Experiences of absorption and smooth performance during flow are linked to different aspects of creative thinking Flow, an experience of deep immersion and smooth, effortless performance, is frequently linked to creativity. However, its specific relationship with the core cognitive mechanisms of creative ideation remains unclear. This study (n = 400) investigated how the smooth and immersive dimensions of flow relate to divergent thinking, measured using the Alternate Uses Task (AUT), and how they relate to the spontaneous flow of associations, assessed with the Forward Flow task. State flow was measured in relation to experiences during the AUT, in which participants were required to invent creative uses for common objects. The AUT elicited a partial flow state in which the smooth dimension, in particular, was not fully realized. Smooth performance was associated with increased idea productivity but decreased creativity, especially when responding required inhibition of conventional associations to semantically rich probes. Conversely, immersion was positively associated with creativity and semantic distance, suggesting that deep attentional engagement may facilitate access to remote associations and promote creative ideation. The spontaneous flow of associations (FF) predicted originality and creativity in the AUT independently of flow. The results suggest that the state experienced during the generation of creative uses can be considered a partial flow, or microflow, that does not meet all the requirements of full flow, and that the relative intensity of the smooth and immersive components is associated with a trade-off between the quantity and quality of the outputs.
Neural representation of time across complementary reference frames Humans conceptualize time in terms of space, allowing flexible time construals from various perspectives. We can travel internally through a timeline to remember the past and imagine the future (i.e., mental time travel) or watch from an external standpoint to have a panoramic view of history (i.e., mental time watching). However, the neural mechanisms that support these flexible temporal construals remain unclear. To investigate this, we asked participants to learn a fictional religious ritual of 15 events. During fMRI scanning, they were guided to consider the event series from either an internal or external perspective in different tasks. Behavioral results confirmed the success of our manipulation, showing the expected symbolic distance effect in the internal-perspective task and the reverse effect in the external-perspective task. We found that the activation level in the posterior parietal cortex correlated positively with sequential distance in the external-perspective task but negatively in the internal-perspective task. In contrast, the activation level in the anterior hippocampus positively correlated with sequential distance regardless of the observer’s perspectives. These results suggest that the hippocampus stores the memory of the event sequences allocentrically in a perspective-agnostic manner. Conversely, the posterior parietal cortex retrieves event sequences egocentrically from the optimal perspective for the current task context. Such complementary allocentric and egocentric representations support both the stability of memory storage and the flexibility of time construals.
The anterior cingulate cortex modulates pupil-linked arousal Subcortical structures like the locus coeruleus (LC) are well known to regulate pupil-linked autonomic arousal, while the role of cortical circuits in this process remains largely unclear. We designed a closed-loop optogenetic system to inactivate the anterior cingulate cortex (ACC) in real time during pupil dilations. ACC inactivation decreased the magnitude of spontaneous pupil events. In parallel, ACC population activity scaled with the magnitude of spontaneously occurring pupil dilations. In addition to modulating spontaneous arousal, ACC responses to salient sensory stimuli scaled with the size of evoked pupil dilations and ACC inactivation suppressed saliency-linked pupil events. Last, we show that LC norepinephrine neurons signal arousal faster than the ACC. However, unlike the ACC, LC responses did not scale with the magnitude of pupil dilations. Collectively, our experiments identify the ACC as a key cortical site for sustaining momentary increases in pupil-linked arousal
The Effects of Reliable Social Feedback on Language Learning: Insights from Electroencephalography and Pupillometry 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.
A two-system theory of sensory-evoked brain responses Sudden and isolated sensory stimuli (SISS) likely signal environmental events demanding immediate behavioural responses. These stimuli—which are widely and persistently used in both basic and clinical neuroscience to explore sensory processing and perception—also trigger some of the largest and most widespread electrocortical responses in the awake mammalian brain. These responses are often interpreted as reflecting either modality-specific sensory processing mediated by high-fidelity ‘lemniscal’ thalamocortical pathways to primary sensory cortices, cortico-cortical connections or motor activity.
Here we contend that these interpretations are unjustified. We first describe evidence that the electrocortical responses elicited by the SISS used in systems and cognitive neuroscience are strongly contributed to by non–modality-specific processes mediated by diffuse ‘extralemniscal’ thalamocortical projections. In human EEG, this contribution is reflected in the scalp vertex potential. We then discuss the implications of this ‘two-system’ theory for basic and clinical neuroscience studies, including the neural correlates of consciousness, where widespread responses to sudden, isolated or rare stimuli—often interpreted as signatures of awareness—may instead reflect extralemniscal activity. We conclude by suggesting a mechanism through which transient extralemniscal responses affect ongoing brain activity and promote swift reactions to sudden environmental changes.
