Do you see what I see? The neural bases of joint attention during a live interactive game

Joint attention refers to the ability to coordinate one’s own attention with another on a third entity (e.g. object or common goal). This uniquely human ability emerges late in the first year of life and is critical to social-cognitive and language development; yet the neural bases for this pivotal skill remain largely understudied. Joint attention includes both Responding to Joint Attention (RJA), or following another’s bid for shared attention on an object, and Initiating Joint Attention (IJA), or initiating a bid for shared attention on an object. To identify the neural bases of both IJA and RJA we implemented a dual-video set-up in which both subject and experimenter could monitor each other via video feed in real-time during fMRI data collection. In each trial, participants either followed the experimenter’s gaze to a target (RJA) or cued the experimenter to look at the target (IJA). A control condition, non-joint attention (NJA), was included in which the subject shifted gaze to a target while the experimenter closed her eyes. Greater activation was seen in the dorsal medial prefrontal cortex (dMPFC) and bilateral posterior superior temporal sulcus (pSTS) during joint attention (IJA + RJA) as compared to NJA. RJA elicited greater activation in posterior superior temporal sulcus (pSTS) than NJA while IJA recruited greater activation in dMPFC than NJA. This novel experimental set-up allowed for the first time identification of the neural bases of both initiating and responding to joint attention

Atypical brain activation patterns during a face-to-face joint attention game in adults with autism spectrum disorder

Joint attention behaviors include initiating one's own and responding to another's bid for joint attention to an object, person, or topic. Joint attention abilities in autism are pervasively atypical, correlate with development of language and social abilities, and discriminate children with autism from other developmental disorders. Despite the importance of these behaviors, the neural correlates of joint attention in individuals with autism remain unclear. This paucity of data is likely due to the inherent challenge of acquiring data during a real-time social interaction. We used a novel experimental set-up in which participants engaged with an experimenter in an interactive face-to-face joint attention game during fMRI data acquisition. Both initiating and responding to joint attention behaviors were examined as well as a solo attention (SA) control condition. Participants included adults with autism spectrum disorder (ASD) (n = 13), a mean age- and sex-matched neurotypical group (n = 14), and a separate group of neurotypical adults (n = 22). Significant differences were found between groups within social-cognitive brain regions, including dorsal medial prefrontal cortex (dMPFC) and right posterior superior temporal sulcus (pSTS), during the RJA as compared to SA conditions. Region-of-interest analyses revealed a lack of signal differentiation between joint attention and control conditions within left pSTS and dMPFC in individuals with ASD. Within the pSTS, this lack of differentiation was characterized by reduced activation during joint attention and relative hyper-activation during SA. These findings suggest a possible failure of developmental neural specialization within the STS and dMPFC to joint attention in ASD