Implicit guidance of attention: The priority state space framework

The role of object ownership on online inhibition in peripersonal space

Peripersonal space (PPS), as opposed to extrapersonal space (EPS), refers to the area surrounding the body within which individuals interact with objects or conspecifics. However, objects in PPS can belong to oneself or to others, which was found to influence how these objects are encoded. We analyzed the performances of motor responses in a reachability judgment task concerning self-owned and other-owned objects (cups) presented in PPS or EPS. EMG activities were recorded on the thumbs (flexor pollicis brevis) to detect correct and erroneous motor activations. Behavioral data showed that motor responses were shorter and longer for self-owned cups compared to other-owned cups in PPS and EPS, respectively. Ten percent of trials showed initial response errors, which were higher in the EPS for self-owned cups and in the PPS for other-owned cups. Eighty-two percent of these errors were corrected online, with corrections being more efficient for self-owned cups in the PPS. Overall, the data revealed that reachability judgments were faster and more accurate in the PPS, with more efficient inhibition processes in the presence of motor errors. Motor selection and correction are thus modulated by the social context of object ownership, highlighting the specific role of the PPS in encoding self-relevant objects for action.

Task-irrelevant semantic relationship between objects and scene influence attentional allocation

Recent behavioral evidence suggests that the semantic relationships between isolated objects can influence attentional allocation, with highly semantically related objects showing an increase in processing efficiency. This semantic influence is present even when it is task-irrelevant (i.e., when semantic information is not central to the task). However, given that objects exist within larger contexts, i.e., scenes, it is critical to understand whether the semantic relationship between a scene and its objects continuously influence attention. Here, we investigated the influence of task-irrelevant scene semantic properties on attentional allocation and the degree to which semantic relationships between scenes and objects interact. Results suggest that task-irrelevant associations between scenes and objects continuously influence attention and that this influence is directly predicted by the perceived strength of semantic associations.

From learned value to sustained bias: how reward conditioning changes attentional priority

Introduction

Attentional bias to reward-associated stimuli can occur even when it interferes with goal-driven behavior. One theory posits that dopaminergic signaling in the striatum during reward conditioning leads to changes in visual cortical and parietal representations of the stimulus used, and this, in turn, sustains attentional bias even when reward is discontinued. However, only a few studies have examined neural activity during both rewarded and unrewarded task phases.

Methods

In the current study, participants first completed a reward-conditioning phase, during which responses to certain stimuli were associated with monetary reward. These stimuli were then included as non-predictive cues in a spatial cueing task. Participants underwent functional brain imaging during both task phases.

Results

The results show that striatal activity during the learning phase predicted increased visual cortical and parietal activity and decreased ventro-medial prefrontal cortex activity in response to conditioned stimuli during the test. Striatal activity was also associated with anterior cingulate cortex activation when the reward-conditioned stimulus directed attention away from the target.

Discussion

Our findings suggest that striatal activity during reward conditioning predicts the degree to which reward history biases attention through learning-induced changes in visual and parietal activities.

We know what attention is!

Attention is one of the most thoroughly investigated psychological phenomena, yet skepticism about attention is widespread: we do not know what it is, it is too many things, there is no such thing. The deficiencies highlighted are not about experimental work but the adequacy of the scientific theory of attention. Combining common scientific claims about attention into a single theory leads to internal inconsistency. This paper demonstrates that a specific functional conception of attention is incorporated into the tasks used in standard experimental paradigms. In accepting these paradigms as valid probes of attention, we commit to this common conception. The conception unifies work at multiple levels of analysis into a coherent scientific explanation of attention. Thus, we all know what attention is.

Implicit Selective Attention: The Role of the Mesencephalic-basal Ganglia System

The ability of the brain to recognize and orient attention to relevant stimuli appearing in the visual field is highlighted by a tuning process, which involves modulating the early visual system by both cortical and subcortical brain areas. Selective attention is coordinated not only by the output of stimulus-based saliency maps but is also influenced by top-down cognitive factors, such as internal states, goals, or previous experiences. The basal ganglia system plays a key role in implicitly modulating the underlying mechanisms of selective attention, favouring the formation and maintenance of implicit sensory-motor memories that are capable of automatically modifying the output of priority maps in sensory-motor structures of the midbrain, such as the superior colliculus. The article presents an overview of the recent literature outlining the crucial contribution of several subcortical structures to the processing of different sources of salient stimuli. In detail, we will focus on how the mesencephalic- basal ganglia closed loops contribute to implicitly addressing and modulating selective attention to prioritized stimuli. We conclude by discussing implicit behavioural responses observed in clinical populations in which awareness is compromised at some level. Implicit (emergent) awareness in clinical conditions that can be accompanied by manifest anosognosic symptomatology (i.e., hemiplegia) or involving abnormal conscious processing of visual information (i.e., unilateral spatial neglect and blindsight) represents interesting neurocognitive "test cases" for inferences about mesencephalicbasal ganglia closed-loops involvement in the formation of implicit sensory-motor memories.

