We review the evidence for the conceptual association between arithmetic and space and quantify the effect size in meta-analyses. We focus on three effects: (a) the operational momentum effect (OME), which has been defined as participants\' tendency to overestimate results of addition problems and underestimate results of subtraction problems; (b) the arithmetic cueing effect, in which arithmetic problems serve as spatial cues in target detection or temporal order judgment tasks; and (c) the associations between arithmetic and space observed with eye- and hand-tracking studies. The OME was consistently found in paradigms that provided the participants with numerical response alternatives. The OME shows a large effect size, driven by an underestimation during subtraction while addition was unbiased. In contrast, paradigms in which participants indicated their estimate by transcoding their final estimate to a spatial reference frame revealed no consistent OME. Arithmetic cueing studies show a reliable small to medium effect size, driven by a rightward bias for addition. Finally, eye- and hand-tracking studies point to replicable associations between arithmetic and eye or hand movements. To account for the complexity of the observed pattern, we introduce the Adaptive Pathways in Mental Arithmetic (APiMA) framework. The model accommodates central notions of numerical and arithmetic processing and helps identifying which pathway a given paradigm operates on. It proposes that the divergence between OME and arithmetic cueing studies comes from the predominant use of non-symbolic versus symbolic stimuli, respectively. Overall, our review and findings clearly support an association between arithmetic and spatial processing.

The present review examined the consequences of focal brain injury on spatial attention studied with cueing paradigms, with a particular focus on the disengagement deficit, which refers to the abnormal slowing of reactions following an ipsilesional cue. Our review supports the established notion that the disengagement deficit is a functional marker of spatial neglect and is particularly pronounced when elicited by peripheral cues. Recent research has revealed that this deficit critically depends on cues that have task-relevant characteristics or are associated with negative reinforcement. Attentional capture by task-relevant cues is contingent on damage to the right temporo-parietal junction (TPJ) and is modulated by functional connections between the TPJ and the right insular cortex. Furthermore, damage to the dorsal premotor or prefrontal cortex (dPMC/dPFC) reduces the effect of task-relevant cues. These findings support an interactive model of the disengagement deficit, involving the right TPJ, the insula, and the dPMC/dPFC. These interconnected regions play a crucial role in regulating and adapting spatial attention to changing intrinsic values of stimuli in the environment.

The C1 event-related potential (ERP) captures the earliest stage of feedforward processing in the primary visual cortex (V1). An ongoing debate is whether top-down selective attention can modulate the C1. One side of the debate pointed out that null findings appear to outnumber positive findings; thus, selective attention does not seem to influence the C1. However, this suggestion is not based on a valid approach to summarizing evidence across studies. Therefore, we conducted a systematic review and meta-analysis investigating the effects of selective attention on the C1, involving 47 experiments and 794 subjects in total. Despite heterogeneity across studies, results suggested that attention has a moderate effect on the C1 (Cohen\'s d z  = 0.33, p < .0001); that is, C1 amplitude is larger for visual stimuli that are attended than unattended. These results suggest that C1 is affected by top-down selective attention.

An important mechanism used to selectively process relevant information in the environment is spatial attention. One fundamental way in which spatial attention is deployed is attentional scaling - the process of focusing attentional resources either narrowly or broadly across the visual field. Although early empirical work suggested that narrowing attention improves all aspects of visual processing, recent studies have demonstrated that narrowing attention can also have no effect or even a detrimental impact when it comes to vision that is thought to be mediated via the magnocellular pathway of the visual system. Here, for the first time, we synthesize empirical evidence measuring the behavioral effects of attentional scaling on tasks gauging the contribution of the major neural pathways of the visual system, with the purpose of determining the potential factors driving these contradictory empirical findings. This analysis revealed that attentional scaling could be best understood by considering the unique methodologies used in the research literature to date. The implications of this analysis for theoretical frameworks of attentional scaling are discussed, and methodological improvements for future research are proposed.

