We cannot communicate with our departed one's, that is what i believe. I have heard about people who calim that they talk to departed one's through meditation.But cannot say if thatz true..Logically we cannot.There are 10 (jeevan) parts for a soul, and amoung this 9 gets seperated from the body after death and the last one called "Dhanjayan" remains in the atmosphere.When we do the karma(pinda dhan) after one year, "Dhanjayan" gets seperated and joins with the other 9.Once this is done,it is ready for taking another life.As you know when a person is alive soul gets information about himself or others from the brain..it reads the area in brain where the information has been stored..You might have heard people lose memory and they cannot indentify parents , friends and himself, if some part of the brain is damaged..but he is still alive and lives life but cannot indentify people..So after death when soul leaves body it looses all the information..So how these spiritual centres can indentify your departed one's or how will your departed one's will indentify you for communication...See this just my idea..may be wrong
