This chapter focuses on the effects of attention, including when and where in the brain these effects occur. It begins with studies of visual-spatial attention, expands to different varieties of visual attention (e.g., feature-based attention), and concludes with the effects of attention across sensory modalities. Evidence is presented from ERP studies showing the effects of attention on the P1, N1, and P3 components. The controversy regarding if attention can affect the earliest stage of cortical visual processing (indexed by the C1 component) is highlighted. Neuroimaging evidence for attention effects in striate and extrastriate cortex (e.g., area V3 and the fusiform gyrus) are presented. The controversy about whether attention effects in the thalamus, observed in some fMRI research, represent modulation of feedforward or feedback processing is discussed. Evidence is presented from single-unit recordings that supports the view that spatial attention affects early stages of cortical processing. An intriguing new theory of attention – the rhythmic theory of attention – is presented, along with supporting evidence from human and non-human studies. New evidence for suppressive mechanisms that contribute to selective attention are introduced, and the effects of visual-spatial attention are compared to the effects of feature attention, object attention, and cross-modal attention.

This chapter provides examples of how attention plays an important role in our everyday lives. Real-world examples are used to explain the motivations behind cutting-edge attention research being done in neuroscience labs. These include distracted driving, airport security screening, and radar and sonar monitoring. Vigilance and the ability to sustain attention are introduced as critical mental processes for success at certain jobs. The influence of attention on reading and memory, and the choice of whether to study in silence or with music are discussed. Lapses of attention are described, including how these can have a range of consequences, from the brief embarrassment of not knowing what someone just said to us to the potentially fatal effect of not attending to our driving. Theories of joint attention and social-gaze orienting are introduced to explain how our attention is linked to those around us. The purposeful misdirection of a person’s attention, at multiple levels, by skilled magicians is linked to core processes of attention and perception. This chapter also introduces the idea of training attention, including the effects of playing video games, and explains how proper training protocols require detailed knowledge of the mechanisms of attention.

This chapter describes the processes of attentional control and contrasts the effects of attention on perceptual processing versus the control of attentional orienting. PET, fMRI, and single-unit recordings have identified a bilateral dorsal attention network (DAN) that controls the orienting of attention and a ventral attention network (VAN) that is critical for the reorienting of attention. The intraparietal sulcus (IPS) and frontal eye fields (FEF) have been found to be core elements of the DAN, and the temporal parietal junction (TPJ) and ventral frontal regions are consistently found to be part of the VAN. Internally generated attention, or willed attention, is contrasted to exogenous attention and externally triggered endogenous attention. New methods of analyzing patterns of brain connectivity that hold promise for helping understand individual and group differences in attentional control are described. Neurostimulation studies (e.g., tACS; cTBS; TMS) that are providing evidence for the causal involvement of DAN and VAN to attentional control are discussed, and ERP indices of attention control processes (such as the EDAN, ADAN, and LDAP components) and of executive monitoring (such as the ERN and FRN components) are described. Finally, this chapter discusses the plasticity of attention and brain training techniques such as meditation, neurofeedback, and video games.

This chapter contrasts the voluntary, endogenous influences on attention to the involuntary, exogenous influences on attention. The neural effects of top-down versus bottom-up attention are presented, including how these effects are observed at multiple levels of processing in the brain. Evidence from fMRI and ERP studies show the separate and interacting effects of endogenous and exogenous attention in multiple visual processing regions and on the C1, P1, N1, and P3 components. Inhibition of return (IOR), an attention process unique to reflexive attention is described, along with corresponding ERP evidence. The debate concerning reflexive orienting and contingent capture is discussed, and the effects of special classes of stimuli (e.g., new objects; faces; emotion-inducing stimuli) on the involuntary allocation of attention are introduced. ERP indices of attentional orienting in visual search (e.g., the N2pc component) versus the suppression of distractors (e.g., the PD components) are discussed. This chapter also describes how memory affects attentional allocation, both in the initial capture and the subsequent holding of attention. Finally, theories are introduced that propose that selection history and reward learning play significant roles in the involuntary biasing and allocation of attention.

