scholarly journals Differential Influence of Attention on Gaze and Head Movements

2009 ◽  
Vol 101 (1) ◽  
pp. 198-206 ◽  
Author(s):  
Aarlenne Z. Khan ◽  
Gunnar Blohm ◽  
Robert M. McPeek ◽  
Philippe Lefèvre
Keyword(s):  
Reaction Times ◽  
Stimulus Onset ◽  
Head Movements ◽  
Neck Muscle ◽  
Gaze Shifts ◽  
Opposite Pattern ◽  
Saccade Onset ◽  
Highly Correlated ◽  
Onset Asynchrony ◽  
Electromyographic Signals

A salient peripheral cue can capture attention, influencing subsequent responses to a target. Attentional cueing effects have been studied for head-restrained saccades; however, under natural conditions, the head contributes to gaze shifts. We asked whether attention influences head movements in combined eye–head gaze shifts and, if so, whether this influence is different for the eye and head components. Subjects made combined eye–head gaze shifts to horizontal visual targets. Prior to target onset, a behaviorally irrelevant cue was flashed at the same (congruent) or opposite (incongruent) location at various stimulus-onset asynchrony (SOA) times. We measured eye and head movements and neck muscle electromyographic signals. Reaction times for the eye and head were highly correlated; both showed significantly shorter latencies (attentional facilitation) for congruent compared with incongruent cues at the two shortest SOAs and the opposite pattern (inhibition of return) at the longer SOAs, consistent with attentional modulation of a common eye–head gaze drive. Interestingly, we also found that the head latency relative to saccade onset was significantly shorter for congruent than that for incongruent cues. This suggests an effect of attention on the head separate from that on the eyes.

Tussen Lezen En Luisteren

1992 ◽  
Vol 43 ◽  
pp. 27-38
Author(s):  
Ton Dijkstra
Keyword(s):  
Stimulus Onset Asynchrony ◽  
Divided Attention ◽  
Single Channel ◽  
Reaction Times ◽  
Race Model ◽  
Stimulus Onset ◽  
Sublexical Processing ◽  
Temporal Aspects ◽  
Onset Asynchrony ◽  
Processing Differences

Two divided attention experiments investigated whether graphemes and phonemes can mutually activate each other during bimodal sublexical processing. Dutch subjects reacted to target letters and/or speech sounds in single-channel and bimodal stimuli. In some bimodal conditions, the visual and auditory targets were congruent (e.g., visual A, auditory /a:/), in others they were not (e.g., visual U, auditory /a:/). Temporal aspects of cross-modal activation were examined by varying the stimulus onset asynchrony (SOA) of visual and auditory stimulus components. Processing differences among stimuli (e.g., the letters A and U) were accounted for by correcting the obtained bimodal reaction times by means of the predictions of an independent race-model. Comparing the results of the adapted congruent and incongruent conditions for each SOA, it can be concluded that (a) cross-modal activation takes place in this task situation; (b) it is bidirectional, i.e. it spreads from grapheme to phoneme and vice versa; and (c) it occurs very rapidly.

scholarly journals Effect of Reversible Inactivation of Superior Colliculus on Head Movements

2008 ◽  
Vol 99 (5) ◽  
pp. 2479-2495 ◽  
Author(s):  
Mark M. G. Walton ◽  
Bernard Bechara ◽  
Neeraj J. Gandhi
Keyword(s):  
Superior Colliculus ◽  
Reaction Times ◽  
Movement Control ◽  
Head Movements ◽  
Gaze Shifts ◽  
Gaze Shift ◽  
Reversible Inactivation ◽  
The Gaze ◽  
Made In

