scholarly journals The Spatial Scale of Attention Strongly Modulates Saccade Latencies

2008 ◽  
Vol 99 (4) ◽  
pp. 1743-1757 ◽  
Author(s):  
Mark R. Harwood ◽  
Laurent Madelain ◽  
Richard J. Krauzlis ◽  
Josh Wallman
Keyword(s):  
Spatial Scale ◽  
Reaction Times ◽  
Motor Preparation ◽  
Saccade Latency ◽  
Retinal Eccentricity ◽  
Target Movement ◽  
The Cost ◽  
Latency Distributions

We have previously shown that when a stimulus consisting of two concentric rings moves, saccade latencies are much longer (by 150 ms) when attention is directed to the larger ring than to the smaller ring. Here, we investigated whether this effect can be explained by a deferral of the “cost” of making a saccade while the target remains inside the attentional field, or by purely visual factors (eccentricity or contrast). We found 1) latencies were shorter when attention was directed to small features irrespective of retinal eccentricity; 2) saccade latency distributions were systematically determined by the ratio between the amplitude of the stimulus step and the diameter of the attended ring: stimulus steps that were larger than the attended ring resulted in short latencies, whereas steps smaller than the attended ring resulted in proportionally longer and more variable latencies; 3) this effect was not seen in manual reaction times to the same target movement; and 4) suprathreshold changes in the contrast of targets, mimicking possible attentional effects on perceived contrast and saliency, had little effect on latency. We argue that the spatial scale of attention determines the urgency of saccade motor preparation processes by changing the rate and rate variability of the underlying decision signal, to defer the cost of saccades that result in little visual benefit.

scholarly journals Temporal Interactions of Air-Puff–Evoked Blinks and Saccadic Eye Movements: Insights Into Motor Preparation

2005 ◽  
Vol 93 (3) ◽  
pp. 1718-1729 ◽  
Author(s):  
Neeraj J. Gandhi ◽  
Desiree K. Bonadonna
Keyword(s):  
Eye Movement ◽  
Target Location ◽  
Low Frequency ◽  
Saccadic Eye Movements ◽  
Stimulus Presentation ◽  
Motor Preparation ◽  
Threshold Level ◽  
Saccade Latency ◽  
Sensory Response ◽  
Temporal Interactions

Following the initial, sensory response to stimulus presentation, activity in many saccade-related burst neurons along the oculomotor neuraxis is observed as a gradually increasing low-frequency discharge hypothesized to encode both timing and metrics of the impending eye movement. When the activity reaches an activation threshold level, these cells discharge a high-frequency burst, inhibit the pontine omnipause neurons (OPNs) and trigger a high-velocity eye movement known as saccade. We tested whether early cessation of OPN activity, prior to when it ordinarily pauses, acts to effectively lower the threshold and prematurely trigger a movement of modified metrics and/or dynamics. Relying on the observation that OPN discharge ceases during not only saccades but also blinks, air-puffs were delivered to one eye to evoke blinks as monkeys performed standard oculomotor tasks. We observed a linear relationship between blink and saccade onsets when the blink occurred shortly after the cue to initiate the movement but before the average reaction time. Blinks that preceded and overlapped with the cue increased saccade latency. Blinks evoked during the overlap period of the delayed saccade task, when target location is known but a saccade cannot be initiated for correct performance, failed to trigger saccades prematurely. Furthermore, when saccade and blink execution coincided temporally, the peak velocity of the eye movement was attenuated, and its initial velocity was correlated with its latency. Despite the perturbations, saccade accuracy was maintained across all blink times and task types. Collectively, these results support the notion that temporal features of the low-frequency activity encode aspects of a premotor command and imply that inhibition of OPNs alone is not sufficient to trigger saccades.

Changing the “When” and “What” of Intended Actions

2009 ◽  
Vol 102 (5) ◽  
pp. 2755-2762 ◽  
Author(s):  
Sukhvinder S. Obhi ◽  
Shannon Matkovich ◽  
Robert Chen
Keyword(s):  
Reaction Time ◽  
Simple Reaction Time ◽  
Index Finger ◽  
Sensory Information ◽  
Motor Preparation ◽  
Warning Stimulus ◽  
Inhibitory Mechanism ◽  
Preparatory Period ◽  
The Cost ◽  
Reaction Time Condition

