Sensitivity of express saccades to the expected value of the target

2020 ◽  
Author(s):  
Mohammad Shams-Ahmar ◽  
Peter Thier
Keyword(s):  
Reaction Time ◽  
Time Distribution ◽  
Reaction Times ◽  
Reaction Time Distribution ◽  
Saccade Target ◽  
Visually Guided ◽  
Express Saccades ◽  
Reward Expectancy ◽  
Saccadic Reaction Times ◽  
The Impact

Express saccades, a distinct fast mode of visually guided saccades, are probably underpinned by a specific pathway that is at least partially different from the one underlying regular saccades. Whether and how this pathway deals with information on the subjective value of a saccade target is unknown. We studied the influence of varying reward expectancies and compared it with the impact of a temporal gap between the disappearance of the fixation dot and the appearance of the target on the visually guided saccades of two rhesus macaques (Macaca mulatta). We found that increasing reward expectancy increased the probability and decreased the reaction time of express saccades. The latter influence was stronger in the later parts of the reaction time distribution of express saccades, satisfactorily captured by a linear shift model of change in the saccadic reaction time distribution. Although different in strength, increasing reward expectancy and inserting a temporal gap resulted in similar effects on saccadic reaction times, suggesting that these two factors summon the same mechanism to facilitate saccadic reaction times.

scholarly journals Differential effect of value and salience on saccadic reaction times

2020 ◽  
Author(s):  
Mohammad Shams-Ahmar ◽  
Peter Thier
Keyword(s):  
Reaction Time ◽  
Rhesus Macaques ◽  
Reaction Times ◽  
Saccade Target ◽  
Visually Guided ◽  
Express Saccades ◽  
Visual Objects ◽  
Subjective Value ◽  
Reward Expectancy ◽  
The Impact

ABSTRACTExpress saccades, a mode of visually guided saccades, distinguished from regular saccades by extremely short reaction times, are triggered by inserting a temporal gap between the fixation dot and the saccade target. It is usually assumed that they are produced by a specific pathway in which the superior colliculus plays a key role. Whether and how this pathway deals with information on the subjective value of a saccade target is unknown. We, therefore, studied the influence of varying reward expectancies and compared it with the impact of the presence and absence of a temporal gap between the disappearance of the fixation dot and the appearance of the target on the visually guided saccades of two rhesus macaques (Macaca mulatta). We observed that the introduction of a gap shifted the entire saccadic reaction time distribution to shorter latencies while increasing the probability of express saccades. On the other hand, promoting the monkey’s reward expectancy shortened reaction times and increased peak velocities of regular saccades, and increased the probability of express saccades. Importantly, we observed that the reaction time and peak velocity of express saccades were not sensitive to the value of the saccade target, suggesting that the express pathway does not have access to information on value. We propose a new model on express saccades that treats the salience of visual objects in the scene differently from the subjective value assigned to them.

scholarly journals Gap effect and reaction time distribution: simple vs choice manual responses

1998 ◽  
Vol 31 (10) ◽  
pp. 1313-1318 ◽  
Author(s):  
W. Machado-Pinheiro ◽  
L.G. Gawryszewski ◽  
L.E. Ribeiro-do-Valle
Keyword(s):  
Reaction Time ◽  
Time Distribution ◽  
Reaction Time Distribution ◽  
Gap Effect ◽  
Manual Responses

Accurate reaction time methods demonstrate similar results from different sensory modalities

2021 ◽  
pp. 1-6
Author(s):  
Drew McRacken ◽  
Maddie Dyson ◽  
Kevin Hu
Keyword(s):  
Reaction Time ◽  
Sensory Modality ◽  
Reaction Times ◽  
Time Variability ◽  
Reaction Time Methods ◽  
Test Reaction ◽  
Reaction Time Variability ◽  
Sensory Modalities ◽  
Visual Reaction ◽  
The Impact

Over the past few decades, there has been a significant number of reports that suggested that reaction times for different sensory modalities were different – e.g., that visual reaction time was slower than tactile reaction time. A recent report by Holden and colleagues stated that (1) there has been a significant historic upward drift in reaction times reported in the literature, (2) that this drift or degradation in reaction times could be accounted for by inaccuracies in the methods used and (3) that these inaccurate methods led to inaccurate reporting of differences between visual and tactile based reaction time testing.  The Holden study utilized robotics (i.e., no human factors) to test visual and tactile reaction time methods but did not assess how individuals would perform on different sensory modalities.  This study utilized three different sensory modalities: visual, auditory, and tactile, to test reaction time. By changing the way in which the subjects were prompted and measuring subsequent reaction time, the impact of sensory modality could be analyzed. Reaction time testing for two sensory modalities, auditory and visual, were administered through an Arduino Uno microcontroller device, while tactile-based reaction time testing was administered with the Brain Gauge. A range of stimulus intensities was delivered for the reaction times delivered by each sensory modality. The average reaction time and reaction time variability was assessed and a trend could be identified for the reaction time measurements of each of the sensory modalities. Switching the sensory modality did not result in a difference in reaction time and it was concluded that this was due to the implementation of accurate circuitry used to deliver each test. Increasing stimulus intensity for each sensory modality resulted in faster reaction times. The results of this study confirm the findings of Holden and colleagues and contradict the results reported in countless studies that conclude that (1) reaction times are historically slower now than they were 50 years ago and (2) that there are differences in reaction times for different sensory modalities (vision, hearing, tactile). The implications of this are that utilization of accurate reaction time methods could have a significant impact on clinical outcomes and that many methods in current clinical use are basically perpetuating poor methods and wasting time and money of countless subjects or patients.

