Neural Influences on Multi-Sensory Integration in Complex Settings
March 09, 2010
This project is the first in a new line of Army Research Laboratory basic research methods and tools that provide in sight for later application of neuroscientific principles to operational environments. ARL is investigating the neural underpinning of inter-sensory integration, potential interactions between senses, and the development of physiological markers to monitor and use this information within operational environments. Soldiers are continually bombarded with information from many directions and senses - not only by potential threats in the battlefield but also from increasingly complex display and control systems.
Here, ARL has shown that when participants focus on a difficult task, the clarity with which background, non-attended sounds are represented in the brain depends heavily on whether they are working within the visual or auditory sense at the time. Importantly, this effect occurs at even the most basic levels of hearing, which has strong implications for the design of alerts and displays. Additionally, ARL has identified computational algorithms for assessing the amount of individual variation in the automatic "entrainment" of certain cerebral responses to these background sounds, which will allow an appreciation for differences in Solders' abilities and limits of processing such complicated information.
Despite decades of research on how people maintain attention and associated brain states, there remains a lack of understanding in how the neural processes underpinning the allocation of attention actually affect function in complex, dynamic environments. This mostly stems from previous research being conducted within fairly limited laboratory settings, with the focus only on a single sensory system at a time.
Researchers use high-density electroencephalography (EEG) to assess varied levels of brain function while participants perform fairly difficult visual and auditory discrimination tasks. On- and off-line analyses then focus on the degree to which the non-attended sounds are processed at numerous levels in the nervous system, from initial reception to high level computation.
Continued testing aims to extend the findings to larger samples and establish the efficacy of the processing and identification algorithms for varied tasks and situations. An understanding of how the brain functions in complex, operational environments means that we can exploit this knowledge to effect better system design, which in turn could lead to improved Soldier performance such as more efficient multi-tasking, information processing and decision making.