Using a multi-channel platinum surface electrode array, recordings from cat primary visual cortex were obtained in response to visual stimuli, and electrical stimuli delivered using the elements of the array itself. Neural responses to electrical stimuli were consistent, regardless of stimulus polarity or leading phase (biphasic), although thresholds were lower for monophasic than biphasic pulses. Both visual and electrical stimuli reliably evoked responses with characteristic components, which interacted with each other in a nonlinear summation showing first facilitation then suppression during the window of interaction. The chronaxie for eliciting threshold cortical responses was about 100 νs, and the charge density with a pulse width of 50-100 νs was around 55 νC cm-2. These data form the basis of understanding the types of cortical responses to stimuli delivered by devices suitable for chronic implantation. © 2008 IOP Publishing Ltd.

Item Type:	Refereed Article
Research Division:	Biomedical and Clinical Sciences
Research Group:	Neurosciences
Research Field:	Sensory systems
Objective Division:	Health
Objective Group:	Clinical health
Objective Field:	Clinical health not elsewhere classified
UTAS Author:	Kirkcaldie, MTK (Dr Matthew Kirkcaldie)
ID Code:	55611
Year Published:	2008
Web of Science® Times Cited:	8
Deposited By:	Anatomy and Physiology
Deposited On:	2009-03-12
Last Modified:	2009-06-03
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