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The human brain is extremely flexible and capable of rapidly selecting relevant information in accordance with task goals. Regions of frontoparietal cortex flexibly represent relevant task information such as task rules and stimulus features when participants perform tasks successfully, but less is known about how information processing breaks down when participants make mistakes. This is important for understanding whether and when information coding recorded with neuroimaging is directly meaningful for behavior. Here, we used magnetoencephalography to assess the temporal dynamics of information processing and linked neural responses with goal-directed behavior by analyzing how they changed on behavioral error. Participants performed a difficult stimulus-response task using two stimulus-response mapping rules. We used time-resolved multivariate pattern analysis to characterize the progression of information coding from perceptual information about the stimulus, cue and rule coding, and finally, motor response. Response-aligned analyses revealed a ramping up of perceptual information before a correct response, suggestive of internal evidence accumulation. Strikingly, when participants made a stimulus-related error, and not when they made other types of errors, patterns of activity initially reflected the stimulus presented, but later reversed, and accumulated toward a representation of the "incorrect" stimulus. This suggests that the patterns recorded at later time points reflect an internally generated stimulus representation that was used to make the (incorrect) decision. These results illustrate the orderly and overlapping temporal dynamics of information coding in perceptual decision-making and show a clear link between neural patterns in the late stages of processing and behavior., (© 2022 Massachusetts Institute of Technology. Published under a Creative Commons Attribution 4.0 International (CC BY 4.0) license.)

An evolving view in cognitive neuroscience is that the dorsal visual pathway not only plays a key role in visuomotor behavior but that it also contributes functionally to the recognition of objects. To characterize the nature of the object representations derived by the dorsal pathway, we assessed perceptual performance in the context of the continuous flash suppression paradigm, which suppresses object processing in the ventral pathway while sparing computation in the dorsal pathway. In a series of experiments, prime stimuli, which were rendered imperceptible by the continuous flash suppression, still contributed to perceptual decisions related to the subsequent perceptible target stimuli. However, the contribution of the prime to perception was contingent on the prime's structural coherence, in that a perceptual advantage was observed only for targets primed by objects with legitimate 3-D structure. Finally, we obtained additional evidence to demonstrate that the processing of the suppressed objects was contingent on the magnocellular, rather than the parvocellular, system, further linking the processing of the suppressed stimuli to the dorsal pathway. Together, these results provide novel evidence that the dorsal pathway does not only support visuomotor control but, rather, that it also derives the structural description of 3-D objects and contributes to shape perception.

Sensory information is initially registered within anatomically and functionally segregated brain networks but is also integrated across modalities in higher cortical areas. Although considerable research has focused on uncovering the neural correlates of multisensory integration for the modalities of vision, audition, and touch, much less attention has been devoted to understanding interactions between vision and olfaction in humans. In this study, we asked how odors affect neural activity evoked by images of familiar visual objects associated with characteristic smells. We employed scalp-recorded EEG to measure visual ERPs evoked by briefly presented pictures of familiar objects, such as an orange, mint leaves, or a rose. During presentation of each visual stimulus, participants inhaled either a matching odor, a nonmatching odor, or plain air. The N1 component of the visual ERP was significantly enhanced for matching odors in women, but not in men. This is consistent with evidence that women are superior in detecting, discriminating, and identifying odors and that they have a higher gray matter concentration in olfactory areas of the OFC. We conclude that early visual processing is influenced by olfactory cues because of associations between odors and the objects that emit them, and that these associations are stronger in women than in men.