Re-posted for those who are not telepathically inclined.
This is my opinion on the subject:
I will not go into the debate of whether or not aliens exist, since that is being addressed so eloquently by others on different threads.
First off, there is no physical model concerning the brain to explain telepathy. The impulses that form thoughts in the brain travel through a network of neurons. Basically, a neuron communicates by creating an electrical pulse which triggers a chemical response in the adjoining neuron. The information travels through a physical biological medium (synapses); in other words, it's all hard-wired. So there are no brain-waves being "transmitted" (the operative word) from within our skulls, nor are there receivers located in the brain to pick up any stray brain-waves even if they did exist.
Also, there are no brain-waves created by the human brain that correlate specifically to individual thoughts and/or ideas. The brain-waves that are created (Beta, Alpha, Theta and Delta) indicate at what energy level the brain is functioning at. They DO NOT show what a person is thinking or feeling (trust me, I've been through enough EEG's to know this).
The biggest failure of the claim of ET using telepathy to communicate with humans is the fact that, even if ET had evolved to use some form of transmitted electrical impulse thought transference, humans would not be able to decipher their communication (assuming it were possible to pick-up such transmissions in the first place). The ET brain-wave would require convoluted modulation (coding) which would be much more complex than simple speech. (As an example, try reading an entire paragraph composed in simple binary). Simply put, the human brain is not constructed to receive or decipher any form of brain-wave transmissions.
Something else I was discussing with a friend is the claim that humans may be able to send telepathic communications between themselves. She brought up the stories (most often involving a parent/child relationship) of one person receiving a sudden thought or feeling regarding another person who is some distance away (up to several hundred miles in most stories). The first person calls the second person, only to discover that that person has died, suffered an accident or an attack of a sudden illness (heart attack, etc.). At first glance, it seems as though the second person's experience was instantaneously transferred to the first, breaking the rules concerning relativistic speeds.
But closer examination of such cases reveals some telling discrepancies and inconsistencies that makes such claims seem not as special as first told. The most glaring fault with the reports of this kind is that no evidence has ever been presented to verify that the times of both the accident/illness and the supposed telepathic transfer was in perfect sync (see example below).
Furthermore, these types of cases almost exclusively involve two people who are intimate or related to each other, indicating that there is a preconception or foreknowledge of the individuals physical health or psychological/emotional state (regarding death/illness in the first instance, and anxiety/fear of a journey or occupation in the second). Put another way, the so-called "telepathic receiver" already has an idea as to what to expect when first contacting the second person. One story from the mid-eighties' went as follows:
"Marsha M. was returning home from shopping for groceries when she suddenly felt a sharp pain in her back. The first though she had was of her father, Dean. She immediately got on the phone and called her parents, who lived two-hundred and fifty miles away. She was shocked to discover that her father had slipped off a ladder while working on the gutters and had fallen two stories; dying from the spinal injuries he received."
This story was not exactly a complete hoax, but nor was it proof of telepathy as first claimed. The woman's father was a retiree in his late-sixties suffering from advanced arthritis who insisted on doing potentially dangers yard work himself (he had experienced a similar fall from a ladder the year before while trimming branches from a tree, but had not suffered any serious injuries). Marsha had spoken with her father two days prior to the incident, yet in retelling her story, she insisted that she had not spoken to him for several months (her mother said that Marsha had warned Dean not to do any dangerous yard work during that conversation, but later recanted her statement). Marsha herself had complained of back pain for years, and since she had just finished loading a car full of groceries, the pain she felt could easily be explained by the stress she had put on her back.
Most damning of all, however, was the time involving the phone call. Dean had been taken to hospital in an ambulance and pronounced dead at the scene around ten-thirty AM. Phone records show that Marsha didn't make her call until just after four PM, a discrepancy of nearly six hours.
This is just one example of perhaps thousands, but the points remain:
1) There is no verifiable proof/evidence that has been submitted to support telepathy.
2) There are usually mundane facts to explain those otherwise extraordinary claims.
No, there is no physical model to explain telepathy. It'll have to remain as a subject for science fiction (and abductee claims).
So that, I believe, is the only reasonable conclusion one can reach regarding this subject.