The last decade has seen great progress in the study of the nature of crossmodal links in exogenous and endogenous spatial attention . Exogenous spatial cuing studies of human crossmodal attention and multisensory integration. In C. Spence, & J. Driver , Crossmodal space and crossmodal attention . Oxford, UK: Oxford University Press.], for a recent review). A growing body of research now highlights the existence of robust crossmodal links between auditory, visual, and tactile spatial attention. However, until recently, studies of (...) exogenous and endogenous attention have proceeded relatively independently. In daily life, however, these two forms of attentional orienting continuously compete for the control of our attentional resources, and ultimately, our awareness. It is therefore critical to try and understand how exogenous and endogenous attention interact in both the unimodal context of the laboratory and the multisensory contexts that are more representative of everyday life. To date, progress in understanding the interaction between these two forms of orienting has primarily come from unimodal studies of visual attention. We therefore start by summarizing what has been learned from this large body of empirical research, before going on to review more recent studies that have started to investigate the interaction between endogenous and exogenous orienting in a multisensory setting. We also discuss the evidence suggesting that exogenous spatial orienting is not truly automatic, at least when assessed in a crossmodal context. Several possible models describing the interaction between endogenous and exogenous orienting are outlined and then evaluated in terms of the extant data. (shrink)

The law of prior entry was one of E.B. Titchener’s seven fundamental laws of attention. According to Titchener : “the object of attention comes to consciousness more quickly than the objects which we are not attending to.” Although researchers have been studying prior entry for more than a century now, progress in understanding the effect has been hindered by the many methodological confounds present in early research. As a consequence, it is unclear whether the behavioral effects reported in the majority (...) of published studies in this area should be attributed to attention, decisional response biases, and/or, in the case of exogenous spatial cuing studies of the prior-entry effect, to sensory facilitation effects instead. In this article, the literature on the prior-entry effect is reviewed, the confounds present in previous research highlighted, current consensus summarized, and some of the key questions for future research outlined. In particular, recent research has now provided compelling psychophysical and electrophysiological evidence to support the claim that attending to a sensory modality, spatial location, or stimulus feature/attribute can all give rise to a relative speeding-up of the time of arrival of attended, as compared to relatively less attended stimuli. Prior-entry effects have now been demonstrated following both the endogenous and exogenous orienting of attention, though prior-entry effects tend to be smaller in magnitude when assessed by means of participants’ performance on SJ tasks than when assessed by means of their performance on TOJ tasks. (shrink)

Can we build endogenous expectations about the locus of occurrence of a target without being able to describe them? Participants performed cue–target detection tasks with different proportions of valid and invalid trials, without being informed of these proportions, and demonstrated typical endogenous effects. About half were subsequently able to correctly describe the cue–target relationships . However, even non-verbalizer participants showed endogenous orienting with peripheral cues , not depending solely on practice . Explicit instructions did not bring about dramatic advantages in (...) performance .With central symbolic cues, only verbalizers showed reliable endogenous effects . We concluded that endogenous orienting with peripheral cues can occur independently of participants developing explicit hypotheses about the cue–target relationships. (shrink)

Unconscious stimuli can influence participants’ motor behavior as well as more complex mental processes. Previous cue-priming experiments demonstrated that masked cues can modulate endogenous shifts of spatial attention as measured by choice reaction time tasks. Here, we applied a signal detection task with masked luminance targets to determine the source and the scope of effects of masked stimuli. Target-detection performance was modulated by prime-cue congruency, indicating that prime-cue congruency modulates signal enhancement at early levels of target processing. These effects, however, (...) were only found when the prime was perceptually similar to the cue indicting that primes influence early target processing in an indirect way by facilitating cue processing. Together with previous research we conclude that masked stimuli can modulate perceptual and post-central levels of processing. Findings mark a new limit of the effects of unconscious stimuli which seem to have a smaller scope than conscious stimuli. (shrink)

