Lack of awareness of neuropsychological deficit in cerebral small vessel disease: The relationship with executive and episodic memory functions

A common cause of neuropsychological impairment in older adults is cerebral small vessel disease (SVD), but little is known as to whether lack of awareness of neuropsychological impairment is a feature of this clinical condition. In this study, we investigated awareness deficits in a well‐phenotyped population of patients with SVD (n= 45; 21 with defined concomitant neuropsychological impairment) and made comparisons with 24 Alzheimer's disease (AD) patients and a further 80 control participants. Awareness of performance on a range of neuropsychological measures was examined based on the Brief Memory and Executive Test Battery (BMET) (Brookes, Hannesdottir, Lawrence, Morris, & Markus, 2012 ), exploring the relationship between awareness and memory and executive function. The results revealed significant awareness deficits in both the SVD and AD groups. When splitting the SVD group into those with or without concomitant neuropsychological impairment, only those with neuropsychological impairment showed reduced awareness. For the SVD group, executive function was significantly correlated with awareness but memory was not. By comparison, memory was significantly correlated with awareness in the AD group, with executive function showing a trend but remaining non‐significant. The results show that lack of awareness of deficit is a clinical feature of SVD and indicate that there are distinct neuropsychological associations with awareness deficit for SVD and AD.     

Neuropsychological subgroups of adolescents with conduct disorder

Närhi, V., Lehto‐Salo, P., Ahonen, T. & Marttunen, M. (2010). Neuropsychological subgroups of adolescents with conduct disorder. Scandinavian Journal of Psychology, 51, 278–284. In group‐level studies adolescents with conduct disorder (CD) have been found to have deficiencies in verbal and executive functions. Teichner and Golden (2000) addressed the neuropsychological heterogeneity of CD, and hypothesized the existence of six neuropsychologically different subgroups. We used that theoretical basis to identify subgroups among 77 adolescents with CD and 48 controls. Among subjects with CD we identified subjects with no, diffuse, verbal and executive function deficits, but none with specific memory or visuo‐spatial deficits. In total, neuropsychological deficits altogether were more common among subjects with CD relative to controls, as were specific verbal deficits. Subgroups did not differ in gender distribution, comorbidity of psychiatric disorders, type or severity of CD, or number of psychosocial risk factors. Among subjects with CD, learning disabilities were common. CD is neuropsychologically a heterogeneous disorder, and neuropsychological deficits should be taken into account in assessing and planning interventions for adolescents with CD.     

Neuropsychological function and memory suppression in conversion disorder

Conversion disorder (CD) is a condition where neurological symptoms, such as weakness or sensory disturbance, are unexplained by neurological disease and are presumed to be of psychological origin. Contemporary theories of the disorder generally propose dysfunctional frontal control of the motor or sensory systems. Classical (Freudian) psychodynamic theory holds that the memory of stressful life events is repressed. Little is known about the frontal (executive) function of these patients, or indeed their general neuropsychological profile, and psychodynamic theories have been largely untested. This study aimed to investigate neuropsychological functioning in patients with CD, focusing on executive and memory function. A directed forgetting task (DFT) using words with variable emotional valence was also used to investigate memory suppression. 21 patients and 36 healthy controls completed a battery of neuropsychological tests and patients had deficits in executive function and auditory‐verbal (but not autobiographical) memory. The executive deficits were largely driven by differences in IQ, anxiety and mood between the groups. A subgroup of 11 patients and 28 controls completed the DFT and whilst patients recalled fewer words overall than controls, there were no significant effects of directed forgetting or valence. This study provides some limited support for deficits in executive, and to a lesser degree, memory function in patients with CD, but did not find evidence of altered memory suppression to support the psychodynamic theory of repression.     

