Highlights 1st Neuroimaging Workgroup Meeting in Functional Neurological Disorder (FND). Underscores the importance of FND cohort characterization in brain imaging research. Details methodological approaches taken in FND neuroimaging research to date. Research agenda proposed to definitely elucidate the neural circuitry of FND. Discussions underway regarding having FND researchers join the ENIGMA consortium.

1The sensitisation model suggests paranoia is explained by over-sensitivity to 2 perceived threat in social environments. However, this has been difficult to test 3 experimentally. We report two pre-registered studies that tested i) the sensitisation 4 model as an explanation of paranoia, and; ii) the role of purported maintaining 5 factors in supporting social sensitisation. In study one, we recruited a large general 6 population sample (N=987) who serially interacted with other participants in multi-7round Dictator games, matched to fair, partially fair, or unfair partners. Participants 8 rated attributions of harmful intent and self-interest after each interaction. In study 9 two (N=1011), a new sample of participants completed the same procedure and 10 additionally completed measures of anxiety, worry and interpersonal sensitivity. As 11 predicted, paranoid ideation predicted higher and faster overall harmful intent 12 attributions, whereas attributions of self-interest were unaffected, supporting the 13 sensitisation model. Contrary to predictions, neither worry nor anxiety predicted 14 harmful intent attributions while interpersonal sensitivity predicted decreased harmful 15 intent attributions. In a third exploratory study we combined data sets to examine the 16 effect of paranoia on trial by trial attributional changes when playing fair and unfair 17dictators. Paranoia predicted a greater reduction in harmful intent attributions when 18 playing a fair but not unfair dictator, suggesting paranoia may also exaggerate the 19 volatility of beliefs about the harmful intent of others. 20 21

Altered dopamine transmission is thought to influence the formation of persecutory delusions. However, despite extensive evidence from clinical studies there is little experimental evidence on how modulating the dopamine system changes social attributions related to paranoia, and the salience of beliefs more generally. Twenty seven healthy male participants received 150mg L-DOPA, 3 mg haloperidol, or placebo in a double-blind, randomised, placebo-controlled study, over three within-subject sessions. Participants completed a multi-round Dictator Game modified to measure social attributions, and a measure of belief salience spanning themes of politics, religion, science, morality, and the paranormal. We preregistered predictions that altering dopamine function would affect (i) attributions of harmful intent and (ii) salience of paranormal beliefs. As predicted, haloperidol reduced attributions of harmful intent across all conditions compared to placebo. L-DOPA reduced attributions of harmful intent in fair conditions compared to placebo. Unexpectedly, haloperidol increased attributions of self-interest about opponents’ decisions. There was no change in belief salience within any theme. These results could not be explained by scepticism or subjective mood. Our findings demonstrate the selective involvement of dopamine in social inferences related to paranoia in healthy individuals.

Autism spectrum disorders involve pervasive developmental abnormalities in social communication, socio-emotional reciprocity, and restricted and repetitive interests. They are likely to be caused by abnormalities in multiple brain regions, including 'underconnectivity' between components of networks subserving a variety of cognitive functions.