Covert orienting to the locations of targets and distractors: Effects on response channel activation in a flanker task

2002 ◽  
Vol 55 (3) ◽  
pp. 917-936 ◽  
Author(s):  
Tony Ro ◽  
Liana Machado ◽  
Nancy Kanwisher ◽  
Robert D. Rafal
Keyword(s):  
Spatial Attention ◽  
Flanker Task ◽  
Channel Activation ◽  
Covert Orienting ◽  
Exogenous Cues ◽  
Colour Patch ◽  
Target Locations ◽  
Response Channel ◽  
Flanker Interference

The role of covert orienting of attention in response channel activation was examined using the flanker interference and precueing paradigms. Four experiments assessed the influence of distractors on the discrimination of a target colour patch under cueing conditions (three with non-informative, exogenous cues and one with informative, endogenous cues) that modulated attention at the flanker or target locations. Across all of the experiments, the amount of interference generated by the distractors was not modulated by the facilitation and inhibition of return induced by spatial attention precues. These results are consistent with previous reports of patients with neglect, which demonstrated that flanker interference proceeds at unattended locations (Audet, Bub, & Lecours, 1991; Cohen, Ivry, Rafal, & Kohn, 1995), and they suggest that response channel activation can occur independently from spatial attention.

Central-Cue Discriminability Modulates Object-Based Attention by Influencing Spatial Attention

2012 ◽  
Vol 59 (3) ◽  
pp. 132-137 ◽  
Author(s):  
Morris Goldsmith ◽  
Menahem Yeari
Keyword(s):  
Spatial Attention ◽  
Luminance Contrast ◽  
Attentional Focus ◽  
Perceptual Representation ◽  
Object Representations ◽  
Attentional Deployment ◽  
Object Based ◽  
Target Locations ◽  
Central Arrow

The role of central-cue discriminability in modulating object-based effects was examined using Egly, Driver, and Rafal’s (1994) “double-rectangle” spatial cueing paradigm. Based on the attentional focusing hypothesis (Goldsmith & Yeari, 2003), we hypothesized that highly discriminable central-arrow cues would be processed with attention spread across the two rectangles (potential target locations), thereby strengthening the perceptual representation of these objects so that they influence the subsequent endogenous deployment of attention, yielding object-based effects. By contrast, less discriminable central-arrow cues should induce a more narrow attentional focus to the center of the display, thereby weakening the rectangle object representations so that they no longer influence the subsequent attentional deployment. Central-arrow-cue discriminability was manipulated by size and luminance contrast. The results supported the predictions, reinforcing the attentional focusing hypothesis and highlighting the need to consider central-cue discriminability when designing experiments and in comparing experimental results.

scholarly journals A unique role of endogenous visual-spatial attention in rapid processing of multiple targets.

2011 ◽  
Vol 37 (4) ◽  
pp. 1065-1073 ◽  
Author(s):  
Emmanuel Guzman-Martinez ◽  
Marcia Grabowecky ◽  
German Palafox ◽  
Satoru Suzuki
Keyword(s):  
Spatial Attention ◽  
Multiple Targets ◽  
Unique Role ◽  
Visual Spatial Attention ◽  
Visual Spatial ◽  
Rapid Processing

The role of different cues in the brain mechanism on visual spatial attention

2006 ◽  
Vol 16 (10) ◽  
pp. 1045-1050
Author(s):  
Song Weiqun ◽  
Lou Yuejia ◽  
Chi Song ◽  
Ji Xunming ◽  
Ling Feng ◽  
...  
Keyword(s):  
Spatial Attention ◽  
Visual Spatial Attention ◽  
Visual Spatial ◽  
Brain Mechanism ◽  
The Brain

The Role of Online Visual Feedback for the Control of Target-Directed and Allocentric Hand Movements

2011 ◽  
Vol 105 (2) ◽  
pp. 846-859 ◽  
Author(s):  
Lore Thaler ◽  
Melvyn A. Goodale
Keyword(s):  
Visual Feedback ◽  
Visual Information ◽  
Sensory Feedback ◽  
Sensory Information ◽  
Movement Control ◽  
Sensorimotor Control ◽  
Hand Movements ◽  
Cast Doubt ◽  
Target Locations

Studies that have investigated how sensory feedback about the moving hand is used to control hand movements have relied on paradigms such as pointing or reaching that require subjects to acquire target locations. In the context of these target-directed tasks, it has been found repeatedly that the human sensory-motor system relies heavily on visual feedback to control the ongoing movement. This finding has been formalized within the framework of statistical optimality according to which different sources of sensory feedback are combined such as to minimize variance in sensory information during movement control. Importantly, however, many hand movements that people perform every day are not target-directed, but based on allocentric (object-centered) visual information. Examples of allocentric movements are gesture imitation, drawing, or copying. Here we tested if visual feedback about the moving hand is used in the same way to control target-directed and allocentric hand movements. The results show that visual feedback is used significantly more to reduce movement scatter in the target-directed as compared with the allocentric movement task. Furthermore, we found that differences in the use of visual feedback between target-directed and allocentric hand movements cannot be explained based on differences in uncertainty about the movement goal. We conclude that the role played by visual feedback for movement control is fundamentally different for target-directed and allocentric movements. The results suggest that current computational and neural models of sensorimotor control that are based entirely on data derived from target-directed paradigms have to be modified to accommodate performance in the allocentric tasks used in our experiments. As a consequence, the results cast doubt on the idea that models of sensorimotor control developed exclusively from data obtained in target-directed paradigms are also valid in the context of allocentric tasks, such as drawing, copying, or imitative gesturing, that characterize much of human behavior.