Separate and overlapping mechanisms of statistical regularities and salience processing in the occipital cortex and dorsal attention network

Attention selects behaviorally relevant inputs for in-depth processing. Beside the role of traditional signals related to goal-directed and stimulus-driven control, a debate exists regarding the mechanisms governing the effect of statistical regularities on attentional selection, and how these are integrated with other control signals. Using a visuo-spatial search task under fMRI, we tested the joint effects of statistical regularities and stimulus-driven salience. We found that both types of signals modulated occipital activity in a spatially specific manner. Salience acted primarily by reducing the attention bias towards the target location when associated with irrelevant distractors, while statistical regularities reduced this attention bias when the target was presented at a low probability location, particularly at the lower levels of the visual hierarchy. In addition, we found that both statistical regularities and salience activated the dorsal frontoparietal network. Additional exploratory analyses of functional connectivity revealed that only statistical regularities modulated the inter-regional coupling between the posterior parietal cortex and the occipital cortex. These results show that statistical regularities and salience signals are both spatially represented at the occipital level, but that their integration into attentional processing priorities relies on dissociable brain mechanisms.

Statistical learning of target and distractor spatial probability shape a common attentional priority computation

Converging evidence recently put forward the notion that dedicated neurocognitive mechanisms do exist for the suppression of salient, but irrelevant distractors. Along this line, it is plausible to hypothesize that, in appropriate contexts, experience-dependent forms of attentional learning might selectively induce plastic changes within this dedicated circuitry, thus allowing an independent shaping of priorities at the service of attentional filtering. Conversely, previous work suggested that statistical learning (SL) of both target and distractor spatial probability distributions converge in adjusting only the overall attentional priority of locations: in fact, in the presence of an independent manipulation, either related to the target or to the distractor only, SL induces indirect effects (e.g., changes in filtering efficiency due to an uneven distribution of targets), suggesting that SL-induced plastic changes affect a shared neural substrate. Here we tested whether, when (conflicting) target- and distractor-related manipulations are concurrently applied to the very same locations, dedicated mechanisms might support the selective encoding of spatial priority in relation to the specific attentional operation involved. In three related experiments, human healthy participants discriminated the direction of a target arrow, while ignoring a salient distractor, if present; both target and distractor spatial probability distributions were concurrently manipulated in relation to each single location. Critically, the selection bias produced by the target-related SL was marginally reduced by an adverse distractor contingency, and the suppression bias generated by the distractor-related SL was erased, or even reversed, by an adverse target contingency. Our results suggest that even conflicting target- and distractor-related SL manipulations result in the adjustment of a unique spatial priority computation, likely because the process directly relies on direct plastic alterations of shared spatial priority map(s).

Object-based inhibition of return in three-dimensional space: From simple drawings to real objects

Cued to an object in space, inhibition of the attended location can spread to the entire object. Although object-based inhibition of return (IOR) studies in a two-dimensional plane have been documented, the IOR has not been explored when objects cross depth in three-dimensional (3D) space. In the present study, we used a virtual reality technique to adapt the double-rectangle paradigm to a 3D space, and manipulated the cue validity and target location to examine the difference in object-based IOR between far and near spaces under different object representations. The study showed that the object-based IOR of simple drawings existed only in near space, whereas object-based IOR of real objects existed only in far space at first, and as the object similarity decreases, it appeared in both far and near spaces.

Attentional shift to the newer object in the successive and simultaneous distractors previewing search

When some distractors (old items) appear before the other distractors and the target (new items) during an inefficient visual search task, the old items are effectively excluded from the search (preview benefit). Previous studies have shown that this preview benefit is observed when items are presented in two temporal stages, namely the initial and second displays. In this situation, new and old items are defined by a single time point (i.e., new items appearing), and the newness of the items is constant through the target search. However, in the real world, the newness of items is updated by the newer objects appearing, which requires more complex computations to detect relevant information among them. The present study examined whether previewing affects the attentional shift to a newer object if multiple new items appear successively. I used the modified preview-search paradigm, which contains three temporally separated displays, and examined what happens if the singleton target appears 200 ms after other distractors appear in the third display. This successive (search) condition was compared to the simultaneous (search) condition in which no distractors were presented in the initial display, and all distractors appeared simultaneously in the second display. The results showed that attentional shift to a newer object requires more time in the successive condition than in the simultaneous condition (Experiment 1). Moreover, the search cost for the newer target would not be induced by a mere difference in the onset timings (Experiment 2) and would occur when the duration of the initial distractors was short, and thus visual marking of the initial distractors might not occur maximally (Experiment 3). Therefore, previewing degrades attentional shift to a newer object when multiple new items appear successively.

