Dysfunction of a distributed neural circuitry in schizophrenia patients during a working-memory performance

2005 ◽  
Vol 35 (2) ◽  
pp. 187-196 ◽  
Author(s):  
A. MENDREK ◽  
K. A. KIEHL ◽  
A. M. SMITH ◽  
D. IRWIN ◽  
B. B. FORSTER ◽  
...  

Background. In a recent longitudinal study of first-episode schizophrenia patients, we found that while dysfunction of the right dorsolateral prefrontal cortex (DLPFC), right thalamus, left cerebellum and cingulate gyrus normalized with antipsychotic treatment and significant reduction in symptomatology, the left DLPFC, left thalamus, and right cerebellum remained disturbed. In the present study we investigated whether these abnormalities are also present in clinically stable, relatively well-functioning schizophrenia patients in comparison to control subjects during performance of the N-back working-memory task.Method. Twelve schizophrenia and 12 control subjects completed the study. The functional images collected during scanning were analyzed using a random-effects model in a restricted set of six regions of interest (ROIs). In addition, the exploratory search in the entire brain volume was performed.Results. The ROI analyses revealed relative underactivation in the region of the left DLPFC and the right cerebellum, as well as overactivation in the left cerebellum. The exploratory whole-brain search exposed additional overactivation in the medial frontal, anterior cingulate, and left parietal cortices.Conclusions. The present study provides evidence of significant underactivations in stable schizophrenia patients in regions that we have previously observed to be dysfunctional in acutely psychotic and partially remitted patients, together with extensive overactivations in several regions that potentially reflect some compensatory mechanism or increased effort on the working-memory task.

2015 ◽  
Vol 30 (2) ◽  
pp. 242-250 ◽  
Author(s):  
S. Ittig ◽  
E. Studerus ◽  
M. Papmeyer ◽  
M. Uttinger ◽  
S. Koranyi ◽  
...  

AbstractBackground:Several sex differences in schizophrenia have been reported including differences in cognitive functioning. Studies with schizophrenia patients and healthy controls (HC) indicate that the sex advantage for women in verbal domains is also present in schizophrenia patients. However, findings have been inconsistent. No study focused on sex-related cognitive performance differences in at-risk mental state for psychosis (ARMS) individuals yet. Thus, the aim of the present study was to investigate sex differences in cognitive functioning in ARMS, first episode psychosis (FEP) and HC subjects. We expected a better verbal learning and memory performance of women in all groups.Methods:The neuropsychological data analysed in this study were collected within the prospective Früherkennung von Psychosen (FePsy) study. In total, 118 ARMS, 88 FEP individuals and 86 HC completed a cognitive test battery covering the domains of executive functions, attention, working memory, verbal learning and memory, IQ and speed of processing.Results:Women performed better in verbal learning and memory regardless of diagnostic group. By contrast, men as compared to women showed a shorter reaction time during the working memory task across all groups.Conclusion:The results provide evidence that women generally perform better in verbal learning and memory, independent of diagnostic group (ARMS, FEP, HC). The finding of a shorter reaction time for men in the working memory task could indicate that men have a superior working memory performance since they responded faster during the target trials, while maintaining a comparable overall working memory performance level.


2005 ◽  
Vol 17 (7) ◽  
pp. 1026-1042 ◽  
Author(s):  
Agatha Lenartowicz ◽  
Anthony R. McIntosh

The anterior cingulate (AC) cortex seems to be similarly engaged by attentional and memory processes. We tested the hypothesis that this common activation is best explained by changes in the regions interacting (functionally connected) with AC. Subjects were tested on two variants of a 2-back working memory task: a standard version with strong attentional demands, and a cued version that more strongly promoted memory retrieval. AC activation, measured with functional MRI, was found in both tasks, although more sustained in the standard condition. The regions functionally connected to the AC, and the relation of these activity patterns to memory performance, were completely different across tasks. In the standard task, the pattern related to a speed-accuracy tradeoff, whereas the connectivity pattern unique to the cued task related only to better accuracy. By virtue of these changing patterns of functional connectivity, the contribution of AC to attention-and memory-driven performance was similarly changed.


