Journal of neuroscience methods
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J. Neurosci. Methods · Jun 2008
Multicenter StudyDefault mode network as revealed with multiple methods for resting-state functional MRI analysis.
Recently, human brain activity during a resting-state has attracted increasing attention. Several studies have found that there are two networks: the default mode network and its anti-correlation network. Some studies have subsequently showed that the functions of brain areas within the default mode network are crucial in human mental activity. ⋯ Our results showed the existence of these two networks prominently and consistently during a resting- and conscious-state across the three methods. This consistency was exhibited in four independent groups of normal adults. Moreover, the current results provided evidences that the brain areas within the two anti-correlated networks are highly integrated at both the intra- and inter-regional level.
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J. Neurosci. Methods · Jun 2008
A voltage-controlled current source with regulated electrode bias-voltage for safe neural stimulation.
A current source for neural stimulation is presented which converts arbitrary voltage signals to current-controlled signals while regulating the offset-voltage across the stimulation electrodes in order to keep the electrodes in an electrochemical state that allows for injecting a maximum charge. The offset-voltage can either be set to 0V or to a bias-voltage, e.g. of a few 100mV, as it can be advantageous for fully exploiting the charge injection capacity of iridium oxide electrodes.