No abstract

The social motivation hypothesis posits that aberrant neural response to human faces in autism is attributable to atypical social development and consequently reduced exposure to faces. The specificity of deficits in neural specialization remains unclear, and alternative theories suggest generalized processing difficulties. The current study contrasted neural specialization for social information versus non-social information in 36 individuals with autism and 18 typically developing individuals matched for age, race, sex, handedness, and cognitive ability. Event-related potentials elicited by faces, inverted faces, houses, letters, and pseudoletters were recorded. Groups were compared on an electrophysiological marker of neural specialization (N170), as well as behavioral performance on standardized measures of face recognition and word reading/decoding. Consistent with prior results, individuals with autism displayed slowed face processing and decreased sensitivity to face inversion; however, they showed comparable brain responses to letters, which were associated with behavioral performance in both groups. Results suggest that individuals with autism display atypical neural specialization for social information but intact specialization for non-social information. They concord with the notion of specific dysfunction in social brain systems rather than non-specific information processing difficulties in autism.

The study was designed to assess neonatal immunity of chicks hatched from breeders fed diets supplemented with beta-carotene, canthaxanthin, lutein, or vitamin E. Broiler breeder birds were fed experimental diets consisting of control, 0.04% beta-carotene, 0.04% canthaxanthin, 0.04% lutein, 0.03% alpha-tocopherol acetate, or 0.04% beta-carotene plus 0.03% alpha-tocopherol acetate. Three weeks after initiation of experimental feeding, birds were vaccinated against Newcastle disease virus. Chicks hatched from the eggs of these breeders were used to determine the neonatal immune responses. There were no significant differences in weight gain and antibody titers of 3-wk-old chicks. 3H-Thymidine uptake by bursal lymphocytes when stimulated with tetrahydrofuran was significantly higher for the chicks hatched from breeders fed diets supplemented with vitamin E, or vitamin E plus beta-carotene, than in controls. 3H-Thymidine uptake by splenic lymphocytes when stimulated with concanavalin A and phorbol 12-myristate 13 acetate was significantly higher for the chicks hatched from breeders fed diets supplemented with vitamin E or beta-carotene alone, or vitamin E plus beta-carotene, than for the control chicks. Chicks hatched from hens supplemented with vitamin E had significantly higher antibody titers at 1 and 7 d of age than chicks from the control group. Vitamin E supplementation of breeder birds increased the immune response of their progeny.

No abstract

We studied time-based neural activity with event-related potentials (ERPs) in young adults during a computer-simulated ball-toss game. Experiencing fair play initially, participants were ultimately excluded by other players. Dense-array ERPs showed time-dependent associations between slow-wave activity (580–900 ms) in left prefrontal/medial frontal cortical regions for exclusion events and self-reported distress. More subtle ‘micro-rejections’ during fair play showed a similar distress to ERP association (420–580 ms). In both cases, greater positive amplitude neural activity was associated with less post-exclusion distress. Findings suggest that rapidly occurring neural responses to social exclusion events are linked to individual differences in ostracism-related distress. Relations emerged even during fair play, providing a window into the neural basis of more subtle social-cognitive perceptual processes.

Event-related brain potentials were examined in 32 adolescents (50% female) from a high-risk sample, who were exposed to cocaine and other drugs prenatally. Adolescents were selected for extreme high- or low-risk behavior on the Balloon Analog Risk Task, a measure of real-world risk-taking propensity. The feedback error-related negativity (fERN), an event-related potential (ERP) that occurs when an expected reward does not occur, was examined in a game in which choices lead to monetary gains and losses with feedback delayed 1 or 2 s. The fERN was clearly visible in the fronto-central scalp region in this adolescent sample. Feedback type, feedback delay, risk status, and sex were all associated with fERN variability. Monetary feedback also elicited a P300-like component, moderated by delay and sex. Delaying reward feedback may provide a means for studying complementary functioning of dopamine and norepinephrine systems.

Due to the numerous health benefits associated with consumption of antioxidants such as alpha-tocopherol and beta-carotene, an experiment was conducted to determine dietary levels that would significantly enhance their concentration in chicken egg yolks. In the experiment, 127 Single Comb White Leghorn laying hens were divided into treatment groups (n = 40 per treatment group) and fed diets containing 0, 50, 100, 200, or 400 mg/kg beta-carotene, dl-alpha-tocopheryl acetate, or their combination. Yolk alpha-tocopherol increased (P < .05) from the control level of 144 micrograms/g of yolk to 477 micrograms/g of yolk when 400 mg dl-alpha-tocopheryl acetate/kg of diet was supplemented. Yolk retinol levels increased (P < .05) from 11.6 micrograms/g of yolk in controls to 13.9 micrograms/g of yolk at 200 mg beta-carotene/kg of diet. beta-Carotene content in the yolk also increased (P < .05) from .14 micrograms/g of yolk in controls to 5.19 micrograms/g of yolk at 200 mg beta-carotene/kg of diet. Supplemental beta-carotene markedly decreased the yolk deposition of alpha-tocopherol when the two compounds were fed together. Egg production, egg weight, and egg yield were not affected by dietary supplementations. Although the data indicated that it is possible to significantly increase the concentration of all three compounds in chicken eggs, because of the relative expense involved it may not be commercially viable to increase egg yolk concentrations of beta-carotene or retinol by supplementing beta-carotene in the diet.

Guar gum production yields a high protein guar meal that can be subdivided into germ and hull fractions. Feeding high concentrations of guar meal reduces body weight and feed efficiency in chickens due to the presence of a residual guar gum. Two experiments determined the upper feeding levels of guar meal and the hull and germ fractions in broiler chickens. An industrial source beta-mannanase (Hemicell) also was fed in combination with guar meals. Experiment 1 utilized a 3 x 4 factorial design to feed broiler chickens diets containing guar germ, guar hull, or guar meal at 4 levels (2.5, 5.0, 7.5, and 10.0%) compared with a negative control diet. Results indicated that any of the 3 guar meals could be fed at a 2.5% dietary inclusion rate without adversely affecting broiler chicken growth to 6 wk of age. In experiment 2, a 4 x 2 factorial design consisting of the 3 by-products meals at 5% inclusion and soybean meal control with and without enzyme tested whether Hemicell could increase inclusion rates without decreasing broiler growth or feed consumption to 6 wk of age. Addition of Hemicell to feed had no effect on measures of growth in chickens fed the control diet. Hemicell significantly improved feed:gain ratio of diets containing 5% of each fraction of guar meal versus the untreated diets. Feed:gain ratio for the Hemicell-treated 5% germ fraction diet was improved to control diet levels. Results indicated that the upper feeding level of guar meal and germ and hull fraction of guar meal is 2.5%, and addition of beta-mannanase (Hemicell) increases the upper feeding level for the germ fraction to 5%.