Intelligence, Task Difficulty, and the Regulation of Activity in the Brain’s Default Mode Network This study investigates intelligence-related differences in the adjustment of brain activity and connectivity to varying cognitive demands, testing for a moderation of an association between intelligence and neural efficiency by task difficulty. In 72 young adults (34 female, 38 male), fMRI brain activity changes during a decision-making task with five levels of difficulty were related to intelligence scores from a nonverbal matrix reasoning test. In frontoparietal, subcortical, and cerebellar regions activated during task processing, we observed smaller increases in brain activity in more intelligent participants—independent of task difficulty. However, in two regions of the default mode network, dorsomedial prefrontal cortex and left angular gyrus, more intelligent participants showed greater decreases in activity with increasing task difficulty. Furthermore, with increasing difficulty, more intelligent participants showed greater increases in functional connectivity of dorsomedial prefrontal cortex and angular gyrus. These findings suggest a more dynamic adjustment of neural processing to varying cognitive demands in more intelligent individuals. Particularly when it comes to more difficult tasks, more intelligent people seem to be better able to down-regulate activity in the brain’s default mode network. Due to the relatively small sample size, these findings must be considered preliminary. While their interpretation should therefore be treated with caution, they suggest conceptually new avenues for replication in larger samples. As far as the observed processes reflect the suppression of task-unrelated neural processing and a better focus on the task at hand, they can potentially explain the general performance advantage of more intelligent individuals across various cognitive tasks.
Similar Response Dynamics Represent Opposite Behaviors and Rewards in Frontal Cortex Frontal Cortex (FC) plays a pivotal role in adaptively controlling actions and their dynamics in response to incoming sensory signals. We explored FC encoding of identical stimuli and their behavioral consequences when they signified diametrically opposite responses depending on task context. Two groups of female ferrets performed Go-NoGo auditory categorization tasks with opposite contingencies and rewards, and diverse stimuli. Remarkably, despite opposite stimulus-action associations, single-unit responses were similar across all tasks, being more sustained and stronger to Target sounds (signaling a change in action) than to Reference sounds (indicating maintenance of ongoing actions) especially during task engagement. Overall activity was composed of three distinct dynamic response profiles. Each corresponded to a separate neuronal cluster and exhibited a different role in relation to the succession of task events. Decoding based on the temporal structure of population responses revealed distinct decoders that were aligned to different task events. Similar to single unit findings, the β-band power extracted from the FC local field potentials (LFPs) was strongly and similarly modulated during Target stimuli across all tasks despite opposite behavioral actions. In contrast, power in all other LFP frequency bands varied significantly across task stimuli and actions. Based on these findings, we propose the FC encodes a common, highly abstract representation of all the different behavioral tasks. We further outline a hypothetical model of pathway-specific functional projections from the tripartite FC neuronal clusters to the basal ganglia, consistent with previous evidence for the conjoint roles of the FC and striatum in adaptive motor control.
Controlling spatio-temporal sequences of neural activity by local synaptic changes The neural basis of behavior is believed to consist of sequential patterns of neural activity in the relevant brain regions. Behavioral flexibility also requires neural circuit mechanisms that support dynamic control of sequential activity. However, mechanisms to control and reconfigure sequential activity have received little attention. Here, we show that recurrently connected networks with heterogeneous connectivity and a smooth spatial in-degree landscape (which may arise due to asymmetric neuron morphologies) provide a robust mechanism to evoke and control sequential activity. By modulating the synaptic strength of only a few neurons in local neighborhoods, we uncovered high-impact locations that can start, stop, extend, gate, and redirect sequences. Interestingly, highimpact locations coincide with mid in-degree regions. We demonstrate that these motifs can flexibly reconfigure sequential activity, and hence, provide a framework for fast and flexible computations on behavioral timescales, while the individual parts of the pathways remain rigid and reliable.
We need to explain subjective experience, but its explanation may not be mechanistic Models of consciousness need to explain both the objective correlates of conscious experience as well as its subjective structure. However, such an explanation would not need to entail a reduction exclusively in terms of physical or neural systems. A model that intends to avoid such reduction is integrated information theory (IIT). In this article, we discuss the explanatory rationale of IIT, its potential inconsistencies and its consequences for the neuroscience of consciousness more broadly. In particular, we identify ambiguities regarding the directionality of the explanation, i.e. important tensions between IIT’s purported ontological and epistemological primacy of experience, and its explanatory aim of accounting for consciousness in physical, operational terms. Across the text, we propose several ways to avoid these issues and eventually complement, enhance or replace the model. The main goal is to motivate clarification among IIT-proponents and inform IIT-opponents on accurate points of contention, without thereby misrepresenting the model. In our final section, we introduce alternative explanatory paths: mathematical, processual, and autonomy-based types of explanations. These novel and sound explanatory strategies may better inspire the next generation of models of consciousness.