Because of limitations in the oculomotor range, many gaze shifts must be accomplished using coordinated movements of the eyes and head. Stimulation and recording data have implicated the primate superior colliculus (SC) in the control of these gaze shifts. The precise role of this structure in head movement control, however, is not known. The present study uses reversible inactivation to gain insight into the role of this structure in the control of head movements, including those that accompany gaze shifts and those that occur in the absence of a change in gaze. Forty-five lidocaine injections were made in two monkeys that had been trained on a series of behavioral tasks that dissociate movements of the eyes and head. Reversible inactivation resulted in clear impairments in the animals’ ability to perform gaze shifts, manifested by increased reaction times, lower peak velocities, and increased durations. In contrast, comparable effects were not found for head movements (with or without gaze shifts) with the exception of a very small increase in reaction times of head movements associated with gaze shifts. Eye-head coordination was clearly affected by the injections with gaze onset occurring relatively later with respect to head onset. Following the injections, the head contributed slightly more to the gaze shift. These results suggest that head movements (with and without gaze shifts) can be controlled by pathways that do not involve SC.

Unconscious and Conscious Processing of Negative Emotions Examined Through Affective Priming

2013 ◽  
Vol 112 (2) ◽  
pp. 607-625 ◽  
Author(s):  
Chisa Okubo ◽  
Toshiki Ogawa
Keyword(s):  
Stimulus Onset Asynchrony ◽  
Negative Emotions ◽  
Reaction Times ◽  
Stimulus Onset ◽  
Emotional States ◽  
Conscious Processing ◽  
Emotional Pictures ◽  
Emotional Conflicts ◽  
Conscious Processes ◽  
Onset Asynchrony

This study investigated unconscious and conscious processes by which negative emotions arise. Participants (26 men, 47 women; M age = 20.3 yr.) evaluated target words that were primed with subliminally or supraliminally presented emotional pictures. Stimulus onset asynchrony was either 200 or 800 msec. With subliminal presentations, reaction times to negative targets were longer than reaction times to positive targets after negative primes for the 200-msec. stimulus onset asynchrony. Reaction times to positive targets after negative or positive primes were shorter when the stimulus onset asynchrony was 800 msec. For supraliminal presentations, reaction times were longer when evaluating targets that followed emotionally opposite primes. When emotional stimuli were consciously distinguished, the evoked emotional states might lead to emotional conflicts, although the qualitatively different effects might be caused when subliminally presented emotion evoking stimulus was appraised unconsciously; that possibility was discussed.

scholarly journals Countermanding Eye-Head Gaze Shifts in Humans: Marching Orders Are Delivered to the Head First

2005 ◽  
Vol 94 (1) ◽  
pp. 883-895 ◽  
Author(s):  
Brian D. Corneil ◽  
James K. Elsley
Keyword(s):  
Head Movement ◽  
Reaction Times ◽  
Race Model ◽  
Saccadic Eye Movements ◽  
Oculomotor System ◽  
Stop Signal ◽  
Head Movements ◽  
Gaze Shifts ◽  
Gaze Shift ◽  
Countermanding Task

The countermanding task requires subjects to cancel a planned movement on appearance of a stop signal, providing insights into response generation and suppression. Here, we studied human eye-head gaze shifts in a countermanding task with targets located beyond the horizontal oculomotor range. Consistent with head-restrained saccadic countermanding studies, the proportion of gaze shifts on stop trials increased the longer the stop signal was delayed after target presentation, and gaze shift stop-signal reaction times (SSRTs: a derived statistic measuring how long it takes to cancel a movement) averaged ∼120 ms across seven subjects. We also observed a marked proportion of trials (13% of all stop trials) during which gaze remained stable but the head moved toward the target. Such head movements were more common at intermediate stop signal delays. We never observed the converse sequence wherein gaze moved while the head remained stable. SSRTs for head movements averaged ∼190 ms or ∼70–75 ms longer than gaze SSRTs. Although our findings are inconsistent with a single race to threshold as proposed for controlling saccadic eye movements, movement parameters on stop trials attested to interactions consistent with a race model architecture. To explain our data, we tested two extensions to the saccadic race model. The first assumed that gaze shifts and head movements are controlled by parallel but independent races. The second model assumed that gaze shifts and head movements are controlled by a single race, preceded by terminal ballistic intervals not under inhibitory control, and that the head-movement branch is activated at a lower threshold. Although simulations of both models produced acceptable fits to the empirical data, we favor the second alternative as it is more parsimonious with recent findings in the oculomotor system. Using the second model, estimates for gaze and head ballistic intervals were ∼25 and 90 ms, respectively, consistent with the known physiology of the final motor paths. Further, the threshold of the head movement branch was estimated to be 85% of that required to activate gaze shifts. From these results, we conclude that a commitment to a head movement is made in advance of gaze shifts and that the comparative SSRT differences result primarily from biomechanical differences inherent to eye and head motion.

