From Coarse to Fine? Spatial and Temporal Dynamics of Cortical Face Processing

Primary vision segregates information along 2 main dimensions: orientation and spatial frequency (SF). An important question is how this primary visual information is integrated to support high-level representations. It is generally assumed that the information carried by different SF is combined following a coarse-to-fine sequence. We directly addressed this assumption by investigating how the network of face-preferring cortical regions processes distinct SF over time. Face stimuli were flashed during 75, 150, or 300 ms and masked. They were filtered to preserve low SF (LSF), middle SF (MSF), or high SF (HSF). Most face-preferring regions robustly responded to coarse LSF, face information in early stages of visual processing (i.e., until 75 ms of exposure duration). LSF processing decayed as a function of exposure duration (mostly until 150 ms). In contrast, the processing of fine HSF, face information became more robust over time in the bilateral fusiform face regions and in the right occipital face area. The present evidence suggests the coarse-to-fine strategy as a plausible modus operandi in high-level visual cortex

Conjunctive input processing drives feature selectivity in hippocampal CA1 neurons

Feature-selective firing allows networks to produce representations of the external and internal environments. Despite its importance, the mechanisms generating neuronal feature selectivity are incompletely understood. In many cortical microcircuits the integration of two functionally distinct inputs occurs nonlinearly through generation of active dendritic signals that drive burst firing and robust plasticity. To examine the role of this processing in feature selectivity, we recorded CA1 pyramidal neuron membrane potential and local field potential in mice running on a linear treadmill. We found that dendritic plateau potentials were produced by an interaction between properly timed input from entorhinal cortex and hippocampal CA3. These conjunctive signals positively modulated the firing of previously established place fields and rapidly induced new place field formation to produce feature selectivity in CA1 that is a function of both entorhinal cortex and CA3 input. Such selectivity could allow mixed network level representations that support context-dependent spatial maps.Howard Hughes Medical InstituteRikagaku Kenkyūjo (Japan

European Code against Cancer 4th Edition:Diet and cancer

AbstractLifestyle factors, including diet, have long been recognised as potentially important determinants of cancer risk. In addition to the significant role diet plays in affecting body fatness, a risk factor for several cancers, experimental studies have indicated that diet may influence the cancer process in several ways. Prospective studies have shown that dietary patterns characterised by higher intakes of fruits, vegetables, and whole-grain foods, and lower intakes of red and processed meats and salt, are related to reduced risks of death and cancer, and that a healthy diet can improve overall survival after diagnosis of breast and colorectal cancers. There is evidence that high intakes of fruit and vegetables may reduce the risk of cancers of the aerodigestive tract, and the evidence that dietary fibre protects against colorectal cancer is convincing. Red and processed meats increase the risk of colorectal cancer. Diets rich in high-calorie foods, such as fatty and sugary foods, may lead to increased calorie intake, thereby promoting obesity and leading to an increased risk of cancer. There is some evidence that sugary drinks are related to an increased risk of pancreatic cancer.Taking this evidence into account, the 4th edition of the European Code against Cancer recommends that people have a healthy diet to reduce their risk of cancer: they should eat plenty of whole grains, pulses, vegetables and fruits; limit high-calorie foods (foods high in sugar or fat); avoid sugary drinks and processed meat; and limit red meat and foods high in salt

Gender differences in disordered eating and weight dissatisfaction in Swiss adults : which factors matter?

Research results from large, national population-based studies investigating gender differences in weight dissatisfaction and disordered eating across the adult life span are still limited. Gender is a significant factor in relation to weight dissatisfaction and disordered eating. However, the reasons for gender differences in these conditions are still poorly understood. The aim of this study was to examine gender differences in weight dissatisfaction and disordered eating in the general Swiss adult population and to identify gender-specific risk factors.METHODS: The study population consisted of 18156 Swiss adults who completed the population-based Swiss Health Survey 2007. Self-reported weight dissatisfaction, disordered eating and associated risk factors were assessed. In order to examine whether determinants of weight dissatisfaction and disordered eating (dieting to lose weight, binge eating, and irregular eating) differ in men and women, multivariate logistic regressions were applied separately for women and men.RESULTS: Although more men than women were overweight, more women than men reported weight dissatisfaction. Weight category, smoking status, education, and physical activity were significantly associated with weight dissatisfaction in men and women. In women, nationality and age were also significant factors. Gender-specific risk factors such as physical activity or weight category were identified for specific disordered eating behaviours.CONCLUSIONS: The results suggest that gender specific associations between predictors and disordered eating behaviour should be considered in the development of effective prevention programs against disordered eating.Research results from large, national population-based studies investigating gender differences in weight dissatisfaction and disordered eating across the adult life span are still limited. Gender is a significant factor in relation to weight dissatisfaction and disordered eating. However, the reasons for gender differences in these conditions are still poorly understood. The aim of this study was to examine gender differences in weight dissatisfaction and disordered eating in the general Swiss adult population and to identify gender-specific risk factors

Energy intake and appetite are related to antral area in healthy young and older subjects

BackgroundGastric distension reduces food intake, and antral, rather than proximal, gastric distension may be the dominant mechanism in the induction of appetite-related sensations. Healthy aging is associated with reduced appetite.ObjectiveWe examined the effects of different energy preloads on appetite, plasma cholecystokinin, antral area, and subsequent energy intake in healthy older and young subjects.DesignOn 3 separate days, 12 young and 12 older subjects consumed 400 mL of a drink containing either 0 kcal (water), 250 kcal, or 750 kcal 70 min before a buffet-style meal.ResultsHunger was less in the older than in the young subjects (P ConclusionIn healthy young and older subjects, the suppression of subsequent energy intake by a liquid preload is nutrient dependent and comparable, and both satiation and satiety are related to antral area and (presumably) antral distension.Kerstin Sturm, Barbara Parker, Judith Wishart, Christine Feinle-Bisset, Karen L Jones, Ian Chapman, and Michael Horowit

The droplet size of intraduodenal fat emulsions influences antropyloroduodenal motility, hormone release, and appetite in healthy males

© 2009 American Society for Clinical NutritionBackgroundThe presence of fat in the small intestine modulates gastrointestinal motility, stimulates plasma cholecystokinin and peptide YY release, and suppresses appetite and energy intake. These effects are dependent on the lipolysis of fat.ObjectiveOur aim was to evaluate the hypothesis that increasing the droplet size of a fat emulsion would attenuate these effects.DesignTen healthy, lean males were studied on 4 separate occasions in single-blind randomized order. Antropyloroduodenal pressures, plasma triglycerides, cholecystokinin, peptide YY, and appetite were measured during 120-min intraduodenal infusions of fat emulsions comprising 3 different droplet sizes: 1) 0.26 microm (LE-0.26), 2) 30 microm (LE-30), and 3) 170 microm (LE-170) in addition to saline (control). Energy intake at a buffet lunch was quantified immediately after the infusions.ResultsIncreasing the droplet size of the lipid emulsion was associated with diminished suppression of antral (r = 0.75, P ConclusionsThe acute effects of intraduodenal fat emulsions on gastrointestinal function and appetite are dependent on fat droplet size. These observations have implications for the design of functional foods to maximize effects on those gut functions that are involved in the suppression of appetite.Radhika V. Seimon, Timothy Wooster, Bärbel Otto, Matthew Golding, Li Day, Tanya J. Little, Michael Horowitz, Peter M. Clifton and Christine Feinle-Bisse