1,721,018 research outputs found
THE COGNITIVE REPRESENTATION OF ACTION: MODULATION EFFECTS BETWEEN ACTION AND PERCEPTION AS MEDIATED BY THE EVENT CODING
Full text linkGaspare Galati, Teresa Scalisi, Pierluigi Zoccolott
Attending to multiple visual streams: Interactions between location-based and category-based attentional selection
No full textBehavioral studies indicate that subjects are able to divide attention between multiple streams of information at different locations. However, it is still unclear to what extent the observed costs reflect processes specifically associated with spatial attention, versus more general interference due the concurrent monitoring of multiple streams of stimuli. Here we used a factorial design to disentangle the correlates of location- versus category-based selection processes during fMRI. In all conditions, participants were presented with two overlapping visual stimuli (red shapes and green shapes) in each hemifield. In different blocks, subjects either: (1) attended to one single stimulus category, red shapes or green shapes, in one hemifield; (2) attended to both stimulus categories in the same hemifield; (3) attended to one single stimulus category, but monitoring both hemifields at the same time; or (4) attended to one stimulus category in one hemifield, and the other category in the opposite hemifield. The behavioral data showed the expected costs of dividing spatial attention across the two hemifields, and the cost of monitoring two stimulus categories versus one category. The imaging data revealed activation of a dorsal fronto-parietal network, both for dividing spatial attention and for monitoring multiple stimulus categories. However, unlike behavioral data, the imaging results also showed a significant interaction between location- and category-based attention within the same network. This demonstrates that the fronto-parietal cortex engages in both of these selective attention functions, and that a mere increase in task difficulty cannot explain colocalization of these processes. We conclude that, under conditions ofmultiple streams monitoring, fronto-parietal regions control location- and category-based attentional selection. ©2008 Massachusetts Institute of Technology
Neural correlates of divided attention in natural scenes
No full textIndividuals are able to split attention between separate locations, but divided spatial attention incurs the additional requirement of monitoring multiple streams of information. Here, we investigated divided attention using photos of natural scenes, where the rapid categorization of familiar objects and prior knowledge about the likely positions of objects in the real world might affect the interplay between these spatial and nonspatial factors. Sixteen participants underwent fMRI during an object detection task. They were presented with scenes containing either a person or a car, located on the left or right side of the photo. Participants monitored either one or both object categories, in one or both visual hemifields. First, we investigated the interplay between spatial and nonspatial attention by comparing conditions of divided attention between categories and/or locations. We then assessed the contribution of top-down processes versus stimulus-driven signals by separately testing the effects of divided attention in target and nontarget trials. The results revealed activation of a bilateral frontoparietal network when dividing attention between the two object categories versus attending to a single category but no main effect of dividing attention between spatial locations. Within this network, the left dorsal premotor cortex and the left intraparietal sulcus were found to combine task-and stimulus-related signals. These regions showed maximal activation when participants monitored two categories at spatially separate locations and the scene included a nontarget object. We conclude that the dorsal frontoparietal cortex integrates top-down and bottom-up signals in the presence of distractors during divided attention in real-world scenes
Shifting attention across spaces while driving: are hands-free mobile phones really safer?