Humans often have to modify the timing and/or type of their planned actions on the basis of new sensory information. In the present experiments, participants planned to make a right index finger keypress 3 s after a warning stimulus but on some trials were interrupted by a temporally unpredictable auditory tone prompting the same action ( experiment 1) or a different action ( experiment 2). In experiment 1, by comparing the reaction time (RT) to tones presented at different stages of the preparatory period to RT in a simple reaction time condition, we determined the cost of switching from an internally generated mode of response production to an externally triggered mode in situations requiring only a change in when an action is made (i.e., when the tone prompts the action at a different time from the intended time of action). Results showed that the cost occurred for interruption tones delivered 200 ms after a warning stimulus and remained relatively stable throughout most of the preparatory period with a reduction in the magnitude of the cost during the last 200 ms prior to the intended time of movement. In experiment 2, which included conditions requiring a change in both when and what action is produced on the tone, results show a larger cost when the switched to action is different from the action being prepared. We discuss our results in the light of neurophysiological experiments on motor preparation and suggest that intending to act is accompanied by a general inhibitory mechanism preventing premature motor output and a specific excitatory process pertaining to the intended movement. Interactions between these two mechanisms could account for our behavioral results.

scholarly journals Beta-band desynchronization reflects uncertainty in effector selection during motor planning

2021 ◽  
Author(s):  
Milou J.L. van Helvert ◽  
Leonie Oostwoud Wijdenes ◽  
Linda Geerligs ◽  
W. Pieter Medendorp
Keyword(s):  
Time Window ◽  
Brain Activity ◽  
Motor Planning ◽  
Reaction Times ◽  
Motor Preparation ◽  
Motion Artifact ◽  
Theta Band ◽  
Beta Band ◽  
Target Uncertainty ◽  
Band Power

AbstractWhile beta-band activity during motor planning is known to be modulated by uncertainty about where to act, less is known about its modulations to uncertainty about how to act. To investigate this issue, we recorded oscillatory brain activity with EEG while human participants (n = 17) performed a hand choice reaching task. The reaching hand was either predetermined or of participants’ choice, and the target was close to one of the two hands or at about equal distance from both. To measure neural activity in a motion-artifact-free time window, the location of the upcoming target was cued 1000-1500 ms before the presentation of the target, whereby the cue was valid in 50% of trials. As evidence for motor planning during the cueing phase, behavioral observations showed that the cue affected later hand choice. Furthermore, reaction times were longer in the choice than in the predetermined trials, supporting the notion of a competitive process for hand selection. Modulations of beta-band power over central cortical regions, but not alpha-band or theta-band power, were in line with these observations. During the cueing period, reaches in predetermined trials were preceded by larger decreases in beta-band power than reaches in choice trials. Cue direction did not affect reaction times or beta-band power, which may be due to the cue being invalid in 50% of trials, retaining effector uncertainty during motor planning. Our findings suggest that effector uncertainty, similar to target uncertainty, selectively modulates beta-band power during motor planning.New & NoteworthyWhile reach-related beta-band power in central cortical areas is known to modulate with the number of potential targets, here we show, using a cueing paradigm, that the power in this frequency band, but not in the alpha or theta-band, is also modulated by the uncertainty of which hand to use. This finding supports the notion that multiple possible effector-specific actions can be specified in parallel up to the level of motor preparation.

Spatial Causality in Bilateral Symmetry Detection

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 181-181
Author(s):  
J Hulleman ◽  
A H J Oomes
Keyword(s):  
Spatial Scale ◽  
Multiple Scales ◽  
Reaction Times ◽  
Bilateral Symmetry ◽  
Scale Space ◽  
Causality Principle ◽  
Circular Aperture ◽  
Fine Scale ◽  
Black And White ◽  
Random Patterns

We studied the influence of spatial scale on the detection of vertical and horizontal bilateral symmetry. The causality principle in scale - space theory states that increasing the spatial scale in a representation can only result in a decrease of structure. Consequently, a pattern can be random on the fine scale and symmetric on the coarse scale, never the reverse. Stimuli were bilaterally symmetric or random patterns, black-and-white on a grey background, with a circular aperture. The minimal scale was systematically varied and stimuli ranged from conventional noise patterns, through Dalmatian texture, to cow-like patterns. Observers had to judge whether a briefly presented pattern was ‘symmetric’ or ‘random’. Symmetric patterns resulted in a high accuracy (95%) with no influence of scale, and reaction times with a small linear decrease for increasing scale. Random patterns yielded an accuracy increasing from 70% at the smallest scale to 95% at the middle scales. Reaction times showed a similar pattern: largest at the smallest scales and decreasing to values equal to the symmetric condition at the middle scales. Results were similar for vertical and horizontal bilateral symmetry, though the effect for small scales in the random condition was more pronounced in the horizontal case. We conclude that bilateral symmetry is processed at multiple scales with coarse structures available slightly earlier than fine ones. The dramatic decrease of performance for fine-scale patterns is due to the causality effect; random patterns are judged as symmetric when the smallest scale information is not (yet) available.

