Structural MRI Correlates of Episodic Memory Processes in Parkinson's Disease Without Mild Cognitive Impairment.

BackgroundChanges in episodic memory are common early in Parkinson's disease (PD) and may be a risk factor for future cognitive decline. Although medial temporal lobe (MTL) memory and frontostriatal (FS) executive systems are thought to play different roles in distinct components of episodic memory impairment in PD, no study has investigated whether different aspects of memory functioning are differentially associated with MTL and FS volumes in nondemented patients without mild cognitive impairment (PD-woMCI).ObjectivesThe present study investigated MRI markers of different facets of memory functioning in 48 PD-woMCI patients and 42 controls.MethodsRegional volumes were measured in structures comprising the MTL and FS systems and then correlated with key indices of memory from the California Verbal Learning Test.ResultsIn PD-woMCI patients, memory was impaired only for verbal learning, which was not associated with executive, attention/working memory, or visuospatial functioning. Despite an absence of cortical atrophy, smaller right MTL volumes in patients were associated with poorer verbal learning, long delayed free recall, long delayed cued recall, and recognition memory hits and false positives. Smaller right pars triangularis (inferior frontal) volumes were also associated with poorer long delayed cued recall and recognition memory hits. These relationships were not found in controls.ConclusionsThe findings indicate that MTL volumes are sensitive to subtle changes in almost all facets of memory in PD-woMCI, whereas FS volumes are sensitive only to memory performances in cued-testing formats

Visual perception without awareness in a patient with posterior cortical atrophy: impaired explicit but not implicit processing of global information

Journal ArticleA patient with progressive posterior cortical atrophy (PCA) was examined on several tests of visual cognition. The patient displayed multiple visual cognitive deficits, which included problems identifying degraded stimuli, attending to two or more stimuli simultaneously, recognizing faces, tracing simple visual stimuli, matching simple shapes, and copying objects. The patient was also impaired in identifying visual targets contained at the global level within global-local stimuli (i.e., smaller letters that compose a larger letter). Although the patient denied any conscious awareness of the global form, he nevertheless displayed a normal pattern of global interference when asked to identify local level targets. Thus, the patient processed the global information despite not being consciously aware of such information. These results suggest that global-local processing can take place in the absence of awareness. Possible neurocognitive mechanisms explaining this dissociation are discuss

“The True Story of Seven Strangers Picked to Have Their Lives Taped”: Studying Race as Constructed on Reality Television

The present work examines the construction of race on reality television through the use of an exemplar in this genre, MTV's The Real World. By the sheer fact of its popularity and ubiquity, as The Real World is nearly two decades old and is the longest-running example of the genre, reality television programming warrants deeper academic investigation. The present work argues that as we are consuming mass media, we are also consuming specific ideas about our social world. These ideas inform audiences and are necessary to uncover in order to learn about the social structure of our racialized society. Findings reveal race and ethnicity is embedded in our culture and how this show has communicated race through its depiction and even exclusion. Further, findings reveal that racial and ethnic relations are most often depicted as a "Black versus White" issue. The current work focuses specifically on the construction of race because of the similarly ubiquitous nature of race in society. Because The Real World is a long-running series, it provides an ample database from which to sample for a discourse analysis. The show is marketed and viewed by a specific target audience such that it allows for the exploration of one of the research arguments: that we must continue to rethink and challenge our view that mass media audience members, specifically here television, are passive consumers of material. The present work seeks to extend the application of theoretical contributions of Hall, Morley, Ang, and Jenkins by applying models to a type of programming that complicates the vision of media where consumers and producers are identifiably different spheres. The field of reality television programming is unique because of its dependence on viewers to become cast members and participants in the media production process. Finally, as previous research has shown, even in fictional settings viewers have conflated the individual who plays a character and the character the actor is playing. Thus by analyzing issues of race, where the line between real and unreal is purposely blurred the impact of how race is constructed can be quite great

A Comparison of the neural correlates that underlie rule-based and information-integration category learning

