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This chapter reviews some of the main themes of research on attentional mechanisms, focusing on the contributions of electrophysiological studies to current cognitive models of attention. Topics discussed include visual-spatial attention, visual feature selection, executive processes of visual attention, auditory selective attention, and auditory feature selection.

This chapter reviews work on visual attention. Attention is the process by which some objects or locations are selected to receive more processing than others. Two types of attention are discussed: covert attention is defined as paying attention without moving the eyes; overt attention is defined as selectively processing one location over others by moving the eyes to point at that location. Several models of covert spatial attention are discussed, including the idea that covert attention is like a spotlight or a zoom lens, and that covert attention might select information either early on in visual processing or later. The following section discusses possible relationships between covert and overt attention with three positions outlined: that they are independent; that a shift of overt attention is preceded by a shift of covert attention; or that covert attentional effects are a by-product of the overt orienting system (the pre-motor theory). The speed of covert attention and the neurophysiology of attention are discussed. Non-spatial attentional processes are reviewed including attention to objects and attention to visual properties. The chapter ends with an analysis of the role of attention within active vision, and argues that movements of the eye are the primary way in which attention is directed in vision.

This chapter aims to formulate a neurodynamical theory and model that addresses the issues of how spatial and object attention mechanisms can be integrated and can function as a unitary system in visual search and visual recognition tasks. An important novel idea in this model is that the dorsal stream and the ventral stream interact at multiple points and levels, and the locus of intersection is a function of the scale of analysis. The model can reproduce the findings of a number of attention-related neurophysiological experiments and it provides a united conceptual framework to account for several apparently disparate psychological processes such as spatial and object attention, object recognition and localization, and serial and parallel search.

Perception and behaviour depend not only on the stimulation transduced at our various sensory epithelia, but also on which aspects of this stimulation are attended. ‘Selective attention’ is the generic term for those processes that enable selective processing of incoming sensory stimuli, so that information relevant to our current goals, or stimulation that has intrinsic salience or biological significance, gets processed more thoroughly than other competing information. This chapter focuses on spatial aspects of endogenous (voluntary) selective attention and their implications for integration and interactions between different senses.

This chapter reviews results from event-related potential (ERP) studies that investigated crossmodal links in endogenous spatial attention between vision, audition, and touch. It discusses the effects of such links in endogenous attention on the processing of visual, auditory, and tactile stimuli at currently attended or unattended locations, with respect to the questions of whether these links primarily affect modality-specific perceptual or post-perceptual processes. It then addresses the question of whether behavioural and electrophysiological effects of crossmodal links in spatial attention merely result from optional processing strategies, or reflect genuine constraints on the processing of sensory information within and across modalities. It discusses the spatial coordinate frames involved in crossmodal links in spatial attention. The final section reviews ERP studies investigation attentional control processes.

This chapter focuses on the issue of whether stimulation at around the same place and time, in more than one sensory modality, has any effects on perceptual processing and/or on covert spatial attention in humans. Topics discussed include exogenous spatial-cuing paradigms, initial studies of exogenous crossmodal spatial cuing, crossmodal cuing effects in speeded orthogonal spatial-cuing tasks, crossmodal cuing effects revealed by speeded ‘implicit spatial discrimination’ go/no-go tasks, and combined behavioural and electrophysiological evidence for visual-upon-auditory exogenous crossmodal spatial influences.

This chapter proposes the stage theory of attention and action, which holds that decisions to shift gaze to a particular location are almost entirely dependent upon two cognitive processes. The first is a selection process corresponding with the allocation of visual-spatial attention, and the second is a response process that produces movements of the eyes or other effectors. Importantly, though, attentional allocation and response preparation, although linked, are distinct process accomplished by different networks of neurons spanning multiple cortical and subcortical structures. By bringing into focus the sensory-motor transformations underlying flexible, visually guided behavior, this theory moves beyond the biased competition theory (that only addresses target selection and attention allocation) and the premotor theory of attention (that identifies target selection entirely with saccade preparation). The theory also provides a framework for understanding rapid error correction, flexible stimulus-response mapping, and the adjustment of processing speed relative to accuracy.

This chapter addresses the varying definitions of “modularity” assumed by different fields (e.g., philosophy, psychology, neuroscience), and focuses on evaluating Fodor's notion of information encapsulation. It is shown that attentional instructions can modulate low-level visual processes, and that visual input of a moving face can modulate the auditory perception of a phoneme. In fact, cortical regions in the ferret's brain that normally receive auditory input can learn to accommodate incoming synapses from the optic tract. Thus, although it is clear that various anatomical regions of the brain are somewhat specialized for specific perceptual abilities, the fluidity and ubiquity with which they interact in real-time indicates that cognitive processes, such as spatial attention, visual event recognition, and speech perception, exhibit not modularity but instead something that might be called distribularity.

This chapter presents an overview of the research on visual attention, which has been studied extensively in cognitive psychology and neuroscience. The studies discussed are limited to the major empirical findings on visual attention that have implications for the scientific understanding of consciousness. The chapter includes studies on feature-based attention, spatial attention, object-based attention, effortless attention, the mechanisms supporting the different forms of attention (e.g., neural structures and pathways), and the evolution of these mechanisms. This review is important for the book’s primary argument that consciousness and attention must be dissociated at some level, as there are functionally different forms of attention that seem to operate independently and to have evolved at different times from each other—an argument that is difficult to make for consciousness.

