Emergence of an abstract categorical code enabling the discrimination of temporally structured tactile stimuli

The problem of neural coding in perceptual decision making revolves around two fundamental questions: (i) How are the neural representations of sensory stimuli related to perception, and (ii) what attributes of these neural responses are relevant for downstream networks, and how do they influence decision making? We studied these two questions by recording neurons in primary somatosensory (S1) and dorsal premotor (DPC) cortex while trained monkeys reported whether the temporal pattern structure of two sequential vibrotactile stimuli (of equal mean frequency) was the same or different. We found that S1 neurons coded the temporal patterns in a literal way and only during the stimulation periods and did not reflect the monkeys' decisions. In contrast, DPC neurons coded the stimulus patterns as broader categories and signaled them during the working memory, comparison, and decision periods. These results show that the initial sensory representation is transformed into an intermediate, more abstract categorical code that combines past and present information to ultimately generate a perceptually informed choiceThis work was supported in part by the Dirección de Asuntos del Personal Académico de la Universidad Nacional Autónoma de México and Consejo Nacional de Ciencia y Tecnología (R.R.) and Grant FIS2015-67876-P (to N.P.

Spirituality, Faith, and Mild Alzheimer\u27s Disease

There is some evidence for a positive association between spirituality, cognitive, and behavioral functioning in people with Alzheimer’s disease (AD). However, to our knowledge there is no published data to date that provides an explanatory model for these findings. Twenty-eight individuals with mild AD received in-depth interviews and measures of cognitive, behavioral, emotional, and spiritual functioning to gain insight into this question in this mixed methods study. Findings revealed that people with mild AD can actively engage in meaningful discussion about how spirituality influences their experience of living with AD; that they remain deeply devoted to a relationship with the transcendent (i.e., God, higher power, spirit) and their spiritual communities; that they value and benefit from the sacred aspects of their day-to-day lives; and that their core spiritual values, beliefs, and practices can be activated to help them adapt to the uncertainty of living with AD. Additionally, persons with AD who are experiencing spiritual struggle tend to experience a greater degree of anxiety, depression, and behavioral changes as compared to those who do not, suggesting that spiritual struggle is a risk factor for poorer outcomes in this population. Implications for future research, clinical practice, and community care are provided including how researchers and clinicians can effectively adapt traditional measures of spirituality for use with this population; the importance of integrating spirituality into the assessment and treatment of people with AD; and the role spiritual communitie

A Topos Perspective on State-Vector Reduction

A preliminary investigation is made of possible applications in quantum theory of the topos formed by the collection of all $M$-sets, where $M$ is a monoid. Earlier results on topos aspects of quantum theory can be rederived in this way. However, the formalism also suggests a new way of constructing a `neo-realist' interpretation of quantum theory in which the truth values of propositions are determined by the actions of the monoid of strings of finite projection operators. By these means, a novel topos perspective is gained on the concept of state-vector reduction

The in vitro effects of artificial and natural sweeteners on the immune system using whole blood culture assays

This article investigates the effects of commercially available artificial (aspartame, saccharin, sucralose) and natural sweeteners (brown sugar, white sugar, molasses) on the immune system. Human whole blood cultures were incubated with various sweeteners and stimulated in vitro with either phytohemagglutinin or endotoxin. Harvested supernatants were screened for cytotoxicity and cytokine release. Results showed that none of the artificial or natural sweeteners proved to be cytotoxic, indicating that no cell death was induced in vitro. The natural sweetener, sugar cane molasses (10 ug=mL), enhanced levels of the inflammatory biomarker IL-6 while all artificial sweeteners (10 ug=mL) revealed a suppressive effect on IL-6 secretion (P<0.001). Exposure of blood cells to sucralose-containing sweeteners under stimulatory conditions reduced levels of the biomarker of humoral immunity, Interleukin-10 (P<0.001). The cumulative suppression of Interleukin-6 and Interleukin-10 levels induced by sucralose may contribute to the inability in mounting an effective humoral response when posed with an exogenous threat.Web of Scienc

Large-scale structural organization of social networks

The characterization of large-scale structural organization of social networks is an important interdisciplinary problem. We show, by using scaling analysis and numerical computation, that the following factors are relevant for models of social networks: the correlation between friendship ties among people and the position of their social groups, as well as the correlation between the positions of different social groups to which a person belongs.Comment: 5 pages, 3 figures, Revte

Growing Scale-Free Networks with Tunable Clustering

We extend the standard scale-free network model to include a ``triad formation step''. We analyze the geometric properties of networks generated by this algorithm both analytically and by numerical calculations, and find that our model possesses the same characteristics as the standard scale-free networks like the power-law degree distribution and the small average geodesic length, but with the high-clustering at the same time. In our model, the clustering coefficient is also shown to be tunable simply by changing a control parameter - the average number of triad formation trials per time step.Comment: Accepted for publication in Phys. Rev.

Structure of a large social network

We study a social network consisting of over $10^4$ individuals, with a degree distribution exhibiting two power scaling regimes separated by a critical degree $k_{\rm crit}$, and a power law relation between degree and local clustering. We introduce a growing random model based on a local interaction mechanism that reproduces all of the observed scaling features and their exponents. Our results lend strong support to the idea that several very different networks are simultenously present in the human social network, and these need to be taken into account for successful modeling.Comment: 5 pages, 5 figure