The "nasiyah" (forelock): the prefrontal cortex and lying

NEU-01 Surah Al-ʻAlaq Verse 15-16 2026-09-04 20:58:41
Quranic verses

كَلَّا لَئِن لَّمْ يَنتَهِ لَنَسْفَعًا بِالنَّاصِيَةِ نَاصِيَةٍ كَاذِبَةٍ خَاطِئَةٍ

No! If he does not desist, We will surely drag him by the forelock — a lying, sinning forelock.

Surah Al-ʻAlaq (96:15-16)

In Surah Al-ʻAlaq (96:15-16), the Quran addresses Abu Jahl, who sought to prevent the Prophet ﷺ from praying:

"No! If he does not desist, We will surely drag him by the forelock — a lying, sinning forelock."

The Arabic term nâsiyah (ناصية) designates the front of the head, the frontal region of the skull. The Quran remarkably attributes lying and sin to this specific region of the head, rather than to the brain as a whole or to any other part of the body.

Modern neuroscience has established that the prefrontal cortex, located precisely behind the forehead (the "front of the head"), is the seat of higher executive functions: planning, decision-making, inhibition and social behavioral control. It is this region that is characteristically activated during lying and deception.

A landmark meta-analysis published in Cerebral Cortex (Christ et al., 2009) used the activation likelihood estimation (ALE) method to identify, across numerous neuroimaging studies, the brain regions consistently more active during deceptive than truthful responses. The results converge on the prefrontal cortex and adjacent regions, confirming that lying mobilizes the executive control system.

More recent studies using functional near-infrared spectroscopy (fNIRS) and functional magnetic resonance imaging (fMRI) have replicated these findings, showing bilateral prefrontal activation during the production of lies, whether about past events or personal beliefs.

This convergence between the Quranic text and neuroscience is all the more striking because, in the 7th century, no anatomical or physiological knowledge allowed one to associate lying with the frontal region of the brain. Ancient civilizations generally located mental functions in the heart or the chest.

Level of evidence: The role of the prefrontal cortex in executive control and the production of lying is firmly established by neuroscientific consensus (convergent ALE meta-analyses). The convergence with the Quranic verse is strong, although it falls within a scientific interpretation of the text rather than a demonstration in the strict sense.

Scientific findings

  • 2008-2009: ALE meta-analysis (Christ et al., Cerebral Cortex) identifying the prefrontal cortex as a region consistently activated during lying
  • 2017: fMRI study (PMC5390719) showing prefrontal activation when lying about past events and personal beliefs
  • 2021: fNIRS study (Oxford Academic, SCAN) replicating bilateral prefrontal activation during deception
  • 2021: Meta-analytic connectivity modelling (PLOS ONE) confirming the involvement of the bilateral anterior prefrontal area

Scientific references

  • The contributions of prefrontal cortex and executive control to deception: evidence from activation likelihood estimate meta-analyses — Christ S.E., Van Essen D.C., Watson J.M., Brubaker L.E., McDermott K.B. (Cerebral Cortex, 19(7), 1557-1566, 2009)
  • Neural correlates of deception: lying about past events and personal beliefs — PMC5390719 (Cognitive, Affective, & Behavioral Neuroscience, 2017)
  • Prefrontal activation during deception: an fNIRS study — Oxford Academic (Social Cognitive and Affective Neuroscience (SCAN), 2021)
  • Meta-analytic connectivity modelling of deception-related brain regions — PLOS ONE (PLOS ONE, 16(8), e0248909, 2021)
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