Kirsten G. Volz

Predicting events of varying probability: uncertainty investigated by fMRI

Many everyday life predictions rely on the experience and memory of event frequencies, i.e., natural samplings. We used functional magnetic resonance imaging (fMRI) to investigate the neural substrates of prediction under varying uncertainty based on a natural sampling approach. The study focused particularly on a comparison with other types of externally attributed uncertainty, such as guessing, and on the frontomedian cortex, which is known to be engaged in many types of decisions under uncertainty. On the basis of preceding stimulus cues, participants predicted events that occurred with probabilities ranging from p = 0.6 to p = 1.0. In contrast to certain predictions in a control task, predictions under uncertainty elicited activations within a posterior frontomedian area (mesial BA 8) and within a set of subcortical areas which are known to subserve dopaminergic modulations. The parametric analysis revealed that activation within the mesial BA 8 significantly increased with increasing uncertainty. A comparison with other types of uncertainty indicates that frontomedian correlates of frequency-based prediction appear to be comparable with those induced in long-term stimulus-response adaptation processes such as hypothesis testing, in contrast to those engaged in short-term error processing such as guessing.

Why am I unsure? Internal and external attributions of uncertainty dissociated by fMRI

Behavioral evidence suggests that the perceived reason of uncertainty causes different coping strategies to be implemented, particularly frequency ratings with externally attributed uncertainty and memory search with internally attributed uncertainty. We used functional magnetic resonance imaging (fMRI) to investigate whether processes related to these different attributions of uncertainty differ also in their neural substrates. Participants had to predict events that were uncertain due to internal factors, that is, insufficient knowledge. Data were compared with a preceding study in which event prediction was uncertain due to external factors, that is, event probabilities. Parametric analyses revealed the posterior frontomedian cortex, that is, mesial Brodmann Area 8 (BA 8) as the common cortical substrate mediating processes related to uncertainty no matter what the cause of uncertainty. However, processes related to the two differently attributed types of uncertainty differed significantly in relation to the brain network that was coactivated. Only processes related to internally attributed uncertainty elicited activation within the mid-dorsolateral and posterior parietal areas known to underlie working memory (WM) functions. Together, findings from both experiments suggest that there is a common cerebral correlate for uncertain predictions but different correlates for coping strategies of uncertainty. Concluding, BA 8 reflects that we are uncertain, coactivated networks what we do to resolve uncertainty.

What Neuroscience Can Tell about Intuitive Processes in the Context of Perceptual Discovery

According to the Oxford English Dictionary, intuition is the ability to understand or know something immediately, without conscious reasoning. Most people would agree that intuitive responses appear as ideas or feelings that subsequently guide our thoughts and behaviors. It is proposed that people continuously, without conscious attention, recognize patterns in the stream of sensations that impinge upon them. What exactly is being recognized is not clear yet, but we assume that people detect potential content based on only a few aspects of the input (i.e., the gist). The result is a vague perception of coherence which is not explicitly describable but instead embodied in a gut feeling or an initial guess, which subsequently biases thought and inquiry. To approach the nature of intuitive processes, we used functional magnetic resonance imaging when participants were working at a modified version of the Waterloo Gestalt Closure Task. Starting from our conceptualization that intuition involves an informed judgment in the context of discovery, we expected activation within the median orbito-frontal cortex (OFC), as this area receives input from all sensory modalities and has been shown to be crucially involved in emotionally driven decisions. Results from a direct contrast between intuitive and nonintuitive judgments, as well as from a parametric analysis, revealed the median OFC, the lateral portion of the amygdala, anterior insula, and ventral occipito-temporal regions to be activated. Based on these findings, we suggest our definition of intuition to be promising and a good starting point for future research on intuitive processes.

Why You Think Milan is Larger than Modena: Neural Correlates of the Recognition Heuristic

When ranking two alternatives by some criteria and only one of the alternatives is recognized, participants overwhelmingly adopt the strategy, termed the recognition heuristic (RH), of choosing the recognized alternative. Understanding the neural correlates underlying decisions that follow the RH could help determine whether people make judgments about the RHs applicability or simply choose the recognized alternative. We measured brain activity by using functional magnetic resonance imaging while participants indicated which of two cities they thought was larger (Experiment 1) or which city they recognized (Experiment 2). In Experiment 1, increased activation was observed within the anterior frontomedian cortex (aFMC), precuneus, and retrosplenial cortex when participants followed the RH compared to when they did not. Experiment 2 revealed that RH decisional processes cannot be reduced to recognition memory processes. As the aFMC has previously been associated with self-referential judgments, we conclude that RH decisional processes involve an assessment about the applicability of the RH.

Decision-making and the frontal lobes

Purpose of reviewThis article reviews the most significant advances concerning the neural correlates of decision-making with emphasis on those imaging studies investigating the neural implementation of evaluative judgment processes. This is done against the background of current concepts from the field of judgment and decision-making. Recent findingsActual neuroscientific findings suggest that subject to the extent of how deeply a decision-maker has to explore his/her value system in order to reach a decision, distinguishable orbital and medial prefrontal areas will be engaged. Decisions low in costs mapping the values onto the decision problem mainly rely on orbital and ventromedial prefrontal cortex, whereas decisions high in costs particularly draw on anterior–medial and dorsomedial prefrontal areas. This suggestion is related to the anatomic properties of the respective areas. SummaryCombining neuroimaging data with concepts from research in judgment and decision-making may facilitate advances in our understanding of the contrast between normative theories and descriptive theories of decision-making. Incorporating findings from research on decision-making behavior in patients with specific prefrontal lesions may have much to offer for an understanding of both the areas’ functions and cognitive theories on decision-making.

