Psychology and neuroscience research typically adopt a reductionist, deductive approach to study particular cognitive and neurobiological processes. Empirical research in these fields has largely resorted to abstraction and simplification in order to achieve maximal control over as many variables as possible, while isolating or randomizing other intervening or potentially confounding factors. Despite their obvious advantages and past effectiveness, such experimental protocols lack the distinctive complexity of real life. The Hasson Lab attempts to develop complementary paradigms to study the neural activity that drives human behavior under natural and realistic conditions. Below we summarize two current lines of research in the lab: Mapping of temporal receptive windows and two-brain communication.
Topographic mapping of a hierarchy of temporal receptive windows
In everyday life, memories of the past are constantly integrated with incoming information. Indeed, the contents of memory cannot be separated from ongoing stimulus processing (Fuster, 1997), as brain areas involved in primary processing also need to accumulate information across time (Lewis, 1979; Fuster, 1997; Kiebel et al., 2008; Buonomano and Maass, 2009; Albright, 2012). Consider, for example, how present and prior information converge when listening to speech: each phoneme achieves its meaning in the context of a word, each word in a sentence, and each sentence in a discourse. Thus, information gathered over milliseconds, seconds, and minutes all contributes to understanding. Comprehension of each word, sentence, or idea also relies on knowledge accumulated in the listener’s brain over many years. However, there is little research on the neural processes that allow the brain to gather information over time. The long-term goal of our laboratory is to understand how the brain uses information accumulated across multiple timescales, ranging from milliseconds to days, to make sense of moment-to-moment incoming information.
In everyday life, we spend most of our time interacting with other individuals. The complexity of face-to-face interactions, however, has hindered scientists from directly probing the neural mechanisms underlying such interactive processes. Our new analytical methods remove such experimental boundaries and enable us to study the interaction between two brains in the course of natural verbal communication. Our results indicate that during successful communication the speaker’s and listener’s brains exhibit joint, temporally coupled, response patterns. Such neural coupling substantially diminishes in the absence of communication, for instance, when listening to an unintelligible foreign language. In addition, more extensive speaker–listener neural couplings result in more successful communication. This study opened a new line of research that aims to characterize the neural substrate of interpersonal communication.