Tactile shape discrimination for moving stimuli.

In this study, we explored spatial-temporal dependencies and their impact on the tactile perception of moving objects. Building on previous research linking visual perception and human movement, we examined if an imputed motion mechanism operates within the tactile modality. We focused on how biological coherence between space and time, characteristic of human movement, influences tactile perception. An experiment was designed wherein participants were stimulated on their right palm with tactile patterns, either ambiguous (incongruent conditions) or non-ambiguous (congruent conditions) relative to a biological motion law (two-thirds power law) and asked to report perceived shape and associated confidence. Our findings reveal that introducing ambiguous tactile patterns (1) significantly diminishes tactile discrimination performance, implying motor features of shape recognition in vision are also observed in the tactile modality, and (2) undermines participants' response confidence, uncovering the accessibility degree of information determining the tactile percept's conscious representation. Analysis based on the Hierarchical Drift Diffusion Model unveiled the sensitivity of the evidence accumulation process to the stimulus's informational ambiguity and provides insight into tactile perception as predictive dynamics for reducing uncertainty. These discoveries deepen our understanding of tactile perception mechanisms and underscore the criticality of predictions in sensory information processing.

Multitasking costs on metacognition in a triple-task paradigm.

Multitasking situations, such as using one's phone while driving, are increasingly common in everyday life. Experimental psychology has long documented the costs of multitasking on task performance; however, little is known of the effects it has on the metacognitive processes that monitor such performance. The present study is a step toward filling this void by combining psychophysical procedures with complex multitasking. We devised a multimodal paradigm in which participants performed a sensorimotor tracking task, a visual discrimination task, and an auditory 2-back working memory task, either separately or concurrently, while also evaluating their task performance every ~15 s. Our main finding is that multitasking decreased participants' awareness of their performance (metacognitive sensitivity) for all three tasks. Importantly, this result was independent of the multitasking cost on task performance, and could not be attributed to confidence leak, psychological refractory period, or recency effects on self-evaluations. We discuss the implications of this finding for both metacognition and multitasking research.

The neural correlates of ongoing conscious thought.

A core goal in cognitive neuroscience is identifying the physical substrates of the patterns of thought that occupy our daily lives. Contemporary views suggest that the landscape of ongoing experience is heterogeneous and can be influenced by features of both the person and the context. This perspective piece considers recent work that explicitly accounts for both the heterogeneity of the experience and context dependence of patterns of ongoing thought. These studies reveal that systems linked to attention and control are important for organizing experience in response to changing environmental demands. These studies also establish a role of the default mode network beyond task-negative or purely episodic content, for example, implicating it in the level of vivid detail in experience in both task contexts and in spontaneous self-generated experiential states. Together, this work demonstrates that the landscape of ongoing thought is reflected in the activity of multiple neural systems, and it is important to distinguish between processes contributing to how the experience unfolds from those linked to how these experiences are regulated.

Probing the effect of the expected-speed violation illusion.

Motion perception is complex for the brain to process, involving interacting computations of distance, time, and speed. These computations can be biased by the context and the features of the perceived moving object, giving rise to several types of motion illusions. Recent research has shown that, in addition to object features and context, lifelong priors can bias attributes of perception. In the present work, we investigated if such long acquired expectations can bias speed perception. Using a two-interval forced-choice (2-IFC) task, we asked 160 participants in different experiments to judge which of two vehicles, one archetypically fast (e.g. a motorbike), and one comparatively slower (e.g. a bike), was faster. By varying the objective speeds of the two-vehicle types, and measuring the participants' point of subjective equality, we observed a consistent bias in participants' speed perception. Counterintuitively, in the first three experiments the speed of an archetypically slow vehicle had to be decreased relative to that of an archetypically fast vehicle, for the two to be judged as the same. Similarly, in the next three experiments, an archetypically fast vehicle's speed had to be increased relative to an archetypically slow vehicle's speed, for the two to be perceived as equal. Four additional control experiments replicated our results. We define this newly found bias as the expected-speed violation illusion (ESVI). We believe the ESVI as conceptually very similar to the size-weight illusion, and discuss it within the Bayesian framework of human perception.