Attention and platypuses

This perspective piece discusses a set of attentional phenomena that are not easily accommodated within current theories of attentional selection. We call these phenomena attentional platypuses, as they allude to an observation that within biological taxonomies the platypus does not fit into either mammal or bird categories. Similarly, attentional phenomena that do not fit neatly within current attentional models suggest that current models are in need of a revision. We list a few instances of the "attentional platypuses" and then offer a new approach, that we term dynamically weighted prioritization, stipulating that multiple factors impinge onto the attentional priority map, each with a corresponding weight. The interaction between factors and their corresponding weights determines the current state of the priority map which subsequently constrains/guides attentional allocation. We propose that this new approach should be considered as a supplement to existing models of attention, especially those that emphasize categorical organizations. This article is categorized under: Psychology > Attention Psychology > Perception and Psychophysics Neuroscience > Cognition.

What attention is. The priority structure account

'Everyone knows what attention is' according to William James. Much work on attention in psychology and neuroscience cites this famous phrase only to quickly dismiss it. But James is right about this: 'attention' was not introduced into psychology and neuroscience as a theoretical concept. I argue that we should therefore study attention with broadly the same methodology that David Marr has applied to the study of perception. By focusing more on Marr's Computational Level of analysis, we arrive at a unified answer to the question of what attention is, what role it plays in the mind, and why organisms like us have that capacity. I propose a methodology for studying attention at Marr's Computational Level that optimizes in a three-dimensional space: it should capture core aspects of our first-person experience of attention, be explanatorily powerful in psychology and neuroscience, and fertile in an interdisciplinary context. I show how this methodology leads to what I call the priority structure account of attention. Attention is what organizes current information to make it more useful for the organism. We can identify it by four features. Attention, in this way, helps a cognitive system to integrate its informational state with its current motivational state. I describe how this account improves on alternatives and shows why attention is a useful concept in many disciplines and for connecting them. This article is categorized under: Philosophy > Psychological Capacities Psychology > Attention Philosophy > Foundations of Cognitive Science.

The Attractiveness of Masked Faces Is Influenced by Race and Mask Attitudes

This study tests the influence of wearing a protective face mask on the perceived attractiveness of the wearer. Participants who identified as White, and who varied in their ideological stance toward mask wearing, rated the attractiveness of facial photographs. The photos varied in baseline attractiveness (low, medium, and high), race (White and Asian), and whether or not the face was wearing a protective mask. Attitudes regarding protective masks were measured after the rating task using a survey to identify participants as either pro- or anti-mask. The results showed that masked individuals of the same race were generally rated as more attractive than unmasked individuals, but that masked individuals of another race were rated as less attractive than unmasked individuals. Moreover, pro-mask participants rated masked individuals as generally more attractive than unmasked individuals, whereas anti-maskers rated masked individuals as less attractive. A control experiment, replicating the procedure but replacing the protective masks with a partially occluding notebook, showed that these effects were mask-specific. These results demonstrate that perceived attractiveness is affected by characteristics of the viewer (attitudes toward protective masks), their relationship to the target (same or different race), and by circumstances external to both (pandemic).

Refocusing neuroscience: moving away from mental categories and towards complex behaviours

Mental terms-such as perception, cognition, action, emotion, as well as attention, memory, decision-making-are epistemically sterile. We support our thesis based on extensive comparative neuroanatomy knowledge of the organization of the vertebrate brain. Evolutionary pressures have moulded the central nervous system to promote survival. Careful characterization of the vertebrate brain shows that its architecture supports an enormous amount of communication and integration of signals, especially in birds and mammals. The general architecture supports a degree of 'computational flexibility' that enables animals to cope successfully with complex and ever-changing environments. Here, we suggest that the vertebrate neuroarchitecture does not respect the boundaries of standard mental terms, and propose that neuroscience should aim to unravel the dynamic coupling between large-scale brain circuits and complex, naturalistic behaviours. This article is part of the theme issue 'Systems neuroscience through the lens of evolutionary theory'.

The past, present, and future of selection history

The last ten years of attention research have witnessed a revolution, replacing a theoretical dichotomy (top-down vs. bottom-up control) with a trichotomy (biased by current goals, physical salience, and selection history). This third new mechanism of attentional control, selection history, is multifaceted. Some aspects of selection history must be learned over time whereas others reflect much more transient influences. A variety of different learning experiences can shape the attention system, including reward, aversive outcomes, past experience searching for a target, target‒non-target relations, and more. In this review, we provide an overview of the historical forces that led to the proposal of selection history as a distinct mechanism of attentional control. We then propose a formal definition of selection history, with concrete criteria, and identify different components of experience-driven attention that fit within this definition. The bulk of the review is devoted to exploring how these different components relate to one another. We conclude by proposing an integrative account of selection history centered on underlying themes that emerge from our review.