Unconscious stimuli can influence participants’ motor behavior but also more complex mental processes. Recent research has gradually extended the limits of effects of unconscious stimuli. One field of research where such limits have been proposed is spatial cueing, where exogenous automatic shifts of attention have been distinguished from endogenous controlled processes which govern voluntary shifts of attention. Previous evidence suggests unconscious effects on mechanisms of exogenous shifts of attention. Here, we applied a cue-priming paradigm to a spatial cueing task with (...) arbitrary cues by centrally presenting a masked symmetrical prime before every cue stimulus. We found priming effects on response times in target discrimination tasks with the typical dynamic of cue-priming effects indicating that central symmetrical stimuli which have been associated with endogenous orienting can modulate shifts of spatial attention even when they are masked. Prime–Cue Congruency effects of perceptual dissimilar prime and cue stimuli suggest that these effects cannot be entirely reduced to perceptual repetition priming of cue processing. In addition, priming effects did not differ between participants with good and poor prime recognition performance consistent with the view that unconscious stimulus features have access to processes of endogenous shifts of attention. (shrink)

In this study, voluntary and involuntary visual attention focused on different interpretations of a bistable image, were investigated using magnetoencephalography. A Necker cube with sinusoidally modulated pixels' intensity in the front and rear faces with frequencies 6.67 Hz and 8.57 Hz, respectively, was presented to 12 healthy volunteers, who interpreted the cube as either left- or right-oriented. The tags of these frequencies and their second harmonics were identified in the average Fourier spectra of the MEG data recorded from the visual (...) cortex. In the first part of the experiment, the subjects were asked to voluntarily control their attention by interpreting the cube orientation as either being on the left or right. Accordingly, we observed the dominance of the corresponding spectral component, and voluntary attention performance was measured. In the second part of the experiment, the subjects were asked to focus their gaze on a red marker at the center of the cube image without putting forth effort in its interpretation. The alternation of the dominant spectral energies at the second harmonics of the stimulation frequencies was treated as changes in the cube orientation. Based on the results of the first experimental stage and using a wavelet analysis, we developed a method which allowed us to identify the currently perceived cube orientation. Finally, we characterized involuntary attention using the distribution of dominance times when focusing attention on one of the cube orientations, which was related to voluntary attention performance and brain noise. In particular, we confirmed our hypothesis that higher attention performance is associated with stronger brain noise. (shrink)

ABSTRACTIn verbal communication, affective information is commonly conveyed to others through spatial terms. This study used a target location discrimination task with neutral, positive and negative stimuli to test the automaticity of the emotion-space association, both in the vertical and horizontal spatial axes. The effects of stimulus type on emotion-space representations were also probed. A congruency effect was observed in the vertical axis: detection of upper targets preceded by positive stimuli was faster. This effect occurred for all stimulus types, indicating (...) that the emotion-space association is not dependent on sensory modality and on the verbal content of affective stimuli. (shrink)

By combining a flanker task and a cuing task into a single paradigm, the authors assessed the effects of orienting and alerting on conflict resolution and explored how normal aging and Alzheimer’s disease (AD) modulate these attentional functions. Orienting failed to enhance conflict resolution; alerting was most beneficial for trials without conflict, as if acting on response criterion rather than on information processing. Alerting cues were most effective in the older groups— healthy aging and AD. Conflict resolution was impaired only (...) in AD. Orienting remained unchanged across groups. These findings provide evidence of different life span developmental and clinical trajectories for each attentional network. (shrink)

Despite the fact that attention is a core property of all perceptual and cognitive operations, our understanding of its neurophysiological mechanisms is far from complete. There are many theoretical models that try to fill this gap in knowledge, though practically all of them concentrate only on either involuntary (bottom-up) or voluntarily (top-down) aspect of attention. At the same time, both aspects of attention are rather integrated in the living brain. In this chapter we attempt to conceptualise both aspects of attentional (...) state within the theory of Operational Architectonics of brain and mind functioning, which provides a plausible theoretical basis for neurophysiological understanding of how attention is brought to existence in the living brain. (shrink)