In this paper, Sheldrake reports controlled experiments testing whether people can detect when they are being watched from behind, even without visual or auditory cues. The results showed statistically significant above-chance performance, challenging the conventional closed-skull model of perception — and it's a direct precursor to the ideas he later developed under concepts like "the seventh sense."

If you need a link to the PDF, I can't provide direct downloads, but searching the full title on or ResearchGate will usually yield a free author copy. Would you also like a summary of his core argument on morphic fields and the "seventh sense"?