Neuroanatomical Markers of Social Hierarchy Recognition in Humans: A Combined ERP/MRI Study

Abstract

Social hierarchy is an ubiquitous principle of social organization across animal species. Although some progress has been made in our understanding of how humans infer hierarchical identity, the neuroanatomical basis for perceiving key social dimensions of others remains unexplored. Here, we combined event-related potentials and structural MRI to reveal the neuroanatomical substrates of early status recognition. We designed a covertly simulated hierarchical setting in which participants performed a task either with a superior or with an inferior player. Participants showed higher amplitude in the N170 component when presented with a picture of a superior player compared with an inferior player. Crucially, the magnitude of this effect correlated with brain morphology of the posterior cingulate cortex, superior temporal gyrus, insula, fusiform gyrus, and caudate nucleus. We conclude that early recognition of social hierarchies relies on the structural properties of a network involved in the automatic recognition of social identity.

Social brains and divides: the interplay between social dominance orientation and the neural sensitivity to hierarchical ranks

“…Since our study focused on the responses to neutral faces outside competitive, learning or rewarding contexts and used no perceptual cues such as symbols (eg. stars indicating the rank), uniforms, facial dominance features or body postures12142021222324, the DLPFC and the pSTS activations observed here may constitute the minimal, task-independent brain network involved in social rank perception. Predominantly right-sided, this core network may coordinate with additional areas depending on the task and/or the nature of the ongoing social interaction.…”

Short exposure to a foreign accent impacts subsequent cognitive processes

“…Videos were used to establish initial hierarchical features. To reinforce the social hierarchy, participants then played a visual discrimination game adapted from Santamaría-García's studies (Santamaría-García et al, 2015, 2014, which consisted of two panels with different numbers of red dots (Figure 1, panel B). Participants had up to one second to decide which panel contained more dots (by using the up/down arrows).…”

“…Counter-balancing speakers allowed avoiding any potential effect of idiosyncratic features, stereotypes associated with or familiarity with a particular accent, which have been shown to affect the speaker's perception and speech comprehension (e.g., Caffarra & Martin, 2018;Roessel et al, 2017). To avoid interaction between gender and hierarchy, we intended to present participants with speakers of the same gender as theirs, as done in previous studies that used a similar hierarchy phase (Santamaría-García, 2014;Santamaría-García et al, 2015, 2014Zink et al, 2008).…”

“…We first introduced Dutch native participants to four people (thereafter, 'speakers') via short videos. To ensure any modulation in the perception of the speaker was due to the accent and not to the speaker's social status, we set up the speakers' status in a 'hierarchy phase' that proved successful in previous studies (Santamaría-García, Burgaleta, & Sebastián-Gallés, 2015;Santamaría-García, Pannunzi, Ayneto, Deco, & Sebastián-Gallés, 2014;Zink et al, 2008). The speakers briefly described themselves and their life achievements, either positive/successful achievements or negative/nonsuccessful ones.…”

Dynamical Representation of Dominance Relationships in the Human Rostromedial Prefrontal Cortex

“…In the past, human social dominance has been mostly studied using pre-established ranks depicted by perceptual cues [5,13], thereby sidestepping the issue that social dominance is usually dynamically changing and needs to be learned. Numerous cortical and subcortical areas have been involved in social hierarchy processing [14], but it is unclear whether these brain structures indeed causally influence dominance-related behaviors and how their contributions in this respect differ.…”