Activation of Monkey Locus Coeruleus Neurons Varies With Difficulty and Performance in a Target Detection Task

2004 ◽  
Vol 92 (1) ◽  
pp. 361-371 ◽  
Author(s):  
Janusz Rajkowski ◽  
Henryk Majczynski ◽  
Edwin Clayton ◽  
Gary Aston-Jones
Keyword(s):  
Locus Coeruleus ◽  
Target Detection ◽  
Response Times ◽  
Behavioral Responses ◽  
Early Response ◽  
Detection Task ◽  
Correct Rejection ◽  
Small Magnitude ◽  
Sensory Stimuli ◽  
Target Detection Task

We previously reported that noradrenergic neurons in the monkey locus coeruleus (LC) are activated selectively by target stimuli in a target detection task. Here, we varied the discrimination difficulty in this task and recorded impulse activity of LC neurons to analyze LC responses on error trials and in relation to behavioral response times (RTs). In easy and difficult discrimination conditions, LC neurons responded preferentially to target stimuli with phasic activation. These responses consistently preceded behavioral responses regardless of task difficulty. Latencies for LC and behavioral responses increased similarly for difficult compared with easy discrimination trials. LC response latencies were also shorter for fast RT trials compared with slow RT trials regardless of difficulty, indicating a close temporal relationship between LC and behavioral responses. This relationship was confirmed with response-locked histograms of LC activity, which yielded more temporally synchronized LC responses than stimulus-locked histograms. Population histograms of LC activity revealed that nontarget stimuli resulting in false alarm responses produced phasic LC activation (although smaller than for target-hit trials), and nontarget stimuli resulting in correct rejection responses yielded a small inhibition in LC activity. Population analyses also revealed that LC responses included an early, small excitatory component that was not previously detected. This early response was nondiscriminative because it was similar for target and nontarget stimulus trials. These results indicate that LC neurons exhibit early small magnitude responses that are closely linked to sensory stimuli. In addition, these cells show a later, larger magnitude response that is temporally linked to behavioral responses. These and other results lead us to hypothesize that LC responses are driven by decision processes and help facilitate subsequent behavioral responses.

Effects of Cognitive Foveal Load on a Peripheral Single-Target Detection Task

1993 ◽  
Vol 77 (2) ◽  
pp. 515-533 ◽  
Author(s):  
H. S. Chan ◽  
Alan J. Courtney
Keyword(s):  
Cognitive Load ◽  
Task Performance ◽  
Target Detection ◽  
Significant Interaction ◽  
Response Times ◽  
Detection Task ◽  
Large Dispersion ◽  
Single Target ◽  
Four Levels ◽  
Target Detection Task

This experiment investigated the effects of foveal cognitive load on a primary peripheral single-target detection task. Four levels of foveal task with cognitive loads involving identification and summation of numerals were used. Number of correct targets detected seemed unaffected by the foveal load in the near periphery but a decrement occurred beyond 7.7°. Response times for correct responses showed large dispersion compared with that for correct locations. At a low cognitive load, foveal task performance showed no deterioration for all eccentricities tested, but at a higher cognitive load performance declined gradually across eccentricities. Mild evidence of runnel vision was obtained as indicated by the significant interaction of cognitive loads × eccentricities. Resources theory accounted well for the results.

scholarly journals Locus coeruleus neurons encode the subjective difficulty of triggering and executing actions

PLoS Biology ◽  
2021 ◽  
Vol 19 (12) ◽  
pp. e3001487
Author(s):  
Pauline Bornert ◽  
Sebastien Bouret
Keyword(s):  
Locus Coeruleus ◽  
Target Detection ◽  
Force Production ◽  
Indirect Evidence ◽  
Detection Task ◽  
Cognitive Effort ◽  
Transient Activation ◽  
Physical Challenges ◽  
Task Parameters ◽  
Target Detection Task

