Attention and TNT (Targeted Neuroplasticity Training) in Los Vagus

Abstract - Part 1

Current studies of task-related response in a newly defined tertiary cortical area - the rostral region in the ventral posterior area (VPr) have lead to several new insights about processing in higher order auditory cortex. The VPr area is defined physiologically by differences in response latency and frequency tuning from adjacent secondary areas. Tonotopic mapping of the auditory cortex in the posterior ectosylvian gyrus (PEG) reveals a reversal in frequency from the high frequency area in PPF to low frequency and broad-band responses that mark the dorsal boundary of VPr. This tonotopic reversal boundary is also reflected by a clear increase in response latency in VPr. Compared to responses in lower auditory cortical areas (primary auditory cortex (A1) and secondary areas (PPF and PSF in dorsal PEG)), responses in VPr in the awake, quietly listening ferret show multiple differences - longer latencies, broader tuning, decreased linearity.

A key distinctive property of VPr is that it shows the long-term effect of task learning on neuronal encoding and in shaping responses to task-relevant stimuli. Trained animals showed enhanced responses in VPr to behaviorally learned target stimuli even in the quiescent, non-task, passive listening condition. Such responses were not observed in lower auditory areas, nor were they observed in VPr in a task-naïve animal.In VPr, there was an additional increase in contrast between target and reference stimuli during active task performance (i.e. enhanced target responses and suppressed reference responses in active task conditions in the behaving ferret).In addition to onset and sustained responses to task stimuli, VPr neurons also showed sustained post-stimulus responses following target stimuli during active task performance. These post-stimulus responses coincided with the time course of the post-stimulus shock window and may encode the imminent danger of the shock and be part of an early audiomotor alerting response. 

Abstract - Part 2

A variety of studies have shown therapeutic effects of vagal nerve stimulation (VNS) and other studiessuggest that it may possible use as a way to enhance neuroplasticity and behavioral learning. Many of these effects may be due the known effect of VNS on release of neuromodulators acetylcholine and norepinephrine. I will review the background and rationale for current and ongoing studies of VNS funded by DARPA.