402 research outputs found
Large-Scale Brain Networks Supporting Divided Attention across Spatial Locations and Sensory Modalities
No full textHigher-order cognitive processes were shown to rely on the interplay between large-scale neural networks. However, brain networks involved with the capability to split attentional resource over multiple spatial locations and multiple stimuli or sensory modalities have been largely unexplored to date. Here I re-analyzed data from Santangelo et al. (2010) to explore the causal interactions between large-scale brain networks during divided attention. During fMRI scanning, participants monitored streams of visual and/or auditory stimuli in one or two spatial locations for detection of occasional targets. This design allowed comparing a condition in which participants monitored one stimulus/modality (either visual or auditory) in two spatial locations vs. a condition in which participants monitored two stimuli/modalities (both visual and auditory) in one spatial location. The analysis of the independent components (ICs) revealed that dividing attentional resources across two spatial locations necessitated a brain network involving the left ventro- and dorso-lateral prefrontal cortex plus the posterior parietal cortex, including the intraparietal sulcus (IPS) and the angular gyrus, bilaterally. The analysis of Granger causality highlighted that the activity of lateral prefrontal regions were predictive of the activity of all of the posteriors parietal nodes. By contrast, dividing attention across two sensory modalities necessitated a brain network including nodes belonging to the dorsal frontoparietal network, i.e., the bilateral frontal eye-fields (FEF) and IPS, plus nodes belonging to the salience network, i.e., the anterior cingulated cortex and the left and right anterior insular cortex (aIC). The analysis of Granger causality highlights a tight interdependence between the dorsal frontoparietal and salience nodes in trials requiring divided attention between different sensory modalities. The current findings therefore highlighted a dissociation among brain networks implicated during divided attention across spatial locations and sensory
modalities, pointing out the importance of investigating effective connectivity of largescale brain networks supporting complex behavior
Forced to remember: When memory is biased by salient information
No full textThe last decades have seen a rapid growing in the attempt to understand the key factors involved in the internal memory representation of the external world. Visual salience have been found to provide a major contribution in predicting the probability for an item/object embedded in a complex setting (i.e., a natural scene) to be encoded and then remembered later on. Here I review the existing literature highlighting
the impact of perceptual- (based on low-level sensory features) and semantics-related salience (based on high-level knowledge) on short-term memory representation, along with the neural mechanisms underpinning the interplay between these factors. The available evidence reveal that both perceptual- and semantics-related factors affect attention selection mechanisms during the encoding of natural scenes.
Biasing internal memory representation, both perceptual and semantics factors increase the probability to remember high- to the detriment of low-saliency items. The available evidence also highlight an interplay between these factors, with a reduced impact of perceptual-related salience in biasing memory representation as a function of the increasing availability of semantics-related salient information. The neural mechanisms underpinning this interplay involve the activation of different portions of the frontoparietal attention control network. Ventral regions support the assignment of selection/encoding priorities based on high-level semantics, while the involvement of dorsal regions reflects priorities assignment based on low-level sensory features
Assessing the automaticity of intramodal and crossmodal spatial attentional orienting
No full textIn this talk, we review recent research that has attempted to assess just how automatic the intramodal and crossmodal reflexive orienting of spatial attention really is. A number of studies will be described in which we have investigated how manipulating the perceptual / working memory load of a central attention-demanding auditory or visual task influences the exogenous cuing effects elicited by the peripheral
presentation of spatially-nonpredictive, auditory, visual, tactile, and bimodal audiovisual cues (Santangelo
et al. 2006; Santangelo and Spence, submitted). The
results of these experiments clearly show that intramodal and crossmodal spatial cuing effects are typically eliminated under conditions where a central attention-demanding stream is presented in either the auditory or visual modality. Our results therefore suggest that reflexive unimodal visual, auditory, and tactile orienting are not truly automatic. The only
exception to this result appears to be that the exogenous attentional orienting elicited by the presentation of bimodal audiovisual cues (while no more effective in-and-of-themselves than unimodal cues) appear resistant to concurrent task demands: That is, the peripheral presentation of a bimodal cue appears capable of capturing a person’s spatial attention regardless of what else they happen to be doing at the same time. Overall, our results add further weight to the view that auditory, visual, and tactile reflexive