Confidence can be automatically integrated across two visual decisions.

Humans can estimate their confidence in making correct decisions, but these confidence judgments are biased by their other estimations, an effect known as confidence leak. However, it remains unclear whether this effect arises automatically. Here, we address this issue by having participants make two visual decisions and give confidence ratings for one or for both decisions within each trial. Using the well-known interaction between task difficulty and response accuracy as a proxy for confidence, we found that confidence ratings for one decision were greater when the other decision was also associated with greater confidence, even when the latter was not explicitly rated. For one of the two tasks, this confidence leak also occurred when participants knew in advance that no confidence rating would be required for the other task. Our results support the idea that confidence can be automatically integrated across decisions. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Resilience of perceptual metacognition in a dual-task paradigm.

When people do multiple tasks at the same time, it is often found that their performance is worse relative to when they do those same tasks in isolation. However, one aspect that has received little empirical attention is whether the ability to monitor and evaluate one's task performance is also affected by multitasking. How does dual-tasking affect metacognition and its relation to performance? We investigated this question through the use of a visual dual-task paradigm with confidence judgments. Participants categorized both the color and the motion direction of moving dots, and then rated their confidence in both responses. Across four experiments, participants (N = 87) exhibited a clear dual-task cost at the perceptual level, but no cost at the metacognitive level. We discuss this resilience of metacognition to multitasking costs, and examine how our results fit onto current models of perceptual metacognition.

The Confidence Database.

Understanding how people rate their confidence is critical for the characterization of a wide range of perceptual, memory, motor and cognitive processes. To enable the continued exploration of these processes, we created a large database of confidence studies spanning a broad set of paradigms, participant populations and fields of study. The data from each study are structured in a common, easy-to-use format that can be easily imported and analysed using multiple software packages. Each dataset is accompanied by an explanation regarding the nature of the collected data. At the time of publication, the Confidence Database (which is available at https://osf.io/s46pr/) contained 145 datasets with data from more than 8,700 participants and almost 4 million trials. The database will remain open for new submissions indefinitely and is expected to continue to grow. Here we show the usefulness of this large collection of datasets in four different analyses that provide precise estimations of several foundational confidence-related effects.

The role of task difficulty in theoretical accounts of mind wandering.

Recent research has indicated that reducing the difficulty of a task by increasing the predictability of critical stimuli produces increases in intentional mind wandering, but, contrary to theoretical expectations, decreases in unintentional mind wandering. Here, we sought to determine whether reducing task difficulty by reducing working-memory load would yield similar results. Participants completed an easy (Choice Response Time; CRT) task and a relatively difficult (Working Memory; WM) task, and intermittently responded to thought probes asking about intentional and unintentional mind wandering. As in prior studies, we found higher rates of intentional mind wandering during the easy compared to the more difficult task. However, we also found more unintentional mind wandering during the difficult compared to the easy task. We discuss these results in the context of theoretical accounts of mind wandering.

Fast random motion biases judgments of visible and occluded motion speed.

Human sensitivity to speed differences is very high, and relatively high when one has to compare the speed of an object that disappears behind an occluder with a standard. Nevertheless, different speed illusions (by contrast, adaptation, dynamic visual noise) affect proper speed judgment for both visible and occluded moving objects. In the present study, we asked whether an illusion due to non-directional motion noise (random dynamic visual noise, rDVN) intervenes at the level of speed encoding, thus affecting speed discrimination, or at the level of speed decoding by non-sensory decision-making mechanisms, indexed by speed overestimation of visible and invisible motion. In Experiment 1, participants performing a temporal two-Alternative Forced Choice task, judged the speed of a target moving in front of the rDVN or a static visual noise (SVN). In Experiment 2 and 3, the target disappeared behind the rDVN/SVN, and participants reported whether the target reappeared early or late (Experiment 2), or the time to contact (TTC) with the end of the occluded trajectory (Experiment 3). In Experiment 1 and 2, we found that rDVN affected the point of subjective equality (pse) of the individual's psychometric function in a way indicating speed overestimation, while not affecting speed discrimination threshold (just noticeable differences, jnd). In Experiment 3 the rDVN reduced the TTC. Though not entirely consistent, our results suggest that a similar speed decoding mechanism, which read-out motion information to form a perceptual decision, operates regarding of whether motion is visible or invisible.