This chapter presents the varied types of attention deficits that are observed in different special populations. These provide evidence for the importance of attention in many aspects of our lives, and this chapter explains how studies of these patients continues to motivate and shape much of the neuroscience research that will be covered in subsequent chapters. Patients suffering from unilateral neglect syndrome, subsequent to brain lesions, have revealed a network of temporo-parietal and ventral frontal regions, lateralized largely to the right hemisphere, that is critical for disengaging and reorienting attention. These patients also provide evidence for the distinction between space-based versus object-based attention. Damage to subcortical structures in the thalamus and superior colliculus are linked to deficits in engaging and moving attention, respectively. The history and current diagnostic criteria for attention deficit hyperactivity disorder (ADHD) are described, along with how this disorder affects multiple processes of attention. Symptoms of ADHD and the neglect syndrome are used to introduce the concepts of executive control, the filtering of irrelevant distractors, and the balance of top-down and bottom-up influences on attention. The possibility that dysfunctional attention mechanisms may also play a role in autism, schizophrenia, and anxiety disorders is discussed.

This chapter introduces a fundamental aspect of attention that is beginning to be understood at a deeper level because of neuroscience research. In addition to how attention is allocated at one instant in time, new research is showing that there are temporal limits to attention and that a complete understanding of attention requires understanding the timing of attention. The “attentional blink” phenomenon is discussed, along with neuroscience evidence linking attention and consciousness. The brain mechanisms of attending to time are compared to those involved in attending to space and to static properties of objects. This chapter also explores the relation between attention and memory, highlighting the holding of attention. The factors that determine attentional dwell time, and the brain regions affecting this type of control are introduced. Classic and modern theories of the role of rhythms in the brain are discussed, and evidence from fMRI, ERPs, and single-unit recordings are presented that provide evidence for internally generated versus externally triggered rhythms in the alpha, beta, theta, and gamma frequency bands. The importance of neural entrainment and the synchrony of neural activity within and across brain regions is discussed, in relation to its role in attentional control and conscious processing.

This chapter explores “predictive coding” models, which challenge classic theories of perception and brain function. By incorporating details of both the connectivity between brain areas and the levels of microcircuitry within cortical regions, these models suggest a radical new way to conceive of perception and cognition. Whereas classic models assume that feed-forward, or bottom-up, processing is mainly responsible for our perception, predictive coding theories suggest that top-down models determine our perception, with bottom-up processing simply correcting errors in those models. Neuroscience evidence is presented for the abundance of top-down connections, the efficiency of neural coding, the role of expectancy in attention, and how the balance of top-down and bottom-up processing is related to the dysfunctional attention processes in some clinical groups. The allocation of attention is thought to be a dynamic and changing process wherein top-down hyper-priors are integrated with current priors that are being continually updated within and across levels. According to such models, attention affects the expected precision (reliability) of bottom-up information and the likelihood that this information will be used to update the current top-down models. Predictive coding theories that are opening new ways of thinking about the neural mechanisms that drive our attention are discussed.

This chapter covers the history of attention research and introduces the main issues that are being actively studied today. Key figures in the development of attention as a topic of scientific research are highlighted, including William James, Hermann von Helmholtz, Franciscus Donders, Colin Cherry, Donald Broadbent, Anne Treisman, and Michael Posner. The events leading up to the “cognitive revolution” are described and the initial studies of attention motivated by the “cocktail party phenomenon” are introduced. Classic paradigms to test the functions of attention are described, including the “shadowing task”, the Posner cuing paradigm, visual search tasks, the Eriksen flanker task, and the attention network task (ANT). The distinction between overt attention and covert attention is explained, and the link between attention and eye-movements is discussed. Important theories of attention are introduced, including the early versus late selection controversy, the spotlight and zoom-lens models of attention, the motor theory of attention, and feature integration theory. The relation of attention to consciousness is introduced and the concepts of distraction and mind-wandering are introduced.

This chapter describes the many methods of Cognitive Neuroscience that are revealing the neural processes underlying complex cognitive processes in the brain. The benefits and limitations of each method are discussed, highlighting how there is no single “best” method and how the choice of method in any experiment should be motivated by the hypothesis being evaluated. Neuropsychology provides novel insights into the neural bases of cognitive processes but is limited because it relies on naturally occurring lesions. Neuroimaging methods (fMRI, PET, fNIRS) provide excellent spatial resolution but cannot assess the temporal order of neural activity across regions. Electroencephalography (EEG) and magnetoencephalography (MEG) can track neural activity in real time, but their spatial precision is limited because they are recorded from outside the head. Neurostimulation methods (TMS, tDCS, tACS) can uniquely assess causality by testing if, and when, a brain area is necessary for a particular function. Methods using non-human animals (e.g., single-unit recordings) can provide the highest levels of spatial and temporal precision, but they are limited to mental processes that the non-human animals can be trained to do. This chapter ends with a comparison of methods that includes portability, spatial precision, and temporal resolution.