Journal of Cognitive Neuroscience最新文献

Humans complete different types of sequences as a part of everyday life. These sequences can be divided into two important categories: those that are abstract, in which the steps unfold according to a rule at super-second to minute time scale, and those that are motor, defined solely by individual movements and their order that unfold at the subsecond to second timescale. For example, the sequence of making spaghetti consists of abstract tasks (preparing the sauce and cooking the noodles) and nested motor actions (stir pasta water). Previous work shows neural activity increases (ramps) in the rostrolateral prefrontal cortex (RLPFC) during abstract sequence execution. During motor sequence production, activity occurs in regions of PFC. However, it remains unknown if ramping is a signature of motor sequence production as well or solely an attribute of abstract sequence monitoring and execution. We tested the hypothesis that significant ramping activity occurs during motor sequence production in the RLPFC. Contrary to our hypothesis, we did not observe significant ramping activity in the RLPFC during motor sequence production, but we found significant ramping activity in bilateral inferior parietal cortex, in regions distinct from those observed during an abstract sequence task. Our results suggest different prefrontal-parietal circuitry may underlie abstract versus motor sequence execution.

Chinese speakers have long suffered from character amnesia in handwriting, failing to handwrite a character despite being able to recognize it. However, it remains unclear whether character amnesia arises from the failure in accessing orthographic representations in the orthographic lexicon, reduced graphemic information in the graphemic buffer, or/and weakened phonology-orthography links. To address this issue, we employed functional near-infrared spectroscopy to identify brain regions that are associated with character amnesia. In particular, we tested whether character amnesia is associated with deactivation in the fusiform gyrus (FG), the superior parietal gyrus (SPG), or the supramarginal gyrus (SMG), which have been shown to be respectively associated with the orthographic lexicon, graphemic buffer, and phonology-orthography conversion. In a handwriting-to-dictation task, 23 Cantonese-speaking adults handwrote a character according to a dictation prompt and then reported whether they correctly handwrote the character or suffered from character amnesia. Functional near-infrared spectroscopy results showed that, compared with correct handwriting, character amnesia elicited reduced activation in the bilateral FG, the SPG, and the SMG. Parametric analyses showed that character frequency and number of strokes positively correlated with activation of the FG and the SPG, respectively. Functional connectivity analyses revealed that, compared with correct handwriting, character amnesia was associated with decreased connectivity between the left FG and the left SMG, the right FG and the right SMG, the right FG and the right SPG, the right FG and the left SMG, and the right FG and the left SPG. Together, these results suggest that character amnesia is associated with decayed orthographic representations (in the orthographic lexicon) and failure in phonology-orthography conversion, resulting in reduced orthographic information being retrieved (into the graphemic buffer) for handwriting execution.

A central debated question in the study of object-based attention (OBA) is whether attention to the object-mediated deployment of attention is obligatory and automatic [Chen, Z., & Cave, K. R. Reinstating object-based attention under positional certainty: The importance of subjective parsing. Perception & Psychophysics, 68, 992-1003, 2006] or whether the pattern of results is driven by other non-obligatory factors, such as prioritization of invalid target locations [Shomstein, S., & Yantis, S. Object-based attention: Sensory modulation or priority setting? Perception & Psychophysics, 64, 41-51, 2002]. However, virtually all behavioral measures attributed to OBA are based on examining performance on invalid-cue trials, the inclusion of which confounds the assessment of the automaticity hypothesis. Our approach to resolve this issue is to determine whether effects of OBA can be observed in a 100% valid cueing paradigm. In this article, we investigate the obligatory nature of OBA by leveraging the spatial specificity of fMRI and the retinotopic organization of early visual cortex. We aimed to identify potential neural correlates of OBA in the complete absence of invalid trials. Participants perform a version of the classic two-rectangle OBA paradigm while we simultaneously measure changes in BOLD signals arising from retinotopically organized cortical areas V1, V2, and V3. In the first half of the experiment, we used the classic two-rectangle OBA paradigm except that the cue was 100% valid. In the second half, we reduced cue validity to more closely match standard OBA paradigms (runs containing invalid trials). We analyzed BOLD signals arising from our ROIs in V1, V2, and V3 according to their topographic correspondences with the ends of the rectangles in the visual field and compared these. We then compared responses in each ROI according to where the cue had occurred (cued, uncued-same-object, uncued-other-object location). We replicated this procedure in Experiment 2, but changed the layout of the two rectangles from a vertical to a horizontal configuration. Critical result: We observed statistically significant effects of OBA in V3 (Experiment 1) and V1-2 (Experiment 2) in both the 100% valid runs and in runs containing invalid trials. Moreover, the effects of OBA were no smaller in the 100% runs compared with runs containing invalid trials. Conclusion: We see BOLD modulation at the uncued locations consistent with neural correlates of OBA.