How do we decide what to do? Resting-state connectivity patterns and components of self-generated thought linked to the development of more concrete personal goals.

Human cognition is not limited to the available environmental input but can consider realities that are different to the here and now. We describe the cognitive states and neural processes linked to the refinement of descriptions of personal goals. When personal goals became concrete, participants reported greater thoughts about the self and the future during mind-wandering. This pattern was not observed for descriptions of TV programmes. Connectivity analysis of participants who underwent a resting-state functional magnetic resonance imaging scan revealed neural traits associated with this pattern. Strong hippocampal connectivity with ventromedial pre-frontal cortex was common to better-specified descriptions of goals and TV programmes, while connectivity between hippocampus and the pre-supplementary motor area was associated with individuals whose goals were initially abstract but became more concrete over the course of the experiment. We conclude that self-generated cognition that arises during the mind-wandering state can allow goals to be refined, and this depends on neural systems anchored in the hippocampus.

When attention wanders: Pupillometric signatures of fluctuations in external attention.

Attention is not always directed to events in the external environment. On occasion our thoughts wander to people and places distant from the here and now. Sometimes, this lack of external attention can compromise ongoing task performance. In the current study we set out to understand the extent to which states of internal and external attention can be determined using pupillometry as an index of ongoing cognition. In two experiments we found that periods of slow responding were associated with elevations in the baseline pupil signal over three and a half seconds prior to a behavioural response. In the second experiment we found that unlike behavioural lapses, states of off-task thought, particularly those associated with a focus on the past and with an intrusive quality, were associated with reductions in the size of the pupil over the same window prior to the probe. These data show that both states of large and small baseline pupil size are linked to states when attention is not effectively focused on the external environment, although these states have different qualities. More generally, these findings illustrate that subjective and objective markers of task performance may not be equivalent and underscore the importance of developing objective indicators that can allow these different states to be understood.

What did you have in mind? Examining the content of intentional and unintentional types of mind wandering.

It has recently been argued that researchers should distinguish between mind wandering (MW) that is engaged with and without intention. Supporting this argument, studies have found that intentional and unintentional MW have behavioral/neural differences, and that they are differentially associated with certain variables of theoretical interest. Although there have been considerable inroads made into the distinction between intentional/unintentional MW, possible differences in their content remain unexplored. To determine whether these two types of MW differ in content, we had participants complete a task during which they categorized their MW as intentional or unintentional, and then provided responses to questions about the content of their MW. Results indicated that intentional MW was more frequently rated as being future-oriented and less vague than unintentional MW. These findings shed light on the nature of intentional and unintentional MW and provide support for the argument that researchers should distinguish between intentional and unintentional types.

Knowing me, knowing you: Resting-state functional connectivity of ventromedial prefrontal cortex dissociates memory related to self from a familiar other.

Material related to the self, as well as to significant others, often displays mnemonic superiority through its associations with highly organised and elaborate representations. Neuroimaging studies suggest this effect is related to activation in regions of medial prefrontal cortex (mPFC). Incidental memory scores for trait adjectives, processed in relation to the self, a good friend and David Cameron were collected. Scores for each referent were used as regressors in seed-based analyses of resting state fMRI data performed in ventral, middle and dorsal mPFC seeds, as well as hippocampal formation. Stronger memory for self-processed items was predicted by functional connnectivity between ventral mPFC, angular gyrus and middle temporal gyri. These regions are within the default mode network, linked to relatively automatic aspects of memory retrieval. In contrast, memory for items processed in relation to best friends, was better in individuals whose ventral mPFC showed relatively weak connectivity with paracingulate gyrus as well as positive connectivity with lateral prefrontal and parietal regions associated with controlled retrieval. These results suggest that mechanisms responsible for memory related to ourselves and personally-familiar people are partially dissociable and reflect connections between ventral mPFC, implicated in schema-based memory, and regions implicated in more automatic and controlled aspects of retrieval.

