Conversation effects on neural mechanisms underlying reaction time to visual events while viewing a driving scene: fMRI analysis and asynchrony model.

This neuroimaging study investigated the neural mechanisms of the effect of conversation on visual event detection during a driving-like scenario. The static load paradigm, established as predictive of visual reaction time in on-road driving, measured reaction times to visual events while subjects watched a real-world driving video. Behavioral testing with twenty-eight healthy volunteers determined the reaction time effects from overt and covert conversation tasks in this paradigm. Overt and covert conversation gave rise to longer visual event reaction times in the surrogate driving paradigm compared to just driving with no conversation, with negligible effect on miss rates. The covert conversation task was then undertaken by ten right-handed healthy adults in a 4-Tesla fMRI magnet. We identified a frontal-parietal network that maintained event detection performance during the conversation task while watching the driving video. Increased brain activations for conversation vs. no conversation during such simulated driving was found not only in language regions (Broca's and Wernicke's areas), but also specific regions in bilateral inferior frontal gyrus, bilateral anterior insula and orbitofrontal cortex, bilateral lateral prefrontal cortex (right middle frontal gyrus and left frontal eye field), supplementary motor cortex, anterior and posterior cingulate gyrus, right superior parietal lobe, right intraparietal sulcus, right precuneus, and right cuneus. We propose an Asynchrony Model in which the frontal regions have a top-down influence on the synchrony of neural processes within the superior parietal lobe and extrastriate visual cortex that in turn modulate the reaction time to visual events during conversation while driving.

Cortical activation during menopausal hot flashes.

OBJECTIVE: To determine regions of brain activation associated with menopausal hot flashes and sweating. DESIGN: Controlled laboratory study. SETTING: University medical center. PATIENT(S): Symptomatic postmenopausal women and asymptomatic eumenorrheic women. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Brain activation measured by functional magnetic resonance imaging. RESULT(S): Significant (P<.001) areas of activation during hot flashes in symptomatic women included the insula and anterior cingulate cortex. Sweating in the eumenorrheic women was associated (P<.001) with activity in the anterior cingulate and superior frontal gyrus. CONCLUSION(S): Activation of the insular cortex is associated with the "rush of heat" described during menopausal hot flashes. Thermoregulation in humans appears to be represented in a distributed cortico-subcortical network rather than in a single localized structure.

Cognitive avionics and watching spaceflight crews think: generation-after-next research tools in functional neuroimaging.

Confinement and isolation have always confounded the extraordinary endeavor of human spaceflight. Psychosocial health is at the forefront in considering risk factors that imperil missions of 1- to 2-yr duration. Current crewmember selection metrics restricted to behavioral observation by definition observe rather than prevent performance degradation and are thus inadequate when preflight training cannot simulate an entire journey. Nascent techniques to monitor functional and task-related cortical neural activity show promise and can be extended to include whole-brain monitoring. Watching spaceflight crews think can reveal the efficiency of training procedures. Moreover, observing subcortical emotion centers may provide early detection of developing neuropsychiatric disorders. The non-invasive functional neuroimaging modalities electroencephalography (EEG), magnetoencephalography (MEG), magnetic resonance imaging (MRI), and near-infrared spectroscopy (NIRS), and highlights of how they may be engineered for spacecraft are detailed. Preflight and in-flight applications to crewmember behavioral health from current generation, next generation, and generation-after-next neuroscience research studies are also described. The emphasis is on preventing the onset of neuropsychiatric dysfunctions, thus reducing the risk of mission failure due to human error.