BackgroundEmotion identification is a fundamental component of social cognition. Although it is well established that a general cognitive decline occurs with advancing age, the effects of age on emotion identification is still unclear. A meta-analysis by Ruffman and colleagues (2008) explored this issue, but much research has been published since then, reporting inconsistent findings.MethodsTo examine age differences in the identification of facial expressions of emotion, we conducted a meta-analysis of 24 empirical studies (N = 1,033 older adults, N = 1,135 younger adults) published after 2008. Additionally, a meta-regression analysis was conducted to identify potential moderators.ResultsResults show that older adults less accurately identify facial expressions of anger, sadness, fear, surprise, and happiness compared to younger adults, strengthening the results obtained by Ruffman et al. (2008). However, meta-regression analyses indicate that effect sizes are moderated by sample characteristics and stimulus features. Importantly, the estimated effect size for the identification of fear and disgust increased for larger differences in the number of years of formal education between the two groups.DiscussionWe discuss several factors that might explain the age-related differences in emotion identification and suggest how brain changes may account for the observed pattern. Furthermore, moderator effects are interpreted and discussed.

The cytokine gamma interferon (IFN-γ) plays a major role in the control of Mycobacterium avium infections. We assessed whether the progressive growth of virulent strains of M. avium was associated with alterations in the production of this cytokine as evaluated by reverse transcription-PCR and detection of immunoreactive cytokine in the serum and in spleen homogenates. We found that IFN-γ was induced during infection by a virulent strain ofM. avium to similar or even higher extents than the levels found during infections by a less virulent strain whose growth was controlled. IFN-γ produced during infection by both mycobacterial strains was partly derived from T cells and led to activation of macrophages, namely, those that were infected. Concomitant with the development of the infection with the virulent strain of M. avium there was an extensive depletion of lymphocytes in the spleen. Thymectomy alone promoted the proliferation of the virulent, but not of the less virulent, strain of M. avium. Our data indicate that virulent strains of M. avium resist the antimicrobial mechanisms of IFN-γ-activated macrophages and raise the possibility that a second, T-cell-dependent signal is required for the effective control of mycobacterial replication inside macrophages.

GoncË alves A-S, Appelberg R. The Involvement of the Chemokine Receptor CXCR2 in Neutrophil Recruitment in LPS-Induced Inflammation and in Mycobacterium avium Infection. Scand J Immunol 2002;55:585±591 Knockout mice for CXC receptor 2 (CXCR2) chemokine receptor were used to study the recruitment of neutrophils during acute and chronic inflammatory responses. When treated with lipopolysaccharide (LPS), either intraperitoneally or intratracheally, these animals had a significant reduction in the neutrophil recruitment in the first 24±48 h as compared with control mice. During 15 days of intraperitoneal infection by Mycobacterium avium, the knockout mice showed significantly reduced numbers of neutrophils in the peritoneal cavity as compared with the control mice. In contrast, the recruitment of neutrophils to the lungs during an aerogenic M. avium infection was not affected by the CXCR2 mutation throughout the 60 days of the study. Finally, we could not find any impact of the mutation on the mycobacterial growth of the infected animals. These findings indicate that CXCR2 may be essentially involved in acute inflammatory responses where an early and rapid recruitment of neutrophils is observed.Dr R. Appelberg, IBMC, Rua do Campo Alegre 823,

Aging is associated with changes in cognitive and affective functioning, which likely shape older adults' social cognition. As the neural and psychological mechanisms underlying age differences in social abilities remain poorly understood, the present study aims to extend the research in this field. To this purpose, younger (n = 30; M age = 26.6), middle-aged (n = 30; M age = 48.4), and older adults (n = 29; M age = 64.5) performed a task designed to assess affective perspective-taking, during an EEG recording. In this task, participants decided whether a target facial expression of emotion (FEE) was congruent or incongruent with that of a masked intervener of a previous scenario, which portrayed a neutral or an emotional scene. Older adults showed worse performance in comparison to the other groups. Regarding electrophysiological results, while younger and middle-aged adults showed higher late positive potentials (LPPs) after FEEs congruent with previous scenarios than after incongruent FEEs, older adults had similar amplitudes after both. This insensitivity of older adults' LPPs in differentiating congruent from incongruent emotional context-target FEE may be related to their difficulty in generating information about others' inner states and using that information in social interactions.

SUMMARYC57Bl/6 mice and mice de®cient in the CD40 molecule were infected with three strains of Mycobacterium avium. Two of the M. avium strains proliferated more extensively in CD40-de®cient (CD40 À/À ) mice than in control mice. The increased susceptibility to infection of CD40 À/À mice was associated with the generation of poorer interleukin-12 (IL-12) p40 and interferon-g (IFN-g) responses as compared to the controls, suggesting a role for CD40 in the development of protective immunity. In contrast, direct triggering of CD40 on infected macrophages failed to induce any anti-mycobacterial activity in infected macrophages.

Although navigation is common in many animals, only a few perform true navigation, meaning that they have the ability to return to a given place by relying on indirect cues obtained at the release site (i.e., by relying on information from a ''map and compass'' mechanism). The common intertidal fish, Lipophrys pholis, is thought to have homing abilities through a mechanism that primarily makes use of familiar landmarks (i.e., piloting). Anecdotal reports that individuals return to their home pools after release at unfamiliar sites suggest that L. pholis might use cues collected at the release site to find their way back (i.e., they might use map and compass information). Using a completely artificial setup, we tested the homing abilities of L. pholis as a function of age, sex, and familiarity with the release site. The findings showed that motivation for homing is present only in the adult phase and is independent of sex and/or familiarity with the release site. Moreover, adults released at a completely unfamiliar place oriented themselves in a direction roughly similar to that of their home pools. The fact that L. pholis were tested in a complete artificial environment means that hydrodynamic cues can be excluded as playing a role in this process and restricts the candidate options (e.g., magnetic cues). The ability to perform navigation based on a ''map and compass'' mechanism raises many interesting questions about the learning process, once these individuals have restricted home ranges during their lives. In vertebrate navigation, the cues used during the navigation process are a question of debate, and L. pholis offers an outstanding model to test hypotheses and ultimately provide answers.

Iowa Gambling Task (IGT) is one of the most widely used tools to assess economic decision-making. However, the research tradition on aging and the Iowa Gambling Task (IGT) has been mainly focused on the overall performance of older adults in relation to younger or clinical groups, remaining unclear whether older adults are capable of learning along the task. We conducted a meta-analysis to examine older adults' decision-making on the IGT, to test the effects of aging on reversal learning (45 studies) and to provide normative data on total and block net scores (55 studies). From the accumulated empirical evidence, we found an average total net score of 7.55 (±25.9). We also observed a significant reversal learning effect along the blocks of the IGT, indicating that older adults inhibit the prepotent response toward immediately attractive options associated with high losses, in favor of initially less attractive options associated with long-run profit. During block 1, decisions of older adults led to a negative gambling net score, reflecting the expected initial pattern of risk-taking. However, the shift toward more safe options occurred between block 2 (small-to-medium effect size) and blocks 3, 4, 5 (medium-to-large effect size). These main findings highlight that older adults are able to move from the initial uncertainty, when the possible outcomes are unknown, to decisions based on risk, when the outcomes are learned and may be used to guide future adaptive decision-making.

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