•We provide the first quantitative assessment of neurocognitive theories of obesity.•These results were obtained with quantitative meta-analyses of fMRI studies.•Overall, we provide support for an ...incentive sensitization theory of obesity.•Obese individuals have greater activation of reward regions for visual food cues.•The brain of obese individuals is more sensitive to hunger and less to satiety.
The dysregulation of food intake in chronic obesity has been explained by different theories. To assess their explanatory power, we meta-analyzed 22 brain-activation imaging studies. We found that obese individuals exhibit hyper-responsivity of the brain regions involved in taste and reward for food-related stimuli. Consistent with a Reward Surfeit Hypothesis, obese individuals exhibit a ventral striatum hyper-responsivity in response to pure tastes, particularly when fasting. Furthermore, we found that obese subjects display more frequent ventral striatal activation for visual food cues when satiated: this continued processing within the reward system, together with the aforementioned evidence, is compatible with the Incentive Sensitization Theory. On the other hand, we did not find univocal evidence in favor of a Reward Deficit Hypothesis nor for a systematic deficit of inhibitory cognitive control. We conclude that the available brain activation data on the dysregulated food intake and food-related behavior in chronic obesity can be best framed within an Incentive Sensitization Theory. Implications of these findings for a brain-based therapy of obesity are briefly discussed.
Visual drug cues are powerful triggers of craving in drug abusers contributing to enduring addiction. According to previous qualitative reviews, the response of the orbitofrontal cortex to such cues ...is sensitive to whether subjects are seeking treatment. Here we re-evaluate this proposal and assessed whether the nature of the drug matters. To this end, we performed a quantitative meta-analysis of 64 neuroimaging studies on drug-cue reactivity across legal (nicotine, alcohol) or illegal substances (cocaine, heroin). We used the ALE algorithm and a hierarchical clustering analysis followed by a cluster composition statistical analysis to assess the association of brain clusters with the nature of the substance, treatment status, and their interaction. Visual drug cues activate the mesocorticolimbic system and more so in abusers of illegal substances, suggesting that the illegal substances considered induce a deeper sensitization of the reward circuitry. Treatment status had a different modulatory role for legal and illegal substance abusers in anterior cingulate and orbitofrontal areas involved in inter-temporal decision making. The class of the substance and the treatment status are crucial and interacting factors that modulate the neural reactivity to drug cues. The orbitofrontal cortex is not sensitive to the treatment status per se, rather to the interaction of these factors. We discuss that these varying effects might be mediated by internal predispositions such as the intention to quit from drugs and external contingencies such as the daily life environmental availability of the drugs, the ease of getting them and the time frame of potential reward through drug consumption.
According to the "classic" and the "new" model, developmental dyslexia (DD) is associated with dysfunctions of the left temporoparietal (TP), ventral occipitotemporal (vOT) and frontal brain ...circuits. However, these models make different anatomo-functional predictions about the effects of age and orthographic depth on the neural correlates of DD. To test the influence of age and orthographic depth and their interaction on the neurobiology of reading we meta-analyzed 34 fMRI studies by combining the CluB and the GingerALE methods. Our meta-analytic results challenged both models and allowed us to generate a refined neurocognitive framework called the "Anatomo-functional, Developmental, and Orthographic Depth (ADOD) model of DD". The ADOD model describes the interacting effects of age and orthography on the neurobiology of DD and suggests brand new conceptions on the role of the left TP cortex in reading together with a subtler parcellation of the vOT areas according to a rostro-caudal gradient.
This paper analyzes the characteristics of beneficiaries who drop out of the Mexican conditional cash transfer program
Oportunidades to determine if dropping out of the program is a result of ...self-targeting by the non-poor or the exclusion of the target poor population. Using
Oportunidades’ administrative data and a discrete duration model, the analysis indicates that wealthier beneficiaries have greater odds of dropping out, suggesting that conditionality acts as a screening device. The results also indicate that administrative factors and the provider of health services to beneficiaries also have an important influence on whether beneficiaries remain in or leave the program.
Aims
To conduct a randomized placebo controlled double‐blind crossover trial in order to evaluate a loratadine‐pseudoephedrine combination (L+PS) in children with seasonal allergic rhinitis.
Methods
...Forty children (15 males; 25 females), aged 3–15 years, were included in this study. They were randomized to receive L+PS (0.2 mg kg−1 body weight–2.4 mg kg−1 body weight respectively) or placebo (PLA) for 14 days. After 7 days of washout, patients were shifted to the other treatment for a further 14 days. Nasal symptoms (sneezing/itching, congestion, nasal dripping) and signs (turbinal swelling, retronasal drainage), rated on a scale ranging from: 1. absent to 5. very intense, and their sum or mean total symptom score (MTSS) were used as efficacy measurement.
