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.

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.

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.

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.

Saving the Perruchet effect: A role for the strength of the association in associative learning

2018 ◽  
Vol 72 (6) ◽  
pp. 1379-1386
Author(s):  
Arnaud Destrebecqz ◽  
Michaël Vande Velde ◽  
Estibaliz San Anton ◽  
Axel Cleeremans ◽  
Julie Bertels
Keyword(s):  
Reaction Time ◽  
Associative Strength ◽  
Process Model ◽  
Reaction Times ◽  
Reaction Time Task ◽  
Dual Process ◽  
Time Pattern ◽  
Motor Priming ◽  
Initial Block ◽  
The Impact

In a partial reinforcement schedule where a cue repeatedly predicts the occurrence of a target in consecutive trials, reaction times to the target tend to decrease in a monotonic fashion, while participants’ expectancies for the target decrease at the same time. This dissociation between reaction times and expectancies—the so-called Perruchet effect—challenges the propositional view of learning, which posits that human conditioned responses result from conscious inferences about the relationships between events. However, whether the reaction time pattern reflects the strength of a putative cue-target link, or only non-associative processes, such as motor priming, remains unclear. To address this issue, we implemented the Perruchet procedure in a two-choice reaction time task and compared reaction time patterns in an Experimental condition, in which a tone systematically preceded a visual target, and in a Control condition, in which the onset of the two stimuli were uncoupled. Participants’ expectancies regarding the target were recorded separately in an initial block. Reaction times decreased with the succession of identical trials in both conditions, reflecting the impact of motor priming. Importantly, reaction time slopes were steeper in the Experimental than in the Control condition, indicating an additional influence of the associative strength between the two stimuli. Interestingly, slopes were less steep for participants who showed the gambler’s fallacy in the initial block. In sum, our results suggest the mutual influences of motor priming, associative strength, and expectancies on performance. They are in line with a dual-process model of learning involving both a propositional reasoning process and an automatic link-formation mechanism.

Mental health assessment in undergraduate students using DASS21 and Visual Working Memory Task

2021 ◽  
Author(s):  
Gautam Kumar Baboo ◽  
Veeky Baths
Keyword(s):  
Working Memory ◽  
Reaction Time ◽  
Undergraduate Students ◽  
Reading Ability ◽  
Time Window ◽  
Memory Task ◽  
Reaction Times ◽  
Emotional States ◽  
Post Intervention ◽  
The Impact

Substantial adolescence is spent in an academic environment where the student can experience varying intensities of depression, stress, and anxiety, which can be fatal. To address this concern, we utilized the Depression Anxiety and Stress Survey (DASS) 21 and Modified Sternberg working memory, thereby assessing the emotional states and assessing the impact on the cognitive ability of students (n=37, F=7) in terms of working memory. An intervention was provided (Art of Living YES+ program) for ten days. The assessment is carried out in the time window of two months before and after the intervention. F-test and T-test(p≤0.05) on the scores and reaction time are performed for hypothesis testing. This statistical analysis reveals that both the depression category and stress category reject the null hypothesis. Among the thirty-seven, only five students took part in the post-intervention assessment, the scores in 28% of the questions had lower scores, and 19 % did not have any change; however, there was an increase in the scores in 42% of the questions. No significant changes are observed in the working memory ability of the students. Based on reaction time analysis: 11.62%, 16.27%, and 25.58% are outliers for each type of question, respectively. Two participants showed significantly lower reaction times, indicating a faster reading ability than the rest. This study shows that the intervention can positively impact emotional states-depression, stress, and affect working memory abilities.

scholarly journals The Impact of LED Color Rendering on the Dark Adaptation of Human Eyes at Tunnel Entrances

2020 ◽  
Vol 17 (5) ◽  
pp. 1566 ◽  
Author(s):  
En-Zhong Zhao ◽  
Li-Li Dong ◽  
Yang Chen ◽  
Qi Lou ◽  
Wen-Hai Xu
Keyword(s):  
Reaction Time ◽  
Traffic Safety ◽  
Dark Adaptation ◽  
Reaction Times ◽  
Warning Signs ◽  
Color Temperature ◽  
Target Color ◽  
Color Rendering ◽  
The Impact ◽  
Tunnel Entrance