Recruitment of a contralateral head turning synergy by stimulation of monkey supplementary eye fields

2012 ◽  
Vol 107 (6) ◽  
pp. 1694-1710 ◽  
Author(s):  
Brendan B. Chapman ◽  
Michael A. Pace ◽  
Sharon L. Cushing ◽  
Brian D. Corneil
Keyword(s):  
Muscle Activity ◽  
Head Movements ◽  
Oculomotor Control ◽  
Central Position ◽  
Neck Muscle ◽  
Gaze Shifts ◽  
Head Turning ◽  
Supplementary Eye Fields ◽  
Muscle Responses ◽  
Stimulation Of

The supplementary eye fields (SEF) are thought to enable higher-level aspects of oculomotor control. The goal of the present experiment was to learn more about the SEF's role in orienting, specifically by examining neck muscle recruitment evoked by stimulation of the SEF. Neck muscle activity was recorded from multiple muscles in two monkeys during SEF stimulation (100 μA, 150–300 ms, 300 Hz, with the head restrained or unrestrained) delivered 200 ms into a gap period, before a visually guided saccade initiated from a central position (doing so avoids confounds between initial position and prestimulation neck muscle activity). SEF stimulation occasionally evoked overt gaze shifts and/or head movements but almost always evoked a response that invariably consisted of a contralateral head turning synergy by increasing activity on contralateral turning muscles and decreasing activity on ipsilateral turning muscles (when background activity was present). Neck muscle responses began well in advance of evoked gaze shifts (∼30 ms after stimulation onset, leading gaze shifts by ∼40–70 ms on average), started earlier and attained a larger magnitude when accompanied by progressively larger gaze shifts, and persisted on trials without overt gaze shifts. The patterns of evoked neck muscle responses resembled those evoked by frontal eye field (FEF) stimulation, except that response latencies from the SEF were ∼10 ms longer. This basic description of the cephalomotor command evoked by SEF stimulation suggests that this structure, while further removed from the motor periphery than the FEF, accesses premotor orienting circuits in the brain stem and spinal cord in a similar manner.

scholarly journals Neck Muscle Responses to Stimulation of Monkey Superior Colliculus. I. Topography and Manipulation of Stimulation Parameters

2002 ◽  
Vol 88 (4) ◽  
pp. 1980-1999 ◽  
Author(s):  
Brian D. Corneil ◽  
Etienne Olivier ◽  
Douglas P. Munoz
Keyword(s):  
Superior Colliculus ◽  
Head Movements ◽  
Emg Activity ◽  
Eye Position ◽  
Neck Muscle ◽  
Evoked Responses ◽  
Inferior Rectus ◽  
Gaze Shifts ◽  
Stimulation Current ◽  
Stimulation Of