The role of white matter hyperintensities and medial temporal lobe atrophy in age-related executive dysfunctioning

Various studies support an association between white matter hyperintensities (WMH) and deficits in executive function in nondemented ageing. Studies examining executive functions and WMH have generally adopted executive function as a phrase including various functions such as flexibility, inhibition, and working memory. However, these functions include distinctive cognitive processes and not all may be affected as a result of WMH. Furthermore, atrophy of the medial temporal lobe (MTA) is frequently observed in ageing. Nevertheless, in previous studies of nondemented ageing MTA was not considered when examining a relationship between white matter and executive function. The goal of the present study was to examine how WMH and MTA relate to a variety of executive functions, including flexibility, fluency, inhibition, planning, set shifting, and working memory. Strong correlations were observed between WMH and MTA and most of the executive functions. However, only MTA was related to flexibility and set shifting performance. Regression analysis furthermore showed that MTA was the strongest predictor of working memory, after which no further significant association with WMH was noted. Alternatively, both MTA and periventricular hyperintensities independently predicted inhibition performance. These findings emphasize the importance of MTA when examining age-related decline in executive functioning.     

Can Constructive Thinking Predict Decision Making?

We assume that executive function constitutes an integrated set of cognitive processes that mediate working memory, planning, inhibition, flexibility, and decision making. Despite the acknowledged theoretical connection between executive function processes and emotional intelligence, such relationships have rarely been investigated. The purpose of this study was to examine the potential relationship between constructive thinking, conceived as a component of emotional intelligence, and executive function, as indexed by various existing neuropsychological and experimental instruments. We used the Constructive Thinking Inventory as a measure of emotional intelligence. We found that some constructive thinking subscales were able to predict distinct executive function variables. Emotional Coping, Categorical Thinking, and Esoteric Thinking subscales explained performance on various measures of executive function. Thus, we conclude that intervention programs designed to train a specific component of emotional intelligence, namely constructive thinking, could also facilitate performance in executive function processes, and vice versa. Copyright © 2011 John Wiley & Sons, Ltd.     

Neuropsychological profile in patients with schizotypal personality disorder or schizophrenia

Neuropsychological impairments have been consistently reported in patients with schizophrenia. As little is known whether subjects with schizotypal personality disorder exhibit neurocognitive dysfunction similar to that in schizophrenia, we assessed the neuropsychological profile of 15 subjects with schizotypal personality disorder and compared it with that for 15 patients with schizophrenia and for 15 psychiatrically normal volunteers. All participants were administered a standard neuropsychological battery assessing language ability, spatial ability, visuomotor function, verbal memory, visual memory, auditory attention, visual attention, and executive function. Performance on most of the cognitive domains was impaired in patients with schizotypal personality disorder but less than patients with schizophrenia. Specifically, impairment in verbal memory and visuomotor ability in patients with schizotypal personality disorder and patients with schizophrenia were comparable, while patients with schizophrenia performed worse on the test of executive function than did patients with schizotypal personality disorder. As a whole, cognitive deficits in patients with schizotypal personality disorder were qualitatively similar to, but quantitatively milder than, those for patients with schizophrenia. The results suggest that cognitive abilities related to frontotemporal lobe function are disturbed across these schizophrenia-spectrum disorders.     

执行功能与精神分裂症

执行功能障碍是精神分裂症最重要的认知功能障碍,与精神分裂症其它方面的障碍有着密不可分的关系。文章在相关的认知神经心理学和临床研究的基础上,分别综述了精神分裂症执行功能障碍的特点、研究方法、相关脑机制,执行功能与注意、记忆等一般认知功能间的关系,执行功能与精神症状间的联系及其在诊断、康复、判断预后方面的作用等。对精神分裂症执行功能障碍的认识有助于更深入地理解其病因机制,并有利于临床评价与防治     

Neuropsychological findings of extrapontine myelinolysis without central pontine myelinolysis

Central pontine myelinolysis (CPM) and extrapontine myelinolysis (EPM) are well recognized syndromes related to the rapid correction of hyponatremia, which are reported to show brain stem signs and various movement disorders. Cognitive dysfunction and neuropsychological findings, however, have seldom been reported. Cognitive manifestations in osmotic myelinolysis may have been underestimated due to the prominent brain stem symptoms and movement disorders. We report a case of EPM without CPM and describe the neuropsychological findings of EPM. The absence of CPM in this case made it possible to test neuropsychological function in the acute stage. Neuropsychological testing showed severe impairment of attention, verbal and visual memory, visuospatial function, and frontal/executive function. Language and language-related functions were normal except naming.     

