Efforts to map the functional architecture of the developing human brain have shown that connectivity between and within functional neural networks changes from childhood to adulthood. Although prior work has established that the adult precuneus distinctively modifies its connectivity during task versus rest states [Utevsky, A. V., Smith, D. V., & Huettel, S. A. Precuneus is a functional core of the default-mode network. Journal of Neuroscience , 34 , 932–940, 2014], it remains unknown how these connectivity patterns emerge over development. Here, we use fMRI data collected at two longitudinal time points from over 250 participants between the ages of 8 and 26 years engaging in two cognitive tasks and a resting-state scan. By applying independent component analysis to both task and rest data, we identified three canonical networks of interest—the rest-based default mode network and the task-based left and right frontoparietal networks (LFPN and RFPN, respectively)—which we explored for developmental changes using dual regression analyses. We found systematic state-dependent functional connectivity in the precuneus, such that engaging in a task (compared with rest) resulted in greater precuneus–LFPN and precuneus–RFPN connectivity, whereas being at rest (compared with task) resulted in greater precuneus–default mode network connectivity. These cross-sectional results replicated across both tasks and at both developmental time points. Finally, we used longitudinal mixed models to show that the degree to which precuneus distinguishes between task and rest states increases with age, due to age-related increasing segregation between precuneus and LFPN at rest. Our results highlight the distinct role of the precuneus in tracking processing state, in a manner that is both present throughout and strengthened across development.

Cognitive neuroscience, as a discipline, links the biological systems studied by neuroscience to the processing constructs studied by psychology. By mapping these relations throughout the literature of cognitive neuroscience, we visualize the semantic structure of the discipline and point to directions for future research that will advance its integrative goal. For this purpose, network text analyses were applied to an exhaustive corpus of abstracts collected from five major journals over a 30-month period, including every study that used fMRI to investigate psychological processes. From this, we generate network maps that illustrate the relationships among psychological and anatomical terms, along with centrality statistics that guide inferences about network structure. Three terms— prefrontal cortex , amygdala , and anterior cingulate cortex —dominate the network structure with their high frequency in the literature and the density of their connections with other neuroanatomical terms. From network statistics, we identify terms that are understudied compared with their importance in the network (e.g., insula and thalamus ), are underspecified in the language of the discipline (e.g., terms associated with executive function), or are imperfectly integrated with other concepts (e.g., subdisciplines like decision neuroscience that are disconnected from the main network). Taking these results as the basis for prescriptive recommendations, we conclude that semantic analyses provide useful guidance for cognitive neuroscience as a discipline, both by illustrating systematic biases in the conduct and presentation of research and by identifying directions that may be most productive for future research.

Although lateral prefrontal cortex (LPFC) is clearly involved in decision-making, competing functional characterizations exist. One characterization posits that activation reflects the need to select among competing representations. In contrast, recent fMRI research suggests that activation is driven by the criterial classification of representations, even with minimal competition. To adjudicate between these hypotheses, we used event-related fMRI and contrasted tasks that required different numbers of criterial classifications prior to response in both perceptual and memory domains. Additionally, we manipulated the level of interstimulus competition by increasing the number of probes. Experiment 1 demonstrated that LPFC activation tracked the number of intermediate classifications during trials yet was insensitive to the number of competing probes and the behavioral decline accompanying competition. Furthermore, Experiment 2 demonstrated equivalent increases in LPFC activation for a task requiring two overt criterial classifications (independent classification) and one requiring two covert criterial classifications prior to the single overt response (same–different judgment). As found in Experiment 1, both tasks showed greater activation than a judgment requiring only one classification act (forced choice). These data indicate that LPFC responses reflect the number of executed criterial classifications or judgments, independent of the number of competing stimuli and the overt response demands of the decision task.

