Journal of Cognitive Neuroscience最新文献

Mental time travel (MTT), the ability to mentally project backward and forward in time, relies on navigating a hierarchical organization of mental representations, ranging from higher-level (semantic) to lower-level (episodic) knowledge structures. Ventromedial prefrontal cortex (vMPFC) is thought to initiate the activation of personal semantic information during MTT, but its precise role in the temporal dynamics of MTT remains unclear. In the present study, patients with focal vMPFC lesions, brain-damaged controls, and healthy participants completed a personal semantic interview followed by an MTT task in which they were instructed to remember past events and imagine future events while "thinking aloud," namely, uttering every information that came to their mind while constructing events. vMPFC patients showed degraded personal semantic information in the personal semantic interview compared with the control groups. In the MTT task, they generated more repeated events and fewer specific events than the control groups. Moreover, they exhibited atypical, "backward" transitions from lower-level (e.g., extended and repeated events) to higher-level (e.g., personal semantics) knowledge structures, indicative of an alteration of retrieval dynamics following vMPFC damage. These findings confirm that vMPFC damage impairs personal semantic memory and alters the retrieval dynamics of event construction, hindering access to specific events.

The perception of a stimulus can be accelerated by another that precedes it. Perceptual acceleration has been observed in a range of tasks, at varying timescales, and arises by virtue of providing advance spatial and/or temporal information about upcoming stimuli. Here, we examined perceptual acceleration during visual temporal integration. Temporal integration occurs when successive stimuli appear that fit together in time as well as space. As such, stimuli arriving first during temporal integration partially predict those that follow. Although temporal integration is a rapid process, we reasoned that this information may cause perceptual acceleration during temporal integration. We used multivariate pattern analysis of EEG data from a missing element task, designed to measure the visual temporal integration of two successive stimulus displays, so that we were able to precisely track the representation associated with the integrated percept in time. We manipulated the delay between our displays and observed commensurate acceleration of the resultant integrated representation. The degree of acceleration first increased from early (100 msec after stimulus onset) to intermediate (200 msec) processing stages, before decreasing again at a later stage (400 msec). The results thus suggest that perceptual acceleration occurs during temporal integration but is nonlinear, such that some time that is gained at one moment in the process can be lost again at another.

Language learning is often a social process, and social feedback may play a motivational role. We examined the neurophysiological correlates of word learning with feedback varying in reliability (accuracy) and social content. In a forced-choice task, participants learned to associate novel auditory words with known objects and received feedback. There were three types of feedback: Social Reliable (always providing accurate feedback regarding performance), Social Unreliable (providing random feedback: 50% correct and 50% incorrect feedback irrespectively of the performance), and Symbolic Reliable (always accurate feedback). Posttraining behavioral performance was better for words learned with social and symbolic reliable feedback. ERP amplitudes and pupil dilation showed differences as a function of feedback reliability and social content. In the reliable conditions, before feedback, stimulus-preceding negativity amplitude grew as learning progressed, likely due to the expectation of receiving positive feedback. During feedback, late positive complex amplitude for positive feedback diminished as learning progressed but not for negative feedback, which was likely consistently used for context updating. These effects were not observed for unreliable feedback, probably because its value was not used for updating information. Pupillometry results corroborated this showing greater dilation for negative versus positive feedback in reliable conditions. Finally, when feedback was social, processing was associated with more frontal activation and behavioral performance was closely correlated with both ERP and pupillometry results. Overall, our findings show differential processing of feedback depending on its informational and social content, advancing our understanding of how social and cognitive processes interact to shape word learning.

Attention restoration theory suggests that natural environments offer greater restorative benefits compared with urban settings. While previous research has used behavioral and questionnaire measures to demonstrate the effects of nature exposure on cognition, mood, and stress, fewer studies have explored physiological measures. This study used EEG and ECG to investigate the behavioral and psychophysiological markers of nature restoration, along with estimating the moderating influence of individual differences in nature relatedness on restorative effects. Forty participants were randomly assigned to view either natural or urban images in a short virtual exposure after completion of a cognitively fatiguing Stroop task. EEG and ECG were continuously recorded throughout a pre/post design measuring heart rate variability, ERPs, EEG frequency band power, cognitive performance (digit span test, flanker go/no-go task), mood (Positive and Negative Affect Schedule), and state mindfulness (Mindful Attention Awareness Scale). Scores on the Nature Relatedness Scale were utilized as a moderator variable. EEG results showed an increase in alpha power during both nature and urban exposures. A neural index of inhibitory control (N2 ERP amplitude) was decreased for the nature group only, possibly reflecting more efficient inhibitory attentional processing. Nature relatedness moderated environmental effects for alpha and beta power, overall RT, and positive affect, whereby effects were enhanced when exposures aligned with nature relatedness level. In conclusion, this study suggests that nature exposure can influence cortical inhibitory mechanisms involved in suppressing distractions. The influence of nature relatedness indicates that nature restoration is not necessarily universal but contingent on individuals' connection to a given environment.

Attentional selectivity focuses on what is currently relevant. Relevance changes frequently in everyday life, triggering rapid reassignments of attentional priorities. Such reassignments are often not associated with behavioral changes and are thus difficult to assess objectively. Here, we measured rapid, covert switches between preparatory task settings (attentional templates) in visual search, as they occurred in real time. Participants searched for color-defined targets in search displays that appeared unpredictably either early (after 700 msec) or late (after 1500 msec) on each trial. In Experiment 1, early and late targets were defined by different colors. Participants first had to activate a template for the early target color and then switch to a template for the late target color if no early search display appeared. In Experiment 2, cues signaled whether the initial target template had to be maintained or changed. Template activation states were tracked with N2pc components to rapid sequences of irrelevant probes matching either the early or late target color. A template for the early target color was active from about 300 msec before the expected arrival of early search displays, followed by a template switch. Switches based on endogenous temporal expectations emerged more gradually in time than switches in response to external cues. Presenting cues in Experiment 2 triggered a temporary search template deactivation even when the target color remained unchanged, indicating that template maintenance is subject to an attentional blink. Results demonstrate that rapid switches between attentional templates in visual search can be tracked with high temporal precision.

