Imaging the Human Parental Brain

This chapter presents data on the brain basis of human parental behavior and thoughts. In this chapter, high resolution and noninvasive brain imaging technique of blood-oxygen-dependant functional magnetic resonance imaging (fMRI) are used to measure regional brain activity in response to infant auditory, visual, and related stimuli. FMRI assays brain activity by indirectly measuring changes in regional blood oxygenation. The differences between a region's oxygenated and deoxygenated hemoglobin, between states of action vs. inaction for instance, provide characteristic magnetic signals localized to millimeters that are detected by scanners positioned around each subject's head. An important caveat throughout the interpretation of parenting fMRI studies, however, is that these brain activity measurements are indirect and represent an integration of instantaneous electrical brain activity over at least seconds. Furthermore, fMRI related blood flow change lags behind synaptic events over 3-6 seconds. Furthermore, experimental design captures brain activity over periods of a few seconds or tens of seconds. On the one hand, short blocks or events may capture briefly held mental states, but miss bigger changes such as sustained emotion, while on the other hand longer blocks may capture more complex brain responses, but also average them out making subtle responses more difficult to detect. Brain activity during these blocks may then be measured and compared between periods of attending to stimuli of interest and control stimuli to generate maps of the brain indicating differences in brain activity that may be important for one set of perceptions and thoughts vs. another. © 2008