Polygraph Test UK Explained
and Why We Use P300 EEG Instead
Searching for a polygraph test or lie detector test in the UK? This page explains exactly how traditional polygraph testing works, typical accuracy levels, and key risks – and then shows why Deception Detection has chosen to work exclusively with advanced P300 EEG brainwave analysis instead.
Important: We do not offer traditional polygraph tests. All testing at Deception Detection uses P300 EEG technology – a modern, brain‑based approach to deception detection.
Looking for detailed science? Read our EEG guide: P300-response.html · or see how our infidelity testing uses EEG instead of outdated polygraph methods.
How a Traditional Polygraph Test Works
Polygraph tests – often called “lie detector tests” – have been used for decades in the UK and worldwide. They do not directly detect lies. Instead, they record indirect stress responses while carefully structured questions are asked.
Sensors, Charts and Stress Responses
A polygraph examiner attaches several sensors to the subject, typically including:
- Breathing bands around the chest and abdomen
- Blood pressure cuff around the arm
- Skin conductance (sweat) sensors on the fingers
- Sometimes additional movement sensors for fidgeting
As the examiner asks a series of control, irrelevant and relevant questions, the polygraph machine tracks changes in:
- Heart rate and blood pressure
- Breathing rate and pattern
- Skin conductance (sweat gland activity)
The underlying assumption is simple: deception causes stress, and stress produces measurable physiological changes.
Typical Accuracy: Around 60–70%
Independent research places traditional polygraph accuracy around 60–70% in real‑world conditions. Results can be heavily influenced by:
- General anxiety or nervousness (even when telling the truth)
- Medical conditions and medication
- Examiner technique and interpretation
- Deliberate countermeasures (physical or mental)
Key takeaway
A polygraph test does not read your mind or detect lies directly. It measures stress, which can be caused by many factors unrelated to deception. This is why we consider it too unreliable as a primary tool for serious investigations.
Limitations of Polygraph Testing
Before choosing any lie detection method , it’s important to understand the limitations. This is especially true for polygraph tests in relationship, family, or legal disputes .
False Positives & False Negatives
Because polygraph tests measure stress rather than direct brain activity, they can produce:
- False positives – honest people marked as “deceptive” because they are anxious, traumatised or over‑thinking the result
- False negatives – deceptive people passing the test by staying calm, rehearsing answers or using countermeasures
In emotional contexts (e.g. infidelity , family disputes), the person telling the truth is often more distressed than the person hiding information. This is one of the reasons we do not rely on polygraph technology .
Susceptibility to Countermeasures
There are now widely published techniques aimed at manipulating polygraph charts – from subtle breathing control to physical discomfort and complex mental tasks.
Even well‑trained examiners can miss sophisticated countermeasures, especially when:
- The subject has rehearsed for the test
- Online guides or forums have been followed
- There is a strong incentive or financial gain for passing
Why this matters
In high‑stakes cases, you need evidence that cannot easily be faked. This is why Deception Detection has invested in P300 EEG – a technology based on direct brainwave recognition , not stress.
Polygraph vs P300 EEG: Visual Comparison
On the left: a traditional polygraph test, with multiple straps and physiological sensors tracking stress. On the right: a modern P300 EEG brainwave headband, measuring direct neural recognition responses.
Why We Use P300 EEG Instead of Polygraph
We are regularly contacted by people searching for “polygraph test UK” or “lie detector test near me” . After reviewing the science, we chose to specialise exclusively in P300 EEG – a more modern, brain‑based approach to deception detection .
Traditional Polygraph (Information Only)
Approx. 60–70% AccuracyUses multiple body sensors to monitor physiological stress responses while questions are asked. We do not offer polygraph tests at Deception Detection – we explain them here so you can make an informed choice.
- Measures heart rate, breathing and sweat (stress responses)
- Results depend heavily on examiner interpretation
- Can be influenced by anxiety, medication and fatigue
- Vulnerable to deliberate countermeasures
- Longer test times (often 2–3 hours per session)
P300 EEG Brainwave Testing (Our Service)
Approx. 95% AccuracyOur 8‑channel P300 EEG system measures direct brainwave recognition responses to carefully designed visual and audio stimuli – not indirect stress.
- Measures event‑related brain responses (P300 spike)
- Objective, computer‑assisted analysis of neural data
- Less sensitive to general anxiety or nervousness
- Highly resistant to common polygraph countermeasures
- Shorter sessions (often 45–90 minutes including consultation)
Learn how P300 works in detail in our dedicated guide: P300-response.html
Considering a Polygraph Test in the UK?
Before you commit to a traditional lie detector test, consider whether a 60–70% accuracy, stress‑based method is acceptable for your case. Our clients – including families, businesses and legal professionals – choose P300 EEG because it offers brain‑based analysis, higher accuracy and clearer documentation.