No full textAudio-visual dynamic remapping in an endogenous spatial attention task
No full textSeveral studies on cross-modal attention showed that remapping processes between sensory modalities occur in the spatial orienting of attention. One hypothesis that accounts for such links is that spatial attention operates upon representations of common locations in the external space. However, convincing evidence only exists for cross-modal links in spatial orienting, leaving the dynamics of these effects unexplored. Four experiments were designed to cope with this issue by having participants being involved in an endogenous orienting task to visual and auditory target stimuli. Targets on invalid trials were embedded into two different kinds of sequences of stimuli: (1) long sequences, wherein three valid trials in one modality preceded the invalid trial in the other modality; (2) short sequences, wherein only one valid trial in one modality preceded the invalid trial in the other modality. Results revealed modality-specific meridian effects in the short sequences, and a significant decrement of the modality-specific meridian effect in the long sequences. The results of these experiments indicate that cross-modal links in visual and auditory spatial attention are based on representations of common locations in the external space across sensory modalities. Moreover, the results strongly support the hypothesis that representations of space are dynamically built and updated according to task demands. (c) 2006 Elsevier B.V. All rights reserved
Art and Psychological Well-Being: Linking the Brain to the Aesthetic Emotion
No full textEmpirical studies suggest that art improves health and wellbeing among individuals. However, how aesthetic appreciation affects our cognitive and emotional states to promote physical and psychological wellbeing is still unclear. In this review, we consider the idea that the positive emotional output elicited from the aesthetic experience affects mood, and indirectly promotes health and wellbeing.
First, we examine evidence that arts promoting wellbeing involve art museums, healthcare settings, and education. Second, we review some neuroimaging studies addressing aesthetic experience and emotional processing. In particular, we leveraged advances in neuroaesthetics to explore different hypotheses about the determinants of aesthetic pleasure during art reception, in the attempt to clarify how experiencing art promotes wellbeing. Finally, we propose research on aesthetic experience and psychophysiological measures of stress, with the goal of promoting a focused use of art as a tool for improving wellbeing and health
The costs of monitoring simultaneously two sensory modalities decrease when dividing attention in space
No full textTraditional views of multisensory integration emphasise the advantage of stimulating or attending to different senses at one single spatial location. We challenge this view demonstrating that in-parallel processing of two sensory modalities can be more efficient when attention is spatially divided rather than focused. We asked subjects to monitor simultaneously vision and audition either at one location (focused attention) or in the two opposite hemifields (divided attention) or to monitor one single modality at one or two locations. Behavioural results demonstrated that the costs of monitoring two modalities, versus one modality, decrease when spatial attention is divided between two separate locations compared with focused attention. Neuroimaging data revealed increased activity in the posterior-parietal cortex (PPC) when monitoring two modalities at different locations, while no specific region was recruited in the focused attention conditions. We suggest that supramodal control and the integration of spatial representations hinders the selection of independent sensory streams when attention is spatially focused, while a greater exploitation of modality-specific resources and the engagement of PPC allows in-parallel processing when attention is spatially divided. © 2009 Elsevier Inc. All rights reserved
Goal-completion processes affect the attentional blink
No full textPeople are notably limited in processing information from the outside world. For instance, they frequently fail to identify the second of two targets presented in close succession (attentional blink, AB). Theories of the AB have mostly focused upon early stimuli processing. However, here we show that late, goal-completion processes play an important role. We report findings from a rapid serial visual presentation task with three targets (T1, T2, and T3). Participants set to achieve one single goal for T1 and T2 (reporting the sum of the two), and to detect T3, showed an AB effect upon T3 but not upon T2, while participants set to achieve separate goals for the three targets showed an AB effect upon both T2 and T3. This finding raises questions about the nature of AB, suggesting that theories of the AB must take into account processes involved in goal switching. © 2007 Psychology Press
Shifting attention across near and far spaces: Implications for the use of hands-free cell phones while driving
No full textIn three experiments, participants performed two tasks concurrently during driving. In the peripheral detection task, they responded manually to visual stimuli delivered through a LED placed on the internal rear mirror; in the conversation task, they were engaged in a conversation with a passenger, or through earphone-operated, loudspeaker-operated, or hand-held cell phones. Results showed that drivers were slower at responding to the visual stimuli when conversing through a hand-held cell phone or an earphone-operated cell phone than when conversing through a loudspeaker-operated cell phone or with a passenger. These results suggest that due to the brain coding the space into multiple representations, devices that make phone conversations taking place in the near, personal space make drivers slower at responding to visual stimuli, compared to devices that make the conversation occurring in a far space. © 2008 Elsevier Ltd. All rights reserved
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