K+ATP-channel activation causes marked vasodilation in the hypertensive neonatal pig lung

1992 ◽  
Vol 263 (5) ◽  
pp. H1532-H1536 ◽  
Author(s):  
J. M. Pinheiro ◽  
A. B. Malik
Keyword(s):  
Potential Role ◽  
Channel Blocker ◽  
Ringer Solution ◽  
Vasomotor Tone ◽  
Channel Activation ◽  
Pulmonary Vasodilation ◽  
Pulmonary Arterial ◽  
Neonatal Pig ◽  
Dose Dependent

We studied the potential role of ATP-sensitive potassium (K+ATP) channel activation in mediating pulmonary vasodilation in newborn piglets. Piglet lungs (n = 14, ages 1-4 days) were artificially perfused with recirculating Ringer solution containing bovine serum albumin and statistically inflated using 95% O2-5% CO2. We measured pulmonary arterial pressure (Ppa) and distribution of pulmonary vascular resistance (using double-occlusion method). Under resting conditions (Ppa 13.7 +/- 1.6 cmH2O, mean +/- SE), the K+ATP channel agonist BRL 38227 (lemakalim, 10(-7) and 10(-6) M) caused small dose-dependent pulmonary vasodilation. This response was diminished by the K+ATP-channel blocker glibenclamide (10(-5) M). Pretreatment of lungs with indomethacin (10(-5) M) and N omega-nitro-L-arginine (10(-5) M) to inhibit cyclooxygenase- and nitric oxide (NO)-related vasodilation, respectively, resulted in a marked increase in the baseline Ppa to 85.6 +/- 11.2 cmH2O. Injection of BRL 38227 (10(-7) M and 10(-6) M) in these lungs decreased Ppa to 72.5 +/- 8.5 (P < 0.01) and 19.3 +/- 0.9 cmH2O (P < 0.01), respectively; the corresponding times for half-recovery of Ppa (t1/2R) were 5.7 +/- 4.3 and > 20 min. Glibenclamide (10(-5) M) abolished the response to 10(-7) M BRL 38227 and significantly diminished (P < 0.05) the decreases in Ppa and t1/2R in response to 10(-6) M BRL 38227 but not to acetylcholine (10(-10) M). We conclude that activation of K+ATP channels has a minimal role in maintaining basal pulmonary vasomotor tone but is able to induce marked vasodilation when NO and cyclooxygenase-dependent vasodilatory mechanisms are inhibited.

EEG Signal Decomposition Evidence for a Role of Perceptual Processes during Conflict-related Behavioral Adjustments in Middle Frontal Regions

2020 ◽  
Vol 32 (7) ◽  
pp. 1381-1393
Author(s):  
Nico Adelhöfer ◽  
Christian Beste
Keyword(s):  
Time Window ◽  
Flanker Task ◽  
Decomposition Methods ◽  
Signal Decomposition ◽  
Conflict Monitoring ◽  
Stimulus Response ◽  
Eeg Data ◽  
Congruency Sequence Effect ◽  
Trial History

Conflict monitoring processes are central to cope with fluctuating environmental demands. However, the efficacy of these processes depends on previous trial history/experience, which is reflected in the “congruency sequence effect” (CSE). Several theoretical accounts have been put forward to explain this effect. Some accounts stress the role of perceptual processes in the emergence of the CSE. As yet, it is elusive how these perceptual processes are implemented on a neural level. We examined this question using a newly developed moving dots flanker task. We combine decomposition methods of EEG data and source localization. We show that perceptual processes modulate the CSE and can be isolated in neurophysiological signals, especially in the N2 ERP time window. However, mechanisms relating perception to action are also coded and modulated in this time window. We show that middle frontal regions (BA 6) are associated with processes dealing with purely perceptual processes. Inferior frontal regions (BA 45) are associated with processes dealing with stimulus–response transition processes. Likely, the neurophysiological modulations reflect unbinding processes at the perceptual level, and stimulus–response translation level needed to respond correctly on the presented (changed) stimulus–response relationships. The data establish a direct relationship between psychological concepts focusing on perceptual processes during conflict monitoring and neurophysiological processes using signal decomposition.

Sign in / Sign up

Export Citation Format

Share Document