Shadowing the wandering mind: how understanding the mind-wandering state can inform our appreciation of conscious experience.

The mind-wandering state illustrates two fundamental aspects of consciousness: its generative nature, which is reflected by the stimulus-independent content of thought that occurs when our minds wander; and metacognition, the unique capacity of the mind to reflect and understand itself. Self-generated thought, which allows us to consider people and events that are not present in the immediate environment, and metacognition, allowing us to introspect and report our inner experiences, are both essential to the scientific study of mind-wandering. Nevertheless, they also inevitably lead to specific issues that mirror more general problems in the field of consciousness research. The generative nature of consciousness makes it difficult to have direct control on the phenomenon, and the act of introspecting on inner experience has the potential to influence the state itself. We illustrate how the field of mind-wandering research can overcome these problems. Its generative nature can be understood by triangulating the objective measures (such as neural function) with subjective measures of experience and it can be manipulated indirectly by varying the demands of the external environment. Furthermore, we describe candidate covert markers for the mind-wandering state, which allow the phenomenon to be observed without direct interference, minimizing the concern that instructions to introspect necessarily change conscious experience. WIREs Cogn Sci 2016, 7:233-246. doi: 10.1002/wcs.1392 For further resources related to this article, please visit the WIREs website.

Representing Representation: Integration between the Temporal Lobe and the Posterior Cingulate Influences the Content and Form of Spontaneous Thought.

When not engaged in the moment, we often spontaneously represent people, places and events that are not present in the environment. Although this capacity has been linked to the default mode network (DMN), it remains unclear how interactions between the nodes of this network give rise to particular mental experiences during spontaneous thought. One hypothesis is that the core of the DMN integrates information from medial and lateral temporal lobe memory systems, which represent different aspects of knowledge. Individual differences in the connectivity between temporal lobe regions and the default mode network core would then predict differences in the content and form of people's spontaneous thoughts. This study tested this hypothesis by examining the relationship between seed-based functional connectivity and the contents of spontaneous thought recorded in a laboratory study several days later. Variations in connectivity from both medial and lateral temporal lobe regions was associated with different patterns of spontaneous thought and these effects converged on an overlapping region in the posterior cingulate cortex. We propose that the posterior core of the DMN acts as a representational hub that integrates information represented in medial and lateral temporal lobe and this process is important in determining the content and form of spontaneous thought.

Shaped by the Past: The Default Mode Network Supports Cognition that Is Independent of Immediate Perceptual Input.

Although many different accounts of the functions of the default mode network (DMN) have been proposed, few can adequately account for the spectrum of different cognitive functions that utilize this network. The current study used functional magnetic resonance imaging (fMRI) to explore the hypothesis that the role of the DMN in higher order cognition is to allow cognition to be shaped by information from stored representations rather than information in the immediate environment. Using a novel task paradigm, we observed increased BOLD activity in regions of the medial prefrontal cortex and posterior cingulate cortex when individuals made decisions on the location of shapes from the prior trial and decreased BOLD activity when individuals made decisions on the location of shapes on the current trial. These data are inconsistent with views of the DMN as a task-negative system or one that is sensitive only to stimuli with strong personal or emotional ties. Instead the involvement of the DMN when people make decisions about where a shape was, rather than where it is now, supports the hypothesis that the core hubs of the DMN allow cognition to be guided by information other than the immediate perceptual input. We propose that a variety of different forms of higher order thought (such as imagining the future or considering the perspective of another person) engage the DMN because these more complex introspective forms of higher order thought all depend on the capacity for cognition to be shaped by representations that are not present in the external environment.