“You’re gaslighting me.” These days, it’s a phrase tossed around casually, sometimes in jest, sometimes over the smallest fib.
But real gaslighting is far more serious.
A few carefully chosen words can serve as deliberate psychological manipulation, enough to make someone question their memory, judgment, and even their grip on reality.
It’s not just lying. It is a calculated effort to distort reality until a person begins to distrust their own mind.
By Hatty Willmoth
According to neuroscientist Dr Eamonn Walsh, the human brain is surprisingly vulnerable to this kind of influence.
The brain as “neural code”
Walsh, who studies hypnosis and verbal suggestion, argues that our perception of reality is constructed internally and can therefore be influenced externally.
“The world really only exists inside your head,” he explains.
“Language is a kind of code. As we’re speaking to each other, that code is transferred into neural activity.”
What we hear, remember, and even perceive visually is filtered through this internal neural framework.
And according to Walsh, that framework can be manipulated.
“Our reality is sensory,” he says, “based on our memory and beliefs about the world, and each one of those things can be manipulated, because it’s just neural code.”
The power of verbal suggestion
The term “gaslighting” originates from the 1944 film Gaslight, in which a husband manipulates his wife into doubting her sanity by denying changes she can clearly see happening around her.
That same psychological process can occur in real life.
Researchers have demonstrated that verbal suggestion alone can alter perception.
In one study by American researcher Stephen Kosslyn, participants were shown colourful grids and told the colours were fading.
By the end of the experiment, many genuinely reported seeing greyscale images.
Another group viewed monochrome images but were told they were becoming vibrant with colour. Participants reported seeing colours that did not exist.
A recreation of the vibrant Mondrian grid used by Kosslyn and colleagues in their study of colour perception in highly hypnotisable subjects.
Brain scans showed corresponding neural activity suggesting participants were not simply pretending.
Walsh says this demonstrates how easily perception can be altered through language and suggestion.
The slippery slope of manipulation
Gaslighting rarely happens all at once.
Instead, Walsh says it develops gradually, step by step, much like hypnosis.
In hypnotic experiments, participants are slowly guided into altered perceptions through attention, focus, repetition, and suggestion.
Manipulative relationships often function in the same way.
Traditional hypnotism often uses techniques such as counting, breathwork, or repetitive focus to make the mind more receptive to suggestion. Credit: bymuratdeniz via Getty
A manipulator may slowly isolate someone from friends or external viewpoints while repeatedly undermining their confidence in their own memories and perceptions.
Because trust and emotional attachment are already present, the victim may begin accepting the manipulator’s version of events over their own experiences.
Over time, this can create dependence on the manipulator’s interpretation of reality.
Who is most vulnerable?
According to Walsh, some people are naturally more suggestible than others.
However, suggestibility is not linked to intelligence.
Instead, it appears connected to a psychological trait known as “absorption”, the tendency to become deeply immersed in sensory or imaginative experiences.
For example, highly suggestible individuals may vividly imagine flames as being alive or become deeply emotionally engaged with stories and mental imagery.
People who strongly immerse themselves in imagination or sensory experiences may be more suggestible. Credit: Jose A. Teijeiro via Getty
Walsh notes that suggestibility can also have advantages, including creativity, imagination, and even an increased ability to block pain.
But it may also leave some individuals more vulnerable to manipulation.
“Over time, suggestible individuals may more easily accept the gaslighter’s version of events, doubting their own emotions or reasoning,” Walsh says.
Alcohol and drugs may further increase vulnerability to suggestion and manipulation.
Protecting yourself from gaslighting
Walsh recommends staying alert to subtle manipulative phrases such as:
“I never said that.”
“You’re remembering it wrong.”
“Nobody else saw that happen.”
He advises people to maintain trusted social connections and seek external verification when reality feels uncertain.
Keeping written records, diary entries, or saved messages may also help reinforce confidence in one’s own memory.
Most importantly, Walsh says manipulation often begins subtly.
One small distortion can gradually become many.
And by the time someone realises what is happening, their confidence in their own perceptions may already have been significantly weakened.
About the expert
Dr Eamonn Walsh is a neuroscientist at King’s College London, where he serves as Programme Lead for MSc Neuroscience and Reader in Neuroscience Education.
His research focuses on how verbal suggestion can alter the brain’s representation of the body and perception of reality.