2021 ◽  
Vol 11 (10) ◽  
pp. 1358
Author(s):  
Xue Guo ◽  
Ziyuan Li ◽  
Liangyou Zhang ◽  
Qiang Liu

Previous studies have found that transcranial alternating current stimulation (tACS) can significantly enhance individuals’ working memory performance. However, it is still unclear whether the memory performance enhancement was attributed to the quantity or the quality of working memory. The current study applies tACS over the right parietal cortex at slower (4 Hz) and faster (7 Hz) frequencies to participants with high and low working memory capacities in a color recall memory task. This enabled us to explore the tACS effects on the quantity and quality of the working memory for individuals with different memory capacities. The results revealed that slower frequency (4 Hz) tACS enhanced the quality of memory representations, and faster frequency (7 Hz) tACS principally impaired the quantity of working memory. The underlying mechanism of this effect might be that tACS at different frequencies modulate the memory resources, which then selectively affect the quantity and quality of memory representations. Importantly, individual traits, as well as memory strategies, may be crucial factors to consider when testing the effect of tACS on working memory performance.


2011 ◽  
Vol 26 (S2) ◽  
pp. 938-938
Author(s):  
K. Langbein ◽  
M. Dietzek ◽  
G. Mingoia ◽  
R. Maitra ◽  
M. Weisbrod ◽  
...  

IntroductionWorking memory deficits are considered a core feature of disturbed cognition in schizophrenia. Recent neuropsychological studies in twins suggest that there are shared genetic factors between schizophrenia and executive processes.AimWe used a co-twin control design to test the hypothesis that prefrontal activation during a working memory task is seen both in affected as well as unaffected twins discordant for schizophrenia, thus reflecting genetic load on this putative endophenotype.MethodsAs part of EUTwinsS, a multi-centre collaborative study on twins with schizophrenia, we obtained functional MRI scans during a Sternberg working memory task (with one maintenance and one manipulation variations) of twins discordant for schizophrenia (5 monozygotic pairs, 7 dizygotic pairs) and compared them to 10/4 healthy MZ/DZ twins, matched for age and gender.ResultsComparing the overall task-related effects (p < 0.001, uncorrected), we found stronger activation in control twins compared to either Sz-affected or unaffected twins in the right middle frontal gyrus and medial fronto-orbital cortex, and compared to Sz-affected twins also in the left cerebellum and right inferior occipital cortex. Comparing the manipulation vs. maintenance trials, healthy controls showed stronger activation than Sz-affected twins in the left hippocampus, but smaller in right caudate and anterior cingulate, while unaffected co-twins showed diminished right middle and left superior and middle frontal gyri compared to either group.ConclusionsWhile diminished prefrontal activation in unaffected co-twins might indicate compensatory processes during executive control, the overall activation deficits are consistent with a genetic effect on prefrontal cortical efficiency.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Ting Sun ◽  
Pengfei Zhao ◽  
Xiaowei Jiang ◽  
Yifang Zhou ◽  
Chao Li ◽  
...  

Background. Cognitive impairments are documented in schizophrenia (SZ) and bipolar disorder (BD) and may be related to gray matter volumes (GMVs). Thus, this study is aimed at exploring whether the association between cognitive impairments and GMV alterations is similar in patients with SZ and BD and understanding the underlying neurobiological mechanisms. Methods. A total of 137 adult subjects (46 with SZ, 35 with BD, and 56 age-, sex-, and education-matched healthy controls (HC)) completed the MATRICS Consensus Cognitive Battery (MCCB) and structural magnetic resonance imaging scanning. We performed group comparisons of the cognitive impairments, the GMV alterations, and the association between them. Results. Compared with HC, the patients with SZ and BD showed shared deficits in 4 cognitive domains (i.e., processing speed, working memory, problem solving, and social cognition) and the composite. SZ and BD had commonly decreased GMVs, mainly in the insula, superior temporal pole, amygdala, anterior cingulate, and frontal cortices (superior, middle, opercular inferior, and orbital frontal gyrus). No correlation between MCCB scores and GMVs was detected in SZ. However, for BD, working memory was relevant to the right hemisphere (i.e., right insula, amygdala, superior temporal pole, and medial and dorsolateral superior frontal gyrus). Limitations. The major limitations were that not all patients were the first-episode status and no medication. Conclusions. The association was mainly limited to the BD group. Thus, the underlying pathophysiology of the cognitive deficits, in terms of GMV alterations, may be diverse between two disorders.


