Violence: heightened brain attentional network response is selectively muted in Down syndrome

Jeffrey S Anderson,Jared A Nielsen,Julie R Korenberg,Jamie O Edgin,Scott M Treiman,Li Dai,Michael A Ferguson,Guido Gerig

doi:10.1186/s11689-015-9112-y

Abstract

BackgroundThe ability to recognize and respond appropriately to threat is critical to survival, and the neural substrates subserving attention to threat may be probed using depictions of media violence. Whether neural responses to potential threat differ in Down syndrome is not known.MethodsWe performed functional MRI scans of 15 adolescent and adult Down syndrome and 14 typically developing individuals, group matched by age and gender, during 50 min of passive cartoon viewing. Brain activation to auditory and visual features, violence, and presence of the protagonist and antagonist were compared across cartoon segments. fMRI signal from the brain’s dorsal attention network was compared to thematic and violent events within the cartoons between Down syndrome and control samples.ResultsWe found that in typical development, the brain’s dorsal attention network was most active during violent scenes in the cartoons and that this was significantly and specifically reduced in Down syndrome. When the antagonist was on screen, there was significantly less activation in the left medial temporal lobe of individuals with Down syndrome. As scenes represented greater relative threat, the disparity between attentional brain activation in Down syndrome and control individuals increased. There was a reduction in the temporal autocorrelation of the dorsal attention network, consistent with a shortened attention span in Down syndrome. Individuals with Down syndrome exhibited significantly reduced activation in primary sensory cortices, and such perceptual impairments may constrain their ability to respond to more complex social cues such as violence.ConclusionsThese findings may indicate a relative deficit in emotive perception of violence in Down syndrome, possibly mediated by impaired sensory perception and hypoactivation of medial temporal structures in response to threats, with relative preservation of activity in pro-social brain regions. These findings indicate that specific genetic differences associated with Down syndrome can modulate the brain’s response to violence and other complex emotive ideas.Electronic supplementary materialThe online version of this article (doi:10.1186/s11689-015-9112-y) contains supplementary material, which is available to authorized users.

Highlights

The ability to recognize and respond appropriately to threat is critical to survival, and the neural substrates subserving attention to threat may be probed using depictions of media violence
Activation maps for the five event-related contrasts studied are shown for Down syndrome and control samples in Fig. 1a, thresholded at p < 0.001, cluster corrected by false discovery rate, for display
Antagonist on screen, and violence contrasts, the activated regions closely conformed to the expected location of the dorsal attention network, including bilateral intraparietal sulcus, frontal eye fields, and middle temporal cortex

Summary

Introduction

The ability to recognize and respond appropriately to threat is critical to survival, and the neural substrates subserving attention to threat may be probed using depictions of media violence. Little is known about brain activation differences in individuals with Down syndrome. In another study of object recognition, correlations between brain activation and a metric of visuospatial ability were demonstrated in middle and dorsal frontal gyri in Down syndrome but in the occipital and parietal lobes for typically developing individuals [7]. Hyperconnectivity between the anterior temporal and anterior cingulate cortex, in addition to reduced within-network connectivity in the dorsal attention network, was observed by Pujol and colleagues [10]. These findings contributed to impaired scores on adaptive function testing [10]. For a near-infrared spectroscopy study performed on infants with Down syndrome, lower mean connectivity between channels was observed [11]

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Discussion

Conclusion