scholarly journals Reaction Time Distribution Analysis of Neuropsychological Performance in an ADHD Sample

2006 ◽  
Vol 12 (2) ◽  
pp. 125-140 ◽  
Author(s):  
Aaron S. Hervey ◽  
Jeffery N. Epstein ◽  
John F. Curry ◽  
Simon Tonev ◽  
L. Eugene Arnold ◽  
...  
Keyword(s):  
Reaction Time ◽  
Time Distribution ◽  
Reaction Time Distribution ◽  
Neuropsychological Performance ◽  
Distribution Analysis

VEP latency and some properties of simple motor reaction-time distribution

1990 ◽  
Vol 52 (1) ◽  
pp. 28-34 ◽  
Author(s):  
Piotr Jaśkowski ◽  
Antoni Pruszewicz ◽  
Piotr Świdzinski
Keyword(s):  
Reaction Time ◽  
Time Distribution ◽  
Reaction Time Distribution ◽  
Motor Reaction ◽  
Motor Reaction Time ◽  
Simple Motor ◽  
Vep Latency

Occurrence of express saccades under isoluminance and low contrast luminance conditions

1991 ◽  
Vol 7 (5) ◽  
pp. 505-510 ◽  
Author(s):  
Heike Weber ◽  
Burkhart Fischer ◽  
Michael Bach ◽  
Franz Aiple
Keyword(s):  
Human Subjects ◽  
Reaction Times ◽  
Luminance Contrast ◽  
Saccade Target ◽  
White Background ◽  
Color Contrast ◽  
Express Saccades ◽  
Low Contrast ◽  
Green Background ◽  
White Target

AbstractSaccadic reaction times (SRTs) of three human subjects were analyzed. The gap paradigm was used (i.e. fixation point offset precedes target onset) to obtain high proportions of express saccades (i.e. saccades of extremely short reaction times) in the SRT distributions. In one set of experiments, the luminance of the (red) saccade target was varied from brighter to darker than the (green) background including an isoluminance condition. Express saccades were obtained in response to pure color contrast stimuli with about the same frequency and reaction time as to stimuli with both color and luminance contrast. In a second experiment, the luminance contrast of a white target on a white background was lowered below 10%. Again the number of express saccades was not reduced. Thus, in contrast to other perceptual phenomena the visual neural mechanisms underlying the generation of express saccades are not affected by isoluminance nor low contrast luminance.

scholarly journals Back-translating a rodent measure of negative bias into humans: the impact of induced anxiety and unmedicated mood and anxiety disorders

2017 ◽  
Author(s):  
Jessica Aylward ◽  
Claire Hales ◽  
Emma Robinson ◽  
Oliver J Robinson
Keyword(s):  
Reaction Time ◽  
Anxiety Disorders ◽  
Computational Model ◽  
Treatment Options ◽  
Reaction Times ◽  
Current Treatment ◽  
Anxiety Symptoms ◽  
Mood And Anxiety Disorders ◽  
Affective Bias ◽  
The Impact

AbstractBackgroundMood and anxiety disorders are ubiquitous but current treatment options are ineffective for large numbers of sufferers. Moreover, recent years have seen a number of promising pre-clinical interventions fail to translate into clinical efficacy in humans. Improved treatments are unlikely without better animal-human translational pipelines. Here, we directly adapt–i.e. back-translate - a rodent measure of negative affective bias into humans, and explore its relationship with a)pathological mood and anxiety symptoms (study one) and b)transient induced anxiety (study two).MethodParticipants who met criteria for mood or anxiety disorder symptomatology according to a face-to-face neuropsychiatric interview were included in the symptomatic group. N = 77(47 asymptomatic; Female = 21; 30 symptomatic; Female = 25) participants completed study one and N = 47 asymptomatic participants (25 female) completed study two. Outcome measures were choice ratios, reaction times and parameters recovered from a computational model of reaction time; the drift diffusion model (DDM).ResultsSymptomatic individuals demonstrated increased negative affective bias relative to asymptomatic individuals (proportion high reward = 0.42(SD = 0.14), and 0.53(SD = 0.17), respectively) as well as reduced DDM drift rate (p = 0.004). No significant effects were observed for the within-subjects anxiety-induction in study 2.ConclusionHumans with pathological anxiety symptoms directly mimic rodents undergoing anxiogenic manipulation. The lack of sensitivity to transient anxiety suggests the paradigm may, moreover, be primarily sensitive to clinically relevant symptoms. Our results establish a direct translational pipeline (and candidate therapeutics screen) from negative affective bias in rodents to pathological mood and anxiety symptoms in humans, and link it to a computational model of reaction time.

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