2018 ◽  
Author(s):  
Anthony Paul Zanesco ◽  
Ekaterina Denkova ◽  
Scott L. Rogers ◽  
William K. MacNulty ◽  
Amishi P. Jha

Cognitive ability is a key selection criterion for entry into many elite professions. Herein, we investigate whether mindfulness training (MT) can enhance cognitive performance in elite military forces. The cognitive effects of a short-form 8-hour MT program contextualized for military cohorts, referred to as Mindfulness-Based Attention Training (MBAT), were assessed. Servicemembers received either a 2-week (n = 40) or 4-week (n = 36) version of MBAT, or no training (NTC, n = 44). Sustained attention and working memory task performance along with self-reported cognitive failures were assessed at study onset (T1) and 8-weeks later (T2). In contrast to both the NTC and 2-week MT groups, the 4-week MT group significantly improved over time on attention and working memory outcome measures. Among the 4-week more so than the 2-week MBAT participants, working memory performance improvements were correlated with their amount of out-of-class MT practice. In addition to these group-wise effects, all participants receiving MBAT decreased in their self-reported cognitive failures from T1 to T2. Importantly, none of these improvements were related to self-reported task motivation. Together, these results suggest that short-form MT, when delivered over a 4-week delivery schedule, may be an effective cognitive training tool in elite military cohorts.


2021 ◽  
Vol 11 (7) ◽  
pp. 935
Author(s):  
Ying Xing Feng ◽  
Masashi Kiguchi ◽  
Wei Chun Ung ◽  
Sarat Chandra Dass ◽  
Ahmad Fadzil Mohd Hani ◽  
...  

The effect of stress on task performance is complex, too much or too little stress negatively affects performance and there exists an optimal level of stress to drive optimal performance. Task difficulty and external affective factors are distinct stressors that impact cognitive performance. Neuroimaging studies showed that mood affects working memory performance and the correlates are changes in haemodynamic activity in the prefrontal cortex (PFC). We investigate the interactive effects of affective states and working memory load (WML) on working memory task performance and haemodynamic activity using functional near-infrared spectroscopy (fNIRS) neuroimaging on the PFC of healthy participants. We seek to understand if haemodynamic responses could tell apart workload-related stress from situational stress arising from external affective distraction. We found that the haemodynamic changes towards affective stressor- and workload-related stress were more dominant in the medial and lateral PFC, respectively. Our study reveals distinct affective state-dependent modulations of haemodynamic activity with increasing WML in n-back tasks, which correlate with decreasing performance. The influence of a negative effect on performance is greater at higher WML, and haemodynamic activity showed evident changes in temporal, and both spatial and strength of activation differently with WML.


Author(s):  
Selma Lugtmeijer ◽  
◽  
Linda Geerligs ◽  
Frank Erik de Leeuw ◽  
Edward H. F. de Haan ◽  
...  

AbstractWorking memory and episodic memory are two different processes, although the nature of their interrelationship is debated. As these processes are predominantly studied in isolation, it is unclear whether they crucially rely on different neural substrates. To obtain more insight in this, 81 adults with sub-acute ischemic stroke and 29 elderly controls were assessed on a visual working memory task, followed by a surprise subsequent memory test for the same stimuli. Multivariate, atlas- and track-based lesion-symptom mapping (LSM) analyses were performed to identify anatomical correlates of visual memory. Behavioral results gave moderate evidence for independence between discriminability in working memory and subsequent memory, and strong evidence for a correlation in response bias on the two tasks in stroke patients. LSM analyses suggested there might be independent regions associated with working memory and episodic memory. Lesions in the right arcuate fasciculus were more strongly associated with discriminability in working memory than in subsequent memory, while lesions in the frontal operculum in the right hemisphere were more strongly associated with criterion setting in subsequent memory. These findings support the view that some processes involved in working memory and episodic memory rely on separate mechanisms, while acknowledging that there might also be shared processes.


