Auditory cortex measurement with fNIRS
A little while ago we received an interesting request to measure both the temporal lobe and frontal lobe simultaneously in children with behavioral disabilities. The setup time needs to be reduced to an absolute minimum due to the behavioral nature of these children. To realize this, we came up with a combination of two of our devices, the Octamon and the Oxymon. With the Octamon the whole frontal lobe can be measured with virtually no setup time, while the Oxymon is capable of measuring in hairy areas like the temporal lobe.
As a prove of concept the auditory cortex was engaged using an auditory task. In this single participant pilot study, an activation of the auditory cortex located in the temporal lobe was observed while no major changes in oxygenation in the frontal lobe are visible. After approximately 5 seconds a clear hemodynamic response can be seen in the temporal lobe near the auditory cortex while the frontal lobe remains almost constant.
This is an example of two Artinis devices working together simultaneously, producing one single synchronized data file which can be assessed with our proprietary Oxysoft software. This can be done with any combination of Artinis devices, enabling e.g. combining simultaneous brain and muscle measurements using NIRS.
The data has been projected to the MNI-ICBM-152 (2009) template, the time range is sped up by a factor two, the position of transmitters and receivers are estimates and the color scale is optimized for contrast. This is a single participant pilot experiment, no conclusions should be drawn based on this data.
EEG and fNIRS are complementary measuring techniques. EEG measures electrophysiological brain activation, that is the electromagnetic field created when neurons in the brain are firing. fNIRS measures the hemodynamic response, that is the change of oxygen in the blood when a brain region becomes active. By combining EEG and fNIRS, a more complete picture of brain activity is obtained: activation of neurons and energy demand of neurons.
Over the years we have developed both hardware-based and software-based options for data synchronization. In this blog we will explore the different options and discuss the advantages and disadvantages of each.
A common question we get from our customers is what is a baseline and how to use it. Generally with fNIRS, the absolute values are arbitrary. The period before a stimulus is often referred to as the baseline. In this blog we will describe the do's and don'ts of baselines.
At Artinis we consider ultimate success to be good publications by our customers. To see how we are doing we have systematically searched Google Scholar for NIRS and fNIRS publications.
An insight guide into NIRS head-cap development by our designer Wout Kregting
Get an impression of our latest fNIRS device on Youtube.
Auditory cortex measurement with fNIRS.