Hand Position Affects Saccadic Reaction Times in Monkeys and Humans

2008 ◽  
Vol 99 (5) ◽  
pp. 2194-2202 ◽  
Author(s):  
David Thura ◽  
Driss Boussaoud ◽  
Martine Meunier
Keyword(s):  
Reaction Times ◽  
Oculomotor System ◽  
The Other ◽  
Hand Position ◽  
Visually Guided ◽  
Daily Life Activities ◽  
Delay Duration ◽  
Behavioral Evidence ◽  
Left Target ◽  
Delay Dependent

In daily life, activities requiring the hand and eye to work separately are as frequent as activities requiring tight eye–hand coordination, and we effortlessly switch from one type of activity to the other. Such flexibility is unlikely to be achieved without each effector “knowing” where the other one is at all times, even when it is static. Here, we provide behavioral evidence that the mere position of the static hand affects one eye movement parameter: saccadic reaction time. Two monkeys were trained and 11 humans instructed to perform nondelayed or delayed visually guided saccades to either a right or a left target while holding their hand at a location either near or far from the eye target. From trial to trial, target locations and hand positions varied pseudorandomly. Subjects were tested both when they could and when they could not see their hand. The main findings are 1) the presence of the static hand in the workspace did affect saccade initiation; 2) this interaction persisted when the hand was invisible; 3) it was strongly influenced by the delay duration: hand–target proximity retarded immediate saccades, whereas it could hasten delayed saccades; and 4) this held true both for humans and for each of the two monkeys. We propose that both visual and nonvisual hand position signals are used by the primates' oculomotor system for the planning and execution of saccades, and that this may result in a hand–eye competition for spatial attentional resources that explains the delay-dependent reversal observed.

scholarly journals Bilateral saccadic deficits following large and reversible inactivation of unilateral frontal eye field

2014 ◽  
Vol 111 (2) ◽  
pp. 415-433 ◽  
Author(s):  
Tyler R. Peel ◽  
Kevin Johnston ◽  
Stephen G. Lomber ◽  
Brian D. Corneil
Keyword(s):  
Visual Cues ◽  
Brain Area ◽  
Reaction Times ◽  
The Other ◽  
Frontal Eye Field ◽  
Visually Guided ◽  
Reversible Inactivation ◽  
Eye Field ◽  
And Performance ◽  
The Impact

Inactivation permits direct assessment of the functional contribution of a given brain area to behavior. Previous inactivation studies of the frontal eye field (FEF) have either used large permanent ablations or reversible pharmacological techniques that only inactivate a small volume of tissue. Here we evaluated the impact of large, yet reversible, FEF inactivation on visually guided, delayed, and memory-guided saccades, using cryoloops implanted in the arcuate sulcus. While FEF inactivation produced the expected triad of contralateral saccadic deficits (increased reaction time, decreased accuracy and peak velocity) and performance errors (neglect or misdirected saccades), we also found consistent increases in reaction times of ipsiversive saccades in all three tasks. In addition, FEF inactivation did not increase the proportion of premature saccades to ipsilateral targets, as was predicted on the basis of pharmacological studies. Consistent with previous studies, greater deficits accompanied saccades toward extinguished visual cues. Our results attest to the functional contribution of the FEF to saccades in both directions. We speculate that the comparative effects of different inactivation techniques relate to the volume of inactivated tissue within the FEF. Larger inactivation volumes may reveal the functional contribution of more sparsely distributed neurons within the FEF, such as those related to ipsiversive saccades. Furthermore, while focal FEF inactivation may disinhibit the mirroring site in the other FEF, larger inactivation volumes may induce broad disinhibition in the other FEF that paradoxically prolongs oculomotor processing via increased competitive interactions.