The ability of the brain to monitor its own attention is important for controlling attention. The ability to reconstruct and monitor the attention of others is important for behavioral prediction and therefore interaction with others. Do the same cortical networks participate in constructing a metacognitive representation of attention, whether one's own or someone else's attention? We studied the brain activity of human participants in an fMRI scanner. The participants performed two attention-monitoring tasks. One involved focusing attention on their own breathing and pressing a button when they realized their attention had wandered. In the other, participants watched a video of an actor performing the same focused-attention task, and participants pressed the button if the actor's attention appeared to have wandered. In both cases, we analyzed brain activity just before the button presses, when participants were engaged in metacognition with respect to attention. In the Self condition, activity was obtained in a distinctive set of areas including the TPJ, precuneus, dorsomedial pFC, anterior cingulate, and anterior insula. The activity partly overlapped the default mode network, social cognition network, and salience network. In the Other condition, activity was found in a similar set of areas including the TPJ, precuneus, dorsomedial pFC, anterior cingulate, and anterior insula. These results suggest that there may be a common set of cortical areas that provide an overarching mechanism for metacognition concerning attention, although Self and Other processing are also clearly not identical.

Subjective features of memory are often treated as secondary to the objective content of remembered events. However, growing evidence suggests that these features actively shape how memories are constructed, experienced, and used. Rather than treating visual perspective as a peripheral correlate of subjectivity, this review positions it as a key mechanism that shapes the memory. Because perspective can be flexibly controlled and reliably measured, it offers a unique window into how retrieval goals interact with mental simulation to produce vivid and emotionally resonant recollections. Drawing on behavioral and neuroimaging research, this review shows that visual perspective determines the spatial framing of memory and the emotional and sensory qualities of recollection. Focusing on the posterior parietal cortex, it outlines distinct roles for the angular gyrus (AG) and the precuneus in supporting perspective-dependent retrieval. The AG contributes to the selection and maintenance of a retrieval perspective, integrating perceptual and conceptual features into a coherent scene. In contrast, the precuneus supports spatial transformation and modulates the vividness, emotional tone, and embodied character of recollection, particularly when individuals recall events from a nondominant or shifted perspective. Together, these findings position visual perspective as a central mechanism in the construction of subjectivity. Understanding how perspective shapes the process of remembering provides insight into how memory supports emotion regulation, mental simulation, and the continuity of the self across time.

In conversation, future speakers often plan speech simultaneously with comprehension, which means that they must divide attentional resources between these processes. In this EEG study, we used responses to linguistic attention probes (i.e., syllable "BA" presented during spoken sentences) to track temporal variations in attention to comprehension. Participants were asked to listen to prerecorded sentences with expected or unexpected sentence-final words. Each sentence was presented twice, once with and once without the attention probe starting 100 msec after the target word onset. Participants saw a picture 50 msec before the target word. Depending on the test block (picture naming or button press), participants either named the picture or pressed the space bar, both after an 850-msec delay. The probes elicited a negative potential approximately 100 msec after probe onset (i.e., an attention probe effect) in all probe conditions. Unexpectedly, neither word expectancy nor speech planning influenced the timing or strength of the attention probe effect. This indicates that expectancy of words in Dutch does not affect the allocation of attention toward these words 100 msec after their onset (i.e., the time of the probe presentation). Interestingly, engaging in speech planning does not seem to divert attentional resources away from comprehension at the moment of probe presentation. These findings imply that listeners are able to effectively distribute their attentional resources between comprehension and speech planning and carry out these processes at the same time. Considering these unexpected findings, using attention probes might not be the best approach to capture variations in temporal attention in dual-task paradigms.