The dark adaptation of drivers’ eyes at a tunnel entrance seriously affects traffic safety. This can be improved by the design of tunnel lighting. Light-Emitting Diode (LEDs) have been applied as a new type of luminaire in tunnel lighting in recent years, but at present, there are few studies on the influence of color rendering of LEDs on tunnel traffic safety, and there is no explicit indicator for the selection of appropriate color rendering parameters in tunnel lighting specifications, which has aroused researchers’ concern. In this article, several new color rendering evaluation indexes were compared, and as a result, it is considered that CRI2012 (a color difference-based color rendering index) is more suitable for evaluating the color rendering of LEDs used at tunnel entrances. The dark adaptation phenomenon was simulated in the laboratory. Four CRI2012s, three color temperatures and eight colored targets were used in the experiments. The results showed that yellow, silver and white can provide shorter reaction times, while red and brown lead to longer reaction times, which can provide a reference for the design of road and warning signs at tunnel entrances. The effect of target color on reaction time was greater than that of color rendering. Under most target colors, the higher the CRI2012, the shorter the reaction time. When designing the color rendering of the LEDs at a tunnel entrance, the value should thus be as large as possible (close to 100), and a lower color temperature value (about 2800 K) should be selected. This paper provides technical support for tunnel lighting design and a reference for tunnel lighting specifications, which is of significance to improve driving safety and avoid traffic accidents in highway tunnels.

Saccades to somatosensory targets. I. behavioral characteristics

1996 ◽  
Vol 75 (1) ◽  
pp. 412-427 ◽  
Author(s):  
J. M. Groh ◽  
D. L. Sparks
Keyword(s):  
Reaction Time ◽  
Target Location ◽  
Human Subjects ◽  
Reaction Times ◽  
Saccade Target ◽  
Velocity Amplitude ◽  
Visual Frame ◽  
Saccade Velocity ◽  
Saccade Task ◽  
Visual Targets

1. We compared the properties of saccades to somatosensory and visual targets. This comparison provides insight into the translation of sensory signals coding target location in different sensory coordinate frameworks into motor commands of a common format. Vibrotactile stimuli were delivered to the hands, which were fixed in position and concealed beneath a barrier. Saccades of different directions and amplitudes were elicited by the same somatosensory target from different initial eye positions. Both monkeys and humans served as subjects. 2. Somatosensory saccades were less accurate than visual saccades in both humans and monkeys. When the barrier concealing the hands was removed, somatosensory saccade accuracy improved. While the hands were concealed, the visual frame of reference provided by room illumination did not greatly affect saccade accuracy: accuracy was not degraded in complete darkness for two of three monkeys. 3. The endpoints of saccades to a single somatosensory target varied with initial eye position for the monkeys, but not for the human subjects. 4. We also found evidence of an effect of limb position on somatosensory saccades: when human subjects performed the task with crossed hands, the incidence of curved saccades increased. Saccades often began in the direction of the unstimulated hand and curved markedly toward the stimulated hand. When one subject was required to delay the saccade by 600-1,000 ms after target onset (the delayed saccade task), the saccades were straight. Somatosensory saccades were also straight when the hands were not crossed. 5. The reaction times of somatosensory saccades were longer than the reaction times of visual saccades, and they decreased as a function of saccade amplitude. The delayed saccade task reduced the differences between somatosensory and visual saccade reaction times. The reaction times of saccades to very dim visual targets increased into the range found for saccades to somatosensory targets. When the saccade target was the combination of the somatosensory and visual stimuli at the same location, the reaction time was slightly lower than for visual targets alone. 6. The peak velocities of somatosensory saccades were lower than those of visual saccades of the same amplitude. The velocities of saccades to combined somatosensory and visual targets were indistinguishable from those of saccades to visual targets alone. The differences between somatosensory and visual saccade velocity were maintained in the delayed trial type. These differences suggest that the main sequence or velocity-amplitude relationship characteristic of saccades depends on the modality of the target. 7. The implications of these modality-dependent differences in accuracy, reaction time, and saccade velocity are discussed with regard to models of the saccade generator and the coordinate transformation necessary for somatosensory saccades.

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.

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