Does feature intertrial priming guide attention? The jury is still out

Our search performance is strongly influenced by our past experience. In the lab, this influence has been demonstrated by investigating a variety of phenomena, including intertrial priming, statistical learning, and reward history, and collectively referred to as selection history. The resulting findings have led researchers to claim that selection history guides attention, thereby challenging the prevailing dichotomy, according to which top-down and bottom-up factors alone determine attentional priority. Here, we re-examine this claim with regard to one selection-history phenomenon, feature intertrial priming (aka priming of pop-out). We evaluate the evidence that specifically pertains to the role of feature intertrial priming in attentional guidance, rather than in later selective processes occurring after the target is found. We distinguish between the main experimental rationales, while considering the extent to which feature intertrial priming, as studied through different protocols, shares characteristics of top-down attention. We show that there is strong evidence that feature intertrial priming guides attention when the experimental protocol departs from the canonical paradigm and encourages observers to maintain the critical feature in visual working memory or to form expectations about the upcoming target. By contrast, the current evidence regarding the standard feature intertrial priming phenomenon is inconclusive. We propose directions for future research and suggest that applying the methodology used here in order to re-evaluate of the role of other selection history phenomena in attentional guidance should clarify the mechanisms underlying the strong impact of past experience on visual search performance.

Task-Irrelevant Semantic Properties of Objects Impinge on Sensory Representations within the Early Visual Cortex

Objects can be described in terms of low-level (e.g., boundaries) and high-level properties (e.g., object semantics). While recent behavioral findings suggest that the influence of semantic relatedness between objects on attentional allocation can be independent of task-relevance, the underlying neural substrate of semantic influences on attention remains ill-defined. Here, we employ behavioral and functional magnetic resonance imaging measures to uncover the mechanism by which semantic information increases visual processing efficiency. We demonstrate that the strength of the semantic relatedness signal decoded from the left inferior frontal gyrus: 1) influences attention, producing behavioral semantic benefits; 2) biases spatial attention maps in the intraparietal sulcus, subsequently modulating early visual cortex activity; and 3) directly predicts the magnitude of behavioral semantic benefit. Altogether, these results identify a specific mechanism driving task-independent semantic influences on attention.

Statistical learning of target selection and distractor suppression shape attentional priority according to different timeframes

Recent findings suggest that attentional and oculomotor control is heavily affected by past experience, giving rise to selection and suppression history effects, so that target selection is facilitated if they appear at frequently attended locations, and distractor filtering is facilitated at frequently ignored locations. While selection history effects once instantiated seem to be long-lasting, whether suppression history is similarly durable is still debated. We assessed the permanence of these effects in a unique experimental setting investigating eye-movements, where the locations associated with statistical unbalances were exclusively linked with either target selection or distractor suppression. Experiment 1 and 2 explored the survival of suppression history in the long and in the short term, respectively, revealing that its lingering traces are relatively short lived. Experiment 3 showed that in the very same experimental context, selection history effects were long lasting. These results seem to suggest that different mechanisms support the learning-induced plasticity triggered by selection and suppression history. Specifically, while selection history may depend on lasting changes within stored representations of the visual space, suppression history effects hinge instead on a functional plasticity which is transient in nature, and involves spatial representations which are constantly updated and adaptively sustain ongoing oculomotor control.

An egocentric straight-ahead bias in primate's vision

As we plan to reach or manipulate objects, we generally orient our body so as to face them. Other objects occupying the same portion of space will likely represent potential obstacles for the intended action. Thus, either as targets or as obstacles, the objects located straight in front of us are often endowed with a special behavioral status. Here, we review a set of recent electrophysiological, imaging and behavioral studies bringing converging evidence that the objects which lie straight-ahead are subject to privileged visual processing. More precisely, these works collectively demonstrate that when gaze steers central vision away from the straight-ahead direction, the latter is still prioritized in peripheral vision. Straight-ahead objects evoke (1) stronger neuronal responses in macaque peripheral V1 neurons, (2) stronger EEG and fMRI activations across the human visual cortex and (3) faster reactive hand and eye movements. Here, we discuss the functional implications and underlying mechanisms behind this phenomenon. Notably, we propose that it can be considered as a new type of visuospatial attentional mechanism, distinct from the previously documented classes of endogenous and exogenous attention.

A subcortical network for implicit visuo-spatial attention: Implications for Parkinson's Disease

Recent studies in humans and animal models suggest a primary role of the basal ganglia in the extraction of stimulus-value regularities, then exploited to orient attentional shift and build up sensorimotor memories. The tail of the caudate and the posterior putamen both receive early visual input from the superficial layers of the superior colliculus, thus forming a closed-loop. We portend that the functional value of this circuit is to manage the selection of visual stimuli in a rapid and automatic way, once sensory-motor associations are formed and stored in the posterior striatum. In Parkinson's Disease, the nigrostriatal dopamine depletion starts and tends to be more pronounced in the posterior putamen. Thus, at least some aspect of the visuospatial attention deficits observed since the early stages of the disease could be the behavioral consequences of a cognitive system that has lost the ability to translate high-level processing in stable sensorimotor memories.