2019 ◽  
Vol 50 (13) ◽  
pp. 2182-2193 ◽  
Author(s):  
Kirsten B. Bojesen ◽  
Bjørn H. Ebdrup ◽  
Kasper Jessen ◽  
Anne Sigvard ◽  
Karen Tangmose ◽  
...  

AbstractBackgroundPoor response to dopaminergic antipsychotics constitutes a major challenge in the treatment of psychotic disorders and markers for non-response during first-episode are warranted. Previous studies have found increased levels of glutamate and γ-aminobutyric acid (GABA) in non-responding first-episode patients compared to responders, but it is unknown if non-responders can be identified using reference levels from healthy controls (HCs).MethodsThirty-nine antipsychotic-naïve patients with first-episode psychosis and 36 matched HCs underwent repeated assessments with the Positive and Negative Syndrome Scale and 3T magnetic resonance spectroscopy. Glutamate scaled to total creatine (/Cr) was measured in the anterior cingulate cortex (ACC) and left thalamus, and levels of GABA/Cr were measured in ACC. After 6 weeks, we re-examined 32 patients on aripiprazole monotherapy and 35 HCs, and after 26 weeks we re-examined 30 patients on naturalistic antipsychotic treatment and 32 HCs. The Andreasen criteria defined non-response.ResultsBefore treatment, thalamic glutamate/Cr was higher in the whole group of patients but levels normalized after treatment. ACC levels of glutamate/Cr and GABA/Cr were lower at all assessments and unaffected by treatment. When compared with HCs, non-responders at week 6 (19 patients) and week 26 (16 patients) had higher baseline glutamate/Cr in the thalamus. Moreover, non-responders at 26 weeks had lower baseline GABA/Cr in ACC. Baseline levels in responders and HCs did not differ.ConclusionGlutamatergic and GABAergic abnormalities in antipsychotic-naïve patients appear driven by non-responders to antipsychotic treatment. If replicated, normative reference levels for glutamate and GABA may aid estimation of clinical prognosis in first-episode psychosis patients.


2011 ◽  
Vol 42 (1) ◽  
pp. 29-40 ◽  
Author(s):  
R. Kerestes ◽  
C. D. Ladouceur ◽  
S. Meda ◽  
P. J. Nathan ◽  
H. P. Blumberg ◽  
...  

BackgroundPatients with major depressive disorder (MDD) show deficits in processing of facial emotions that persist beyond recovery and cessation of treatment. Abnormalities in neural areas supporting attentional control and emotion processing in remitted depressed (rMDD) patients suggests that there may be enduring, trait-like abnormalities in key neural circuits at the interface of cognition and emotion, but this issue has not been studied systematically.MethodNineteen euthymic, medication-free rMDD patients (mean age 33.6 years; mean duration of illness 34 months) and 20 age- and gender-matched healthy controls (HC; mean age 35.8 years) performed the Emotional Face N-Back (EFNBACK) task, a working memory task with emotional distracter stimuli. We used blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) to measure neural activity in the dorsolateral (DLPFC) and ventrolateral prefrontal cortex (VLPFC), orbitofrontal cortex (OFC), ventral striatum and amygdala, using a region of interest (ROI) approach in SPM2.ResultsrMDD patients exhibited significantly greater activity relative to HC in the left DLPFC [Brodmann area (BA) 9/46] in response to negative emotional distracters during high working memory load. By contrast, rMDD patients exhibited significantly lower activity in the right DLPFC and left VLPFC compared to HC in response to positive emotional distracters during high working memory load. These effects occurred during accurate task performance.ConclusionsRemitted depressed patients may continue to exhibit attentional biases toward negative emotional information, reflected by greater recruitment of prefrontal regions implicated in attentional control in the context of negative emotional information.


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