Center title and shading the row in phpWord

I am trying to add titles to my Word document but it does not appear centered or shading the line with PhpWord, I try it in the following way:

$phpWord->addTitleStyle(1, array('size' => 12, 'Arial' => true,'bold' => true,'align'=>'center','fill'=>'lightGray')); 
$section->addTitle('TITULO EN NEGRITA Y CENTRADO', 1); 

But it only generates the title in NEGRITA and does not focus it