spatial orienting are all controlled by a common underlying neural substrate. Finally, we will also provide a number of examples of how the study of attentional cuing effects under concurrent task demands may be of particular applied relevance, as when considering how best to capture the attention of a car driver (or other interface operator; see Ho et al. 2005, 2006; Ho and Spence 2005)
New perspectives in assessing deception: The evolution of the truth machine
No full textIn recent years a growing interest has arisen in the development of tools for the
detection of deception. Since William M. Marston’s first publication (1917) on the
use of the polygraph as a lie detector, the application of this tool, commonly known
as the truth machine, has evolved. Modern technologies are now trying to push the
issue further, investigating brain activity during deception using functional
Magnetic Resonance Imaging (fMRI). The aim of this paper is to summarise the
evolution of research from the original use of the polygraph to the use of new
technologies in detecting deception, in order to provide an overview of the recent
developments on the use of measurements of deception, and promote new research
in this highly important domain of applied cognitive psychology
Multimodal Investigation on Spatial Attention Mechanisms: A Model of Shared Attention Resources (ShAR)
No full textBirbaumer, Niels Lancioni, Giulio Raffone, Antonin
Affrontare la paura della scuola
No full textUno studio indaga timori, relazione di aiuto e coping negli alunni italiani. Un’esperienza presentata al III Convegno di Education 2.0
Contribution of low-level sensory features and object representation for short term memory of complex visual scenes
No full textNew perspective in assessing deception: The evolution of the truth machine
No full textIn recent years a growing interest has arisen in the development of tools for the detection of deception. Since William M. Marston's first publication (1917) on the use of the polygraph as a lie detector, the application of this tool, commonly known as the truth machine, has evolved. Modern technologies are now trying to push the issue further, investigating brain activity during deception using functional Magnetic Resonance Imaging (fMRI). The aim of this paper is to summarise the evolution of research from the original use of the polygraph to the use of new technologies in detecting deception, in order to provide an overview of the recent developments on the use of measurements of deception, and promote new research in this highly important domain of applied cognitive psychology
The contribution of working memory to divided attention.
No full textPrevious studies have indicated that increasing working memory (WM) load can affect the attentional selection of signals originating from one object/location. Here we assessed whether WM load affects also the selection of multiple objects/locations (divided attention). Participants monitored
either two object-categories (vs. one category; object-based divided attention) or two locations (vs. one location; space-based divided attention) while maintaining in WM either a variable number of objects (object-based WM load) or locations (space-based WM load). Behavioural results showed that WM load affected attentional performance irrespective of divided or focused attention. However, fMRI results showed that the activity associated with object-based divided attention increased linearly with increasing object-based WM load in the left and right intraparietal sulcus (IPS); while, in the same areas, activity associated with space-based divided attention was not affected by any type of WM load. These findings support the hypothesis that WM contributes to the maintenance of resource-demanding attentional sets in a domain-specific manner. Moreover, the dissociable impact of WM load on performance and brain activity suggests that increased IPS activation reflects a recruitment of additional,
domain-specific processing resources that enable dual-task performance under conditions of high WM load and high attentional demand
Individual working memory capacity affects quantitatively but not qualitatively the deployment of attentional resources
No full textWorking memory capacity (WMc) has been traditionally thoughts as involving a fixed number of objects that can be stored at a time (“slot” models). More recent models argued instead that WMc may be based on fixed resources, which can be divided according to the complexity of to-be-stored objects (“resources” models). Here we report evidence showing that both accounts can be valid. We presented participants with everyday pictures for a short period (4 secs). After a retention period of 8 s, we asked participants to verbally report as many objects/details as possible of the previous scenes. We then computed how many times the objects located at either the peak of maximal or minimal saliency in the scene (as indexed by a saliency-map) were recollected by participants. We also measured WMc (K score) using an independent visuo-spatial WM test, namely, the change location task. The results showed that high WMc (i.e., high K score) predicted the amount of objects successfully recollected, in line with a fixed-slot account of WMc. However, the current level of individual WMc failed to predict the probability to recollect maximal- vs. minimal-saliency objects in the scene. This indicates that the deployment of attention resources, within the individual number of fixed-slots, follows bottom-up capture by low-level sensory features (i.e., visual saliency). These findings are in line with the idea that memory representation in complex, real-life situations, can be driven by bottom-up, saliency-related factors that control the allocation of WM “resources” within “fixed” constraints operating at the individual level
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