fMRI dataset of successful and unsuccessful access to complex semantic information

Our ability to effectively retrieve complex semantic knowledge meaningfully impacts our daily lives, yet the interactions between semantic control and semantic representational systems that underly successful access and transient failures in access remain only partially understood. In this fMRI study, we contrast activation during successful semantic access, unsuccessful semantic access due to transient access-failures (i.e., ‘tip-of-the-tongue’, ‘feeling-of-knowing’), and trials where the semantic knowledge was not possessed. Twenty-four participants were presented 240 trivia-based questions relating to person, place, object or scholastic knowledge-domains. Whole brain analyses of the recall event indicate comparable recruitment of prefrontal semantic control systems during successful and unsuccessful semantic access and greater activation in representational systems in successful access. Region-of-interest analysis of domain-selective areas showed that successful access was generally associated with increased responses for both preferred and non-preferred stimuli, with the exception of place-selective regions (PPA, TOS and RSC). Both whole brain and Region-of-interest analysis showed the particular recruitment of place-selective regions during unsuccessful attempts at semantic access, for all stimulus domains. Collectively, these results suggest that prefrontal semantic control systems and classical spatial-knowledge-selective regions work together to locate relevant information and that access to complex knowledge results in a broadening of semantic representation to include regions selective for other knowledge domains.

Methods
Participants read sentences questioning their knowledge on a series of general-knowledge facts. Trials are divided into events where the knowledge was accessed, where access was unsuccessful yet participants felt they possessed the knowledge, and trials where the knowledge was not possessed.

This fMRI data has been slice-time corrected, realigned to correct for head movement, normalised to MNI space and smoothed using a 6mm FWHM isotropic kernel.

Provided are the preprocessed images, first-level analysis and group-level RFX analysis as implemented in SPM.