New study identifies neural hub for memory metacognition

Metacognition is about “knowing about knowing.” It refers to being introspective about how well one knows what they think they know, such as asking oneself questions like “Do I really get this idea?” and “Could I explain it to a friend?”  One controversy in contemporary metacognition research is whether or not such self-awareness of one’s own performance is domain-specific in the cortex. In other words, are the same brain regions engaged in the self-evaluation of one’s own performances across different cognitive domains such as memory as opposed to perception?

A recently published study offers strong evidence consistent with the domain-specificity argument. “We demonstrated that the human precuneus – a sizable and important cognitive hub in the parietal cortex – is causally and selectively implicated in mediating our memory metacognition but not perceptual metacognition,” says Sze Chai Kwok, Associate Professor at East China Normal University and a member of the NYU-ECNU Institute of Brian and Cognitive Science at NYU Shanghai, who is the senior author of the study. The findings, which were published in the July 11 issue of the Journal of Neuroscience, also enhance our understanding of the neural basis of our introspection during memory retrieval.

Using a transient non-invasive neuromodulatory method known as transcranial magnetic stimulation (TMS), researchers temporarily perturbed the precuneal activity of 18 participants before having them perform either a memory or a perceptual task. Inhibition engendered by low-frequency TMS magnetic fields selectively impaired the participants’ metacognitive efficiency during memory but not perceptual discrimination judgment.  

“Zapping the brain with low-frequency inhibitory TMS appears to diminish the participants’ memory metacognition, whereas high-frequency ones are known to increase cortical excitability. It comes naturally to us that we might as well deploy the same armamentarium to increase our general meta-cognitive awareness,” proposes Kwok.

The study was funded by the Ministry of Education of PRC Humanities and Social Sciences Research grant 16YJC190006, STCSM Shanghai Pujiang Program 16PJ1402800, STCSM Natural Science Foundation of Shanghai 16ZR1410200, and NYU Shanghai and the NYU-ECNU Institute of Brain and Cognitive Science at NYU Shanghai.

Journal Reference:

Ye, Q.ǂ, Zou, F.ǂ, Lau, H., Hu, Y., & Kwok, S.C. (2018). Causal evidence for mnemonic metacognition in human precuneusThe Journal of Neuroscience, 38(28), 6379-6387. (ǂ joint-first)