Meeting another's gaze shortens subjective time by capturing attention

Gaze directed at the observer (direct gaze) is an important and highly salient social signal with multiple effects on cognitive processes and behavior. It is disputed whether the effect of direct gaze is caused by attentional capture or increased arousal. Time estimation may provide an answer because attentional capture predicts an underestimation of time whereas arousal predicts an overestimation. In a temporal bisection task, observers were required to classify the duration of a stimulus as short or long. Stimulus duration was selected randomly between 988 and 1479 ms. When gaze was directed at the observer, participants underestimated stimulus duration, suggesting that effects of direct gaze are caused by attentional capture, not increased arousal. Critically, this effect was limited to dynamic stimuli where gaze appeared to move toward the participant. The underestimation was present with stimuli showing a full face, but also with stimuli showing only the eye region, inverted faces and high-contrast eye-like stimuli. However, it was absent with static pictures of full faces and dynamic nonfigurative stimuli. Because the effect of direct gaze depended on motion, which is common in naturalistic scenes, more consideration needs to be given to the ecological validity of stimuli in the study of social attention.

The use of artificial intelligence and robotics in regional anaesthesia

The current fourth industrial revolution is a distinct technological era characterised by the blurring of physics, computing and biology. The driver of change is data, powered by artificial intelligence. The UK National Health Service Topol Report embraced this digital revolution and emphasised the importance of artificial intelligence to the health service. Application of artificial intelligence within regional anaesthesia, however, remains limited. An example of the use of a convoluted neural network applied to visual detection of nerves on ultrasound images is described. New technologies that may impact on regional anaesthesia include robotics and artificial sensing. Robotics in anaesthesia falls into three categories. The first, used commonly, is pharmaceutical, typified by target-controlled anaesthesia using electroencephalography within a feedback loop. Other types include mechanical robots that provide precision and dexterity better than humans, and cognitive robots that act as decision support systems. It is likely that the latter technology will expand considerably over the next decades and provide an autopilot for anaesthesia. Technical robotics will focus on the development of accurate sensors for training that incorporate visual and motion metrics. These will be incorporated into augmented reality and visual reality environments that will provide training at home or the office on life-like simulators. Real-time feedback will be offered that stimulates and rewards performance. In discussing the scope, applications, limitations and barriers to adoption of these technologies, we aimed to stimulate discussion towards a framework for the optimal application of current and emerging technologies in regional anaesthesia.

Elemental and Configural Associative Learning in Spatial Tasks: Could Zebrafish be Used to Advance Our Knowledge?

Spatial learning and memory have been studied for several decades. Analyses of these processes pose fundamental scientific questions but are also relevant from a biomedical perspective. The cellular, synaptic and molecular mechanisms underlying spatial learning have been intensively investigated, yet the behavioral mechanisms/strategies in a spatial task still pose unanswered questions. Spatial learning relies upon configural information about cues in the environment. However, each of these cues can also independently form part of an elemental association with the specific spatial position, and thus spatial tasks may be solved using elemental (single CS and US association) learning. Here, we first briefly review what we know about configural learning from studies with rodents. Subsequently, we discuss the pros and cons of employing a relatively novel laboratory organism, the zebrafish in such studies, providing some examples of methods with which both elemental and configural learning may be explored with this species. Last, we speculate about future research directions focusing on how zebrafish may advance our knowledge. We argue that zebrafish strikes a reasonable compromise between system complexity and practical simplicity and that adding this species to the studies with laboratory rodents will allow us to gain a better understanding of both the evolution of and the mechanisms underlying spatial learning. We conclude that zebrafish research will enhance the translational relevance of our findings.

Independent effects of statistical learning and top-down attention

It is well known that spatial attention can be directed in a top-down way to task-relevant locations in space. In addition, through visual statistical learning (VSL), attention can be biased towards relevant (target) locations and away from irrelevant (distractor) locations. The present study investigates the interaction between the explicit task-relevant, top-down attention and the lingering attentional biases due to VSL. We wanted to determine the contribution of each of these two processes to attentional selection. In the current study, participants performed a search task while keeping a location in spatial working memory. In Experiment 1, the target appeared more often in one location, and appeared less often in other location. In Experiment 2, a color singleton distractor was presented more often in location than in all other locations. The results show that when the search target matched the location that was kept in working memory, participants were much faster at responding to the search target than when it did not match, signifying top-down attentional selection. Independent of this top-down effect, we found a clear effect of VSL as responses were even faster when target (Experiment 1) or the distractor (Experiment 2) was presented at a more likely location in visual field. We conclude that attentional selection is driven by implicit biases due to statistical learning and by explicit top-down processing, each process individually and independently modulating the neural activity within the spatial priority map.