The role of the primate superior colliculus (SC) in orienting head movements was studied by recording electromyographic (EMG) activity from multiple neck muscles following electrical stimulation of the SC. Combining SC stimulation with neck EMG recordings provides an objective and sensitive measure of the SC drive onto neck muscle motoneurons, particularly in relation to evoked gaze shifts. In this paper, we address how neck EMG responses to SC stimulation in head-restrained monkeys depend on the rostrocaudal, mediolateral, and dorsoventral location of the stimulating electrode within the SC and vary with manipulations of the eye position prior to stimulation onset and changes in stimulation current and duration. Stimulation predominantly evoked EMG responses on the muscles obliquus capitis inferior, rectus capitis posterior major, and splenius capitis. These responses became larger in magnitude and shorter in onset latency for progressively more caudal stimulation locations, consistent with turning the head. However, evoked responses persisted even for more rostral stimulation locations usually not associated with head movements. Manipulating initial eye position revealed that the magnitude of evoked responses became stronger as the eyes attained positions contralateral to the side of stimulation, consistent with a summation between a generic command evoked by SC stimulation and the influence of eye position on tonic neck EMG. Manipulating stimulation current and duration revealed that the relationship between gaze shifts and evoked EMG responses is not obligatory: short-duration (<20 ms) or low-current stimulation evoked neck EMG responses in the absence of gaze shifts. However, long-duration stimulation (>150 ms) occasionally revealed a transient neck EMG response aligned on the onset of sequential gaze shifts. We conclude that the SC drive to neck muscle motoneurons is far more widespread than traditionally supposed and is relayed through intervening elements which may or may not be activated in association with gaze shifts.

scholarly journals Crowdsourced Measurement of Reaction Times to Audiovisual Stimuli With Various Degrees of Asynchrony

2018 ◽  
Vol 60 (8) ◽  
pp. 1192-1206 ◽  
Author(s):  
Pavlo Bazilinskyy ◽  
Joost de Winter
Keyword(s):  
Reaction Time ◽  
Visual Stimulus ◽  
Reaction Times ◽  
Stimulus Presentation ◽  
Past Research ◽  
Stimulus Onset ◽  
Task Instructions ◽  
Audiovisual Stimuli ◽  
The Right ◽  
Onset Asynchrony

Objective: This study was designed to replicate past research concerning reaction times to audiovisual stimuli with different stimulus onset asynchrony (SOA) using a large sample of crowdsourcing respondents. Background: Research has shown that reaction times are fastest when an auditory and a visual stimulus are presented simultaneously and that SOA causes an increase in reaction time, this increase being dependent on stimulus intensity. Research on audiovisual SOA has been conducted with small numbers of participants. Method: Participants ( N = 1,823) each performed 176 reaction time trials consisting of 29 SOA levels and three visual intensity levels, using CrowdFlower, with a compensation of US$0.20 per participant. Results were verified with a local Web-in-lab study ( N = 34). Results: The results replicated past research, with a V shape of mean reaction time as a function of SOA, the V shape being stronger for lower-intensity visual stimuli. The level of SOA affected mainly the right side of the reaction time distribution, whereas the fastest 5% was hardly affected. The variability of reaction times was higher for the crowdsourcing study than for the Web-in-lab study. Conclusion: Crowdsourcing is a promising medium for reaction time research that involves small temporal differences in stimulus presentation. The observed effects of SOA can be explained by an independent-channels mechanism and also by some participants not perceiving the auditory or visual stimulus, hardware variability, misinterpretation of the task instructions, or lapses in attention. Application: The obtained knowledge on the distribution of reaction times may benefit the design of warning systems.

Gaze Orienting in Dynamic Visual Double Steps

2005 ◽  
Vol 94 (6) ◽  
pp. 4300-4313 ◽  
Author(s):  
Joyce Vliegen ◽  
Tom J. Van Grootel ◽  
A. John Van Opstal
Keyword(s):  
Reference Frame ◽  
Visual Input ◽  
Head Movements ◽  
Dynamic Feedback ◽  
Dynamic Changes ◽  
Gaze Shifts ◽  
Gaze Shift ◽  
Visuomotor System ◽  
Saccade Onset ◽  
Predictive Remapping

