition test. We used receiver operating characteristic curves for behavioral data analysis.Results The groups did not differ in memory performance based on receiver operating characteristic method in accuracy and discriminability indicators nor mean reaction times for old/new images. The frontal old/new effect expected from prior research was observed for all participants, while a parietal old/new effect was not observed. While, the significant differences in the late parietal component (LPC) amplitude was observed between CG and PU but not between CG and CU nor CU and PU. Linear regression analysis was used to examine the mean amplitude of the LPC component as a predictor of memory performance accuracy indicator. LPC amplitude predicts recognition accuracy only in the CG.Conclusion The results showed alterations in recognition memory processing in CU and PU groups compared to CG, which were not manifested on the behavioral level, and were the most prominent in cannabis polydrug users. We interpret it as a manifestation of the cumulative effect of multiple drug usage in the PU group.

Neural Biases to Covert and Overt Signals of Fear: Dissociation by Trait Anxiety and Depression

2007 ◽  
Vol 19 (10) ◽  
pp. 1595-1608 ◽  
Author(s):  
Leanne M. Williams ◽  
Andrew H. Kemp ◽  
Kim Felmingham ◽  
Belinda J. Liddell ◽  
Donna M. Palmer ◽  
...  
Keyword(s):  
Trait Anxiety ◽  
Time Course ◽  
Event Related Potentials ◽  
Anxiety And Depression ◽  
Controlled Processing ◽  
Parallel Networks ◽  
Related Potentials ◽  
Conscious Attention ◽  
The Impact ◽  
Emotion Encoding

Although biases toward signals of fear may be an evolutionary adaptation necessary for survival, heightened biases may be maladaptive and associated with anxiety or depression. In this study, event-related potentials (ERPs) were used to examine the time course of neural responses to facial fear stimuli (versus neutral) presented overtly (for 500 msec with conscious attention) and covertly (for 10 msec with immediate masking to preclude conscious awareness) in 257 nonclinical subjects. We also examined the impact of trait anxiety and depression, assessed using psychometric ratings, on the time course of ERPs. In the total subject group, controlled biases to overtly processed fear were reflected in an enhancement of ERPs associated with structural encoding (120–220 msec) and sustained evaluation persisting from 250 msec and beyond, following a temporo-occipital to frontal topography. By contrast, covert fear processing elicited automatic biases, reflected in an enhancement of ERPs prior to structural encoding (80–180 msec) and again in the period associated with automatic orienting and emotion encoding (230–330 msec), which followed the reverse frontal to temporo-occipital topography. Higher levels of trait anxiety (in the clinical range) were distinguished by a heightened bias to covert fear (speeding of early ERPs), compared to higher depression which was associated with an opposing bias to overt fear (slowing of later ERPs). Anxiety also heightened early responses to covert fear, and depression to overt fear, with subsequent deficits in emotion encoding in each case. These findings are consistent with neural biases to signals of fear which operate automatically and during controlled processing, feasibly supported by parallel networks. Heightened automatic biases in anxiety may contribute to a cycle of hypervigilance and anxious thoughts, whereas depression may represent a “burnt out” emotional state in which evaluation of fear stimuli is prolonged only when conscious attention is allocated.

scholarly journals Egocentric Navigation Abilities Predict Episodic Memory Performance

2020 ◽  
Vol 14 ◽  
Author(s):  
Giorgia Committeri ◽  
Agustina Fragueiro ◽  
Maria Maddalena Campanile ◽  
Marco Lagatta ◽  
Ford Burles ◽  
...  
Keyword(s):  
Episodic Memory ◽  
Semantic Memory ◽  
Path Integration ◽  
Medial Temporal Lobe ◽  
Declarative Memory ◽  
Memory Performance ◽  
Memory Task ◽  
Recognition Task ◽  
Future Research ◽  
Egocentric Navigation

The medial temporal lobe supports both navigation and declarative memory. On this basis, a theory of phylogenetic continuity has been proposed according to which episodic and semantic memories have evolved from egocentric (e.g., path integration) and allocentric (e.g., map-based) navigation in the physical world, respectively. Here, we explored the behavioral significance of this neurophysiological model by investigating the relationship between the performance of healthy individuals on a path integration and an episodic memory task. We investigated the path integration performance through a proprioceptive Triangle Completion Task and assessed episodic memory through a picture recognition task. We evaluated the specificity of the association between performance in these two tasks by including in the study design a verbal semantic memory task. We also controlled for the effect of attention and working memory and tested the robustness of the results by including alternative versions of the path integration and semantic memory tasks. We found a significant positive correlation between the performance on the path integration the episodic, but not semantic, memory tasks. This pattern of correlation was not explained by general cognitive abilities and persisted also when considering a visual path integration task and a non-verbal semantic memory task. Importantly, a cross-validation analysis showed that participants' egocentric navigation abilities reliably predicted episodic memory performance. Altogether, our findings support the hypothesis of a phylogenetic continuity between egocentric navigation and episodic memory and pave the way for future research on the potential causal role of egocentric navigation on multiple forms of episodic memory.

Event-related potentials in drug-naive schizophrenic patients

1991 ◽  
Vol 29 (3) ◽  
pp. 265-272 ◽  
Author(s):  
Marguirite Radwan ◽  
Haggai Hermesh ◽  
Matti Mintz ◽  
Hanan Munitz
Keyword(s):  
Event Related Potentials ◽  
Schizophrenic Patients ◽  
Related Potentials ◽  
Drug Naïve

scholarly journals A Neurophysiological Study of Semantic Processing in Parkinson’s Disease

2016 ◽  
Vol 23 (1) ◽  
pp. 78-89 ◽  
Author(s):  
Anthony J. Angwin ◽  
Nadeeka N.W. Dissanayaka ◽  
Alison Moorcroft ◽  
Katie L. McMahon ◽  
Peter A. Silburn ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Semantic Processing ◽  
Time Course ◽  
Event Related Potentials ◽  
Mean Amplitude ◽  
Repetition Effects ◽  
Related Potentials ◽  
The Mean ◽  
Written Word

AbstractObjectives: Cognitive-linguistic impairments in Parkinson’s disease (PD) have been well documented; however, few studies have explored the neurophysiological underpinnings of semantic deficits in PD. This study investigated semantic function in PD using event-related potentials. Methods: Eighteen people with PD and 18 healthy controls performed a semantic judgement task on written word pairs that were either congruent or incongruent. Results: The mean amplitude of the N400 for new incongruent word pairs was similar for both groups, however the onset latency was delayed in the PD group. Further analysis of the data revealed that both groups demonstrated attenuation of the N400 for repeated incongruent trials, as well as attenuation of the P600 component for repeated congruent trials. Conclusions: The presence of N400 congruity and N400 repetition effects in the PD group suggests that semantic processing is generally intact, but with a slower time course as evidenced by the delayed N400. Additional research will be required to determine whether N400 and P600 repetition effects are sensitive to further cognitive decline in PD. (JINS, 2017, 23, 78–89)

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