Putting the Nonsocial Into Social Neuroscience: A Role for Domain-General Priority Maps During Social Interactions

Whether on a first date or during a team briefing at work, people’s daily lives are inundated with social information, and in recent years, researchers have begun studying the neural mechanisms that support social-information processing. We argue that the focus of social neuroscience research to date has been skewed toward specialized processes at the expense of general processing mechanisms with a consequence that unrealistic expectations have been set for what specialized processes alone can achieve. We propose that for social neuroscience to develop into a more mature research program, it needs to embrace hybrid models that integrate specialized person representations with domain-general solutions, such as prioritization and selection, which operate across all classes of information (both social and nonsocial). To illustrate our central arguments, we first describe and then evaluate a hybrid model of information processing during social interactions that (a) generates novel and falsifiable predictions compared with existing models; (b) is predicated on a wealth of neurobiological evidence spanning many decades, methods, and species; (c) requires a superior standard of evidence to substantiate domain-specific mechanisms of social behavior; and (d) transforms expectations of what types of neural mechanisms may contribute to social-information processing in both typical and atypical populations.

Affective Bias without Hemispheric Competition: Evidence for Independent Processing Resources in Each Cortical Hemisphere

We assessed the extent of neural competition for attentional processing resources in early visual cortex between foveally presented task stimuli and peripheral emotional distracter images. Task-relevant and distracting stimuli were shown in rapid serial visual presentation (RSVP) streams to elicit the steady-state visual evoked potential, which serves as an electrophysiological marker of attentional resource allocation in early visual cortex. A task-related RSVP stream of symbolic letters was presented centrally at 15 Hz while distracting RSVP streams were displayed at 4 or 6 Hz in the left and right visual hemifields. These image streams always had neutral content in one visual field and would unpredictably switch from neutral to unpleasant content in the opposite visual field. We found that the steady-state visual evoked potential amplitude was consistently modulated as a function of change in emotional valence in peripheral RSVPs, indicating sensory gain in response to distracting affective content. Importantly, the facilitated processing for emotional content shown in one visual hemifield was not paralleled by any perceptual costs in response to the task-related processing in the center or the neutral image stream in the other visual hemifield. Together, our data provide further evidence for sustained sensory facilitation in favor of emotional distracters. Furthermore, these results are in line with previous reports of a “different hemifield advantage” with low-level visual stimuli and are suggestive of independent processing resources in each cortical hemisphere that operate beyond low-level visual cues, that is, with complex images that impact early stages of visual processing via reentrant feedback loops from higher order processing areas.

Functional Imaging of Visuospatial Attention in Complex and Naturalistic Conditions

One of the ultimate goals of cognitive neuroscience is to understand how the brain works in the real world. Functional imaging with naturalistic stimuli provides us with the opportunity to study the brain in situations similar to the everyday life. This includes the processing of complex stimuli that can trigger many types of signals related both to the physical characteristics of the external input and to the internal knowledge that we have about natural objects and environments. In this chapter, I will first outline different types of stimuli that have been used in naturalistic imaging studies. These include static pictures, short video clips, full-length movies, and virtual reality, each comprising specific advantages and disadvantages. Next, I will turn to the main issue of visual-spatial orienting in naturalistic conditions and its neural substrates. I will discuss different classes of internal signals, related to objects, scene structure, and long-term memory. All of these, together with external signals about stimulus salience, have been found to modulate the activity and the connectivity of the frontoparietal attention networks. I will conclude by pointing out some promising future directions for functional imaging with naturalistic stimuli. Despite this field of research is still in its early days, I consider that it will play a major role in bridging the gap between standard laboratory paradigms and mechanisms of brain functioning in the real world.

Emotional Objectivity: Neural Representations of Emotions and Their Interaction with Cognition

Recent advances in our understanding of information states in the human brain have opened a new window into the brain's representation of emotion. While emotion was once thought to constitute a separate domain from cognition, current evidence suggests that all events are filtered through the lens of whether they are good or bad for us. Focusing on new methods of decoding information states from brain activation, we review growing evidence that emotion is represented at multiple levels of our sensory systems and infuses perception, attention, learning, and memory. We provide evidence that the primary function of emotional representations is to produce unified emotion, perception, and thought (e.g., “That is a good thing”) rather than discrete and isolated psychological events (e.g., “That is a thing. I feel good”). The emergent view suggests ways in which emotion operates as a fundamental feature of cognition, by design ensuring that emotional outcomes are the central object of perception, thought, and action.

Experience-Driven Auditory Attention

In addition to conscious goals and stimulus salience, an observer's prior experience also influences selective attention. Early studies demonstrated experience-driven effects on attention mainly in the visual modality, but increasing evidence shows that experience drives auditory selection as well. We review evidence for a multiple-levels framework of auditory attention, in which experience-driven attention relies on mechanisms that acquire control settings and mechanisms that guide attention towards selected stimuli. Mechanisms of acquisition include cue-target associative learning, reward learning, and sensitivity to prior selection history. Once acquired, implementation of these biases can occur either consciously or unconsciously. Future research should more fully characterize the sources of experience-driven auditory attention and investigate the neural mechanisms used to acquire and implement experience-driven auditory attention.

