A Dual Route Model of Empathy: A Neurobiological Prospective.

Abstract

Human beings are physically independent but are psychologically connected. We spend a lot of time dealing with others' intentions, experiences, and internal states. The term empathy describes these phenomena. Previous studies defined empathy as “the ability and tendency to share and understand others' internal state” (Zaki and Ochsner, 2012). Consistent with this definition, accumulated empirical evidence showed that empathy is a multifaceted construct composed of two components, including affective empathy and cognitive empathy (Hoffman, 1984; Decety and Jackson, 2004; Singer, 2006; Uddin et al., 2007; Shamay-Tsoory et al., 2009; Barrett et al., 2016). Recently, ever-growing studies have considered empathy under different viewpoints (e.g., developmental trajectories, naturalism, disordered population, and so on), and have summarized the independence and non-independence of affective empathy and cognitive empathy (Barrett et al., 2016). These studies provide significant contributions to the progress of empathy research. However, we are not yet to fully understand the neurocognitive mechanisms between the affective empathy and cognitive empathy. Three major limitations restrict our knowledge toward empathy. First, it is rare to characterize cognitive and affective empathy in terms of processing speed and involvement of consciousness. Second, previous research often studies cognitive and affective empathy separately. It is hard to identify and explain the interactive nature between these two components. Third, influential factors, including attention and prior knowledge, have not yet been considered in the framework of empathy, thus under-estimating their impacts on empathy processing. Attention and prior knowledge are closely linked with the two aforementioned limitations, specifically processing speed and consciousness involvement as well as the integration of affective empathy and cognitive empathy. Thus, these two factors are discussed in the present opinion. To address these limitations, the present opinion proposes a novel and general framework to summarize both behavioral and neural evidence in the literature. The proposed dual route model of empathy is mainly composed of an automatic, fast, and specific “lower route” with affective empathy as well as a complex, slow, and iterative “higher route” with cognitive empathy. This proposed empathy model aims to integrate these two routes and to include the influences of attention and prior knowledge. Previously, in the domain of emotion neuroscience, Joseph LeDuox, a pioneer to study emotions, proposed a framework with two parallel neural systems, namely a low road and a high road (LeDoux, 1998). Specifically, the low road, which is a fast, subcortical, short-latency pathway with minimal cortical involvement, directly conveys sensory information from the thalamus to the amygdala, allowing stimuli to be processed automatically without consciousness and awareness (Davis, 1992; LeDoux, 1995, 1997). These features of rapid and automatic processes construct the low road emotion processes. In contrast, the high road indicates the visual pathways from retina neuron to visual cortex, and then connects to inferior temporal lobe for processing higher level consciousness of emotion feeling, and finally directs to the amygdala (LeDoux, 1998). These features of slow processing and more involvement of consciousness establish the high road of emotion. The present opinion hypothesizes that empathy also has a similar dual route system, which includes an automatic, fast and lower-level route (i.e., lower route) and a complex, slow and higher-level route (i.e., higher route), inside our brain (Figure ​(Figure1).1). The rest of the paper is organized as a series of introductions for each component of empathy. Also, we consider these components in the proposed dual route model of empathy in order to obtain the whole picture of the empathy processing. Open in a separate window Figure 1 The conceptual visualization for the proposed dual route model of empathy.