Attentional Amplification Research Articles

Attention, awareness and control

Event Abstract Back to Event Attention, awareness and control Catherine Tallon-Baudry1* 1 CNRS, France Attention has long been considered to be the organizing function that brings relevant information to the forefront of our conscious mind. This in turn enables us to control our actions, according to our internal goals. Attention, awareness and control therefore appear to be tightly related: an attended stimulus reaches awareness, subsequently leading to a decision whether or not to act. The objective of this symposium is to illustrate the growing experimental evidence that challenges this view. First, there is a now a strong body of behavioral evidence both in patients and normal subjects showing that attention can operate on, and be triggered by, unconsciously processed stimuli (Bob Kentridge). Second, a double dissociation at the neural level between attentional amplification and awareness-related activity has repeatedly been observed in MEG recordings (Catherine Tallon-Baudry). Third, fMRI data show that responses to unconsciously processed stimuli are controlled by top-down influences (Sid Kouider). Fourth, behavioral studies in normal subjects and patients with micro-lesions of premotor regions reveal that sensory events can trigger unconscious motor plans, which can in turn be controlled in an unconscious manner (Petroc Sumner). Altogether, these results raise the intriguing possibility that subjective experience of external stimuli and of endogenous processes can be disconnected from attention and control, and conversely, that attention and control can be triggered in an automatic manner, outside the focus of conscious perception and volition. Keywords: Attention, fMRI, MEG Conference: XI International Conference on Cognitive Neuroscience (ICON XI), Palma, Mallorca, Spain, 25 Sep - 29 Sep, 2011. Presentation Type: Introduction Topic: Symposium 4: Attention, awareness and control Citation: Tallon-Baudry C (2011). Attention, awareness and control. Conference Abstract: XI International Conference on Cognitive Neuroscience (ICON XI). doi: 10.3389/conf.fnhum.2011.207.00025 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 09 Nov 2011; Published Online: 15 Nov 2011. * Correspondence: Dr. Catherine Tallon-Baudry, CNRS, Paris, France, catherine.tallon-baudry@ens.fr Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Catherine Tallon-Baudry Google Catherine Tallon-Baudry Google Scholar Catherine Tallon-Baudry PubMed Catherine Tallon-Baudry Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

The relation between consciousness and attention: An empirical study using the priming paradigm

Dehaene, Changeux, Naccache, Sackur, and Sergent (2006) and Koch and Tsuchiya (2007) recently proposed taxonomies that distinguish between four processing states, based on bottom-up stimulus strength and top-down attentional amplification. The aim of the present study was to empirically test these processing states using the priming paradigm. Our results showed that attention (prime attended or not) and stimulus strength (prime presented subliminally or not) significantly modulated priming effects: either receiving top-down attention or possessing sufficient bottom-up strength was a prerequisite for a stimulus to elicit priming. When both top-down attention and sufficient bottom-up strength were present, the priming effect was boosted. The origins of the observed priming effects also varied between different processing states. We can conclude that our empirical study using the priming paradigm confirmed the presence of four processing states, which displayed a differential pattern of response priming effects and differential origins of the response priming effects.

Inhibition is picky: Shape difference is a necessary condition for attentional inhibition of irrelevant objects

The present study investigated the conditions for attentional amplification in the processing of relevant objects and for attentional inhibition in the processing of irrelevant objects. Participants reported the color of one of two superimposed objects that was specified by occlusion. Irrelevant color words were presented as part of the relevant object, as part of the irrelevant object, or in the background; the words were either congruent or incongruent with the color of the relevant object. The size of the congruency effects provided a measure of the (relative) strength of the processing of the objects and the background. Finally, the two objects had the same shape in one session and different shapes in another session. In both sessions, results showed larger Stroop effects from words belonging to the relevant object than from words in the background, indicating attentional amplification of the relevant object that was unaffected by object similarity. In contrast, smaller Stroop effects from words belonging to the irrelevant object than from words in the background occurred only when the two objects differed in shape. The latter result suggests that a shape difference is both a necessary and a sufficient condition for inhibiting the processing of an irrelevant visual object.

The role of eye fixations in concentration and amplification effects during multiple object tracking

When tracking spatially extended objects in a multiple object tracking task, attention is preferentially directed to the centres of those objects (attentional concentration), and this effect becomes more pronounced as object length increases (attentional amplification). However, it is unclear whether these effects depend on differences in attentional allocation or differences in eye fixations. We addressed this question by measuring eye fixations in a dual-task paradigm that required participants to track spatially extended objects, while simultaneously detecting probes that appeared at the centres or near the endpoints of objects. Consistent with previous research, we observed concentration and amplification effects: Probes at the centres of objects were detected more readily than those near their endpoints, and this difference increased with object length. Critically, attentional concentration was observed when probes were equated for distance from fixation during free viewing, and concentration and amplification were observed without eye movements during strict fixation. We conclude that these effects reflect the prioritization of covert attention to particular spatial regions within extended objects, and we discuss the role of eye fixations during multiple object tracking.