From executive control to self‐control: predicting problem drinking among college students

This study tested whether individual differences in executive control can be used to predict problem drinking among college students. Performance on tests of executive control functions was contrasted in two groups of students. The groups were defined by how often they experienced negative consequences of drinking. The executive control measures included both objective and self‐report measures from neuropsychological batteries, and a novel measure of working memory scanning that allowed us to test performance on theoretically dissociable executive functions. The students who experienced high levels of negative consequences of drinking made fast decisions, but they displayed high levels of interference from prepotent responses. In addition, the self‐report measure of executive function was a very strong predictor of group membership. Copyright © 2006 John Wiley & Sons, Ltd.     

Cognitive Remediation as an Adjunct Treatment for Substance Use Disorders: A Systematic Review

Neuropsychology Review - Substance use disorders are associated with diverse neuropsychological impairments, with deficits in memory and executive functioning commonly observed. Cognitive...     

Neurocognitive correlates of stereotactic thalamotomy and thalamic stimulation in Parkinsonian patients

In the present paper we have reviewed five different studies that relate to neuropsychological consequences of stereotactic thalamotomy and thalamic stimulation in patients with Parkinson's disease. The neuropsychological results are in a strict sense confined to thalamotomy and thalamic stimulation, although the more general message of the importance of investigating cognitive functions before and after surgery applies to other stereotactic techniques for surgical treatment of movement disorders as well. It is argued in the paper that stereotactic thalamotomy provides a unique model for basic research on the neuropsychology of the thalamus, while in return, neuropsychological tests for cognitive dysfunction after surgery may be the most important clinical follow-up. Three general conclusions seem warranted from the data. (1) Parkinsonian patients are impaired on a range of cognitive functions, including language processing, memory, and executive functions. (2) Stereotactic thalamotomy does not further impair the patient; instead, we observed improvement on some tests, particularly verbal memory. (3) In general, there does not seem to be a laterality effect, depending on which side the thalamotomy lesion is applied. An exception to this are dichotically presented simple speech sounds and autonomic responses. In both instances, left-sided brain stimulation produced enhanced performance, while lesioning the left thalamus impaired dichotic listening performance. Finally, we present a new hypothesis for a mechanism behind the thalamotomy effect, based in part on changes in arousal thresholds.     

The involvement of executive functions in prospective memory performance of adults

The present study examines the relationship between prospective memory performance and executive functioning. The four phases of the prospective memory process—intention formation, intention retention, reinstantiation of the intention, and intention execution—are assumed to require different amounts of executive processing, most of which is demanded in the phases of intention formation and intention execution. At present, though, it is still unclear whether, and to what extent, prefrontal executive systems are involved in different kinds of prospective memory tasks, as some findings suggest that prospective memory might rather rely on nonstrategic processes that are unlikely to depend on prefrontal executive systems. Therefore, this study focuses on the following questions: (1) to what degree does executive functioning predict prospective memory performance in different standard prospective memory tasks and, furthermore, are certain executive measures better predictors than others; (2) are age‐related effects in different prospective memory measures due to individual differences in executive functioning; and (3) do age‐related differences in prospective memory exist that are not explained by individual differences in executive functioning. In a sample of 80 adults (20‐80 years), we applied four instruments to measure prospective memory: a traditional single‐task paradigm, two more complex tasks—one time‐based and one event‐based—and a highly complex multi‐task paradigm. We further assessed a broadly defined construct of executive functioning using several standard neuropsychological tests. Results showed that executive functioning did not predict performance in the simple single‐task paradigm. However, executive functioning, but not age, predicted performance in the two more complex standard tests of prospective remembering, and both executive functioning and age predicted performance in the most complex paradigm. In sum, the obtained data underline the assumption that frontal/ executive functions are related to prospective memory performance across a range of prospective paradigms. It also seems clear that age differences in prospective memory performance partially depend on age‐related individual differences in frontal/executive functions.     