Investigations into ventral prefrontal cortex using mediation models

The ventral prefrontal cortex (vPFC) is a major focus of investigation in neuroscience, particularly in the studies of emotion and emotion-cognition integration. A crucial question concerning the regulatory function of vPFC is how it is recruited, especially how the function maps onto the structure and determines appropriate behavior. In social exclusion studies, mediation model analyses suggest that vPFC regulates distress by disrupting anterior cingulate cortex (ACC) activities, whereas I recently report (Hu, 2018; Neuropsychologia) that ventral medial prefrontal cortex appears to defend the organism from acute stress by activating ACC. In this review, I synthesize and highlight functional imaging research with mediation analysis that over the past decades has begun to offer new insights into the brain mechanisms underlying vPFC. Toward this end, the first section of the paper outlines a model of the processes and neural systems involved in the interaction of emotion and cognition. The second and third sections survey recent research on emotional regulation with negative and positive pathways, respectively, emanating from vPFC. The fourth section summarizes the current dynamic network findings. Functional mediation analysis helps to identify signals within vPFC and others that are common and/or specific to particular information processing. Finally, I provide a personal perspective of the adoption of mediation model analysis in the investigations into vPFC.

Attentional bias toward and distractibility by sexual cues: A meta-analytic integration

From an evolutionary perspective, sexual stimuli are highly salient and are assumed to be processed with high priority. Hence, attentional processing of sexual cues is expected to not only bias attention but to also distract from other cognitive (foreground) tasks. It is, however, unclear to what extent these stimuli capture attention and whether there are differences between men and women. This meta-analysis combined the results of 32 studies employing experiments of attentional bias toward and distraction by sexual stimuli. From these, 13 studies provided data to examine gender differences. Overall, attentional bias and distractibility was lower than anticipated (g_z = 0.43, p < .001) and there was support for the assumption of higher attention bias/interference in men (g_s = 0.29, p = .031). Importantly, there was evidence for the presence of publication bias. With this in mind, findings are discussed in the context of stimulus features, the impact of provoked sexual arousal and motivational state, and gender-specific and -nonspecific neural processing of sexual stimuli which influence attention toward them.

Revealing Dissociable Attention Biases in Chronic Smokers Through an Individual-Differences Approach

Addiction is accompanied by attentional biases (AB), wherein drug-related cues grab attention independently of their perceptual salience. AB have emerged in different flavours depending on the experimental approach, and their clinical relevance is still debated. In chronic smokers we sought evidence for dissociable attention abnormalities that may play distinct roles in the clinical manifestations of the disorder. Fifty smokers performed a modified visual probe-task measuring two forms of AB and their temporal dynamics, and data on their personality traits and smoking history/status were collected. Two fully dissociable AB effects were found: A Global effect, reflecting the overall impact of smoke cues on attention, and a Location-specific effect, indexing the impact of smoke cues on visuospatial orienting. Importantly, the two effects could be neatly separated from one another as they: (i) unfolded with dissimilar temporal dynamics, (ii) were accounted for by different sets of predictors associated with personality traits and smoking history and (iii) were not correlated with one another. Importantly, the relevance of each of these two components in the single individual depends on a complex blend of personality traits and smoking habits, a result that future efforts addressing the clinical relevance of addiction-related AB should take into careful consideration.

Affectively Biased Competition: Sustained Attention is Tuned to Rewarding Expressions and is Not Modulated by Norepinephrine Receptor Gene Variant

It is well established that emotionally salient stimuli evoke greater visual cortex activation than neutral ones, and can distract attention from competing tasks. Yet less is known about underlying neurobiological processes. As a proxy of population level biased competition, EEG steady-state visual evoked potentials are sensitive to competition effects from salient stimuli. Here we wished to examine whether individual differences in norepinephrine activity play a role in emotionally-biased competition.

Our previous research has found robust effects of a common variation in the ADRA2B gene, coding for alpha2B norepinephrine (NE) receptors, on emotional modulation of attention and memory. In the present study, EEG was collected while 87 carriers of the ADRA2B deletion variant and 95 non-carriers (final sample) performed a change detection task in which target gratings (gabor patches) were superimposed directly over angry, happy, and neutral faces. Participants indicated the number of phase changes (0–3) in the target. Overlapping targets and distractors were flickered at a distinct driving frequencies. Relative EEG power for faces vs. targets at the driving frequency served as an index of cortical resources allocated to each of the competing stimuli. Deletion carriers and non-carriers were randomly assigned to Discovery and Replication samples and reliability of results across samples was assessed before the groups were combined for greater power.