Cognitive Processes in Decisions Under Risk are not the Same as in Decisions Under Uncertainty

We deal with risk versus uncertainty, a distinction that is of fundamental importance for cognitive neuroscience yet largely neglected. In a world of risk (“small world”), all alternatives, consequences, and probabilities are known. In uncertain (“large”) worlds, some of this information is unknown or unknowable. Most of cognitive neuroscience studies exclusively study the neural correlates for decisions under risk (e.g., lotteries), with the tacit implication that understanding these would lead to an understanding of decision making in general. First, we show that normative strategies for decisions under risk do not generalize to uncertain worlds, where simple heuristics are often the more accurate strategies. Second, we argue that the cognitive processes for making decisions in a world of risk are not the same as those for dealing with uncertainty. Because situations with known risks are the exception rather than the rule in human evolution, it is unlikely that our brains are adapted to them. We therefore suggest a paradigm shift toward studying decision processes in uncertain worlds and provide first examples.

What is for me is not for you: brain correlates of intertemporal choice for self and other

People have present-biased preferences: they choose more impatiently when choosing between an immediate reward and a delayed reward, than when choosing between a delayed reward and a more delayed reward. Following McClure et al. [McClure, S.M., Laibson, D.I., Loewenstein, G., Cohen, J.D. (2004). Separate neural systems value immediate and delayed monetary rewards. Science, 306, 503.], we find that areas in the dopaminergic reward system show greater activation when a binary choice set includes both an immediate reward and a delayed reward in contrast to activation measured when the binary choice set contains only delayed rewards. The presence of an immediate reward in the choice set elevates activation of the ventral striatum, pregenual anterior cingulate cortex and anterior medial prefrontal cortex. These dopaminergic reward areas are also responsive to the identity of the recipient of the reward. Even an immediate reward does not activate these dopaminergic regions when the decision is being made for another person. Our results support the hypotheses that participants show less affective engagement (i) when they are making choices for themselves that only involve options in the future or (ii) when they are making choices for someone else. As hypothesized, we also find that behavioral choices reflect more patience when choosing for someone else.

The neural implementation of multi-attribute decision making: a parametric fMRI study with human subjects.

Decision making is not a unitary entity but involves rather a series of interdependent processes. Decisions entail a choice between two or more alternatives. Within the complex series of decisional processes, at least two levels can be differentiated: a first level of information integration (process level) and a second level of information interpretation (control level), leading to a subsequent motor response or cognitive process. The aim of this study was to investigate the neural network of these decisional processes. In a single trial fMRI study, we implemented a simple decision-making task, where subjects had to decide between two alternatives represented on five attributes. The similarity between the two alternatives was varied systematically in order to achieve a parametric variation of decisional effort. For easy trials, the two alternatives differed significantly in several attributes, whereas for difficult trials, the two alternatives differed only in small details. The results show a distributed neural network related to decisional effort. By means of time course analysis different subprocesses within this network could be differentiated: regions subserving the integration of the presented information (premotor areas and superior parietal lobe) and regions subserving the interpretation of this information (frontolateral and frontomedial cortex, anterior insula, and caudate) as well as a region in the inferior frontal junction updating task rules.

In-group as part of the self: In-group favoritism is mediated by medial prefrontal cortex activation

Abstract Our identity consists of knowledge about our individual attributes (personal identity) as well as knowledge about our shared attributes derived from our membership in certain social groups (social identity). As individuals seek to achieve a positive self-image, they aim at comparing favorably with other individuals or their in-group comparing favorably with referent out-groups. Imaging data suggest a network centered on the medial prefrontal cortex (MPFC) to instantiate functions that are integral to the self, conceived as the personal self. Given that the social self is constituted by the same mechanisms as the personal self, we expect MPFC activation also for situations in which the social self is addressed, for instance when situations permit evaluative intergroup comparisons. Accordingly, participants worked on a modified version of the minimal group paradigm in the present functional magnetic resonance imaging experiment. Imaging data revealed activation within a network centered on the dorsal MPFC specifically for social identity processes. Furthermore, this activation showed correlation with the displayed in-group bias. The present findings show that social and personal identity processes draw on the same cerebral correlates and hence it is concluded that a network centered on the MPFC subserves functions integral to the self.

A common neural system signaling the need for behavioral changes

In their recent article, Eisenberger and Lieberman [1] present evidence that physical pain, social distress, response conflicts, and errors activate largely overlapping areas in the posterior frontomedian cortex (pFMC) including the dorsal anterior cingulate cortex (dACC). They conclude that this region represents a neural alarm system ‘which detects deviations from the desired standards’ (p. 296). In response, we wish to present a unified view of pFMC that goes beyond this suggestion: an alarm signal makes sense only when it is used for subsequent actions leading to desired consequences.