A scientific model of consciousness: implications for neuropsychiatic diseases

Consciousness is an essential property of human cognition. According to the "Global neuronal workspace" hypothesis designed by Dehaene et al., consciousness results from amplification and synchronisation of distant processors. Frontoparietal loops play a crucial role in this large scale synchronisation. At any given time, many modular cerebral networks are active in parallel and process information unconsciously. An information becomes conscious, however, if the neural population that represents it is mobilized by top-down attentional amplification into a brain-scale state of coherent activity. This long-distance connectivity makes the information available to a variety of processes including perceptual categorization, long-term memorization, evaluation, and intentional action. Behavioral as well as neuroimaging studies using masked subliminal perception support this theoretical view. Among neuropsychiatric disorders, many neuroscientific studies have been devoted to schizophrenia. Some of them conclude on a global brain disconnectivity rather than on specific and localised perturbations. Hence conscious integration may be the core deficit in cognitive disabilities observed in schizophrenia. As shown in recent results, threshold for access to consciousness in schizophrenic patients compared with controls is elevated whereas unconscious processes, such as the ones involved in subliminal priming remain effective. We conclude on the potential use of the "global neuronal workspace" model in other neuropsychiatric diseases such as Alzheimer's disease or multiple sclerosis.

Attention to Surfaces Modulates Motion Processing in Extrastriate Area MT

In the visual system, early atomized representations are grouped into higher-level entities through processes of perceptual organization. Here we present neurophysiological evidence that a representation of a simple object, a surface defined by color and motion, can be the unit of attentional selection at an early stage of visual processing. Monkeys were cued by the color of a fixation spot to attend to one of two transparent random-dot surfaces, one red and one green, which occupied the same region of space. Motion of the attended surface drove neurons in the middle temporal (MT) visual area more strongly than physically identical motion of the non-attended surface, even though both occurred within the spotlight of attention. Surface-based effects of attention persisted even without differential surface coloring, but attentional modulation was stronger with color. These results show that attention can select surface representations to modulate visual processing as early as cortical area MT.

Neurocognitive effects of phobia-related stimuli in animal-fearful individuals

Two experiments were conducted to explore neurocognitive effects of phobia-related stimuli. Contingency assessments and event-related potentials (ERPs) were collected from animal-fearful individuals during probabilistic classification learning in diverse motivational-affective contexts. As revealed by ERPs, attentional amplification of cortical sensory processing occurred in response to phobia-related stimuli. In particular, the posterior selection negativity in the ERPs to phobia-related stimuli had its origin in a bottom-up route, probably the amygdaloid-extrastriate cortex path. No evidence for top-down modulation of phobia-related attentional amplification was obtained. The covariation bias occurred only when aversive motivational-affective expectancies prevailed, suggesting a role of retrieval from associative emotional memory. Finally, phobia-related cue competition was probably related to the disruption of elaboration in memory of neutral and aversive stimulus pairings that was induced by belonging pairings of phobia-related and aversive stimuli. The findings have far-reaching implications for the interface between cognition and emotion.

How Does Attention Select and Track Spatially Extended Objects? New Effects of Attentional Concentration and Amplification.

Real-world situations involve attending to spatially extended objects, often under conditions of motion and high processing load. The present experiments investigated such processing by requiring observers to attentionally track a number of long, moving lines. Concurrently, observers responded to sporadic probes as a measure of the distribution of attention across the lines. The results revealed that attention is concentrated at the centers of lines during tracking, despite their uniformity, and that this center advantage grew as the lines became longer: Not only did observers get worse near the endpoints, but they became better at the lines' centers, as if attention became more concentrated as the objects became more extended. These results begin to show how attention is flexibly allocated in online visual processing to extended dynamic objects.

The role of aesthetics in problem solving: some observations and a manifesto

The generation of novel conceptual combinations is an effective strategy for solving unfamiliar problems only if it is accompanied by a mechanism that identifies potential solutions as such. Both mechanistic studies and common phenomenology suggest that in humans this mechanism involves, and is experienced as, an attachment of strong positive emotional response to a candidate solution. Thus, key questions are how such responses can be indicators of solution correctness, how and at what stage of problem solving they are generated, and how and at what stage of problem solving they are attached to representations of candidate solutions. These questions were investigated in an aesthetic problem solving task environment requiring the synthesis of visual and verbal components. The phenomenology observed in this environment suggests that generation and attachment of a sufficient emotional response is necessary for binding of nascent visual and verbal representation components to form a candidate solution, and that executive-driven attentional amplification of nascent representations suppresses the attachment of emotional valence. It also suggests that a complex, multivalent emotional response is characteristic of correct solutions. If this proves to be correct, it will require a re-thinking of the role of executive attention and predefined goals in creative problem solving.