Results
Significant relief was observed; post‐treatment MTSS difference and its percent change were respectively; L+PS=−4.29; 95% CI: −3.64 and −4.94 (27.8%), and PLA=−1.63; 95% CI: −0.95 and −2.31 (10.7%) (P<0.001 baseline vs endpoint and between treatments). Furthermore, L+PS and PLA significantly modified symptoms, but only L+PS significantly modified signs. No clinical changes were observed during the trial; only one patient showed slight transient insomnia when receiving L+PS.
Conclusions
It is concluded that L+PS is useful and well tolerated in children with seasonal allergic rhinitis. However, elements such as placebo effect must be taken into account for planning future trials.
Sunk costs are previous investments of time, effort, or money toward a goal that cannot be recovered. People often honor sunk costs by continuing to pursue a goal, despite the availability of an ...alternative path that would pay off faster, a phenomenon called the sunk cost effect. Prior research has identified variables that influence the sunk cost effect. One variable found in hypothetical scenario-based research and in behavior-based research (Pattison et al., 2011) has been percent of goal completed. The current study was designed to (1) replicate and extend research by Pattison and colleagues and (2) compare results from the same participants on behavior-based and hypothetical scenario-based sunk cost procedures. A pilot study (n = 18) was completed to refine the procedures in advance of the main study. Twenty-five participants were recruited for the main study. Participants completed behavior-based and hypothetical scenario-based tasks to investigate the effects of manipulating percent of task completed on the propensity to continue a course of action. For the behavior-based task, participants were exposed to a sunk cost procedure in which they were presented an initial work requirement of 30 responses. Part of the way through the completion of that requirement they were presented with a choice between staying with that task or switching to another alternative that always required 15 responses. The work requirements were presented in the form of a video game on a computer in which the goal was to kill monsters. A repeated measures design was used to investigate the effect of percent completion of the initial requirement on choice to stay on the initial task. During some trials, it was more beneficial to stay on the initial task (kill the first monster) and during some trials, it was more beneficial to switch to kill the other monster. Staying on the initial work task when it is optimal (requires fewer responses) to switch to the other task is sunk cost behavior. For the hypothetical scenario-based tasks, participants were given a scenario in which continuing on a present course of action entailed losses or was otherwise non-optimal. For example, one scenario entailed completing development of a product that had already been completed by another company. They were asked at various points of completion how likely they were to invest the remaining funds in the project. Overall, participants responded optimally on the behavior-based task and engaged in sunk cost behavior for the hypothetical scenario-based tasks. One explanation for the difference between these tasks is that the behavior-based task may have more discriminable consequences; the consequences for the hypothetical tasks were unknown. Results from the present study, in combination with previous research, suggest that discriminability of a situation is a major determinant of non-optimal persistence on a task. It is possible that what is considered the sunk cost effect in the literature is behavior produced by contingencies in contexts with uncertain or probabilistic outcomes. Verbal behavior may have also played a key role in these results.
We present the first measurement of polarization and CP-violating asymmetries in a B{sub s}{sup 0} decay into two light vector mesons, B{sub s}{sup 0}{yields}{phi}{phi}, and an improved determination ...of its branching ratio using 295 decays reconstructed in a data sample corresponding to 2.9 fb{sup -1} of integrated luminosity collected by the CDF experiment at the Fermilab Tevatron collider. The fraction of longitudinal polarization is determined to be f{sub L}=0.348{+-}0.041(stat){+-}0.021(syst), and the branching ratio B(B{sub s}{sup 0}{yields}{phi}{phi})=2.32{+-}0.18(stat){+-}0.82(syst)x10{sup -5}. Asymmetries of decay angle distributions sensitive to CP violation are measured to be A{sub u}=-0.007{+-}0.064(stat){+-}0.018(syst) and A{sub v}=-0.120{+-}0.064(stat){+-}0.016(syst).
We present the results of a search for pair production of a heavy toplike (t') quark decaying to Wq final states using data corresponding to an integrated luminosity of 5.6 fb{sup -1} collected by ...the CDF II detector in pp collisions at {radical}(s)=1.96 TeV. We perform parallel searches for t'{yields}Wb and t'{yields}Wq (where q is a generic down-type quark) in events containing a lepton and four or more jets. By performing a fit to the two-dimensional distribution of total transverse energy versus reconstructed t{sup '} quark mass, we set upper limits on the t't' production cross section and exclude a standard model fourth-generation t' quark decaying to Wb (Wq) with mass below 358 (340) GeV/c{sup 2} at 95% C.L.
We present a measurement of the top-quark mass using a sample of tt events in 5.7 fb{sup -1} of integrated luminosity from pp collisions at the Fermilab Tevatron with {radical}(s)=1.96 TeV and ...collected by the CDF II Detector. We select events having large missing transverse energy, and four, five, or six jets with at least one jet tagged as coming from a b quark, and reject events with identified charged leptons. This analysis considers events from the semileptonic tt decay channel, including events that contain tau leptons. The measurement is based on a multidimensional template method. We fit the data to signal templates of varying top-quark masses and background templates, and measure a top-quark mass of M{sub top}=172.32{+-}2.4(stat){+-}1.0(syst) GeV/c{sup 2}.
PDF
