Figure 1.

Auditory responses using fMRI and ERP. (a) Anatomical MRI image of live, sedated zebra finch. (b) Functional MRI image with area of activation (voxels with activity above significance threshold) shown here for colony males averaged over birds and stimuli. In the statistical parametric maps, each colored voxel indicates stimulus-related activity (during stimulus) that is significantly above baseline activity (silence) (p <0.005, multiple test corrected); color scale indicates correlation coefficient between signal intensity and the stimulus indicating function. Yellow voxel indicates greater significance of activation (higher correlation coefficient) and red indicates lower significance. (c) Functional image from coronal view shows medial activation (sagittal slices 4 and 5) in the posterior forebrain. FMRI analysis focused on the size of the active area in this region of interest. (d) Epidural electrode cap. (e) Spatial distribution of first principal component of electrode potentials indicates that the main variability (74%) across time, stimuli and birds in the event related potentials is in the rostro-caudal direction. (f) Example of event related potential (ERP) waveforms in the anterior and posterior electrodes in response to a short conspecific call.