Prism Adaptation (PA) is a behavioral task to assess visuo-motor plasticity and to ameliorate the symptoms of unilateral spatial neglect. Several studies have addressed the effects of PA on both sensory-motor and cognitive processing and the contribution of different brain regions to PA, although via non standardized procedures. The aim of the present review is to gather findings from the neuro-imaging and neuro-stimulation fields and put forward an interpretative framework for PA. The available evidence supports that sensory-motor effects of PA would mainly relate to the activation of a cerebello-parietal network, while the effects on spatial cognition would be mediated by bottom-up activation of temporal and prefrontal regions. The consolidation of PA effects would rely on activity of the motor cortex. The use of standardized PA procedures is strongly recommended for a systematic and accurate investigation of the neural mechanisms of PA.

The possibility to induce a transient modulation of visuo-spatial attention boosted so far the implementation of the prism adaptation in a variety of domains. This sensorimotor technique has been adopted to investigate the neural plasticity in neurologically healthy individuals, as well as to ameliorate deficit of visuo-spatial attention (which characterizes neglect patients\' performance). We review here evidence about a new promising application of prisms in exploring how the human brain represents the subjective time flow on a spatially oriented \"mental time line\". Converging observations in healthy individuals suggest that altering spatial attention processing via prism adaptation can influence the spatial representation of time. These modulatory effects are generalizable to different aspects of time, such as the abilities to estimate time duration and to mentally travel in time. Furthermore, data from brain damaged patients, with a special focus on right brain-damaged patients with neglect, indicate that prismatic procedure ameliorates temporal deficits, hence paving the way to novel clinical applications. We conclude by discussing the possible cognitive mechanisms and neural circuits of the prism adaptation effects on time.

Different electrophysiological components have been associated with behavioural facilitation and inhibition of return (IOR), although there is no consensus about which of these components are essential to the mechanism/s underlying the cueing effects. Different spatial attention hypotheses propound different roles for these components. In this review, we try and describe these inconsistencies by first presenting the electrophysiological component modulations of exogenous spatial attention as predicted by different attentional hypotheses. We then review and quantitatively analyze data from the existing electrophysiological studies trying to accommodate their findings. Variables such as the task at hand, the temporal properties and interactions between cues and targets, the presence/absence of intervening events, or stimuli arrangement in the visual field, might critically explain the discrepancies between the theoretical predictions and the electrophysiological modulations that both facilitation and IOR produce. We conclude that there is no single neural marker for facilitation and IOR because the behavioural effect that is observed depends on the contribution of several components: perceptual (P1), late-perceptual (N1, Nd), spatial selection (N2pc), and decision processes (P3). Many variables determine the electrophysiological modulations of different attentional orienting mechanisms, which jointly define the observed spatial cueing effects.

In this review, we evaluate the neurophysiological, neuropsychological, and psychophysical evidence relevant to the claim that multisensory information is processed differently depending on the region of space in which it happens to be presented. We discuss how the majority of studies of multisensory interactions in the depth plane that have been conducted to date have focused on visuotactile and audiotactile interactions in frontal peripersonal space and underline the importance of such multisensory interactions in defining peripersonal space. Based on our review of studies of multisensory interactions in depth, we question the extent to which peri- and extra-personal space (both frontal and rear) are characterized by differences in multisensory interactions (as evidenced by multisensory stimuli producing a different behavioral outcome as compared to unisensory stimulation). In addition to providing an overview of studies of multisensory interactions in different regions of space, our goal in writing this review has been to demonstrate that the various kinds of multisensory interactions that have been documented may follow very similar organizing principles. Multisensory interactions in depth that involve tactile stimuli are constrained by the fact that such stimuli typically need to contact the skin surface. Therefore, depth-related preferences of multisensory interactions involving touch can largely be explained in terms of their spatial alignment in depth and their alignment with the body. As yet, no such depth-related asymmetry has been observed in the case of audiovisual interactions. We therefore suggest that the spatial boundary of peripersonal space and the enhanced audiotactile and visuotactile interactions that occur in peripersonal space can be explained in terms of the particular spatial alignment of stimuli from different modalities with the body and that they likely reflect the result of prior multisensory experience.