Decoding the Mystery: Sensing the Presence of 'Someone' in the Room Despite Being Alone

In 2006, Swiss physicians documented an extraordinary case in the Research Report journal. A patient with a brain tumor claimed to witness up to seven versions of himself simultaneously present in a room.

If you've ever experienced these peculiar sensations, you're not alone: Entering a hotel room, or sometimes your own home, and feeling like 'someone' is there – even though, upon searching, you are clearly alone.

Similarly, walking down a dimly lit street and sensing someone walking behind you, yet when you turn around, the path remains empty, devoid of anyone.

Most frightening is the sensation of waking up, jolting to the awareness of someone sitting silently by your side, present for a while without making any sound or movement.

But once again, when you blink, that figure vanishes. In the state of half-awake, half-asleep, you're left unsure of reality – Was someone truly sitting beside your bed?

In these situations, most people tend to think they've encountered ghosts. However, scientists assert: All these seemingly paranormal experiences can be explained by 21st-century neuroscience.

The feeling of an invisible 'someone' being genuinely present stems from a disruption in the brain, related to regions processing your spatial awareness.

A bizarre entry in medical literature: Man sees 7 versions of himself in the same room

This involves a 41-year-old Swiss ceramic artist, referred to as 'PH,' whose case was reported by doctors at the University Hospital Zurich in the Research Report journal in 2006. PH visited the clinic with symptoms of fatigue, dizziness, and loss of appetite.

Occasionally, he experienced seizures, which led him to seek medical attention. During the examination, PH vividly recounted an event that happened three months prior, which he believed marked the onset of his condition.

One night, while sleeping, PH suddenly awoke to find his body split in two: The left side remained normal, while the right side was physically and consciously separated.

Besides the right side of his body, PH also saw a man around 50 years old. Despite the stranger looking older, with different blonde hair, the patient felt this man was still a part of himself.

Intrigued, PH stood up, walked toward the blonde-haired man to get a clear look at his face. Strangely, when PH stood up, the man also stood up, and when PH looked to the right, the blonde man also turned his gaze to the right.

This duplicate mimicked exactly the actions of PH.

The strangeness didn't stop there. As PH tried to scrutinize the blonde man, he suddenly realized to his right there was another group of people. 'About 2 meters from me, I saw a woman around 50 with a blonde bun. About 4 meters further, there were two girls, both around 20,' recounted PH.

Lastly, about 20 meters at the end of the room, he saw a boy of indeterminate age. The boy often stood on the blurred boundary between light and dark, sometimes appearing, sometimes disappearing.

Intuitively, PH believed that a total of 7 people were present in the room with him. All 7 had a connection to each other and to him. PH referred to them as a 'family,' believing that this entire family was 'sharing the same soul' with him.

As proof, when PH stood up, everyone else stood up, when he knelt, everyone knelt. When PH looked to the right, everyone looked to the right, except for the two girls who stood chatting while looking at him.

At the farthest distance at the end of the room, that boy was the only entity with relatively independent actions. He played comfortably, appearing and disappearing, quite independent of PH's actions.

What happened to this man?

With PH's peculiar report, doctors at the University Hospital Zurich subjected him to a series of tests, brain imaging, and cognitive assessments. Results showed his vision was entirely normal. PH also performed well in memory, psychological, and nervous system tests.

Only the brain scan revealed a tumor in the left hemisphere. The tumor had invaded and affected two areas, the posterior island and the temporal-parietal junction (TPJ).

Doctors explained this might be the reason PH saw different versions of himself coexisting in the room. The posterior island is the brain region processing internal body information, linked to how you perceive your body, from the heartbeat in your chest to feelings and intuitions in cognition.

The junction of the temporal parietal is where the summit and the parietal summit in the brain meet. Here, our brain processes a range of sensory information, allowing it to draw a map locating us in space.

Conduct a small experiment with this brain region by closing your eyes. Can you still vaguely imagine where you are sitting in the room, knowing the positions of obstacles, chairs, and the boundaries of the walls, right?

Now, use your right hand to touch your left shoulder, even the position of each finger on your left hand. If your temporal parietal junction is functioning well, you can perform these movements accurately without opening your eyes.

That's how the TPJ defines the boundaries of your body with the external space, locates them in the room, and creates a virtual map showing your presence in the world.

Through experiments on volunteers, scientists have demonstrated that stimulation in the temporal parietal junction area creates strange experiences, where the stimulated person can see or perceive their own body from a different perspective.

Stimulating TPJ in the left hemisphere creates a shadow behind the volunteer, while stimulating TPJ in the right hemisphere creates an Out-of-Body sensation, making the volunteer report the feeling of seeing themselves from a third-person perspective:

A replication experiment of the presence of others in the room

Returning to PH, this patient has a tumor compressing the temporal parietal junction in the left hemisphere. Therefore, doctors suspect it has disrupted the TPJ's activity, causing the man to see a series of apparitions appearing on his right side.

Literature has also documented many similar cases, such as a patient shot in the left brain in 1959, claiming his body was later divided into three parts. He saw two other versions of himself on the left and right side of the physical body in action.

In 1924, a 32-year-old schizophrenic patient even reported seeing 'seven entities emerging from myself, one after another... All of them look like me, mimicking actions according to my thoughts'.

But the truth is, you don't need to have a brain tumor, get shot in the head, or suffer from schizophrenia to experience these strange phenomena.

In 2014, Swiss neuroscientist Olaf Blanke conducted an experiment demonstrating how the human brain can easily be deceived to create out-of-body illusions or feel the presence of a stranger in the room.

The experiment involved a robot 'master/slave', capable of mimicking each other's behaviors:

Participants in the experiment take turns standing between these two robots. They control the master robot, while the slave robot replicates precisely the movements of the master robot, creating pokes on the volunteer's back.

When the pokes synchronize with each other, and there is no time delay, blindfolded volunteers report a strange sensation in which they feel as if they are standing behind and poking their own back:

However, when the programmed slave robot is reprogrammed to create pokes with delays and asynchronously with the master robot, the strange sensation turns into feeling like someone in the room is standing behind them and performing those pokes:

Brain scans conducted during the experiment further confirm the involvement of the solar crown junction region in this sense of presence. Some Parkinson's patients participating in the experiment are those most severely affected.

Scientists explain: Whenever we perform a movement, our brain makes a series of predictions about what will happen to our senses. For example, when you prepare to clap your hands, your brain is already prepared for new images and sounds, all happening at the right time.

But if you mess that up, strange things start to happen. The robot is breaking your sensory expectations. It makes you start feeling like what you're doing originates from someone else.

Many Parkinson's patients in their daily lives still report that they perceive someone else being in the room with them. This makes them particularly susceptible to the virtual touches of the robot.

Two of the volunteers in this experiment felt the presence so strongly that they shuddered and had to pause the experiment midway.

In summary, through clever experiments, neuroscience studies, and case reports of patients in the past, scientists have demonstrated to us that the sense of presence of a 'someone' around you doesn't come from the sixth sense or the ability to see ghosts.

Instead, this is simply a temporary desynchronization between signals in the brain, often associated with an area of the brain called the temporoparietal junction (TPJ). Patients with brain injuries, conditions like Parkinson's, cancer, or psychotic disorders are the most prone to experiencing this sensation.

But even regular individuals in certain situations, such as when struggling to sleep, facing stress, and exhaustion, can also experience this strange sense of presence.

Reference Theconversation, Sciencedirect, Time, Vice, BMC