scholarly journals Aging-related attention deficits in frequency discrimination amid task-irrelevant stimulus differences

2019 ◽  
Vol 40 (3) ◽  
pp. 225-228
Author(s):  
Blas Espinoza-Varas ◽  
Praveen Jajoria ◽  
Hyunsook Jang
Keyword(s):  
Irrelevant Stimulus ◽  
Frequency Discrimination ◽  
Attention Deficits ◽  
Task Irrelevant

scholarly journals Age-related differences in processing task-irrelevant stimulus properties: a single-trial ERP study

2011 ◽  
Vol 11 (11) ◽  
pp. 204-204 ◽  
Author(s):  
K. Wieczorek ◽  
C. Gaspar ◽  
C. Pernet ◽  
G. Rousselet
Keyword(s):  
Irrelevant Stimulus ◽  
Single Trial ◽  
Stimulus Properties ◽  
Processing Task ◽  
Age Related ◽  
Task Irrelevant

scholarly journals Localizing the Neural Substrate of Reflexive Covert Orienting

2012 ◽  
Vol 6 (1) ◽  
Author(s):  
Valerie Higenell ◽  
Brian J. White ◽  
Joshua R. Hwang ◽  
Douglas P. Munoz
Keyword(s):  
Visual Processing ◽  
Irrelevant Stimulus ◽  
Attention Capture ◽  
Visual Orientation ◽  
Gaze Behavior ◽  
Processing Stage ◽  
Visual Events ◽  
Neural Substrate ◽  
Task Irrelevant ◽  
Subsequent Target

The capture of covert spatial attention by salient visual events influences subsequent gaze behavior. A task irrelevant stimulus (cue) can reduce (Attention capture) or prolong (Inhi-bition of return) saccade reaction time to a subsequent target stimulus depending on the cue-target delay. Here we investigated the mechanisms that underlie the sensory-based account of AC/IOR by manipulating the visual processing stage where the cue and target interact. In Experiment 1, liquid crystal shutter goggles were used to test whether AC/IOR occur at a monocular versus binocular processing stage (before versus after signals from both eyes converge). In Experiment 2, we tested whether visual orientation selective mechanisms are critical for AC/IOR by using oriented “Gabor” stimuli. We found that the magnitude of AC and IOR was not different between monocular and interocular viewing conditions, or between iso- and ortho-oriented cue-target interactions. The results suggest that the visual mechanisms that contribute to AC/IOR arise at an orientation-independent binocular processing stage.

The effect of task-irrelevant stimulus ‘graspability’ on reaching actions

2012 ◽  
Vol 25 (0) ◽  
pp. 99
Author(s):  
Samuel Couth ◽  
Ellen Poliakoff ◽  
Emma Gowen
Keyword(s):  
Reaction Times ◽  
Irrelevant Stimulus ◽  
Inhibitory Effect ◽  
Stimulus Onset ◽  
Reaching Movement ◽  
Visual Spatial ◽  
Onset Delay ◽  
Task Irrelevant ◽  
And Control ◽  
Previous Reaction

Reaching and grasping requires integration of visual, proprioceptive and somatosensory inputs. Previous research has shown that manipulating the ‘graspabilty’ of a visual stimulus influences reaction times to that stimulus (e.g., Tucker and Ellis, 1998). Here we explored whether this same effect can be extended to the planning and online control of arm movements. Participants made a mimed reaching movement with their left or right hand depending on the colour of images of affordance (door handles) and control stimuli (a row of dots of similar size and orientation as the door handle). Stimulus onset was manipulated by changing when the grey stimulus changed colour. Stimuli either pointed towards (compatible) or pointed away from (incompatible) the responding hand. Spatially compatible affordance stimuli facilitated reach onset compared to other stimuli and compatibility combinations, replicating previous reaction time studies. This can be attributed to a priming of the motor system by spatially compatible affording items. Results also indicated a larger outwards deviation of reach trajectory for spatially incompatible control stimuli compared to spatially compatible control stimuli, which waned with stimulus onset delay. This reveals an immediate inhibitory effect on reach trajectory, such that outwards movement is over-compensated to negate this incompatible orientation. Overall, we observed that the effect of visual spatial compatibility on reach kinematics differs with the action relevance of the stimulus. We are currently exploring how this multisensory visuomotor effect changes with age.

scholarly journals Context-specific proportion congruent effects: Compound-cue contingency learning in disguise

2018 ◽  
Vol 72 (5) ◽  
pp. 1119-1130 ◽  
Author(s):  
James R Schmidt ◽  
Céline Lemercier
Keyword(s):  
Attentional Control ◽  
Congruency Effect ◽  
Irrelevant Stimulus ◽  
Response Speed ◽  
Contingency Learning ◽  
Conflict Monitoring ◽  
Stroop Paradigm ◽  
Context Specific ◽  
Task Irrelevant ◽  
Compound Cue

