Another study found that vivid visualization accompanied by emotion triggered more activation in visual processing systems than did images alone. (discovermagazine.com)
So this is related to the heart rate in the sense that a higher intensity means both a higher heart rate and more activation of the aerobic (Type I) muscle fibers. (philmaffetone.com)
Another study found that vivid visualization accompanied by emotion triggered more activation in visual processing systems than images alone did. (discovermagazine.com)