The influential Competition between Verbal and Implicit Systems (COVIS) model proposes that category learning is driven by two competing neural systems – an explicit, verbal, system, and a procedural-based, implicit, system. In the current fMRI study, participants learned either a conjunctive, rule-based, category structure that is believed to engage the explicit system, or an information-integration category structure that is thought to preferentially recruit the implicit system. The rule-based and information-integration category structures were matched for participant error rate, the number of relevant stimulus dimensions and category separation. Under these conditions, considerable overlap in brain activation, including the prefrontal cortex, basal ganglia, and the hippocampus, was found between the rule-based and information-integration category structures. Contrary to the predictions of COVIS, the medial temporal lobes and in particular the hippocampus, key regions for explicit memory, were found to be more active in the information-integration condition than in the rule-based condition. No regions were more activated in rule-based than information-integration category learning. The implications of these results for theories of category learning are discussed.The support of a South West Doctoral Training Centre (SWDTC) Economic and Social Research Council (ESRC) Studentship Award (ES/J50015X/1) to the first author is appreciatively acknowledged. We also thank Todd Maddox for supplying the stimuli used in this study and Greg Ashby for his comments on this work. The participation of University of Exeter student volunteers is also greatly appreciated

The Importance of the US Dollar as the Main Reserve Currency in the World

El status del dólar como moneda de reserva mundial ha sido cuestionado desde el abandono del sistema Bretton Woods por parte de los Estados Unidos en 1971 y se ha agudizado con la entrada del Euro en enero de 1999, a grado tal que hubo quienes cuestionaron la hegemonía de la divisa; y más aún si le agregamos el recientemente y dramático ascenso económico de China. Sin embargo, y a pesar de lo anterior, lo cierto es que el intercambio comercial global y el sistema económico mundial, siguen dependiendo en gran medida del USD debido a la confianza que aún guarda esta moneda entre los países miembros del Fondo Monetario Internacional, a pesar de las vicisitudes que ha enfrentado por diversas razones desde la implementación del USD como moneda de cambio. Al día de hoy, es indudable que continúa siendo la moneda global de facto, a pesar de no poseer un título mundial oficial, adicionalmente a que continúa siendo la principal  moneda   de reserva en el   mundo.The status of the dollar as a world reserve currency has been questioned since the abandonment of the Bretton Woods system by the United States in 1971 and has become more acute with the entry of the Euro in January 1999, to such an extent that there were those who questioned its hegemony of the currency; and even more so if we add the recent dramatic economic rise of China. However, and despite the above, the truth is that global trade exchange and the world economic system continue to depend largely on the USD due to the trust that this currency still has among the member countries of the International Monetary Fund, despite of the vicissitudes it has faced for various reasons since the implementation of the USD as an exchange currency. Today, there is no doubt that it continues to be the de facto global currency, despite not having an official world title, in addition to continuing to be the main reserve currency in the world

Aberrant Intrinsic Activity and Connectivity in Cognitively Normal Parkinson’s Disease

