Causal evidence for frontal cortex organization for perceptual decision making

Abstract

Although recent research has shown that the frontal cortex has a critical role in perceptual decision making, an overarching theory of frontal functional organization for perception has yet to emerge. Perceptual decision making is temporally organized such that it requires the processes of selection, criterion setting, and evaluation. We hypothesized that exploring this temporal structure would reveal a large-scale frontal organization for perception. A causal intervention with transcranial magnetic stimulation revealed clear specialization along the rostrocaudal axis such that the control of successive stages of perceptual decision making was selectively affected by perturbation of successively rostral areas. Simulations with a dynamic model of decision making suggested distinct computational contributions of each region. Finally, the emergent frontal gradient was further corroborated by functional MRI. These causal results provide an organizational principle for the role of frontal cortex in the control of perceptual decision making and suggest specific mechanistic contributions for its different subregions.perception | frontal cortex | hierarchy | TMS | fMRI

Sensory noise increases metacognitive efficiency

“…The model assumes that the information available for metacognition is corrupted by extra noise compared to the information available for the perceptual decision. Several previous papers have proposed similar architecture (Berg & Ma, 2016;De Martino et al, 2013;Jang et al, 2012;Maniscalco & Lau, 2016;Mueller & Weidemann, 2008;Rahnev et al, 2016). Here we tested a strong, and previously unrecognized, prediction of hierarchical models on the relationship between sensory noise and metacognitive efficiency.…”

Moving forward in perceptual decision making

“…Whether this functional differentiation is idiosyncratic to perceptual decision making or directly relates to other cognitive functions, such as cognitive control of actions, is an intriguing question for future research. The current study by Rahnev et al (1) thus paves the way for new avenues of research that investigate the functional differentiation among frontal regions across cognitive domains. Moreover, the study will serve as a starting point for research into the relationship between the neural mechanisms of basic perceptual decisions and those neural mechanisms underlying other forms of decision making, such as value-based or social decisions (3,9).…”

“…This everyday example shows that a complex cascade of events must occur in our brains between the registration of a stimulus by our sensory systems and the potential action that we take in response to this stimulus. A study by Rahnev et al (1) in PNAS investigates the neural mechanism underlying this decision process. The results suggest distinct functional roles of different regions in the frontal lobe in the attentional selection of stimuli, in setting a criterion for the speed-accuracy tradeoff, and in confidence judgments.…”

“…The representation of action rules has been proposed to follow a gradient in the frontal lobe, with simple action rules being encoded in more posterior regions and increasingly abstract action rules being encoded in more anterior regions (8). Rahnev et al (1) reasoned that the neural processes underlying perceptual decision making may follow a similar anterior-posterior gradient within the frontal lobe. They devised an experiment that provided them with behavioral measures of both the criterion setting in terms of the speedaccuracy tradeoff and of observers' decision confidence.…”

Response to Ruby et al: On a ‘failed’ attempt to manipulate conscious perception with transcranial magnetic stimulation to prefrontal cortex

“…Based on only valid data, both the Rounis and Bor et al studies found a null result. In addition, the Ruby et al paper cites a relevant recent TMS prefrontal cortex metacognition paper by Rahnev and colleagues (Rahnev, Nee, Riddle, Larson, & D'Esposito, 2016), where TMS to prefrontal cortex actually enhanced perceptual metacognition. Ruby and colleagues conclude that these results "suggest that different parts of DLPFC perform different [metacognitive] functions."…”