Studies have shown that heavy exposure to visual media, such as television, negatively impacts children’s physical and emotional wellbeing. In a media-saturated contemporary American culture, it is imperative to critically evaluate how constant exposure to media and technology impacts children. Extensive research on the relationship between children and television by scholars such as Schor (2004) reveals that high consumption of media by children results in myriad negative effects, including, but not limited to, lowered self-esteem, depression, anxiety, obesity, strained parent-child relationships, and psychosomatic symptoms. An area less studied, however, is how parents understand and (potentially) mitigate their children’s exposure to media, and how widespread beliefs that children are unable to entertain themselves independent of technology effect patterns of media consumption. This study fills this gap in the literature through an examination of how parental philosophies regarding media use as well as socioeconomic factors impact how much television their children consume. Towards this end, the current research evaluates responses from 100 parents of children under 18 and living at home through an anonymous, ten question online survey. Drawing from prominent media scholars, this research applies Marshall McLuhan’s substantive theory, which holds that it is not the content on the television screen that is important, but rather the act of watching TV itself. The survey found that households with a high income or a single parent are more likely to have children who engage more heavily with media. The survey also found that children with parents who do not believe they are capable of entertaining themselves are more likely to be heavy television users. These findings underscore the importance of parents understanding how TV consumption impacts their children in order to contribute to the growth of a more creative and less screen-dependent world.

Exposure to vocalizations from members of their own species can influence how infants learn to hear and communicate. Eptesicus fuscus is a social mammal that lives in large colonies and uses many types of vocalizations for both communication and echolocation. We hypothesize that due to the fact that they live in large, well organized social groups, big brown bats should be social learners. In order to test this, we presented altered calls that have been raised or lowered in frequency and bandwidth to bats as they developed from infancy to adulthood. In order to limit exposure to natural maternal vocalizations, pups were reversibly deafened with silicon earplugs whenever they were in the presence of other bats. Every other day, we isolated the pups, removed the earplugs, presented altered calls and recorded the pups’ response. At the end of the study, we tested changes in the organization of the auditory nuclei by measuring frequencies of neurons in several layers the inferior colliculus (IC), a central nucleus in the auditory system in response to auditory stimulation. We compared these results to each infant's twin, as Eptesicus fuscus is usually born in pairs. This gives us a genetically similar control raised in identical conditions. Our results suggest a divergence in call frequency beginning in week two, related to the exposure to lowered artificial stimuli. There is also a shift in the organization of the bands of the IC, with larger low frequency bands and smaller high frequency bands. This suggests that the pups not only altered their vocalizations in response to altered stimuli, but that the frequency organization in auditory structures of the brain remains plastic beyond birth. Humans, like bats, are social mammals, and research into mechanisms of IC plasticity may provide some insight into the development of human hearing.

Estrogen has been shown to directly influence auditory function, with high levels of estrogen receptor expression in the central auditory system of mice correlated with elevated high-frequency auditory thresholds. These findings and others raise the possibility that hormonal modulation might be used to treat some hearing deficiencies. The big brown bat, Eptesicus fuscus, provides a unique opportunity to study an easily accessible, complex auditory pathway in a highly social mammalian species. Bats experience large seasonal differences in both estrogen levels and behavior. During fall mating season, males produce “song” calls to attract females. During winter torpor, a state of decreased physiological activity, the need for hearing is greatly reduced. During spring gestation, estrogen levels are high to support a healthy pregnancy and, after giving birth, females are sensitive to the call frequency of their pups. We hypothesized that seasonally fluctuating estrogen levels in the bat brain have a direct effect on auditory processing which varies throughout the year. We measured blood estrogen levels of male and female bats over the course of the year, and recorded sound-evoked responses of single neurons in the central nucleus of the inferior colliculus (IC), the midbrain auditory center. We specifically measured changes in basic response properties such as call selectivity, frequency tuning, and threshold changes. Afterwards, we perfused the bat, sliced the brain into 40µ sections, and stained for estrogen receptors. These measurements enabled us to correlate blood estrogen levels with both estrogen receptor expression throughout the central auditory system of the brain and functional measurements of neural sensitivity and selectivity across the audible frequency range.