scholarly journals The effect of offset cues on saccade programming and covert attention

2018 ◽  
Vol 72 (3) ◽  
pp. 481-490 ◽  
Author(s):  
Daniel T Smith ◽  
Soazig Casteau
Keyword(s):  
Reaction Times ◽  
Motor Preparation ◽  
Covert Attention ◽  
Oculomotor Control ◽  
Covert Orienting ◽  
Cueing Task ◽  
Tightly Coupled ◽  
Saccade Programming ◽  
Saccadic Reaction Times ◽  
Saccade Preparation

Salient peripheral events trigger fast, “exogenous” covert orienting. The influential premotor theory of attention argues that covert orienting of attention depends upon planned but unexecuted eye-movements. One problem with this theory is that salient peripheral events, such as offsets, appear to summon attention when used to measure covert attention (e.g., the Posner cueing task) but appear not to elicit oculomotor preparation in tasks that require overt orienting (e.g., the remote distractor paradigm). Here, we examined the effects of peripheral offsets on covert attention and saccade preparation. Experiment 1 suggested that transient offsets summoned attention in a manual detection task without triggering motor preparation planning in a saccadic localisation task, although there were a high proportion of saccadic capture errors on “no-target” trials, where a cue was presented but no target appeared. In Experiment 2, “no-target” trials were removed. Here, transient offsets produced both attentional facilitation and faster saccadic responses on valid cue trials. A third experiment showed that the permanent disappearance of an object also elicited attentional facilitation and faster saccadic reaction times. These experiments demonstrate that offsets trigger both saccade programming and covert attentional orienting, consistent with the idea that exogenous, covert orienting is tightly coupled with oculomotor activation. The finding that no-go trials attenuates oculomotor priming effects offers a way to reconcile the current findings with previous claims of a dissociation between covert attention and oculomotor control in paradigms that utilise a high proportion of catch trials.

scholarly journals Cognitive processes behind the shooter bias: Dissecting response bias, motor preparation and information accumulation

2021 ◽  
Author(s):  
Marius Frenken ◽  
Wanja Hemmerich ◽  
David Izydorczyk ◽  
Sophie Elisabeth Scharf ◽  
Roland Imhoff
Keyword(s):  
Response Bias ◽  
Cognitive Processes ◽  
A Priori ◽  
Reaction Times ◽  
Motor Preparation ◽  
Total N ◽  
The Public ◽  
Decision Bias ◽  
Model Study ◽  
Racial Biases

A rich body of research points to racial biases in so-called police officer dilemma tasks: participants are generally faster and less error-prone to “shoot” (vs. not “shoot”) Black (vs. White) targets. In three experimental (and two supplemental) studies (total N = 914), we aimed at examining the cognitive processes underlying these findings under fully standardized conditions. To be able to dissect a-priori decision bias, biased information processing and motor preparation, we rendered video sequences of virtual avatars that differed in nothing but the tone of their skin. Modeling the data via drift diffusion models revealed that the threat of a social group can be explicitly learned and mapped accordingly on an a-priori response bias within the model (Study 1). Studies 2 and 3 replicated the racial shooter bias as apparent in faster reaction times in stereotype-consistent trials. This, however, appears to result from stereotype-consistent motoric preparations and execution readiness, but not from pre-judicial threat biases. The results have implications especially for automatic stereotypes in the public.

scholarly journals Arousal modulates the motor interference effect stimulated by pictures of threatening animals

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10876
Author(s):  
Gai Cao ◽  
Peng Liu
Keyword(s):  
Effect Size ◽  
Interference Effect ◽  
Parietal Lobe ◽  
Reaction Times ◽  
Motor Preparation ◽  
Arousal Level ◽  
High Arousal ◽  
Negative Valence ◽  
Motor Priming ◽  
Positive And Negative Valence