Disturbances in intrinsic activity during resting-state functional MRI (rsfMRI) are common in Parkinson’s disease (PD), but have largely been studied in a priori defined subnetworks. The cognitive significance of abnormal intrinsic activity is also poorly understood, as are abnormalities that precede the onset of mild cognitive impairment. To address these limitations, we leveraged three different analytic approaches to identify disturbances in rsfMRI metrics in 31 cognitively normal PD patients (PD-CN) and 30 healthy adults. Subjects were screened for mild cognitive impairment using the Movement Disorders Society Task Force Level II criteria. Whole-brain data-driven analytic approaches first analyzed the amplitude of low-frequency intrinsic fluctuations (ALFF) and regional homogeneity (ReHo), a measure of local connectivity amongst functionally similar regions. We then examined if regional disturbances in these metrics altered functional connectivity with other brain regions. We also investigated if abnormal rsfMRI metrics in PD-CN were related to brain atrophy and executive, visual organization, and episodic memory functioning. The results revealed abnormally increased and decreased ALFF and ReHo in PD-CN patients within the default mode network (posterior cingulate, inferior parietal cortex, parahippocampus, entorhinal cortex), sensorimotor cortex (primary motor, pre/post-central gyrus), basal ganglia (putamen, caudate), and posterior cerebellar lobule VII, which mediates cognition. For default mode network regions, we also observed a compound profile of altered ALFF and ReHo. Most regional disturbances in ALFF and ReHo were associated with strengthened long-range interactions in PD-CN, notably with regions in different networks. Stronger long-range functional connectivity in PD-CN was also partly expanded to connections that were outside the networks of the control group. Abnormally increased activity and functional connectivity appeared to have a pathological, rather than compensatory influence on cognitive abilities tested in this study. Receiver operating curve analyses demonstrated excellent sensitivity (≥90%) of rsfMRI variables in distinguishing patients from controls, but poor accuracy for brain volume and cognitive variables. Altogether these results provide new insights into the topology, cognitive relevance, and sensitivity of aberrant intrinsic activity and connectivity that precedes clinically significant cognitive impairment. Longitudinal studies are needed to determine if these neurocognitive associations presage the development of future mild cognitive impairment or dementia

El dinero, su evolución hasta el siglo XXI

It is indisputable that the digital revolution is underway in every sense. Today cryptocurrencies are on the way to stopping being considered a “trend”, so digital money is seen as a substitute for physical money to carry out commercial and financial transactions. The issuance of money by the Central Banks and its distribution through private banking will no longer be the same. Based on the above, this paper covers the terms currently used to denominate the "bargaining currency" used by various companies and inclusive countries, supporting the research in secondary sources. This paper addresses how digitization will allow, and allow in some cases, Central Banks, banks, and companies outside the financial sector to create digital money. Access, availability, and use will be through electronic devices without the intervention of financial intermediaries. One of its main attributes is consumer acceptance and trust, the same ones that can be affected by these new concepts: digital money and cryptocurrency. The terms used to define them are confusing and can lead to distrust of these new means of payment and even their acceptance.Es indiscutible que la revolución digital está en marcha en todo sentido. Hoy día las criptomonedas están en camino de dejar de ser consideradas “moda” y el dinero digital se vislumbra como el sustituto del dinero físico para realizar transacciones comerciales y financieras. La emisión de dinero por parte de los Bancos Centrales y su distribución a través de la Banca privada ya no será la misma. Con base en lo anterior, el presente trabajo abarca los términos actualmente utilizados para denominar la “moneda de cambio” utilizada por diversas empresas e incluso países, sustentando la investigación en fuentes secundarias. Se mostrará cómo la digitalización permitirá y permite en algunos casos, a Bancos Centrales, bancos, y empresas ajenas al sector financiero crear dinero digital. El acceso, su disposición, y uso será a través de dispositivos electrónicos sin la intervención de intermediarios financieros. Siendo de sus principales atributos la aceptación y confianza del consumidor, mismos que se pueden ver afectados por estos nuevos conceptos: dinero digital y criptomoneda. Los términos que se están utilizando para su definición son confusos y pueden llevar a desconfiar de estos nuevos medios de pago y por tanto a su aceptación