Ongoing thoughts play a critical role in modulating cognitive performance, with phenomena such as mind wandering consistently associated with decreased task accuracy and prolonged RTs. However, the neural mechanisms underlying the influence of thought dimensions on cognition and behavior remain unclear. To elucidate this, we used EEG to investigate how two key thought dimensions-deliberate control (deliberate vs. spontaneous thoughts) and task relatedness (on-task vs. off-task thoughts)-modulate RT during a simple RT task. Behavioral results showed that both on-task and more deliberate thoughts were associated with shorter RTs compared to off-task and more spontaneous thoughts. Neurodynamic analyses revealed that on-task and deliberate thoughts were characterized by prestimulus increases in both frequency sliding, reflecting faster phase-based neural speed, and sample entropy, reflecting higher neural uncertainty/flexibility. Both prestimulus frequency sliding and sample entropy were significantly related to the degree of poststimulus intertrial phase coherence, which, in turn, correlated with RT. This sequential relationship suggests that phase-based neural dynamics play a crucial role in mediating the relationship of thought with task-related behavior. Together, these findings suggest that phase-based neural dynamics could play a key modulatory role across the divide of prestimulus and poststimulus activity in shaping the influence of ongoing thoughts (deliberate control and task relatedness) on task execution and its related behavior (RT).

Emotional processing is ubiquitous in everyday life, informing goal pursuit not only in response to current demands but also in anticipation of future outcomes. Lateral pFC (LPFC) function supports cognitive control, and emerging evidence suggests a unique role for its anterior-most region-the lateral frontal pole (FPl)-in integrating putatively amygdala-originated emotion signals with goal information. However, whether these organizational properties of LPFC are expressed during the anticipation of future threat remains unknown. Here, we used finite impulse response modeling and pattern similarity analysis to examine dynamic engagement and representational properties of distinct LPFC regions during threat anticipation requiring goal-directed action. Healthy participants (n = 67, 51 female) were scanned during a threat-of-shock paradigm consisting of a prolonged (18 sec) countdown to possible shock administration. Threat unpleasantness and controllability were manipulated orthogonally: In controllable trials, participants could avoid an unpleasant or mild shock by making a successful time-sensitive response; in uncontrollable trials, shocks were administered regardless of performance. LPFC robustly coded for anticipated threat unpleasantness, with FPl showing the strongest modulation by threat unpleasantness and controllability relative to caudal and mid-LPFC regions. While caudal and mid-LPFC maintained independent representations of threat unpleasantness and controllability, FPl held conjunctive threat-and-controllability representations, which were associated with successful motor performance following unpleasant threat anticipation. Stronger conjunctive FPl representations were also associated with greater inverse amygdala-FPl coupling. Together, these findings provide insight into LPFC organization under naturalistic emotional challenges and highlight a key role for FPl in integrating affective and control-related information during threat anticipation to support goal-directed action.

A growing body of evidence indicates that spontaneous, moment-to-moment fluctuations of the EEG alpha power (7-15 Hz) affect perception, with a lower amplitude of alpha oscillations right before the stimulus onset facilitating its detection and visibility. However, whether a similar relationship exists also at the interindividual level has not yet been established. Therefore, the present study aimed to determine whether resting-state alpha power constitutes a robust trait-like predictor of differences in cortical excitability and perceptual abilities. To this end, we used data collected from 302 participants who took part in an EEG recording session and, on separate days, performed a battery of visual tasks and had phosphene and motor thresholds estimated with TMS (here n = 45). Resting-state EEG signals were characterized in terms of both oscillatory (periodic) and background (aperiodic) components. We found that higher overall alpha power predicted higher phosphene thresholds (but not motor thresholds). However, across several behavioral paradigms-using different types of tasks and stimuli, and analyzing both objective accuracy and subjective visibility-we did not find evidence that alpha activity correlated with perceptual abilities. Therefore, although alpha power robustly predicts perception of visual threshold stimuli at the intra-individual level, our study suggests that the relation between alpha power and perception does not extend to the interindividual level.

There exists a dynamic interplay among the neural mechanisms that underlie decision-making and memory in the brain, with mounting evidence suggesting that the anterior hippocampus plays a role in how we represent past experiences as well as how we engage in choice behavior. A key question, then, is how the anterior hippocampus represents memories of our choices. Prior research has identified conceptual similarity between choice options as a critical factor influencing hippocampal involvement in decision-making. Building on this, we investigated how remembering chosen versus unchosen options from conceptually similar and dissimilar choice scenarios affects hippocampal memory representations. In a preregistered fMRI study, participants made a series of decisions between pairs of food options that were either conceptually similar or dissimilar and then completed an item recognition memory task for the previously presented options. Using representational similarity analysis, we examined hippocampal overlap during recognition among chosen and unchosen options from both similar and dissimilar choice trials. Our key finding was higher anterior but not posterior hippocampal similarity when remembering options from the conceptually similar compared with conceptually dissimilar trials, and further analysis showed that this was not explained simply by concept overlap. Complementary multivariate whole-brain analysis further revealed neural patterns of covariance that distinguished between memory for chosen/unchosen options across the similar and dissimilar trials. Taken together, these findings suggest that the way the brain-particularly the anterior hippocampus-stores and retrieves memories is profoundly impacted by the context in which deliberation occurs.