FETZ, Eberhard

<p>Apr 11, 2016 08:56 PM</p>

<p>see lecture notes below &nbsp;from his MBC talk today..</p>

<p>&nbsp;
Closed-loop interactions between the brain and implantable computers open new opportunities for brain research and clinical applications.&nbsp;</p>

<p>We are investigating the consequences of direct connections produced by an <strong>autonomous implantable bidirectional brain-computer interface [BBCI</strong>].</p>

<p>This device consists of battery-powered electronics connected to <strong>electrodes that record the activity of motor cortex cells and/or muscles</strong>.&nbsp;</p>

<p>It <strong>operates continuously during free behavior and generates activity-dependent stimulation of the brain or spinal cord</strong>.&nbsp;</p>

<p>The <strong>neural activity is processed by a programmable computer chip</strong> and can be converted in <strong>real-time to activity-contingent stimul</strong>i.</p>

<p><strong> A promising application is to bridge impaired biological connections</strong>, a paradigm that was demonstrated for <strong>cortically controlled electrical stimulation of paralyzed forearm muscles</strong> (Moritz et al, Nature, 2008), and<strong> cortically controlled intraspinal stimulation </strong>(Nishimura et al, Frontiers in Neuroscience, 2013).</p>

<p>Given sufficient time to adapt to an implanted BBCI the brain could learn to incorporate such artificial recurrent connections into normal behavior.</p>

<p><strong> A second application of the BBCI is to produce Hebbian plasticity through spike-triggered stimulation; this can strengthen neural connections,</strong> as demonstrated for neighboring motor cortical sites (Jackson et al, Nature, 2006).</p>

<p>Similar plastic changes can be produced <strong>in motor cortex by EMG-triggered stimulation </strong>(Lucas &amp; Fetz, J. Neurosci. 2013). <strong>The strength of corticospinal connections can be modified by cortically triggered intraspinal stimulation,</strong> in a manner consistent with spike-timing dependent plasticity (Nishimura et al, Neuron, 2013).&nbsp;</p>

<p><strong>Such activity-dependent stimulation has clinical potential for targeted strengthening of neural connections weakened by stroke or injury</strong> (Edwardson et al Exp. Brain Res. 2013).</p>

<p>A third application of the <strong>BBCI is to deliver intracranial reinforcing stimuli contingent on patterns of neural or muscular activity, thus implementing prolonged periods of operant conditioning during free behavior</strong>. The novel BBCI paradigm has numerous potential applications, depending on the input signals, the computed transform and the output targets.
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<p>hjhjh</p>