Conflict between task-relevant and task-irrelevant stimulus information leads to impairment in response speed and accuracy. For instance, in the colour-word Stroop paradigm, participants respond slower and less accurately to the print colour of incongruent colour words (e.g., “red” printed in green) than to congruent colour words (e.g., “green” in green). Importantly, this congruency effect is diminished when the trials in an experiment are mostly incongruent, relative to mostly congruent, termed a proportion congruent effect. When distracting stimuli are mostly congruent in one context (e.g., location or font) but mostly incongruent in another context (e.g., another location or font), the congruency effect is still diminished in the mostly incongruent context, termed a context-specific proportion congruent (CSPC) effect. Both the standard proportion congruent and CSPC effects are typically interpreted in terms of conflict-driven attentional control, frequently termed conflict adaptation or conflict monitoring. However, in two experiments, we investigated contingency learning confounds in context-specific proportion congruent effects. In particular, two variants of a dissociation procedure are presented with the font variant of the CSPC procedure. In both, robust contingency learning effects were observed. No evidence for context-specific control was observed. In fact, results trended in the wrong direction. In all, the results suggest that CSPC effects may not be a useful way of studying attentional control.

Covert attention regulates saccadic reaction time by routing between different visual-oculomotor pathways

2012 ◽  
Vol 107 (6) ◽  
pp. 1748-1755 ◽  
Author(s):  
Shaobo Guan ◽  
Yu Liu ◽  
Ruobing Xia ◽  
Mingsha Zhang
Keyword(s):  
Reaction Time ◽  
Relative Proportion ◽  
Irrelevant Stimulus ◽  
Bimodal Distribution ◽  
Abrupt Onset ◽  
Saccadic Reaction Time ◽  
Covert Attention ◽  
Visuomotor Transformation ◽  
Express Saccade ◽  
Task Irrelevant

Covert attention modulates saccadic performance, e.g., the abrupt onset of a task-irrelevant visual stimulus grabs attention as measured by a decrease in saccadic reaction time (SRT). The attentional advantage bestowed by the task-irrelevant stimulus is short-lived: SRT is actually longer ∼200 ms after the onset of a stimulus than it is when no stimulus appears, known as inhibition of return. The mechanism by which attention modulates saccadic reaction is not well-understood. Here, we propose two possible mechanisms: by selective routing of the visuomotor signal through different pathways (routing hypothesis) or by general modulation of the speed of visuomotor transformation (shifting hypothesis). To test them, we designed a cue gap paradigm in which a 100-ms gap was introduced between the fixation point disappearance and the target appearance to the conventional cued visual reaction time paradigm. The cue manipulated the location of covert attention, and the gap interval resulted in a bimodal distribution of SRT, with an early mode (express saccade) and a late mode (regular saccade). The routing hypothesis predicts changes in the proportion of express saccades vs. regular saccades, whereas the shifting hypothesis predicts a shift of SRT distribution. The addition of the cue had no effect on mean reaction time of express and regular saccades, but it changed the relative proportion of two modes. These results demonstrate that the covert attention modification of the mean SRT is largely attributed to selective routing between visuomotor pathways rather than general modulation of the speed of visuomotor transformation.

scholarly journals Defining the V5/MT neuronal pool for perceptual decisions in a visual stereo-motion task

2016 ◽  
Vol 371 (1697) ◽  
pp. 20150260 ◽  
Author(s):  
Kristine Krug ◽  
Tamara L. Curnow ◽  
Andrew J. Parker
Keyword(s):  
Three Dimensional ◽  
Irrelevant Stimulus ◽  
Neuronal Firing ◽  
Single Neurons ◽  
Stereo Motion ◽  
The Face ◽  
Dot Motion ◽  
Visual Cortex Neurons ◽  
Task Irrelevant ◽  
Binocular Depth

In the primate visual cortex, neurons signal differences in the appearance of objects with high precision. However, not all activated neurons contribute directly to perception. We defined the perceptual pool in extrastriate visual area V5/MT for a stereo-motion task, based on trial-by-trial co-variation between perceptual decisions and neuronal firing (choice probability (CP)). Macaque monkeys were trained to discriminate the direction of rotation of a cylinder, using the binocular depth between the moving dots that form its front and rear surfaces. We manipulated the activity of single neurons trial-to-trial by introducing task-irrelevant stimulus changes: dot motion in cylinders was aligned with neuronal preference on only half the trials, so that neurons were strongly activated with high firing rates on some trials and considerably less activated on others. We show that single neurons maintain high neurometric sensitivity for binocular depth in the face of substantial changes in firing rate. CP was correlated with neurometric sensitivity, not level of activation. In contrast, for individual neurons, the correlation between perceptual choice and neuronal activity may be fundamentally different when responding to different stimulus versions. Therefore, neuronal pools supporting sensory discrimination must be structured flexibly and independently for each stimulus configuration to be discriminated. This article is part of the themed issue ‘Vision in our three-dimensional world'.

Sign in / Sign up

Export Citation Format

Share Document