Visual stimuli are initially represented in a retinotopic reference frame. To maintain spatial accuracy of gaze (i.e., eye in space) despite intervening eye and head movements, the visual input could be combined with dynamic feedback about ongoing gaze shifts. Alternatively, target coordinates could be updated in advance by using the preprogrammed gaze-motor command (“predictive remapping”). So far, previous experiments have not dissociated these possibilities. Here we study whether the visuomotor system accounts for saccadic eye–head movements that occur during target presentation. In this case, the system has to deal with fast dynamic changes of the retinal input and with highly variable changes in relative eye and head movements that cannot be preprogrammed by the gaze control system. We performed visual–visual double-step experiments in which a brief (50-ms) stimulus was presented during a saccadic eye–head gaze shift toward a previously flashed visual target. Our results show that gaze shifts remain accurate under these dynamic conditions, even for stimuli presented near saccade onset, and that eyes and head are driven in oculocentric and craniocentric coordinates, respectively. These results cannot be explained by a predictive remapping scheme. We propose that the visuomotor system adequately processes dynamic changes in visual input that result from self-initiated gaze shifts, to construct a stable representation of visual targets in an absolute, supraretinal (e.g., world) reference frame. Predictive remapping may subserve transsaccadic integration, thus enabling perception of a stable visual scene despite eye movements, whereas dynamic feedback ensures accurate actions (e.g., eye–head orienting) to a selected goal.

Neck Muscles in the Rhesus Monkey. II. Electromyographic Patterns of Activation Underlying Postures and Movements

2001 ◽  
Vol 86 (4) ◽  
pp. 1729-1749 ◽  
Author(s):  
Brian D. Corneil ◽  
Etienne Olivier ◽  
Frances J. R. Richmond ◽  
Gerald E. Loeb ◽  
Douglas P. Munoz
Keyword(s):  
Muscle Activation ◽  
Neck Muscles ◽  
Head Movements ◽  
Emg Activity ◽  
Neck Muscle ◽  
Spatial And Temporal Patterns ◽  
Gaze Shifts ◽  
Antagonist Muscles ◽  
Agonist And Antagonist ◽  
Head Positions

Electromyographic (EMG) activity was recorded in ≤12 neck muscles in four alert monkeys whose heads were unrestrained to describe the spatial and temporal patterns of neck muscle activation accompanying a large range of head postures and movements. Some head postures and movements were elicited by training animals to generate gaze shifts to visual targets. Other spontaneous head movements were made during orienting, tracking, feeding, expressive, and head-shaking behaviors. These latter movements exhibited a wider range of kinematic patterns. Stable postures and small head movements of only a few degrees were associated with activation of a small number of muscles in a reproducible synergy. Additional muscles were recruited for more eccentric postures and larger movements. For head movements during trained gaze shifts, movement amplitude, velocity, and acceleration were correlated linearly and agonist muscles were recruited without antagonist muscles. Complex sequences of reciprocal bursts in agonist and antagonist muscles were observed during very brisk movements. Turning movements of similar amplitudes that began from different initial head positions were associated with systematic variations in the activities of different muscles and in the relative timings of these activities. Unique recruitment synergies were observed during feeding and head-shaking behaviors. Our results emphasize that the recruitment of a given muscle was generally ordered and consistent but that strategies for coordination among various neck muscles were often complex and appeared to depend on the specifics of musculoskeletal architecture, posture, and movement kinematics that differ substantially among species.

Phonological and semantic activation in reading two-kanji compound words

2000 ◽  
Vol 21 (4) ◽  
pp. 487-503 ◽  
Author(s):  
AIKO MORITA ◽  
FUMIKO MATSUDA
Keyword(s):  
Stimulus Onset Asynchrony ◽  
Reaction Times ◽  
Stimulus Onset ◽  
Error Rates ◽  
Semantic Activation ◽  
Phonological Information ◽  
Semantic Interference ◽  
Compound Words ◽  
Phonological Interference ◽  
Onset Asynchrony

The purpose of this study was to examine whether phonological information was activated automatically in processing two-kanji compound words. In Experiment 1, 27 participants judged whether pairs of the words were homophones, while another 27 participants judged whether pairs were synonyms. Stimulus onset asynchrony (SOA) was 140 ms, 230 ms, or 320 ms. In Experiment 2, 36 participants were asked to make one of the two judgments, as in Experiment 1. SOA was determined individually. The following results were found. Reaction times showed semantic interference. Phonological interference was observed only under the shortest SOA in Experiment 2. Error rates showed phonological and semantic interferences even when SOA was the longest. These findings support the universal phonological principle.

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