Collectivism Is Associated With Greater Neurocognitive Fluency in Older Adults

Neuropsychological research has been limited in the representation of cultural diversity due to various issues, raising questions regarding the applicability of findings to diverse populations. Nonetheless, culture-dependent differences in fundamental psychological processes have been demonstrated. One of the most basic of these, self-construal (individualism, collectivism), is central to how many other differences are interpreted. Self-construals may have possible consequences on social interactions, emotions, motivation, and cognition. This study aimed to evaluate the impact of self-construal on neurocognitive functions in older adults. A total of 86 community-dwelling older adults 60 years and older were assessed with three common self-report measures of self-construal along individualism and collectivism (IC). A cognitive battery was administered to assess verbal and non-verbal fluency abilities. Latent profile analysis (LPA) was used to categorize individuals according to IC, and one-way analyses of covariance (ANCOVA), including relevant covariates (e.g., ethnicity, gender, linguistic abilities), were used to compare neurocognitive functions between individualists and collectivists. Collectivists outperformed individualists on left frontally-mediated measures of verbal fluency (action, phonemic) after controlling for relevant covariates, F(1,77) = 6.942, p = 0.010, η2 = 0.061. Groups did not differ on semantic fluency, non-verbal fluency, or attention/working memory (all ps > 0.05). These findings suggest a cognitive advantage in collectivists for verbal processing speed with an additional contribution of left frontal processes involved in lexicosemantic retrieval. Self-construal may provide a meaningful descriptor for diverse samples in neuropsychological research and may help explain other cross-cultural differences

Stochastic accumulation of feature information in perception and memory

It is now well established that the time course of perceptual processing influences the first second or so of performance in a wide variety of cognitive tasks. Over the last20 years, there has been a shift from modeling the speed at which a display is processed, to modeling the speed at which different features of the display are perceived and formalizing how this perceptual information is used in decision making. The first of these models(Lamberts, 1995) was implemented to fit the time course of performance in a speeded perceptual categorization task and assumed a simple stochastic accumulation of feature information. Subsequently, similar approaches have been used to model performance in a range of cognitive tasks including identification, absolute identification, perceptual matching, recognition, visual search, and word processing, again assuming a simple stochastic accumulation of feature information from both the stimulus and representations held in memory. These models are typically fit to data from signal-to-respond experiments whereby the effects of stimulus exposure duration on performance are examined, but response times (RTs) and RT distributions have also been modeled. In this article, we review this approach and explore the insights it has provided about the interplay between perceptual processing, memory retrieval, and decision making in a variety of tasks. In so doing, we highlight how such approaches can continue to usefully contribute to our understanding of cognition

Histone deacetylase inhibitor treatment increases the expression of the plasma membrane Ca2+ pump PMCA4b and inhibits migration of melanoma cells independent of ERK

Several new therapeutic options emerged recently to treat metastatic melanoma; however, the high frequency of intrinsic and acquired resistance among patients shows a need for new therapeutic options. Previously, we identified the plasma membrane Ca2+ ATPase 4b (PMCA4b) as a metastasis suppressor in BRAF-mutant melanomas and found that mutant BRAF inhibition increased the expression of the pump, which then inhibited the migratory and metastatic capability of the cells. Earlier it was also demonstrated that histone deacetylase inhibitors (HDACis) upregulated PMCA4b expression in gastric, colon, and breast cancer cells. In this study, we treated one BRAF wild-type and two BRAF-mutant melanoma cell lines with the HDACis, SAHA and valproic acid, either alone, or in combination with the BRAF inhibitor, vemurafenib. We found that HDACi treatment strongly increased the expression of PMCA4b in all cell lines irrespective of their BRAF mutational status, and this effect was independent of ERK activity. Furthermore, HDAC inhibition also enhanced the abundance of the housekeeping isoform PMCA1. Combination of HDACis with vemurafenib, however, did not have any additive effects on either PMCA isoform. We demonstrated that the HDACi-induced increase in PMCA abundance was coupled to an enhanced [Ca2+]i clearance rate and also strongly inhibited both the random and directional movements of A375 cells. The primary role of PMCA4b in these characteristic changes was demonstrated by treatment with the PMCA4-specific inhibitor, caloxin 1c2, which was able to restore the slower Ca2+ clearance rate and higher motility of the cells. While HDAC treatment inhibited cell motility, it decreased only modestly the ratio of proliferative cells and cell viability. Our results show that in melanoma cells the expression of both PMCA4b and PMCA1 is under epigenetic control and the elevation of PMCA4b expression either by HDACi treatment or by the decreased activation of the BRAF-MEK-ERK pathway can inhibit the migratory capacity of the highly motile A375 cells