Towards a cognitive neuroscience of consciousness: basic evidence and a workspace framework

This introductory chapter attempts to clarify the philosophical, empirical, and theoretical bases on which a cognitive neuroscience approach to consciousness can be founded. We isolate three major empirical observations that any theory of consciousness should incorporate, namely (1) a considerable amount of processing is possible without consciousness, (2) attention is a prerequisite of consciousness, and (3) consciousness is required for some specific cognitive tasks, including those that require durable information maintenance, novel combinations of operations, or the spontaneous generation of intentional behavior. We then propose a theoretical framework that synthesizes those facts: the hypothesis of a global neuronal workspace. This framework postulates that, at any given time, many modular cerebral networks are active in parallel and process information in an unconscious manner. An information becomes conscious, however, if the neural population that represents it is mobilized by top-down attentional amplification into a brain-scale state of coherent activity that involves many neurons distributed throughout the brain. The long-distance connectivity of these ‘workspace neurons’ can, when they are active for a minimal duration, make the information available to a variety of processes including perceptual categorization, long-term memorization, evaluation, and intentional action. We postulate that this global availability of information through the workspace is what we subjectively experience as a conscious state. A complete theory of consciousness should explain why some cognitive and cerebral representations can be permanently or temporarily inaccessible to consciousness, what is the range of possible conscious contents, how they map onto specific cerebral circuits, and whether a generic neuronal mechanism underlies all of them. We confront the workspace model with those issues and identify novel experimental predictions. Neurophysiological, anatomical, and brain-imaging data strongly argue for a major role of prefrontal cortex, anterior cingulate, and the areas that connect to them, in creating the postulated brain-scale workspace.

In clear and vivid form?

Over a century ago, James suggested that when we pay attention to a particular object the mind takes possession of it in ‘clear and vivid form’ 1 James W. Principles of Psychology. MacMillan, 1890 Crossref Google Scholar , but what does this mean? In a previous study, Prinzmetal et al. briefly presented observers with a test pattern (e.g. a coloured patch) and then a choice of possible patches to match along this dimension 2 Prinzmetal W. et al. Phenomenology of attention: 1. Color, location, orientation, and spatial frequency. J. Exp. Psychol. Hum. Percept. Perform. 1998; 24: 261-282 Crossref Scopus (134) Google Scholar . They manipulated the amount of attention that the observer could give to the test patch by introducing a distracting task to be performed concurrently. This distraction did not alter the success of the matching response (i.e. the mean response stayed the same) but it did alter the spread of the responses (i.e. the variance). In other words, the perceived value of the stimulus (its colour, brightness, size, etc.) is not altered by attention but our ability to discriminate between similar patterns is altered. Blaser et al. recently complemented this finding by trading-off ‘bottom-up’ and ‘top-down’ influences in a perceptual motion task. They devised a stimulus that provides an assay as to which of two colours is more salient to the observer 3 Blaser E. et al. Measuring the amplification of attention. Proc. Natl. Acad. Sci. U. S. A. 1999; 96: 11681-11686 Crossref PubMed Scopus (86) Google Scholar . This comprises a motion sequence in which a red/green striped pattern is alternated with one whose stripes are made up of low- and high-contrast texture. Whichever colour stripe is most salient is matched with the high-contrast stripe and the perceived motion is in this direction. One can then trade-off the bottom-up saliency (which colour stripe is most different in colour from the background) with top-down instructions (e.g. asking the subject to pay attention to the ‘red’ bars). Paying attention to a given colour did indeed alter the perceived direction of the stimulus and was found to be equivalent to increasing the physical intensity of this colour from 25% to over 100%. How can paying attention not alter the appearance of the stimulus and yet be like altering its physical intensity? The authors suggest that the answer lies in the notion of a salience map, whereby figure/ground decisions and processing priorities are decided. Attention, as well as stimulus intensity, contributes to the salience map, but leaves the actual representation of the stimulus itself unaltered. Thus, perceptual distortions are avoided but we see the object ‘clearly and vividly’.

Measuring the amplification of attention.

An ambiguous motion paradigm, in which the direction of apparent motion is determined by salience (i.e., the extent to which an area is perceived as figure versus ground), is used to assay the amplification of color by attention to color. In the red-green colored gratings used in these experiments, without attention instructions, salience depends on the chromaticity difference between colored stripes embedded in the motion sequence and the yellow background. Selective attention to red (or to green) alters the perceived direction of motion and is found to be equivalent to increasing the physical redness (or greenness) by 25-117%, depending on the observer and color. Whereas attention to a color drastically alters the salience of that color, it leaves color appearance unchanged. A computational model, which embodies separate, parallel pathways for object perception and for salience, accounts for 99% of the variance of the experimental data.

Memory Rehabilitation in Alzheimer's Disease

Until the cause of Alzheimer's disease (AD) is discovered, programs designed to extend functioning are critical to confront the projected increase in cases and the escalating cost of patient management. A program of rehabilitation designed to improve memory was developed that focussed on effortful and involuntary processes of memory and amplification of attention. Eleven patients with probable AD and their spouses enrolled in a four week course to improve their ability to recall names and faces, and recent events. Rehearsal and stimulation of deep processing significantly improved the ability of AD patients to recall name-face relationships. Recall of television content was significantly improved with procedures requiring patients to expend effort while they watched. A significant event technique that provoked emotional memories and produced flashbulb memories was the most effective procedure. Patients had nearly perfect recall for events during days of significant events. Generally the most effecti...