The opening sequence shows 'animal hypnotism'. These are examples of 'tonic immobility', where an animal freezes when faced by a threat. Many species, possibly even humans, display this reflexive behavior.
This episode was aired in 1956, during the height of the Bridey Murphy mania. In 1952 a self taught hypnotist with no background in psychology, 'regressed' a housewife to her supposed previous life as Bridey Murphy in 19th century Ireland. The housewife recounted enough details of this life to fill a best selling book and subsequent hit movie. However, when reporters investigated the details it turned out that Bridget Murphy never existed and the details about 19th century Ireland were all wrong.