Previous research related to the motor interference effect from dangerous objects indicated that delayed responses to dangerous objects were associated with more positive parietal P3 amplitudes, suggesting that great attentional resources were allocated to evaluate the level of danger (i.e., negative valence). However, arousal covaried with valence in this research. Together with previous studies in which the P3 amplitude was found to be increased along with a higher arousal level in the parietal lobe, we raised the issue that more positive parietal P3 amplitudes might also be affected by a high arousal level. To clarify whether valence or arousal impacted the motor interference effect, this study used a motor priming paradigm mixed with a Go/NoGo task and manipulated the valence (negative, neutral and positive) and arousal (medium and high) of target stimuli. Analysis of the behavioral results identified a significant motor interference effect (longer reaction times (RTs) in the negative valence condition than in the neutral valence condition) at the medium arousal level and an increased effect size (increment of RT difference) at the high arousal level. The results indicated that negative valence stimuli may interfere with the prime elicited motor preparation more strongly at the high arousal level than at the medium arousal level. The ERP results identified larger centroparietal P3 amplitudes for the negative valence condition than for the neutral valence condition at a high arousal level. However, the inverse result, i.e., lower centroparietal P3 amplitudes for the negative valence condition than for the neutral valence condition, was observed at a medium arousal level. The ERP results further indicated that the effect size of the behavioral motor interference effect increased because subjects are more sensitive to the negative valence stimuli at the high arousal level than at the medium arousal level. Furthermore, the motor interference effect is related to the negative valence rather than emotionality of the target stimuli because different result patterns emerged between the positive and negative valence conditions. Detailed processes underlying the interaction between valence and arousal effects are discussed.

scholarly journals Interference of Cellular Phone Conversations with Visuomotor Tasks: An ERP Study

2001 ◽  
Vol 15 (1) ◽  
pp. 14-21 ◽  
Author(s):  
Luis García-Larrea ◽  
Caroline Perchet ◽  
Fabien Perrin ◽  
Elena Amenedo
Keyword(s):  
Reaction Times ◽  
Cellular Phone ◽  
Motor Preparation ◽  
Readiness Potential ◽  
Brain Potentials ◽  
Attentional Allocation ◽  
Operating Modes ◽  
Visual Reaction ◽  
P3 Amplitude ◽  
Stimulus Identification

The use of mobile phones has been shown to increase drivers' reaction times (RTs), but whether this results from interference with attention, stimulus identification, or response production remains unclear. We recorded RTs and event-related brain potentials (ERPs) reflecting speed of stimulus processing, attentional allocation, and preparedness to respond during a visual reaction task performed with or without the concomitant use of a mobile phone, in either “hands-free” or “phone-in-hand” operating modes. As expected, maintaining a phone conversation increased RTs to visual targets, this effect being associated with complex ERP effects. Phone conversations did not appear to delay target detection times, as assessed by N2-P3 latencies, but did significantly decrease stimulus-induced alerting and attentional allocation (P3 amplitude) and interfered with motor preparation processes (readiness potential). P3 amplitude drop was identical whatever the mode of phone use, while decrease of readiness potential was progressive from the “hands-free” to the “phone-in-hand” condition. These results suggest that two mechanisms contributed to degrade performance in this experiment: first, a general decrease of attention to sensory inputs, characteristic of “dual-task” situations, probably acting through a delay in sensory-motor transfer times. This effect was independent of whether the phone was handled or “hands-free.” Conversely, the second factor was specifically sensitive to manipulation of the phone and caused a weakening of the readiness to respond with a motor act.

Visuospatial Attention and Motor Preparation in Individuals with Down Syndrome

2003 ◽  
Vol 20 (2) ◽  
pp. 134-149 ◽  
Author(s):  
Elodie Lalo ◽  
Bettina Debû
Keyword(s):  
Young Adults ◽  
Down Syndrome ◽  
Reaction Times ◽  
Motor Preparation ◽  
Visuospatial Attention ◽  
Detection Task ◽  
Target Localization ◽  
Advance Information ◽  
Advanced Knowledge ◽  
Visual Targets

The aim of this study was to assess the ability of young adults with and without Down syndrome (DS) with regard to attention orientation when detecting visual targets. The influence of advanced knowledge of target localization was examined when detection was (aiming task), or was not (detection task), followed by a movement toward the target. Participants were given advance information about the probability of target occurrence at expected locations. Results show that participants with DS benefit from attention orientation. However, they do not appear to use the same attentional strategies as participants without DS do when aiming is required. Analysis of the reaction times also revealed that participants with DS reacted faster in the aiming task rather than in the detection task.

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