Boredom: Managing the Delicate Balance Between Exploration and Exploitation

Neurogenesis occurs in the dentate gyrus of the hippocampus throughout the life of a rodent, but the function of these new neurons and the mechanisms that regulate their birth are unknown. Here we show that significantly more new neurons exist in the dentate gyrus of mice exposed to an enriched environment compared with littermates housed in standard cages. We also show, using unbiased stereology, that the enriched mice have a larger hippocampal granule cell layer and 15 per cent more granule cell neurons in the dentate gyrus.

This article reports the development, validation, and correlates of a self-report measure of boredom proneness. The 28-item Boredom Proneness (BP) Scale demonstrates satisfactory levels of internal consistency (coefficient alpha = .79) and test-retest reliability (r = .83) over a 1-week interval. Evidence of validity for the BP is supported by correlations with other boredom measures and from a set of studies evaluating interest and attention in the classroom. Other hypothesized relationships with boredom were tested, with significant positive associations found with depression, hopelessness, perceived effort, loneliness, and amotivational orientation. Additional findings indicate boredom proneness to be negatively related to life satisfaction and autonomy orientation. The relationship of boredom to other affective states is discussed, and directions for future research are outlined.

Neurons are continually born from endogenous stem cells and added to the dentate gyrus throughout life, but adult hippocampal neurogenesis declines precipitously with age. Short-term exposure to an enriched environment leads to a striking increase in new neurons, along with a substantial improvement in behavioral performance. Could this plastic response be relevant for explaining the beneficial effects of leading "an active life" on brain function and pathology? Adult hippocampal neurogenesis in mice living in an enriched environment from the age of 10 to 20 months was fivefold higher than in controls. Relatively, the increase in neuronal phenotypes was entirely at the expense of newly generated astrocytes. This cellular plasticity occurred in the context of significant improvements of learning parameters, exploratory behavior, and locomotor activity. Enriched living mice also had a reduced lipofuscin load in the dentate gyrus, indicating decreased nonspecific age-dependent degeneration. Therefore, in mice signs of neuronal aging can be diminished by a sustained active and challenging life, even if this stimulation started only at medium age. Activity exerts not only an acute but also a sustained effect on brain plasticity.