Impaired metacognition and reduced neural signals of decision confidence in adults with traumatic brain injury.

Abstract

Objective: Metacognition reflects our capacity to monitor or evaluate other cognitive states as they unfold during task performance, for example, our level of confidence in the veracity of a memory. Impaired metacognition is seen in patients with traumatic brain injury (TBI) and substantially impacts their ability to manage functional difficulties during recovery. Recent evidence suggests that metacognitive representations reflect domain-specific processes (e.g., memory vs. perception) acting jointly with generic confidence signals mediated by widespread frontoparietal networks. The impact of neurological insult on metacognitive processes across different cognitive domains following TBI remains unknown. Method: To assess metacognitive accuracy, we measured decision confidence across both a perceptual and memory task in patients with TBI (n = 27) and controls (n = 28). During the metacognitive tasks, continuous electroencephalography was recorded, and event-related potentials (ERP) were analyzed. Results: First, we observed a deficit in metacognitive efficiency across both tasks suggesting that patients show a loss of perceptual and memorial evidence available for confidence judgments despite equivalent accuracy levels to controls. Second, a late positive-going ERP waveform (500-700 ms) was greater in amplitude for high versus lowconfidence judgements for controls across both task domains. By contrast, in patients with TBI, the same ERP waveform did not vary by confidence level suggesting a deficient or attenuated neural marker of decision confidence postinjury. Conclusions: These findings suggest that diffuse damage to putative frontoparietal regions in patients disrupts domain-general metacognitive accuracy and electrophysiological signals that accumulate evidence of decision confidence. Key PointsQuestion: What are the neurocognitive correlates that underlie impaired self-awareness and confidence (metacognition) in patients with traumatic brain injury (TBI). Findings: We report a domain general deficit in metacognitive ability in TBI patients across two cognitive domains (perception and memory) associated with reduced modulation of a centro-parietal late positivity waveform in TBI patients. Importance: These findings provide insight into how disruption of metacognitive processes may underlie inflexible or perseverative behaviors that are common features following brain injury. Next Steps: Future studies could examine these candidate cognitive and electrophysiological markers in the monitoring of targeted treatment options.

Two distinct stimulus-locked EEG signatures reliably encode domain-general confidence during decision formation

“…Higher amplitudes of this component during decision formation preceded higher confidence ratings. This is consistent with previous studies which found that the CPP scales with both implicit (e.g., statistical) and explicit confidence level (Feuerriegel et al, 2022;Fitzgerald et al, 2022;Gherman & Philiastides, 2015Grogan et al, 2023;Herding et al, 2019;Rausch et al, 2020;Zakrzewski et al, 2019). However, previous studies have focused predominantly on perceptual confidence.…”

“…Based on the topography and timing of the observed clusters, they possibly represent opposite dipoles of the late portion of the P3/central parietal positivity (CPP) component previously implicated in decision-making and subjective measures of perception including confidence (Azizi et al, 2021;Feuerriegel et al, 2022;Fitzgerald et al, 2022;Gherman & Philiastides, 2015Herding et al, 2019;Lim et al, 2020;Tagliabue et al, 2019). Participants' confidence tended to be higher on trials with stronger late CPP amplitude irrespective of the cognitive domain tested, thus highlighting that the CPP reliably reflects domain-general subjective confidence over and above the external stimulus information (i.e., difficulty) and objective accuracy.…”

“…Electroencephalography (EEG) allows for measurement of metacognitively relevant neural activity with high temporal resolution. Previous studies have shown that the strength of stimulus-locked EEG responses during decision formation, including the central parietal positivity/P3 component, scale with the reported and/or implicit level of confidence (Azizi et al, 2021;Feuerriegel et al, 2022;Fitzgerald et al, 2022;Gherman & Philiastides, 2015Herding et al, 2019;Lim et al, 2020;Rausch et al, 2020;Zakrzewski et al, 2019). Additionally, fluctuations in confidence have also been shown to be dependent on both spontaneous and response-locked levels of EEG activity in the alpha-band (8-12Hz) (Faivre et al, 2018;Wöstmann et al, 2019).…”