The functionality of much of human lateral frontal cortex (LFC) has been characterized as "multiple demand" (MD) as these regions appear to support a broad range of cognitive tasks. In contrast to this domain-general account, recent evidence indicates that portions of LFC are consistently selective for sensory modality. Michalka et al. (2015) reported two bilateral regions that are biased for visual attention, superior precentral sulcus (sPCS) and inferior precentral sulcus (iPCS), interleaved with two bilateral regions that are biased for auditory attention, transverse gyrus intersecting precentral sulcus (tgPCS) and caudal inferior frontal sulcus (cIFS). In the present study, we use fMRI to examine both the multiple-demand and sensory-bias hypotheses within caudal portions of human LFC (both men and women participated). Using visual and auditory 2-back tasks, we replicate the finding of two bilateral visual-biased and two bilateral auditory-biased LFC regions, corresponding to sPCS and iPCS and to tgPCS and cIFS, and demonstrate high within-subject reliability of these regions over time and across tasks. In addition, we assess MD responsiveness using BOLD signal recruitment and multi-task activation indices. In both, we find that the two visual-biased regions, sPCS and iPCS, exhibit stronger MD responsiveness than do the auditory-biased LFC regions, tgPCS and cIFS; however, neither reaches the degree of MD responsiveness exhibited by dorsal anterior cingulate/presupplemental motor area or by anterior insula. These results reconcile two competing views of LFC by demonstrating the coexistence of sensory specialization and MD functionality, especially in visual-biased LFC structures. Lateral frontal cortex (LFC) is known to play a number of critical roles in supporting human cognition; however, the functional organization of LFC remains controversial. The "multiple demand" (MD) hypothesis suggests that LFC regions provide domain-general support for cognition. Recent evidence challenges the MD view by demonstrating that a preference for sensory modality, vision or audition, defines four discrete LFC regions. Here, the sensory-biased LFC results are reproduced using a new task, and MD responsiveness of these regions is tested. The two visual-biased regions exhibit MD behavior, whereas the auditory-biased regions have no more than weak MD responses. These findings help to reconcile two competing views of LFC functional organization.

The human cerebral cortex is estimated to comprise 200-300 distinct functional regions per hemisphere. Identification of the precise anatomical location of an individual's unique set of functional regions is a challenge for neuroscience that has broad scientific and clinical utility. Recent studies have demonstrated the existence of four interleaved regions in lateral frontal cortex (LFC) that are part of broader visual attention and auditory attention networks (Michalka et al., 2015; Noyce et al., 2017; Tobyne et al., 2017). Due to a large degree of inter-subject anatomical variability, identification of these regions depends critically on within-subject analyses. Here, we demonstrate that, for both sexes, an individual's unique pattern of resting-state functional connectivity can accurately identify their specific pattern of visual- and auditory-selective working memory and attention task activation in lateral frontal cortex (LFC) using "connectome fingerprinting." Building on prior techniques (Saygin et al., 2011; Osher et al., 2016; Tavor et al., 2016; Smittenaar et al., 2017; Wang et al., 2017; Parker Jones et al., 2017), we demonstrate here that connectome fingerprint predictions are far more accurate than group-average predictions and match the accuracy of within-subject task-based functional localization, while requiring less data. These findings are robust across brain parcellations and are improved with penalized regression methods. Because resting-state data can be easily and rapidly collected, these results have broad implications for both clinical and research investigations of frontal lobe function. Our findings also provide a set of recommendations for future research.

Over repeated viewings of motion along a quasi-random path, ability to reproduce that path from memory improves. To assess the role of expectations and sequence context on such learning, subjects eye movements were measured while trajectories were viewed for subsequent reproduction. As a sequence of motions was repeated, subjects' eye movements became anticipatory, leading the stimulus' motions. To investigate how prediction errors affected eye movements and imitation learning, we injected an occasional deviant motion into a well-learned stimulus sequence, violating subjects' expectation about the motion that would be seen. This unexpected direction of motion in the stimulus sequence did not impair reproduction of the sequence. The externally induced prediction errors promoted one-shot learning: During the very next stimulus presentation, their eye movements showed that subjects now expected the new sequence item to reappear. A second experiment showed that an associative mismatch can facilitate accurate reproduction of an unexpected stimulus. After a deviant sequence item was presented, imitation accuracy for sequences that contained the deviant direction of motion was reduced relative to sequences that restored the original direction of motions. These findings demonstrate that in the context of a familiar sequence, unexpected events can play an important role in learning the sequence.

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Predictable and unpredictable distractors may have very different attentional effects. We adapted the Eriksen flanker task by manipulating the probability with which specific flankers occurred. Subjects reported the orientation of briefly-presented targets, while attempting to ignore four flanking items. Flankers had either standard (90% of trials) or oddball (10%) orientations. Congruent and incongruent configurations were equiprobable, as were target orientations. Odd-ball flanker orientations substantially enhanced the congruency effect: performance was best when the target was congruent with oddball flankers and worst when it was incongruent. From subjects’ electroencephalogram, we extracted the visual mismatch negativity (vMMN) evoked by oddball flanker orientations. Individual differences in vMMN magnitude were predicted by two factors of temperament, orienting sensitivity and attentional control. Subjects appear to exploit distractor predictability to support active inhibition; oddballs disrupt this strategy. Despite subjects’ attempts to ignore the flankers, processing of unexpected distractors strongly influences neural responses and behavioral performance.