Overall happy faces evoked higher competition than angry or neutral faces; however, we observed no hypothesized effects of ADRA2B. Increased competition from happy faces was not due to the effect of low-level visual features or individuals low in social anxiety. Our results indicate that emotionally biased competition during sustained attention, while reliably observed in young adults, is not influenced by commonly observed individual differences linked to NE receptor function. They further indicate an overall pattern of affectively-biased competition for happy faces, which we interpret in relation to previously observed boundary conditions.

Apical Function in Neocortical Pyramidal Cells: A Common Pathway by Which General Anesthetics Can Affect Mental State

It has been argued that general anesthetics suppress the level of consciousness, or the contents of consciousness, or both. The distinction between level and content is important because, in addition to clarifying the mechanisms of anesthesia, it may help clarify the neural bases of consciousness. We assess these arguments in the light of evidence that both the level and the content of consciousness depend upon the contribution of apical input to the information processing capabilities of neocortical pyramidal cells which selectively amplify relevant signals. We summarize research suggesting that what neocortical pyramidal cells transmit information about can be distinguished from levels of arousal controlled by sub-cortical nuclei and from levels of prioritization specified by interactions within the thalamocortical system. Put simply, on the basis of the observations reviewed, we hypothesize that when conscious we have particular, directly experienced, percepts, thoughts, feelings and intentions, and that general anesthetics affect consciousness by interfering with the subcellular processes by which particular activities are selectively amplified when relevant to the current context.

The effect of static versus dynamic stimuli on visual processing of sexual cues in androphilic women and gynephilic men

Models of sexual response posit that attentional processing of sexual cues is requisite for sexual responding. Despite hypothesized similarities in the underlying processes resulting in sexual response, gender differences in sexual arousal patterns are abundant. One such gender difference relates to the stimulus features (e.g. gender cues, sexual activity cues) that elicit a response in men and women. In this study, we examined how stimulus modality (static visual images versus dynamic audiovisual films) and stimulus features (gender, sexual activity and nonsexual contextual cues) influences attentional (i.e. gaze) and elaborative (i.e. self-reported attraction (SRA), self-reported arousal) processing of sexual stimuli. Men's initial and controlled attention was consistently gender-specific (i.e. greater attention towards female targets), and this was not influenced by stimulus modality or the presence of sexual activity cues. By contrast, gender-specificity of women's attention patterns differed as a function of attentional stage, stimulus modality and the features within the stimulus. Degree of specificity was positively predictive of SRA in both genders; however, it was not significantly predictive of self-reported arousal. These findings are discussed in the context of gendered processing of visual sexual information, including a discussion of implications for research designs.

Experiential History as a Tuning Parameter for Attention

[Peer commentary on "Visual selection: usually fast and automatic; seldom slow and volitional," by J. Theeuwes]. Journal of Cognition. In his current opinion piece, Theeuwes emphasizes the role of selection history as a third source of attentional selection, beyond top-down and bottom-up mechanisms, thus challenging traditional dual-process models of attention. While we agree that selection history impacts the allocation of attention, our own work suggests that this terminology may be too restrictive, and propose the simple term history as a better reflection of the impact of learning on our selection biases. Furthermore, we propose that the role of selection/experiential history on attention may not be as a unique third source of attentional selection, but rather as a tuning parameter, allowing certain categories of item to be endowed with greater task-based or feature-driven salience in a context and history dependent manner. This conceptualization presents an alternative to abandoning dual-process models of attention altogether. Rather, we can reimagine how task-based and feature-driven processes may be controlled by past experience in a dynamic and adaptable system.

Visual Selection: Usually Fast and Automatic; Seldom Slow and Volitional; A Reply to Commentaries

In this reply I react to the commentaries of my colleagues to my review article "Visual Selection: Usually Fast and Automatic; Seldom Slow and Volitional" (Theeuwes, 2018). I have organized the reply into separate sections and discuss issues that were commonly raised.

Visual Selection: Usually Fast and Automatic; Seldom Slow and Volitional

Recently it was argued that in addition to top-down and bottom-up processes, lingering biases of selection history play a major role in visual selection (Awh, Belopolsky & Theeuwes, 2012). Since its publication there has been a growing controversy about the terms top-down, bottom-up and selection-history in relation to visual selection. In the current paper we define these terms, discuss some controversies about these terms and explain what kind of effects should be considered to be the result of lingering biases of selection history, i.e., priming, reward/fear, and statistical learning. We discuss the properties of top-down selection (slow, effortful, and controlled) versus the properties of lingering biases of selection history (fast, effortless, and automatic). We adhere the position that the experience with selecting a particular feature or the location of a feature, may boost and sharpen its representation within the priority selection map above and beyond its physical salience. It is as if the experience may render a feature or location subjectively more salient. Our message of the current review is that true top-down control of visual selection occurs far less often than what is typically assumed. Most of the time, selection is based on experience and history. It is fast, automatic and occurs without much, if any, effort.