The brain stem noradrenergic nucleus locus coeruleus (LC) is involved in various costly processes: arousal, stress, and attention. Recent work has pointed toward an implication in physical effort, and indirect evidence suggests that the LC could be also involved in cognitive effort. To assess the dynamic relation between LC activity, effort production, and difficulty, we recorded the activity of 193 LC single units in 5 monkeys performing 2 discounting tasks (a delay discounting task and a force discounting task), as well as a simpler target detection task where conditions were matched for difficulty and only differed in terms of sensory-motor processes. First, LC neurons displayed a transient activation both when monkeys initiated an action and when exerting force. Second, the magnitude of the activation scaled with the associated difficulty, and, potentially, the corresponding amount of effort produced, both for decision and force production. Indeed, at action initiation in both discounting tasks, LC activation increased in conditions associated with lower average engagement rate, i.e., those requiring more cognitive control to trigger the response. Decision-related activation also scaled with response time (RT), over and above task parameters, in line with the idea that it reflects the amount of resources (here time) spent on the decision process. During force production, LC activation only scaled with the amount of force produced in the force discounting task, but not in the control target detection task, where subjective difficulty was equivalent across conditions. Our data show that LC neurons dynamically track the amount of effort produced to face both cognitive and physical challenges with a subsecond precision. This works provides key insight into effort processing and the contribution of the noradrenergic system, which is affected in several pathologies where effort is impaired, including Parkinson disease and depression.

A Comparison of Auditory and Visual Representations of System Confidence to Support Trust Specificity, Attention Management, and Joint Performance in Human-Machine Teams

2021 ◽  
Vol 65 (1) ◽  
pp. 67-71
Author(s):  
Kevin Lieberman ◽  
Nadine Sarter
Keyword(s):  
Target Detection ◽  
Resource Competition ◽  
Visual Target ◽  
Response Times ◽  
Visual Representations ◽  
Detection Task ◽  
Detection Accuracy ◽  
Joint Performance ◽  
Attention Demands ◽  
Target Detection Task

Breakdowns in human-robot teaming can result from trust miscalibration, i.e., a poor mapping of trust to a system’s capabilities, resulting in misuse or disuse of the technology. Trust miscalibration also negatively affects operators’ top-down attention allocation and monitoring of the system. This experiment assessed the efficacy of visual and auditory representations of a system’s confidence in its own abilities for supporting trust specificity, attention management and joint performance in the context of a UAV-supported target detection task. In contrast to earlier studies, neither visual nor auditory confidence information improved detection accuracy. Visual representations of confidence led to slower response times than auditory representations, likely due to resource competition with the visual target detection task. Finally, slower response times were observed when a UAV incorrectly detected a target. Results from this study can inform the design of visual and auditory representations of system confidence in human-machine teams with high attention demands.

Visual Perception of Apparent Motion Abides by Minimization Principles of Geometry

2021 ◽  
Author(s):  
Yaxin Liu ◽  
Stella F. Lourenco
Keyword(s):  
Visual Perception ◽  
Target Detection ◽  
Apparent Motion ◽  
Visual Space ◽  
Detection Task ◽  
Newtonian Physics ◽  
Kinematic Geometry ◽  
Shed Light ◽  
Target Detection Task ◽  
Perceptual Phenomenon

Apparent motion is a robust perceptual phenomenon in which observers perceive a stimulus traversing the vacant visual space between two flashed stimuli. Although it is known that the “filling-in” of apparent motion favors the simplest and most economical path, the interpolative computations remain poorly understood. Here, we tested whether the perception of apparent motion is best characterized by Newtonian physics or kinematic geometry. Participants completed a target detection task while Pacmen- shaped objects were presented in succession to create the perception of apparent motion. We found that target detection was impaired when apparent motion, as predicted by kinematic geometry, not Newtonian physics, obstructed the target’s location. Our findings shed light on the computations employed by the visual system, suggesting specifically that the “filling-in” perception of apparent motion may be dominated by kinematic geometry, not Newtonian physics.

Effect of Feedback on Users’ Immediate Emotions: Analysis of Facial Expressions during a Simulated Target Detection Task

2019 ◽  
Author(s):  
Md Abdullah Al Fahim ◽  
Mohammad Maifi Hasan Khan ◽  
Theodore Jensen ◽  
Yusuf Albayram ◽  
Emil Coman ◽  
...  
Keyword(s):  
Facial Expressions ◽  
Target Detection ◽  
Detection Task ◽  
Target Detection Task
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