The Effect of Symbol Background Color on the Speed of Locating Targets by Adults Without Disabilities: Implications for Augmentative and Alternative Communication Display Design

2019 ◽  
Vol 4 (6) ◽  
pp. 1482-1488
Author(s):  
Jennifer J. Thistle
Keyword(s):  
Augmentative And Alternative Communication ◽  
Reaction Times ◽  
The Other ◽  
Background Color ◽  
Alternative Communication ◽  
Display Design ◽  
Line Drawings ◽  
Research With Children ◽  
Study Participants ◽  
Perceptual Factors

Purpose Previous research with children with and without disabilities has demonstrated that visual–perceptual factors can influence the speech of locating a target on an array. Adults without disabilities often facilitate the learning and use of a child's augmentative and alternative communication system. The current research examined how the presence of symbol background color influenced the speed with which adults without disabilities located target line drawings in 2 studies. Method Both studies used a between-subjects design. In the 1st study, 30 adults (ages 18–29 years) located targets in a 16-symbol array. In the 2nd study, 30 adults (ages 18–34 years) located targets in a 60-symbol array. There were 3 conditions in each study: symbol background color, symbol background white with a black border, and symbol background white with a color border. Results In the 1st study, reaction times across groups were not significantly different. In the 2nd study, participants in the symbol background color condition were significantly faster than participants in the other conditions, and participants in the symbol background white with black border were significantly slower than participants in the other conditions. Conclusion Communication partners may benefit from the presence of background color, especially when supporting children using displays with many symbols.

Items’ Cross-Category Associations as a Confounding Factor in the Implicit Association Test

2001 ◽  
Vol 48 (2) ◽  
pp. 123-134 ◽  
Author(s):  
Melanie C. Steffens ◽  
Inga Plewe
Keyword(s):  
Implicit Association Test ◽  
Confounding Factor ◽  
Reaction Times ◽  
Association Test ◽  
The Other ◽  
Reaction Time Difference ◽  
Implicit Association ◽  
Male And Female ◽  
Research Activities ◽  
Degree Of Association

Abstract. The introduction of the Implicit Association Test (IAT; Greenwald, McGhee, & Schwartz, 1998 ) has stimulated numerous research activities. The IAT is supposed to measure the degree of association between concepts. Instances have to be assigned to these concepts by pressing appropriate keys as quickly as possible. The reaction time difference between certain conditions, termed the IAT effect, is used as an indicator of the degree of the concepts’ association. We tested the hypothesis that the degree of association between one concept (or category) and the instances of the other presented concept also influences reaction times. In our experiment, the instances in the target categories, male and female names, were kept constant. The adjectives in the evaluative categories were manipulated: Either the pleasant adjectives were female-associated and the unpleasant adjectives were male-associated, or vice versa. These stereotypic associations were indeed found to exert a substantial influence on the size of the IAT effect. This finding casts doubt on the assumption that the IAT effect may be interpreted as a pure measure of the degree of association between concepts.

scholarly journals Isomorphism and language-specific devices in comprehension of Korean suffixal passive construction by Mandarin-speaking learners of Korean

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Gyu-Ho Shin ◽  
Sun Hee Park
Keyword(s):  
Native Speakers ◽  
Reaction Times ◽  
The Other ◽  
L2 Acquisition ◽  
Verbal Morphology ◽  
Passive Voice ◽  
Passive Construction ◽  
Case Marking

Abstract Across languages, a passive construction is known to manifest a misalignment between the typical order of event composition (agent-before-theme) and the actual order of arguments in the constructions (theme-before-agent), dubbed non-isomorphic mapping. This study investigates comprehension of a suffixal passive construction in Korean by Mandarin-speaking learners of Korean, focusing on isomorphism and language-specific devices in the passive. We measured learners’ judgment of the acceptability of canonical and scrambled suffixal passives as well as their reaction times (relative to a canonical active transitive). Our analysis generated three major findings. First, learners uniformly preferred the canonical passive to the scrambled passive. Second, as proficiency increased, the judgment gap between the canonical active transitive and the canonical suffixal passive narrowed, but the gap between the canonical active transitive and the scrambled suffixal passive did not. Third, learners (and even native speakers) spent more time in judging the acceptability of the canonical suffixal passive than they did in the other two construction types. Implications of these findings are discussed with respect to the mapping nature involving a passive voice, indicated by language-specific devices (i.e., case-marking and verbal morphology dedicated to Korean passives), in L2 acquisition.

scholarly journals Amide-Type Substrates in the Synthesis of N-Protected 1-Aminomethylphosphonium Salts