工作记忆刷新及其训练效应——经颅直流电刺激的作用

工作记忆刷新是执行功能的重要成分之一。以往研究结合n-back任务和经颅直流电刺激（transcranial direct current stimulation ,tDCS）技术探究刷新能力,发现tDCS技术能够一定程度上增强刷新训练效果并引起大脑神经元相关活动的变化,其增强效果能够维持一定的时间,且能够迁移到其他认知任务之中。但tDCS的干预效果在各项研究中存在一定的差异性。其作用效果会受到训练任务与训练方式、电流强度、电极布局和训练时间间隔等因素的影响。未来研究可以探索tDCS结合刷新训练的最佳刺激参数,以获得最优化的干预效果。     

Extinction memory improvement by the metabolic enhancer methylene blue

We investigated whether postextinction administration of methylene blue (MB) could enhance retention of an extinguished conditioned response. MB is a redox compound that at low doses elevates cytochrome oxidase activity, thereby improving brain energy production. Saline or MB (4 mg/kg intraperitoneally) were administered to rats for 5 d following extinction training of tone-footshock conditioning. Postextinction freezing was lower in rats receiving MB compared with saline, suggesting that MB improved retention of the extinction memory. The MB effect was specific to tone-evoked freezing because there were no differences in pretone freezing. Control subjects similarly injected with MB showed no evidence of nonspecific effects on measures of motor activity and fearfulness. MB-treated rats exhibited both greater retention of extinction and greater overall brain metabolic activity. Rats with higher retention of extinction also showed a relative increase in cytochrome oxidase activity in prefrontal cortical regions, especially anterior infralimbic cortex, dorsal and medial frontal cortex, and lateral orbital cortex. These regional metabolic increases were also correlated to the behavioral freezing index used to assess retention of extinction. It was concluded that MB administered postextinction could enhance retention of extinction memory through an increase in brain cytochrome oxidase activity.     

Neurocognitive ageing of storage and executive processes

Converging behavioural and neuropsychological evidence indicates that age-related changes in working memory contribute substantially to cognitive decline in older adults. Important questions remain about the relationship between working memory storage and executive components and how they are affected by the normal ageing process. In several studies using positron emission tomography (PET), we find age differences in the patterns of frontal activation during working memory tasks. We find that separable age differences can be linked to different cognitive operations underlying short-term information storage, and interference resolution. Some operations are associated with age-related increases in activation, with older adults displaying bilateral activations and recruiting prefrontal areas more than younger adults. Other operations are associated with age-related decreases in activation. We consider the implications of these results for understanding the working memory system and potential compensatory processes in the ageing brain.     

Short theta burst stimulation to left frontal cortex prior to encoding enhances subsequent recognition memory

Deep semantic encoding of verbal stimuli can aid in later successful retrieval of those stimuli from long-term episodic memory. Evidence from numerous neuropsychological and neuroimaging experiments demonstrate regions in left prefrontal cortex, including left dorsolateral prefrontal cortex (DLPFC), are important for processes related to encoding. Here, we investigated the relationship between left DLPFC activity during encoding and successful subsequent memory with transcranial magnetic stimulation (TMS). In a pair of experiments using a 2-session within-subjects design, we stimulated either left DLPFC or a control region (Vertex) with a single 2-s train of short theta burst stimulation (sTBS) during a semantic encoding task and then gave participants a recognition memory test. We found that subsequent memory was enhanced on the day left DLPFC was stimulated, relative to the day Vertex was stimulated, and that DLPFC stimulation also increased participants’ confidence in their decisions during the recognition task. We also explored the time course of how long the effects of sTBS persisted. Our data suggest 2 s of sTBS to left DLPFC is capable of enhancing subsequent memory for items encoded up to 15 s following stimulation. Collectively, these data demonstrate sTBS is capable of enhancing long-term memory and provide evidence that TBS protocols are a potentially powerful tool for modulating cognitive function.     

