This study investigates the effect of aging on alerting, orienting, and conflict resolution by assessing younger (mean age = 25.8) and older (mean age = 67.9) adults' performance in the Attention Network Test that combines, in a single experimental paradigm, a flanker task with alerting and orienting cues. The analyses of response times indicated equivalent orienting and conflict resolution effects in younger and older adults. By contrast, alerting was found to be significantly reduced in the elderly. This result is only marginally in accordance with recent studies addressing the issues of age-related differences in alerting, which provide mixed results. The possible role of methodological differences across studies in accounting for the controversial results concerning the aging affect on alerting is discussed.

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Performance decrements after sleep loss have been extensively studied and are usually attributed to generic attentional deficits. This claim, however, is based on the view of attention as a unitary construct, despite evidence that it should be considered a multidimensional cognitive ability. The aim of the present study was to evaluate the impact of one night of sleep deprivation on the efficiency of three attentional networks, defined by Posner and Raichle (1994) in anatomical and functional terms, as alerting, orienting, and executive control. Thirty participants performed the Attention Network Test at 9:00 a.m. following two different sleep conditions: baseline (a normal night of sleep) and deprivation (24 hrs of wakefulness). Results showed an overall slowing in reaction times and a significant decrease in accuracy after sleep deprivation. Sleep deprivation selectively affected the three attentional networks, given that only executive control efficacy significantly decreased after sleep deprivation. By contrast, phasic alerting and orienting showed no differences in the two sleep conditions. Thus, performance deficits following sleep deprivation do not reflect global attentional deficits.

Upon nighttime experimental awakening of 27 subjects in four sleep conditions (sleep onset early; sleep onset late; Stage 2; and rapid eye movement, REM, sleep), 108 dream reports and their association reports were collected. Dream reports were analyzed for length (temporal units) and content categories (continuity; implausibility; presence of the dreamer [i.e., "the self"], a setting, characters). Associations were classified as episodic, abstract self-referred, and semantic memories. The two sets of results tend to show a basic homogeneity among mentation reports in the four sleep conditions considered. These findings are interpreted as supporting the hypothesis that the same cognitive mechanisms operate, at different levels of engagement, in dream generation rather than the hypothesis of multiple dream-generation systems dependent upon the physiological characteristics of the various sleep stages.