Functional connectivity of specific brain networks related to social and communication dysfunction in adolescents with attention-deficit hyperactivity disorder.

BACKGROUND: Adolescents with attention-deficit hyperactivity disorder (ADHD) may have impaired social cognition and communication. However, the functioning of the brain networks involved in the social cognition and communication impairment in ADHD patients remains unclear. METHODS: In total, 18 adolescents with ADHD and 16 age- and sex-matched typically developing adolescents (controls)-all of whom underwent a brain magnetic resonance imaging examination-were enrolled. Their parents filled out Swanson, Nolan, and Pelham IV (SNAP-IV) and Social Responsiveness Scale (SRS) questionnaires. Functional connectivity analyses based on the default mode network, frontoparietal network, and cinguloopercular network were performed. RESULTS: Compared with controls, adolescents with ADHD exhibited higher total and subscale scores on SNAP-IV and SRS. Higher SNAP-IV and SRS scores were associated with higher functional connectivity between the default mode network (ventromedial prefrontal cortex) and cinguloopercular network (anterior insula) and between the FPN (dorsolateral and prefrontal cortex) and cinguloopercular network, but with lower functional connectivity between the default mode network (posterior cingulate cortex) and frontoparietal network (inferior parietal lobule) and between the default mode network (precuneus) and cinguloopercular network (temporoparietal junction). DISCUSSION: Social cognition and communication impairment and ADHD may commonly share the aberrant functional connectivity in the default mode network, frontoparietal network, and cinguloopercular network.

A systematic review of task-based functional neuroimaging studies investigating language, semantic and executive processes in thought disorder.

The aim of the current systematic review was to synthesise the research that has investigated thought disorder (TD) using task-based functional neuroimaging techniques to target executive, language, or semantic functions. Thirty-five pertinent studies were identified from January 1990 to August 2016. Functional correlates of TD included the superior and middle temporal, fusiform, and inferior frontal gyri bilaterally, as well as the left and right cingulate cortex, the right caudate nucleus, and the cerebellum. TD-related increases and decreases in activation were both evident in most of these regions. However, the specificity of these correlates from general clinical and cognitive influences is unknown. The cortical regions implicated overlap with those thought to contribute to language and semantic systems. Cortico-striatal circuitry may also play a role in some aspects of TD through aberrant salience representation and inappropriate attentional prioritisation. To advance the field further, greater integration across structural, functional, and behavioural measures is required, in addition to non-unitary considerations of TD.

Smile and laughter elicited by electrical stimulation of the frontal operculum.

Laughter and smile are typical expressions of mirth and fundamental means of social communication. Despite their general interest, the current knowledge about the brain regions involved in the production of these expressions is still very limited, and the principal insights come from electrical stimulation (ES) studies in patients, in which, nevertheless, laughter or smile have been elicited very rarely. Previous studies showed that laughter is evoked by the stimulation of nodes of an emotional network encompassing the anterior cingulate, the superior frontal and basal temporal cortex. A common feature of these stimulation studies is that the facial expression was always accompanied by motor awareness and often by mirth, in line with the affective functions attributed to these regions. Little is known, in contrast, on the neural basis of the voluntary motor control of this expression. The objective of this study was to investigate the effect of ES of the frontal operculum (FO), which is considered a crucial node for the linkage of the voluntary motor system for emotional expression and limbic emotional network. We report the case of ES applied to the frontal operculum (FO) in four patients with drug-resistant focal epilepsy undergoing stereo-electroencephalographic (SEEG) implantation of intracerebral electrodes. In all patients, ES applied to the FO produced laughter or smile. Interestingly, in one patient, the production of a smiling expression was also clearly accompanied by the lack of motor awareness. Since the lack of motor awareness has been previously observed only after the stimulation of the voluntary motor network, we speculate that FO is involved in the voluntary control of facial expressions, and is placed at the interface with the emotional network, gating limbic information to the motor system.