Negative outcomes, as identified from external feedback, cause a short-latency negative deflection in the event-related potential (ERP) waveform over medial frontal electrode sites. This brain response, which has been called an “error related negativity” (ERN) or “medial frontal negativity” (MFN), may reflect a coarse evaluation of performance outcomes, such as the valence of a reward within a monetary gambling task. Yet, for feedback to lead to the adaptive control of behavior, other information concerning reward outcomes besides experienced valence may also be important. Here, we used a gambling task in which subjects chose between two options that could vary in both outcome valence (gain or loss) and outcome magnitude (larger or smaller). We measured changes in brain ERP responses associated with the presentation of the outcomes. We found, as shown in prior studies, that valence of the chosen outcome has an early effect upon frontal ERPs, with maximal difference observed at ∼250 msec. However, our results demonstrated that the early ERP responses to outcome feedback were driven not just by valence but by the combination of valence and magnitude for both chosen and unchosen options. Beginning even earlier, at around 150 msec, responses to high-consequence outcomes resulted in a greater, more centrally distributed, positive potential than those involving low-consequence outcomes, independent of valence. Furthermore, the amplitude of these early effects was significantly modulated by the sequence of outcomes in previous trials. These results indicate that early evaluation of feedback goes beyond simple identification of valence—it involves the consideration of multiple factors, including outcome magnitude, context of unchosen options, and prior history.

Previous research has established that age-related decline occurs in measures of cerebral white matter integrity, but the role of this decline in age-related cognitive changes is not clear. To conclude that white matter integrity has a mediating (causal) contribution, it is necessary to demonstrate that statistical control of the white matter–cognition relation reduces the magnitude of age–cognition relation. In this research, we tested the mediating role of white matter integrity, in the context of a task-switching paradigm involving word categorization. Participants were 20 healthy, community-dwelling older adults (60–85 years), and 20 younger adults (18–27 years). From diffusion tensor imaging tractography, we obtained fractional anisotropy (FA) as an index of white matter integrity in the genu and splenium of the corpus callosum and the superior longitudinal fasciculus (SLF). Mean FA values exhibited age-related decline consistent with a decrease in white matter integrity. From a model of reaction time distributions, we obtained independent estimates of the decisional and nondecisional (perceptual–motor) components of task performance. Age-related decline was evident in both components. Critically, age differences in task performance were mediated by FA in two regions: the central portion of the genu, and splenium–parietal fibers in the right hemisphere. This relation held only for the decisional component and was not evident in the nondecisional component. This result is the first demonstration that the integrity of specific white matter tracts is a mediator of age-related changes in cognitive performance.

We investigated using functional magnetic resonance imaging (fMRI) the neural processes associated with performance of a change-detection task. In this task, two versions of the same picture are presented in alternation, separated by a brief mask interval. Even when the two pictures greatly differ (e.g., as when a building is in different locations), subjects report that identification of the change is difficult and often take 30 or more seconds to identify the change. This phenomenon of “change blindness” provides a powerful and novel paradigm for segregating components of visual attention using fMRI that can otherwise be confounded in short-duration tasks. By using a response-contingent event-related analysis technique, we successfully dissociated brain regions associated with different processing components of a visual change-detection task. Activation in the calcarine cortex was associated with task onset, but did not vary with the duration of visual search. In contrast, the pattern of activation in dorsal and ventral visual areas was temporally associated with the duration of visual search. As such, our results support a distinction between brain regions whose activation is modulated by attentional demands of the visual task (extrastriate cortex) and those that are not affected by it (primary visual cortex). A second network of areas including central sulcus, insular, and inferior frontal cortical areas, along with the thalamus and basal ganglia, showed phasic activation tied to the execution of responses. Finally, parietal and frontal regions showed systematic deactivations during task performance, consistent with previous reports that these regions may be associated with nontask semantic processing. We conclude that detection of change, when transient visual cues are not present, requires activation of extrastriate visual regions and frontal regions responsible for eye movements. These results suggest that studies of change blindness can inform understanding of more general attentional processing.