def _pearson_correlation(self, imgs_to_decode):
        """ Decode images using Pearson's r.

        Computes the correlation between each input image and each feature
        image across voxels.

        Args:
            imgs_to_decode: An ndarray of images to decode, with voxels in rows
                and images in columns.

        Returns:
            An n_features x n_images 2D array, with each cell representing the
            pearson correlation between the i'th feature and the j'th image
            across all voxels.
        """
        x, y = imgs_to_decode.astype(float), self.feature_images.astype(float)
        return self._xy_corr(x, y)