61 research outputs found
Adaptive complexity and phenomenal consciousness
Journal ArticleFocuses on epiphenomenalism problems in arguments about evolutionary function of phenomenal consciousness. Implications of cognitive neuropsychology evidence for the structure of phenomenal consciousness; Distinction of different kinds of epiphenominalist arguments; Provision of a developmental basis by complexity argument
Psychosocial status and cognitive achievement in Peru
This paper assesses the importance of psychosocial status in the accumulation of cognitive skills during the transition from mid to late childhood. We use longitudinal data from a cohort of 700 Peruvian children drawn from a very rich dataset, the Young Lives Survey, to test the impact of children's perception of respect at the age of 8 on cognitive achievement 4 years later, controlling for cognitive skills at the age of 8, lagged child and household characteristics, and community fixed effects. This empirical specification is akin to estimating a conditional demand function for cognitive skills, which deals with some of the main pitfalls of skill endogeneity. We find that poorly respected children are linked to a lower rate of cognitive accumulation than their betterârespected counterparts. As expected, we also find that previously accumulated cognitive skills enable higher subsequent cognitive skill accumulation. We go one step further by testing and finding evidence of complementarities across skills. We show that cognitive differences amplify over time between children with low and high psychosocial skills. Overall, our results suggest that psychosocial status, an aspect little studied in the context of developing countries, plays an important role in the acquisition of cognitive skills during childhood
Financing Direct Democracy: Revisiting the Research on Campaign Spending and Citizen Initiatives
The conventional view in the direct democracy literature is that spending against a measure is more effective than spending in favor of a measure, but the empirical results underlying this conclusion have been questioned by recent research. We argue that the conventional finding is driven by the endogenous nature of campaign spending: initiative proponents spend more when their ballot measure is likely to fail. We address this endogeneity by using an instrumental variables approach to analyze a comprehensive dataset of ballot propositions in California from 1976 to 2004. We find that both support and opposition spending on citizen initiatives have strong, statistically significant, and countervailing effects. We confirm this finding by looking at time series data from early polling on a subset of these measures. Both analyses show that spending in favor of citizen initiatives substantially increases their chances of passage, just as opposition spending decreases this likelihood
Early life height and weight production functions with endogenous energy and protein inputs
We examine effects of protein and energy intakes on height and weight growth for children between 6 and 24 months old in Guatemala and the Philippines. Using instrumental variables to control for endogeneity and estimating multiple specifications, we find that protein intake plays an important and positive role in height and weight growth in the 6-24 month period. Energy from other macronutrients, however, does not have a robust relation with these two anthropometric measures. Our estimates indicate that in contexts with substantial child undernutrition, increases in protein-rich food intake in the first 24 months can have important growth effects, which previous studies indicate are related significantly to a range of outcomes over the life cycl
Hyperthermia impairs short-term memory and peripheral motor drive transmission
The aims of this study were to determine (i) the effect of passive hyperthermia on motor drive and cognitive function, and (ii) whether head cooling can limit the hyperthermia-induced alterations. Sixteen subjects were randomly exposed for 2 h to three different conditions: control (Con, 20°C), hot (Hot, 50°C) and hot head cool (HHC â where cold packs were applied to the head under Hot conditions). Three cognitive tests measuring attention and two measuring memory were performed. Neuromuscular testing included electrically evoked muscle action potentials (M-waves) and reflex waves (H-reflex) at rest and during brief (4â5 s) and sustained (120 s) maximal voluntary contractions (MVC) of the plantar flexors. All the tests were performed in the environmental room. During brief MVC, torque was significantly lower in both Hot and HHC as compared to Con (P < 0.05). The decrease in muscle activation was significant in Hot (P < 0.05) but not in HBC (P= 0.07). This was accompanied by peripheral failures in the transmission of the neural drive at both spinal (significant decrements in H-reflexes and V-waves, P < 0.05) and neuromuscular junction (significant decrements in M-waves, P < 0.05) levels. During sustained MVC, muscle activation was further depressed (P < 0.05) without any concomitant failures in M-waves, suggesting neural activation adjustments occurring probably at the supraspinal level. Cerebral perturbations were confirmed by significant decrements in both memory tests in Hot as compared with Con (P < 0.05) but not in simple tests (attention tests) that were not affected by hyperthermia. The decrement in memory capacity suggested the existence of frontal lobe activity impairments. Thus, HHC preserved memory capacity but not the visual memory
Micronutrient supplements for children after deworming
The availability of a few inexpensive, single dose drugs to treat soil-transmitted helminths and schistosomiasis offers the potential to reduce a considerable
burden of acute disease, especially among children sub-Saharan Africa. These
treatments are being promoted as "rapid impact interventions" However, if
helminth infections cause underweight, stunting, anaemia and impaired mental
development in children, how will removing worms alone lead to recovery
without treating the underlying deficits that have been caused or made worse by
helminth disease? Energy, protein and micronutrients are required by children
who are underweight or who have stunted growth; children who are anaemic
will require iron and other micronutrients for haemopoiesis; and children who
have lost education will need remedial teaching. Treating neglected worm
diseases is an essential first step to good health, but anthelmintic drugs need to be integrated with simple and inexpensive nutritional interventions such as
micronutrient supplements to promote recovery and have a rapid effect
Early Maternal Time Investment and Early Child Outcomes
Using large longitudinal survey data from the UK Millennium Cohort Study, this article estimates the relationship between maternal time inputs and early child development. We find that maternal time is a quantitatively important determinant of skill formation and that its effect declines with child age. There is evidence of longâterm effects of early maternal time inputs on later outcomes, especially in the case of cognitive skill development. In the case of nonâcognitive development, the evidence of this longâterm impact disappears when we account for skill persistence
GroEL-Assisted Protein Folding: Does It Occur Within the Chaperonin Inner Cavity?
The folding of protein molecules in the GroEL inner cavity under the co-chaperonin GroES lid is widely accepted as a crucial event of GroEL-assisted protein folding. This review is focused on the data showing that GroEL-assisted protein folding may proceed out of the complex with the chaperonin. The models of GroEL-assisted protein folding assuming ligand-controlled dissociation of nonnative proteins from the GroEL surface and their folding in the bulk solution are also discussed
Early Nutrition and Cognition in Peru
This paper examines the causal link between early childhood nutrition and cognition, applying instrumental variables to sibling-differences for a sample of pre-school aged Peruvian children. Child-specific shocks in the form of food price changes and household shocks during the critical developmental period of a child are used as instruments. The analysis shows significant and positive returns to early childhood nutritional investments. An increase in the Height-for-Age z-score of one standard deviationkeeping other factors constanttranslates into increases in the Peabody Picture Vocabulary Test (PPVT) score of 17-21 percent of a standard deviation. The period of analysis includes the recent global food price crisis that also affected Peru between 2006 and 2008. This therefore is also a quantification of the nutritional and subsequent cognitive costs of food prices on the sample, which could be magnified in later years
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