This chapter attempts to illustrate that parietal lobe, frontal lobes, cingulate gyrus, striatum and thalamus constitute a large-scale network subserving spatial attention, that hemispatial neglect is a syndrome of the network as a whole, and that the complexity of this network is commensurate with the clinical heterogeneity of the neglect syndrome. It is noted that components of the ascending reticular activating system, such as the intralaminar thalamic nuclei, the brainstem raphe nuclei, the nucleus locus ceruleus, the ventral tegmental area-substantia nigra, and the nucleus basalis project to each cortical component of the attentional network. The reviewed data has resulted in the hypothesis that spatial attention is organized at the level of a distributed large-scale network revolving around three cortical components, each of which supports a slightly different neural representation of the extrapersonal space. Each of these components serves a dual purpose: it provides a local network for regional neural computations and also a nodal point for the linkage of distributed information. Moreover, the components of the attentional network can collectively specify whether and how an event in extrapersonal space will attract covert attentional shifts, orientation, foveation, manual grasp, and overt search behaviors.

This chapter describes two attempts to cast light on an attentional model of neglect by trying to specify two important aspects. First, it examines whether the attentional impairment concerns exogenous stimulus-driven attention or endogenous controlled attention. Second, it fits the reaction time (RT) data to the saliency map model of neglect proposed by Anderson, which is a formal model of neglect inspired by clinical data (line bisection). The overall rationale of the approach depends on the idea that speed of RT (and detection performance) at various locations in the visual field depends on both retinal and attentional factors. The RT approach used in the study of the distribution of spatial attention across the visual field in neglect patients without hemianopia has provided evidence in broad agreement with hemispatial theories of neglect. In addition, a clear-cut hemifield difference in performance is shown. Moreover, fitting the RT data to the mathematical model of neglect proposed by Anderson has proved to be a fruitful exercise.

This chapter discusses spatial attention, working memory, and executive function—cognitive functions that are crucial for communicating, learning, and functioning in society. Spatial attention is important for higher-level processes such as navigating in space, attending to relevant stimuli in the environment, and ignoring irrelevant stimuli. It consists of three primary components: alerting, orienting, and executive control. Working memory refers to a basic cognitive process that allows for temporary storage and manipulation of information necessary for numerous complex cognitive tasks such as language, spatial analysis, and decision-making. Executive functioning is a multidimensional construct that includes higher-order cognitive processes such as initiation, planning, problem-solving, cognitive flexibility, behavioral regulation, metacognition, and feedback utilization.

This chapter examines the neurophysiological aspects of temporal orienting in the ventral visual stream. It analyses cellular events which might underlie enhanced perceptual performance and discusses the neurophysiological correlates of spatial attention. The findings reveal that whether visual stimulus is cued spatially or temporally, there are changes in neuronal firing rates, increases in the gamma band visual stimulus which are cued spatially or temporally, and increases in the spectral power of the local field potential (LFP).

This chapter outlines the contribution of the parietal cortex to spatial cognition. It discusses the structure and function in spatial attention and spatial representation of the parietal higher order areas of the dorsal visual stream and describes spatial information processing in the parietal lobe. The chapter considers the neuropsychological syndromes that result from parietal lesions, such as visual neglect, Balint's syndrome, and Gerstmann's syndrome in order to provide a better understanding of the functions of the parietal cortex in spatial cognitive functions.

Broca's area (or, more generally, the left inferior frontal region) is implicated in many language and language-related tasks. This chapter addresses the question of whether it is legitimate to move from this assertion (supported by very large numbers of lesion studies and functional neuroimaging experiments) to the theoretical claim that the exclusive (or even the core) specialization of Broca's area is the mediation of language functions. It shows that particular neuroanatomical regions, including Broca's area, change their functions consequent upon the simultaneous activation of other regions that are effectively connected to a given region.

Outlining possible suggestions in addressing questions related to visual and dorsal streams of visual processing is the main concern of this chapter. Specifically, it attempts to examine the internal functional organization of each of these streams and how they interact in the production of integrated patterns of behaviour. In addition, how the phenomena of visual attention and consciousness map onto the two streams and how the puzzling syndrome of hemispatial neglect fits into this account of cortical visual processing are also assessed. The chapter begins with a discussion on attention and consciousness. Subsequently, physiological studies of visual attention in the dorsal and ventral streams are presented and it is shown that networks of cells in both ventral and dorsal systems appear to participate in spatial attention. Two well-known deficits commonly thought to reflect disorders of spatial attention are also explored: hemispatial neglect and visual extinction.

This chapter examines the relation between chronostasis illusion and spatial attention. It discusses saccadic chronostasis which describes the temporal overestimation of a stimulus seen immediately following a saccade. The findings indicate that prior entry and attention-based temporal dilation are not particularly convincing explanations for the chronostasis illusion. However, there is some controversy regarding the spatial extent of chronostasis and its relationship with the shift of attention that precedes a saccade.

Attention draws forward these historical accounts to the present moment of fixation on digital media. This chapter argues that ignoring the rapid pace of mediatization is disastrous for a community-engaged mapping impulse.

Attention can be defined as a multifaceted gateway to consciousness. We use attention to focus on specific sensory signals (selective attention), to allocate resources to concurrent relevant sources (divided attention), to switch between tasks (alternate attention), to maintain focus on a task for a prolonged period (sustained attention), to ready ourselves for a quick response to sudden novel information (alertness); and all these processes, to some extent, control what sensory signals are processed up to the level of conscious awareness. The multifarious functions of attention often involve multisensory interactions, and in this chapter, will we discuss three broad issues in studying multisensory attention. We will start by considering multisensory spatial attention to signals within different sensory channels in a goal directed manner, in comparison to conditions whereby attention is automatically engaged by external multisensory signals. Next, we will discuss multisensory non-spatial attention. In conclusion, we will discuss the implications for multisensory learning and memory.