Episodic memory effects of gamma frequency precuneus transcranial magnetic stimulation in Alzheimer's disease: A randomized multiple baseline study

Episodic memory decline is the prominent neuropsychological feature of typical Alzheimer's Disease (AD), for which current treatments have a limited clinical response. Recently, gamma entrainment therapy has been used as a non-invasive treatment in AD, providing evidence that it may have the potential to alleviate brain pathology and improve cognitive function in AD patients. At the same time, the precuneus (PC) has been recognized as a key area involved in AD related memory deficits and as a key node of the Default Mode Network. This study aimed to investigate the effectiveness of a 40 Hz Transcranial Magnetic Stimulation (TMS) intervention, delivered bilaterally to the precuneus for 10 days, in improving the patients' episodic memory performance. Secondary outcome variables investigated included general cognitive function, semantic and spatial memory, as well as attention and executive function. A concurrent multiple baseline design across five cases was employed. Four patients completed the study. Visual analysis combined with effect size indices were used to evaluate changes across phases. An increase in the average level of immediate recalled words was observed in three out of four patients. Effect size indices indicated significant improvement of attention skills in two patients. No treatment effect was observed for semantic and visual memory, or for executive function. An immediate treatment effect was observed in all patients' general cognitive function as assessed with the Alzheimer's Disease Assessment Scale (mean reduction of 5 points), which was maintained and improved further three months post-treatment. The neuropsychological evaluations indicated improved performance three months post-treatment in immediate and delayed recall, attention, phonological verbal fluency, anxiety, and neuropsychiatric symptoms. This study provides preliminary evidence for the efficacy of a novel non-pharmacological treatment using gamma-band TMS in addressing cognitive dysfunction in AD.     

Psychogenic amnesia – A malady of the constricted self

Autobiographical–episodic memory is the conjunction of subjective time, autonoetic consciousness and the experiencing self. Understanding the neural correlates of autobiographical–episodic memory might therefore be essential for shedding light on the neurobiology underlying the experience of being an autonoetic self. In this contribution we illustrate the intimate relationship between autobiographical–episodic memory and self by reviewing the clinical and neuropsychological features and brain functional imaging correlates of psychogenic amnesia – a condition that is usually characterized by severely impaired retrograde memory functioning, in absence of structural brain damage as detected by standard imaging. We demonstrate that in this disorder the autobiographical–episodic memory deficits do not exist in isolation, but occur with impairments of the autonoetic self-consciousness, emotional processing, and theory of mind or executive functions. Furthermore functional and metabolic brain alterations involving regions that are agreed upon to exert crucial roles in memory processes were frequently found to accompany the psychogenic memory “loss”.     

Neuropsychological Differences Between Frontotemporal Dementia and Alzheimer's Disease: A Review

This paper surveys the similarities and differences between frontotemporal dementia (FTD) and Alzheimer's disease (AD). The review covers findings primarily from neuropsychological studies on memory, language, attention/executive function, and visuospatial abilities. However, neuropsychiatric and neuroimaging data are also briefly discussed. Distinguishing features of both FTD and AD are described in order to present a comprehensive clinical picture of these dementing diseases, which is essential for the process of differential diagnosis. The cause of specific cognitive deficits is also considered. Our comprehensive review of the empirical literature reveals that AD is characterized by early memory loss and visuospatial problems, while among the main features of FTD are behavioral abnormalities and executive dysfunctions.     

Improving executive functions in 5‐ and 6‐year‐olds: Evaluation of a small group intervention in prekindergarten and kindergarten children

Research suggests a central role of executive functions for children's cognitive and social development during preschool years, especially in promoting school readiness. Interventions aiming to improve executive functions are therefore being called for. The present study examined the effect of a small group intervention implemented in kindergarten settings focusing on basic components of executive functions, i.e., working memory, interference control and cognitive flexibility. A total of 135 children enrolled in Swiss prekindergarten (5‐year‐olds) and kindergarten (6‐year‐olds) were involved. Results revealed that the small group intervention promoted gains in all three included components of executive functions: prekindergarten children substantially improved their working memory and cognitive flexibility processes, whereas significant training effects were found for the kindergarten children in interference control. Implications of these findings for early intervention programs and for tailoring preschool curricula are discussed, particularly with respect to children's school readiness. Copyright © 2011 John Wiley & Sons, Ltd.