Crossmodal Links In Attention Research Articles

Sustained Spatial Attention in Touch: Modality-Specific and Multimodal Mechanisms

Sustained attention to a body location results in enhanced processing of tactile stimuli presented at that location compared to another unattended location. In this paper, we review studies investigating the neural correlates of sustained spatial attention in touch. These studies consistently show that activity within modality-specific somatosensory areas (SI and SII) is modulated by sustained tactile-spatial attention. Recent evidence suggests that these somatosensory areas may be recruited as part of a larger cortical network,also including higher-level multimodal regions involved in spatial selection across modalities. We discuss, in turn, the following multimodal effects in sustained tactile-spatial attention tasks. First, cross-modal attentional links between touch and vision, reflected in enhanced processing of task-irrelevant visual stimuli at tactuallyattended locations, are mediated by common (multimodal) representations of external space. Second, vision of the body modulates activity underlying sustained tactile-spatial attention, facilitating attentional modulation of tactile processing in between-hand (when hands are sufficiently far apart) and impairing attentional modulation in within-hand selection tasks. Finally, body posture influences mechanisms of sustained tactile-spatial attention, relying, at least partly, on remapping of tactile stimuli in external, visuallydefined, spatial coordinates. Taken together, the findings reviewed in this paper indicate that sustained spatial attention in touch is subserved by both modality-specific and multimodal mechanisms. The interplay between these mechanisms allows flexible and efficient spatial selection within and across sensory modalities.

Crossmodal Links in Attention in the Driving Environment: The Roles of Cueing Modality, Signal Timing, and Workload

Multimodal information presentation has been proposed as a means to support timesharing in complex data-rich environments. To ensure the effectiveness of this approach, it is necessary to consider performance effects of recently discovered crossmodal spatial and temporal links in attention, as well as their interaction with other performance-shaping factors. The main goals of this research were to confirm that performance effects of crossmodal links in spatial attention scale to complex environments and to examine how these effects vary as a function of cue modality, signal timing, and workload. In the present study, set in a driving simulation, spatially valid and invalid auditory and tactile cues preceded the presentation of visual targets at various stimulus-onset asynchronies and under different levels of workload induced by simulated wind gusts of varied intensity. The findings from this experiment confirm that visual target identification accuracies and response times are, overall, more accurate and faster when validly-cued. Significant interactions were found between cue validity, stimulus onset asynchrony (SOA), and cue modality, such that valid tactile cueing is most beneficial at shorter (100–200 ms) SOAs, while valid auditory cueing resulted in faster responses than invalid cueing at 500 ms SOAs, but slower responses at 1000 ms SOAs. Tactile error rates were significantly higher than auditory error rates at various interactions of modality and SOA. These findings were robust across all workload conditions. They highlight the need for context-sensitive information presentation and can inform the design of multimodal interfaces for a wide range of application domains.

Sound source location modulates the irrelevant-sound effect

Participants memorized lists of visually presented digits in silence or while ignoring distractor sounds that either came from the front and thus from the direction in which participants' attention was oriented, or from behind. Distractor sounds impaired recall performance, but the largest impairment was observed when the sound source was directionally close to the frontal visual target display. The results are consistent with the assumption of cross-modal attentional links in models of attention, and they are problematic for explanations of the irrelevant-sound effect within working memory models that do not specify an explicit role of attention in the maintenance of information for immediate serial recall.

The Implications of Crossmodal Links in Attention for the Design of Multimodal Interfaces: A Driving Simulation Study

The design of multimodal interfaces rarely takes into consideration recent data suggesting the existence of considerable crossmodal spatial and temporal links in attention. This can be partly explained by the fact that crossmodal links have been studied almost exclusively in spartan laboratory settings with simple cues and tasks. As a result, it is not clear whether they scale to more complex settings. To examine this question, participants in this experiment drove a simulated military vehicle and were periodically presented with lateralized visual indications marking locations of roadside mines and safe areas of travel. Valid and invalid auditory and tactile cues preceded these indications at varying stimulus-onset asynchronies. The findings confirm that the location and timing of crossmodal cue combinations affect response time and accuracy in complex domains as well. In particular, presentation of crossmodal cues at SOAs below 500ms and tactile cuing resulted in lower accuracy and longer response times.

Multimodal information presentation: Design guidance and research challenges

Multimodal interfaces have gained considerable interest in recent years. This trend can be expected to continue as designers try to address challenges like data overload, the need for improved performance of recognition-based systems, a greater sense of immersion in virtual-reality environments, and support for time sharing and attention management in a variety of complex real-world domains. To ensure the robustness and effectiveness of multimodal interfaces, a number of design guidelines have been proposed. The present paper will review guidelines that focus on multimodal information presentation (as opposed to multimodal system input), and it will discuss important research needs in this area, including the exploration of possible uses and benefits of rarely used sensory channels (such as touch and olfaction), the consideration of crossmodal links in attention, the top–down modulation of multimodal information processing, and the need for adaptive and adaptable multimodal interfaces. Relevance to industry Multimodal interfaces will likely find their way into an increasing number of complex data-rich environments. It is critical for engineers and designers to be aware of benefits, requirements, and constraints associated with the design of multimodal displays to ensure their effectiveness and avoid pitfalls of this approach to information presentation.

