Transcranial Magnetic Stimulation to the Middle Frontal Gyrus During Attention Modes Induced Dynamic Module Reconfiguration in Brain Networks

The interaction between dorsal and ventral attention networks (VANs) is mediated by the middle frontal gyrus (MFG), which is functionally connected to both networks. However, the direct role of the MFG in selective and sustained attention remains controversial. In the current study, we used transcranial magnetic stimulation (TMS) and electroencephalography (EEG) to probe the connectivity dynamic changes of MFG-associated regions during different attention modes. The participants underwent visual, selective, and sustained attention tasks to observe TMS-induced network changes. Twenty healthy participants received single-pulse TMS over the left or right MFG during tasks, while synchronous EEG data was acquired. Behavioral results were recorded and time-varying brain network analyses were performed. We found that the MFG is involved in attention processing and that sustained attention was preferentially controlled by the right MFG. Moreover, compared with the right hemisphere, the left hemisphere was associated with selective attention tasks. Visual and selective attention tasks induced MFG-related changes in network nodes were within the left hemisphere; however, sustained attention induced changes in network nodes were in the bilateral posterior MFG. Our findings indicated that the MFG plays a crucial role in regulating attention networks. In particular, TMS-induced MFG alterations influenced key nodes of the time-varying brain network, leading to the reorganization of brain network modules

Social signalling as a framework for second-person neuroscience

Despite the recent increase in second-person neuroscience research, it is still hard to understand which neurocognitive mechanisms underlie real-time social behaviours. Here, we propose that social signalling can help us understand social interactions both at the single- and two-brain level in terms of social signal exchanges between senders and receivers. First, we show how subtle manipulations of being watched provide an important tool to dissect meaningful social signals. We then focus on how social signalling can help us build testable hypotheses for second-person neuroscience with the example of imitation and gaze behaviour. Finally, we suggest that linking neural activity to specific social signals will be key to fully understand the neurocognitive systems engaged during face-to-face interactions

A Frontotemporoparietal network common to initiating and responding to joint attention bids

Joint attention is a fundamental cognitive ability that supports daily interpersonal relationships and communication. The Parallel Distributed Processing model (PDPM) postulates that responding to (RJA) and initiating (IJA) joint attention are predominantly supported by posterior-parietal and frontal regions respectively. It also argues that these neural networks integrate during development, supporting the parallel processes of self- and other-attention representation during interactions. However, direct evidence for the PDPM is limited due to a lack of ecologically valid experimental paradigms that can capture both RJA and IJA. Building on existing interactive approaches, we developed a virtual reality paradigm where participants engaged in an online interaction to complete a cooperative task. By including tightly controlled baseline conditions to remove activity associated with non-social task demands, we were able to directly contrast the neural correlates of RJA and IJA to determine whether these processes are supported by common brain regions. Both RJA and IJA activated broad frontotemporoparietal networks. Critically, a conjunction analysis identified that a subset of these regions were common to both RJA and IJA. This right-lateralised network included the dorsal portion of the middle frontal gyrus (MFG), inferior frontal gyrus (IFG), middle temporal gyrus (MTG), precentral gyrus, posterior superior temporal sulcus (pSTS), temporoparietal junction (TPJ) and precuneus. Additional activation was observed in this network for IJA relative to RJA at MFG, IFG, TPJ and precuneus. This is the first imaging study to directly investigate the neural correlates common to RJA and IJA engagement, and thus support the assumption that a broad integrated network underlies the parallel aspects of both initiating and responding to joint attention.13 page(s

Re-encountering individuals who previously engaged in joint gaze modulates subsequent gaze cueing

We assessed the extent to which previous experience of joint gaze with people (i.e., looking towards the same object) modulates later gaze cueing of attention elicited by those individuals. Participants in Experiments 1 and 2a/b first completed a saccade/antisaccade task while a to-be-ignored face either looked at, or away from, the participants’ eye movement target. Two faces always engaged in joint gaze with the participant, whereas two other faces never engaged in joint gaze. Then, we assessed standard gaze cueing in response to these faces to ascertain the effect of these prior interactions on subsequent social attention episodes. In Experiment 1, the face’s eyes moved before the participant’s target appeared, meaning that the participant always gaze-followed two faces and never gaze-followed two other faces. We found that this prior experience modulated the timecourse of subsequent gaze cueing. In Experiments 2a/b, the participant looked at the target first, then was either followed (i.e., the participant initiated joint gaze), or was not followed. These participants then showed an overall decrement of gaze cueing with individuals who had previously followed participants’ eyes (Experiment 2a), an effect that was associated with autism spectrum quotient scores and modulated perceived trustworthiness of the faces (Experiment 2b). Experiment 3 demonstrated that these modulations are unlikely to be due to the association of different levels of task difficulty with particular faces. These findings suggest that establishing joint gaze with others influences subsequent social attention processes that are generally thought to be relatively insensitive to learning from prior episodes

The Role of Eye Gaze During Natural Social Interactions in Typical and Autistic People

Social interactions involve complex exchanges of a variety of social signals, such as gaze, facial expressions, speech and gestures. Focusing on the dual function of eye gaze, this review explores how the presence of an audience, communicative purpose and temporal dynamics of gaze allow interacting partners to achieve successful communication. First, we focus on how being watched modulates social cognition and behavior. We then show that the study of interpersonal gaze processing, particularly gaze temporal dynamics, can provide valuable understanding of social behavior in real interactions. We propose that the Interpersonal Gaze Processing model, which combines both sensing and signaling functions of eye gaze, provides a framework to make sense of gaze patterns in live interactions. Finally, we discuss how autistic individuals process the belief in being watched and interpersonal dynamics of gaze, and suggest that systematic manipulation of factors modulating gaze signaling can reveal which aspects of social eye gaze are challenging in autism

Social orienting in gaze-based interactions: Consequences of joint gaze

Abstract Jointly attending to a shared referent with other people is a social attention behaviour that occurs often and has many developmental and ongoing social impacts. This thesis focused on examining the online, as well as later emerging, impacts of being the gaze leader of joint attention, which has until recently been under-researched. A novel social orienting response that occurs after viewing averted gaze is reported, showing that a gaze leader will rapidly orient their attention towards a face that follows their gaze: the gaze leading effect. In developing the paradigm necessary for this illustration a number of boundary conditions were also outlined, which suggest the social context of the interaction is paramount to the observability of the gaze leading effect. For example, it appears that the gaze leading effect works in direct opposition to other social orienting phenomenon (e.g. gaze cueing), may be specific to eye-gaze stimuli, and is associated with self-reported autism-like traits. This orienting response is suggested as evidence that humans may have an attention mechanism that promotes the more elaborate social attention state of shared attention. This thesis also assessed the longer term impacts of prior joint gaze interactions, finding that gaze perception can be influenced by prior interactions with gaze leaders, but not with followers, and further there is evidence presented that suggests a gaze leader’s attention will respond differently, later, to those whom have or have not previously followed their gaze. Again, this latter finding is associated with autism-like traits. Thus, the current work opens up a number of interesting research avenues concerning how attention orienting during gaze leading may facilitate social learning and how this response may be disrupted in atypically developing populations