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 552
Author(s):  
Dominika Kozicka ◽  
Paulina Zieleźny ◽  
Karol Erfurt ◽  
Jakub Adamek
Keyword(s):  
Reaction Times ◽  
The Other ◽  
Hydroxyl Group ◽  
Other Hand ◽  
Step Procedure ◽  
Higher Temperature ◽  
Short Time ◽  
Work Up

Herein we describe the development and optimization of a two-step procedure for the synthesis of N-protected 1-aminomethylphosphonium salts from imides, amides, carbamates, or lactams. Our “step-by-step” methodology involves the transformation of amide-type substrates to the corresponding hydroxymethyl derivatives, followed by the substitution of the hydroxyl group with a phosphonium moiety. The first step of the described synthesis was conducted based on well-known protocols for hydroxymethylation with formaldehyde or paraformaldehyde. In turn, the second (substitution) stage required optimization studies. In general, reactions of amide, carbamate, and lactam derivatives occurred at a temperature of 70 °C in a relatively short time (1 h). On the other hand, N-hydroxymethylimides reacted with triarylphosphonium salts at a much higher temperature (135 °C) and over longer reaction times (as much as 30 h). However, the proposed strategy is very efficient, especially when NaBr is used as a catalyst. Moreover, a simple work-up procedure involving only crystallization afforded good to excellent yields (up to 99%).

scholarly journals Corroborating behavioral evidence for the interplay of representational richness and semantic control in semantic word processing

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Laura Bechtold ◽  
Christian Bellebaum ◽  
Paul Hoffman ◽  
Marta Ghio
Keyword(s):  
Word Processing ◽  
Context Effects ◽  
Reaction Times ◽  
Abstract Word ◽  
Judgment Task ◽  
Healthy Adults ◽  
Control Mechanisms ◽  
Contextual Cues ◽  
Semantic Judgment ◽  
Behavioral Evidence

AbstractThis study aimed to replicate and validate concreteness and context effects on semantic word processing. In Experiment 1, we replicated the behavioral findings of Hoffman et al. (Cortex 63,250–266, https://doi.org/10.1016/j.cortex.2014.09.001, 2015) by applying their cueing paradigm with their original stimuli translated into German. We found concreteness and contextual cues to facilitate word processing in a semantic judgment task with 55 healthy adults. The two factors interacted in their effect on reaction times: abstract word processing profited more strongly from a contextual cue, while the concrete words’ processing advantage was reduced but still present. For accuracy, the descriptive pattern of results suggested an interaction, which was, however, not significant. In Experiment 2, we reformulated the contextual cues to avoid repetition of the to-be-processed word. In 83 healthy adults, the same pattern of results emerged, further validating the findings. Our corroborating evidence supports theories integrating representational richness and semantic control mechanisms as complementary mechanisms in semantic word processing.

scholarly journals Giving Subjects the Eye and Showing Them the Finger: Socio-Biological Cues and Saccade Generation in the Anti-Saccade Task

Perception ◽  
10.1068/p7085 ◽  
2012 ◽  
Vol 41 (2) ◽  
pp. 131-147 ◽  
Author(s):  
Nicola J Gregory ◽  
Timothy L Hodgson
Keyword(s):  
Opposite Direction ◽  
Reaction Times ◽  
Oculomotor System ◽  
Short Soas ◽  
Stimulus Onset ◽  
Saccade Direction ◽  
Saccade Task ◽  
Saccadic Reaction Times ◽  
Saccadic Responses ◽  
Gaze Cues

Pointing with the eyes or the finger occurs frequently in social interaction to indicate direction of attention and one's intentions. Research with a voluntary saccade task (where saccade direction is instructed by the colour of a fixation point) suggested that gaze cues automatically activate the oculomotor system, but non-biological cues, like arrows, do not. However, other work has failed to support the claim that gaze cues are special. In the current research we introduced biological and non-biological cues into the anti-saccade task, using a range of stimulus onset asynchronies (SOAs). The anti-saccade task recruits both top–down and bottom–up attentional mechanisms, as occurs in naturalistic saccadic behaviour. In experiment 1 gaze, but not arrows, facilitated saccadic reaction times (SRTs) in the opposite direction to the cues over all SOAs, whereas in experiment 2 directional word cues had no effect on saccades. In experiment 3 finger pointing cues caused reduced SRTs in the opposite direction to the cues at short SOAs. These findings suggest that biological cues automatically recruit the oculomotor system whereas non-biological cues do not. Furthermore, the anti-saccade task set appears to facilitate saccadic responses in the opposite direction to the cues.