An object-centred reference frame for control of grasping: effects of grasping a distractor object on visuomotor control

Previous evidence based on perceptual integration and arbitrary responses suggests extensive cross-modal links in attention across the various modalities. Attention typically shifts to a common location across the modalities, despite the vast differences in their initial coding of space. An issue that remains unclear is whether or not these effects of multisensory coding occur during more natural tasks, such as grasping and manipulating three-dimensional objects. Using kinematic measures, we found strong effects of the diameter of a grasped distractor object on the aperture used to grasp a target object at both coincident and non-coincident locations. These results suggest that interference effects can occur between proprioceptive and visuomotor signals in grasping. Unlike other interference effects in cross-modal attention, these effects do not depend on the spatial relation between target and distractor, but occur within an object-based frame of reference.

Staring in the Eye of Auditory Neglect: Comments on ‘Gaze Direction Modulates Auditory Spatial Deficits in Stroke Patients with Neglect’

In the current issue of Cortex, Pavani and colleagues show that directing gaze toward the contralesional hemifield significantly diminishes the auditory deficits associated with unilateral neglect. The authors suggest that this beneficial effect of gaze direction may arise due to the recruitment of crossmodal attentional links between audition and vision. A complementary interpretation of these findings is that directing gaze toward neglected sound sources encourages the recoding of auditory spatial location in a relatively preserved frame of reference, and that it is through this coordinate transformation process that awareness of auditory stimuli may be regained. Rehabilitation strategies aimed at recoding stimuli within relatively preserved reference frames may be a useful step forward in managing unilateral neglect.

Crossmodal links in endogenous and exogenous spatial attention: evidence from event-related brain potential studies

The adaptive control of behaviour in response to relevant external objects and events often requires the selection of information delivered by different sensory systems, but from the same region in external space. This can be facilitated by crossmodal links in the attentional processing of information across sensory modalities. Results from recent event-related potential (ERP) studies are reviewed that investigated mechanisms underlying such crossmodal links in spatial attention between vision, audition and touch. Crossmodal attention effects were observed for early modality-specific visual, auditory, and somatosensory ERP components, indicating that crossmodal links in spatial attention affect sensory-perceptual processes within modality-specific cortical regions. ERP modulations prior to target events but sensitive to the direction of an attentional shift were remarkably similar during anticipatory covert shifts of visual, auditory, or tactile attention. These results suggest that such attentional shifts are mediated by supramodal frontoparietal control mechanisms. Finally, ERP evidence is reviewed suggesting that effects of crossmodal links in endogenous (voluntary) as well as exogenous (involuntary) spatial attention are mediated by a representations of external space which are updated across postural changes.

Cross-modal links in spatial attention.

A great deal is now known about the effects of spatial attention within individual sensory modalities, especially for vision and audition. However, there has been little previous study of possible cross-modal links in attention. Here, we review recent findings from our own experiments on this topic, which reveal extensive spatial links between the modalities. An irrelevant but salient event presented within touch, audition, or vision, can attract covert spatial attention in the other modalities (with the one exception that visual events do not attract auditory attention when saccades are prevented). By shifting receptors in one modality relative to another, the spatial coordinates of these cross-modal interactions can be examined. For instance, when a hand is placed in a new position, stimulation of it now draws visual attention to a correspondingly different location, although some aspects of attention do not spatially remap in this way. Cross-modal links are also evident in voluntary shifts of attention. When a person strongly expects a target in one modality (e.g. audition) to appear in a particular location, their judgements improve at that location not only for the expected modality but also for other modalities (e.g. vision), even if events in the latter modality are somewhat more likely elsewhere. Finally, some of our experiments suggest that information from different sensory modalities may be integrated preattentively, to produce the multimodal internal spatial representations in which attention can be directed. Such preattentive cross-modal integration can, in some cases, produce helpful illusions that increase the efficiency of selective attention in complex scenes.

Crossmodal attention

Most selective attention research has considered only a single sensory modality at a time, but in the real world, our attention must be coordinated crossmodally. Recent studies reveal extensive crossmodal links in attention across the various modalities (i.e. audition, vision, touch and proprioception). Attention typically shifts to a common location across the modalities, despite the vast differences in their initial coding of space. These spatial synergies in attention can be maintained even when receptors are realigned across the modalities by changes in posture. Some crossmodal integration can arise preattentively. The mechanisms underlying these crossmodal links can be examined in a convergent manner by integrating behavioural studies of normal subjects and brain-damaged patients with neuroimaging and neurophysiological studies.