Attentional blink

About: Attentional blink is a research topic. Over the lifetime, 1346 publications have been published within this topic receiving 53064 citations. The topic is also known as: Attentional blinks.

The brain network underlying attentional blink predicts symptoms of attention deficit hyperactivity disorder in children.

Abstract: Attention deficit hyperactivity disorder (ADHD) is a chronic neuropsychiatric disease that can markedly impair educational, social, and occupational function throughout life. Behavioral deficits may provide clues to the underlying neurological impairments. Children with ADHD exhibit a larger attentional blink (AB) deficit in rapid serial visual presentation (RSVP) tasks than typically developing children, so we examined whether brain connectivity in the neural network associated with AB can predict ADHD symptoms and thus serve as potential biomarkers of the underlying neuropathology. We first employed a connectome-based predictive model analysis of adult resting-state functional magnetic resonance imaging data to identify a distributed brain network for AB. The summed functional connectivity (FC) strength within the AB network reliably predicted individual differences in AB magnitude measured by a classical dual-target RSVP task. Furthermore, the summed FC strength within the AB network predicted individual differences in ADHD Rating Scale scores from an independent dataset of pediatric patients. Our findings suggest that the individual AB network could serve as an applicable neuroimaging-based biomarker of AB deficit and ADHD symptoms.

Awareness & Perception in Rapid Serial Visual Presentation

Abstract: This thesis explores the subjective experience of targets in rapid serial visual presentation (RSVP), an experimental paradigm where visual stimuli are displayed in rapid succession. In RSVP, items appear on the screen so briefly that not every item in the stream can be encoded reliably. Thus, it allows observation of conscious experience at the fringe of perception. The Attentional Blink (AB) - an effect in which an RSVP target is likely to be missed if it follows a fully processed first target - has been used in order to manipulate the accuracy of item identification by varying the target separation and presentation speed. The main focus of studies using RSVP presentation to make inferences about conscious perception has been the question of whether conscious perception is all-or-none or gradual. We initially present some thoughts on the suitability of the AB paradigm for answering this question. Not much is known about the effect of different variables in the paradigm on subjective experience, and it is possible that AB mechanisms affect experience quite differently from other paradigms, limiting the generalisability of findings derived from work within the AB paradigm. Based on this, we follow two lines of evidence: First, we explore the possibility of finding gradations in subjective visibility of targets measured on ratings scales and in the response of the electroencephalogram using a simple single target RSVP. Second, we investigate the effect of target separation and perceived order on this subjective experience in the AB paradigm. Our results indicate that items in single-target RSVP can be perceived in a graded manner, with possible indications of a non-linear jump in brain activity between not-seen and seen items. Regarding subjective experience when separation of two targets is varied, we find a disconnect between accuracy and visibility of the second target when in close proximity to the first, showing relatively low subjective experience considering the high report accuracy. Target separation also affects the number of order confusions, which we find to reduce target visibility under specific conditions. These results add to our understanding of how targets are perceived in RSVP and have implications for research into conscious perception.

On the Common Neural Basis of Temporal and Spatial Dynamics of Attention: Evidence from Human Electroencephalography

Abstract: This thesis investigated, by using electroencephalography (EEG) technique, the deployment of attention in time and space. Specifically –through three experimental chapters– Attentional Blink (AB) and visual search paradigms have been employed to highlight the common functional characteristics of the mechanisms which drive attention in time and space. In Chapter 1, an overview of visual attention is presented. Specifically, I proposed a theoretical introduction regarding the two aspects of visual attention debated throughout the manuscript, namely, the AB phenomenon –that is an effect related to the temporal dynamics of visual attention– and visual spatial attention. Results presented in Chapter 2 show how temporal dynamics of visual attention are affected by the AB effect, by analyzing how detection and encoding of a target are influenced when salient visual information is presented in temporal proximity. In line with Chapter 2, the experiment presents in Chapter 3 merged together, in a single experimental design, the AB and the visual search paradigms. In this study, I investigated whether the deployment of visual spatial attention in space is prone to the same experimental manipulations which influence detection and encoding of targets in the AB paradigm. Given the results, to assess why temporal dynamics of attention are similar both for midline- and lateral- presented information, in Chapter 4 visual spatial attention has been investigated with a visual search task, by comparing the electrophysiological activity elicited by a lateral presented target vs. a midline presented target. Eventually, in Chapter 5, a general discussion highlights the main findings presented in this thesis, by considering them collectively, and by raising future proposals and questions in relation to the topics debated in these Chapters.