The measured time course of subjects' button press responses associated with auditory target hits were convolved with a hemodynamic response function (HRF) for both the sparse and continuous imaging sessions.
In this study, we compared sparse and continuous scanning methods to identify the optimal approach to investigate acoustically evoked cortical, thalamic and midbrain activity in the cat.
Figure 10 shows mean activations during sparse and continuous imaging conditions.
These factors would tend to minimize the acoustic differences between sparse and continuous imaging conditions.
Functional data sets from sparse and continuous imaging were analyzed separately for each subject.
However, aside from enhanced activation magnitudes and a slight anterior/medial shift in distributions, data from sparse and continuous imaging conditions produced similar functional maps.
Figure 8 shows overlaid activation maps to loud (90 dB) and soft (70 dB) sounds averaged across sparse and continuous imaging conditions and hemispheres.
However, there were significant differences in the Anterior-Posterior (A-P) distributions during sparse and continuous Image Acquisitions (F(15,120) = 2.83, p<0.04).
We also created maps that combined data from sparse and continuous imaging conditions using statistical parametric z-score maps were that obtained by converting sparse and continuous F-maps into equivalent z-score maps and then combining the z-scores at each point on the cortical surface.
The IPNLMS and IPAPA algorithms perform very well for both sparse and non-sparse systems.
