Considering the contributions of parent fields to CN, current CN studies, and potential future contributions of CN research we conclude that the combination of culture and neuroscience is both additive and synergistic. Cross-cultural psychology and cognitive neuroscience contribute concepts to CN in an additive fashion. (i) The cultural variations in behavior identified by cross-cultural studies in psychology provide avenues for neuroscientific inquiry. (ii) Cross-cultural psychology and psychological anthropology theory provide useful background and testable hypotheses for CN to explore. (iii) The molecular and systems level mechanisms of neural plasticity identified in animal studies inform CN as these mechanisms also likely underlie neural plasticity that results from cultural experience. (iv) Finally, neuroimaging studies of the effects of expertise on the human brain provide a conceptual and methodological model for CN studies. Cross-cultural psychology and neural plasticity studies in cognitive neuroscience also additively contribute methodologies to CN, as demonstrated in our guidelines. Translational methodologies form parent fields will enhance the explanatory power of CN research. Some of the findings of CN research will also be additive, reflecting a direct union of information from parent fields. For example, neuroimaging will associate brain areas with known cross-cultural differences, and CN research will provide additional evidence of neural plasticity in the human brain.
Culture and neuroscience also have the potential to be truly synergistic; some of the findings of CN may be fundamentally different form those in cross-cultural psychology and neural plasticity research to date. Unique information about the mechanics of human neural plasticity may arise from studying the effects of differential cultural experience on the brain, as cultural experience has properties that differ from expertise and other types of experience previously studies in humans: it is widely shared, not self-selected, socially transmitted, constantly evolving and it influences many cognitive and sensory domains. Additionally, because culture is not self-selected, as expertise in a musical instrument or sport is, it may be easier to tease apart the effects of cultural experience from internal sources of neural variation.
The synergy of cross-cultural studies and neuroscience also holds the potential to reveal some truly novel information about cross-cultural differences in behavior. As in the example of cross-cultural color terminology (Abramov and Gordon, 1994
), the physiology of the nervous system constrains variation in human behavior to some extent. Studying the neurobiological basis of cultural variation may help explain the patterns of cross-cultural behavioral variation described in psychological and anthropological studies. Alternatively, just as Boas (1896
) noted that cross-culturally similar aspects of behavior can have different historical and environmental causes, they may also have different neural underpinnings. For instance, Grön et al.
) found that despite equivalent performance on a nonverbal episodic memory task, Caucasian subjects relied more on the ventral visual stream and Chinese subjects relied more on the dorsal visual stream for neural processing.
Despite the potential novel contributions of CN research, the combination of culture and neuroscience results in some unique logistical challenges. These challenges include cultural differences in the rate of age-related changes in the blood oxygen level dependent (BOLD) signal, differences in brain size and shape, and, most notably, limited availability of non-invasive measures of brain function in different cultures (Park and Gutchess, 2002
). Many of the neuroimaging modalities most appropriate for studying CN questions, such as functional magnetic resonance imaging (fMRI), positron emission tomography (PET), and magneto encephalography (MEG), are not portable and not widely available for research purposes in close proximity to all cultural groups of interest (Han and Northoff, 2008
). Even when neuroimaging methodologies are available locally, the individual characteristics of each imaging device make cross-device comparisons difficult, though feasible with careful matching of hardware and software, (Sutton et al.
). Therefore, although exciting discoveries in CN have already been made (Han and Northoff, 2008
), the full potential of CN research will be reached through a combination of international collaboration, translational methodologies from parent fields, and the further development of new methodologies that address the unique challenges of CN studies such as portable imaging technologies and cross-scanner data comparison.