Effects of Local Nicotinic Activation of the Superior Colliculus on Saccades in Monkeys

2005 ◽  
Vol 93 (1) ◽  
pp. 519-534 ◽  
Author(s):  
Masayuki Watanabe ◽  
Yasushi Kobayashi ◽  
Yuka Inoue ◽  
Tadashi Isa
Keyword(s):  
Superior Colliculus ◽  
Reaction Times ◽  
Low Frequency ◽  
Visually Guided ◽  
Population Activity ◽  
Affected Area ◽  
Movement Field ◽  
Neural Interactions ◽  
Restricted Region

To examine the role of competitive and cooperative neural interactions within the intermediate layer of superior colliculus (SC), we elevated the basal SC neuronal activity by locally injecting a cholinergic agonist nicotine and analyzed its effects on saccade performance. After microinjection, spontaneous saccades were directed toward the movement field of neurons at the injection site (affected area). For visually guided saccades, reaction times were decreased when targets were presented close to the affected area. However, when visual targets were presented remote from the affected area, reaction times were not increased regardless of the rostrocaudal level of the injection sites. The endpoints of visually guided saccades were biased toward the affected area when targets were presented close to the affected area. After this endpoint effect diminished, the trajectories of visually guided saccades remained modestly curved toward the affected area. Compared with the effects on endpoints, the effects on reaction times were more localized to the targets close to the affected area. These results are consistent with a model that saccades are triggered by the activities of neurons within a restricted region, and the endpoints and trajectories of the saccades are determined by the widespread population activity in the SC. However, because increased reaction times were not observed for saccades toward targets remote from the affected area, inhibitory interactions in the SC may not be strong enough to shape the spatial distribution of the low-frequency preparatory activities in the SC.

scholarly journals Attention and the motion after effect: New measurements with visual search reveal important individual differences in adaptability

2018 ◽  
Author(s):  
Michael J. Morgan ◽  
Joshua A. Solomon
Keyword(s):  
Reaction Times ◽  
Visual Pathway ◽  
Human Vision ◽  
The Other ◽  
Test Array ◽  
Mouse Click ◽  
Search Speed ◽  
After Effect ◽  
The One ◽  
Do So

AbstractIt is usually assumed that sensory adaptation is a universal property of human vision. However, in two experiments designed to measure adaptation without bias, we have discovered a minority of participants who were unusual in the extent of their adaptation to motion. One experiment was designed so that targets would be invisible without adaptation; the other, so that adaptation would interfere with target detection. In the first, participants adapted to a spatial array of moving Gabor patches. On each trial the adapting array was followed by a test array in which but all of the test patches except one were identical to their spatially corresponding adaptors; the target moved in the opposite direction to its adaptor. Participants were required to identify the location of the changed target with a mouse click. The ability to do so increased with the number of adapting trials. Neither search speed nor accuracy was affected by an attentionally-demanding conjunction task at the fixation point during adaptation, suggesting low-level (pre-attentive) sites in the visual pathway for the adaptation. However, a minority of participants found the task virtually impossible. In the second experiment the same participants were required to identify the one element in the test array that was slowly moving: reaction times in this case were elevated following adaptation. The putatively weak adapters from the first experiment found this task easier than the strong adapters.

On the use of forward kinematic models in visually guided hand position control—analysis based on ISLES model

2002 ◽  
Vol 44-46 ◽  
pp. 965-972 ◽  
Author(s):  
Eimei Oyama ◽  
Taro Maeda ◽  
Susumu Tachi ◽  
Karl F. MacDorman ◽  
Arvin Agah
Keyword(s):  
Position Control ◽  
Hand Position ◽  
Control Analysis ◽  
Visually Guided ◽  
Kinematic Models ◽  
Forward Kinematic
Sign in / Sign up

Export Citation Format

Share Document