Elsevier

NeuroImage

Volume 18, Issue 4, April 2003, Pages 827-836
NeuroImage

Regular article
Feeling-of-knowing in episodic memory: an event-related fMRI study

https://doi.org/10.1016/S1053-8119(03)00014-4Get rights and content

Abstract

An individual may fail to recall an item from memory but still feel that it would be recognized on a later test, a retrieval state termed the “feeling-of-knowing” (FOK). In this study we used event-related fMRI and the FOK to examine both encoding- and retrieval-related factors that are associated with different levels of recall performance: successful retrieval of a previously studied item, retrieval failure accompanied by the FOK, and retrieval failure without any FOK. The results revealed one predominant pattern of retrieval-related activation: an intermediate level of activation for FOK—less than that associated with successful recall and greater than that associated with unsuccessful recall (frontal and left parietal cortices). Two further patterns were also observed: greater activation for both successful recall and FOK than for unsuccessful recall (left midlateral prefrontal cortex) and greater activation for successful recall than for both FOK and unsuccessful recall (left MTL). Analysis of encoding trials conditional upon subsequent retrieval success revealed a pattern of activation that appeared to predict subsequent recall, but which further analysis indicated to be a better predictor of subsequent recognition. These results provide evidence that the phenomenology of graded recall is represented neurally in frontal and parietal cortices, but that activation at encoding may not precipitate the different levels of recall experience.

Section snippets

Participants

Participants were 17 right-handed, native speakers of English (10 men; ages 18–26 years), with normal or corrected-to-normal vision. Participants received $50 for participation. Informed consent was obtained in a manner approved by the Human Studies Committee of the Massachusetts General Hospital.

Stimuli and cognitive task

Stimuli consisted of 900 nouns selected from the “concrete” items used in an earlier event-related fMRI study (Wagner et al., 1998). Five lists of 180 items, matched for frequency and length, were used

Behavioral data

The distribution of trials across the six response types (see Materials and methods) is presented in Table 1. Almost half of the studied items (46%) were given a DK response during cued recall; the remainder of the responses were fairly evenly divided between FOK (29%) and K (25%). Accuracy during the subsequent recognition test differed significantly between the three cued-recall response types: accuracy was the highest for trials that had been previously given a K response (91%), intermediate

Discussion

This study represents the first event-related fMRI investigation of graded recall success in episodic memory, utilizing FOK in addition to the standard successful and unsuccessful retrieval outcomes.

References (48)

  • A.M. Dale

    Optimal experimental design for event-related fMRI

    Hum. Brain Mapp.

    (1999)
  • R.J. Dolan et al.

    Dissociating prefrontal and hippocampal function in episodic memory encoding

    Nature

    (1997)
  • L.L. Eldridge et al.

    Remembering episodesa selective role for the hippocampus during retrieval

    Nat. Neurosci.

    (2000)
  • G. Fernandez et al.

    Level of sustained entorhinal activity at study correlates with subsequent cued-recall performancea functional magnetic resonance imaging study with high acquisition rate

    Hippocampus

    (1999)
  • G. Fernandez et al.

    Real-time tracking of memory formation in the human rhinal cortex and hippocampus

    Science

    (1999)
  • G. Fernandez et al.

    Successful verbal encoding into episodic memory engages the posterior hippocampusa parametrically analyzed functional magnetic resonance study

    J. Neurosci.

    (1998)
  • P.C. Fletcher et al.

    Frontal lobes and human memoryinsights from functional neuroimaging

    Brain

    (2001)
  • M. Funnell et al.

    In the mind but not on the tonguefeeling of knowing in an anomic patient

  • J.T. Hart

    Memory and the feeling-of-knowing experience

    J. Educ. Psychol.

    (1965)
  • R.N. Henson et al.

    Right prefrontal cortex and episodic memory retrievala functional MRI test of the monitoring hypothesis

    Brain

    (1999)
  • R.N.A. Henson et al.

    Recollection and familiarity in recognition memoryan event-related functional magnetic resonance imaging study

    J. Neurosci.

    (1999)
  • J.S. Janowsky et al.

    Memory and metamemorycomparisons between patients with frontal lobe lesions and amnesic patients

    J. Exp. Psychol. Learn. Mem. Cogn.

    (1989)
  • B.A. Kirchhoff et al.

    Prefrontal-temporal circuitry for episodic encoding and subsequent memory

    J. Neurosci.

    (2000)
  • A. Koriat

    How do we know that we know? The accessibility account of the feeling of knowing

    Psychol. Rev.

    (1993)
  • Cited by (115)

    • Neurobehavioral mechanisms underlying the effects of physical exercise break on episodic memory during prolonged sitting

      2022, Complementary Therapies in Clinical Practice
      Citation Excerpt :

      In the PE group, the stronger functional connectivity between the DLPFC (BA 9) and the anterior PFC (orbitofrontal and frontopolar cortices) corresponded to the increased magnitudes of temporal correlational interactions between the above-mentioned subregions during encoding [67–69] and partially explained the higher nodal efficiency of the anterior PFC [70]. Based on the existing evidence, the DLPFC and the FPC were found to work together on guiding the monitoring and evaluating processes of recollected information during EM retrieval [71–73]. However, in the present study the temporal correlation between the DLPFC and the anterior PFC was observed during the memory encoding phase.

    View all citing articles on Scopus
    View full text