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Updated: Jun 4, 2026

Investigating the Neural Mechanisms of Aware and Unaware Fear Memory with fMRI

Investigating the Neural Mechanisms of Aware and Unaware Fear Memory with fMRI

Published on: October 6, 2011

Knowing not.

P A Kolers¹, S R Palef

¹Department of Psychology, University of Toronto, M5S 1A1, Toronto, Canada.

Memory & Cognition

|February 3, 2011

Summary

This summary is machine-generated.

People can quickly recognize when they don't know something. This study found that knowing "not" can be as fast as knowing facts, challenging previous theories on knowledge acquisition.

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Area of Science:

Cognitive Psychology
Metacognition
Epistemology

Background:

Theorists often assume recognizing ignorance (knowing not) arises solely from failing to confirm knowledge.
Contemporary theories have not extensively explored the speed and mechanisms of recognizing one's own lack of knowledge.
Existing models suggest knowing not is a secondary state, dependent on failed attempts to know.

Purpose of the Study:

To investigate the speed and cognitive processes underlying the recognition of not knowing.
To challenge the assumption that knowing not is merely a consequence of failing to know.
To explore whether knowing not can be an immediate cognitive state.

Main Methods:

A reaction time experiment was designed to measure the speed of "knowing not."

Related Experiment Videos

Last Updated: Jun 4, 2026

Investigating the Neural Mechanisms of Aware and Unaware Fear Memory with fMRI

Investigating the Neural Mechanisms of Aware and Unaware Fear Memory with fMRI

Published on: October 6, 2011

Participants were asked about their knowledge of common nouns and familiarity with specific cities.

Response times for positive affirmations (e.g., "I know this") and negative affirmations (e.g., "I don't know this") were recorded.

Main Results:

Affirmations of negation (reporting "I don't know") were frequently faster than positive reports of knowledge.
This finding contradicts the idea that knowing not is simply the complement of knowing.
The speed of recognizing ignorance suggests a more direct cognitive pathway.

Conclusions:

Knowing not can be achieved as rapidly as positive knowledge.
The ability to execute analytical procedures may facilitate rapid recognition of not knowing.
This suggests a more direct and potentially primary cognitive process for identifying ignorance.