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1.
PLoS One ; 19(9): e0308653, 2024.
Article in English | MEDLINE | ID: mdl-39302892

ABSTRACT

Implicit statistical learning, whereby predictable relationships between stimuli are detected without conscious awareness, is important for language acquisition. However, while this process is putatively implicit, it is often assessed using measures that require explicit reflection and conscious decision making. Here, we conducted three experiments combining an artificial grammar learning paradigm with a serial reaction time (SRT-AGL) task, to measure statistical learning of adjacent and nonadjacent dependencies implicitly, without conscious decision making. Participants viewed an array of six visual stimuli and were presented with a sequence of three auditory (nonsense words, Expt. 1; names of familiar objects, Expt. 2) or visual (abstract shapes, Expt. 3) cues and were asked to click on the corresponding visual stimulus as quickly as possible. In each experiment, the final stimulus in the sequence was predictable based on items earlier in the sequence. Faster responses to this predictable final stimulus compared to unpredictable stimuli would provide evidence of implicit statistical learning, without requiring explicit decision making or conscious reflection. Despite previous positive results (Christiansen et al. 2009 and Misyak et al. 2010) we saw little evidence of implicit statistical learning in any of the experiments, suggesting that in this case, these SRT-AGL tasks were not an effective measure implicit statistical learning.


Subject(s)
Reaction Time , Humans , Reaction Time/physiology , Male , Female , Adult , Young Adult , Learning/physiology , Photic Stimulation , Language , Decision Making/physiology
2.
Scand J Med Sci Sports ; 34(9): e14733, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39308053

ABSTRACT

The StartReact test, increasingly popular for assessing cortico-reticular functioning, is a valid method to influence the firing of reticulospinal tract neurons noninvasively. However, there remains limited evidence on how different stimuli employed in the StartReact test impact motor output in humans. The present study tested elbow flexor responses of 33 adults (aged 26-48 years) to visual stimuli only (LED light), audio-visual (80 dB) stimuli, and startle-inducing audio-visual (120 dB) stimuli sitting with the arm supinated in an electromechanical dynamometer. Surface electromyogram (EMG) recorded muscle activity from the right biceps brachii muscle. Participants were presented with 20 stimuli for each of the three conditions in pseudorandom order with interstimulus intervals of ~8 s. Reaction times were calculated from the stimulus trigger to the initial rise in the EMG signal above 7 × SD from baseline. Rate of torque development (RTD) and EMG signals were recorded throughout and analyzed over their initial 50 ms and 100 ms time-windows. Reaction times were reduced from visual (169 ± 23) to audio-visual (140 ± 23) and further reduced to startle-inducing audio-visual stimuli (108 ± 19, p < 0.001). While RTD and EMG were consistently greatest following startle-inducing stimuli (p < 0.001), they were also enhanced following all audio-visual stimuli over 100 ms (p < 0.05). It appears that startle-inducing audio-visual stimuli result in shorter reaction times, increased RTD, and enhanced muscle activity within the initial 50 ms, likely from subcortical upregulation. However, the 100 ms time-window suggests cortical upregulation following all audio-visual stimuli considering the longer transmission times.


Subject(s)
Electromyography , Muscle, Skeletal , Reaction Time , Humans , Adult , Middle Aged , Male , Muscle, Skeletal/physiology , Reaction Time/physiology , Female , Reflex, Startle/physiology , Photic Stimulation , Torque , Acoustic Stimulation , Arm/physiology , Elbow/physiology
3.
PLoS One ; 19(9): e0310436, 2024.
Article in English | MEDLINE | ID: mdl-39283870

ABSTRACT

Our interest was to evaluate changes in fixation duration as a function of time-on-task (TOT) during a random saccade task. We employed a large, publicly available dataset. The frequency histogram of fixation durations was multimodal and modelled as a Gaussian mixture. For this specific task, we found five fixation types. The "ideal" response would be a single accurate saccade after each target movement, with a typical saccade latency of 200-250 msec, followed by a long fixation (> 800 msec) until the next target jump. We found fixations like this, but they comprised only 10% of all fixations and were the first fixation after target movement only 23.4% of the time. More frequently (57.4% of the time), the first fixation after target movement was short (117.7 msec mean) and was commonly followed by a corrective saccade. Across the entire 100 sec of the task, median total fixation duration decreased. This decrease was approximated with a power law fit with R2 = 0.94. A detailed examination of the frequency of each of our five fixation types over time on task (TOT) revealed that the three shortest duration fixation types became more and more frequent with TOT whereas the two longest fixations became less and less frequent. In all cases, the changes over TOT followed power law relationships, with R2 values between 0.73 and 0.93. We concluded that, over the 100 second duration of our task, long fixations are common in the first 15 to 22 seconds but become less common after that. Short fixations are relatively uncommon in the first 15 to 22 seconds but become more and more common as the task progressed. Apparently. the ability to produce an ideal response, although somewhat likely in the first 22 seconds, rapidly declines. This might be related to a noted decline in saccade accuracy over time.


Subject(s)
Eye-Tracking Technology , Fixation, Ocular , Saccades , Humans , Saccades/physiology , Fixation, Ocular/physiology , Male , Time Factors , Female , Reaction Time/physiology , Adult
4.
Learn Mem ; 31(8)2024 Aug.
Article in English | MEDLINE | ID: mdl-39284619

ABSTRACT

"Pavlovian" or "motivational" biases are the phenomenon that the valence of prospective outcomes modulates action invigoration: the prospect of reward invigorates actions, while the prospect of punishment suppresses actions. Effects of the valence of prospective outcomes are well established, but it remains unclear how the magnitude of outcomes ("stake magnitude") modulates these biases. In this preregistered study (N = 55), we manipulated stake magnitude (high vs. low) in an orthogonalized Motivational Go/NoGo Task. We tested whether higher stakes (a) strengthen biases or (b) elicit cognitive control recruitment, enhancing the suppression of biases in motivationally incongruent conditions. Confirmatory tests showed that high stakes slowed down responding, especially in motivationally incongruent conditions. However, high stakes did not affect whether a response was made or not, and did not change the magnitude of Pavlovian biases. Reinforcement-learning drift-diffusion models (RL-DDMs) fit to the data suggested that response slowing was best captured by stakes prolonging the non-decision time. There was no effect of the stakes on the response threshold (as in typical speed-accuracy trade-offs). In sum, these results suggest that high stakes slow down responses without affecting the expression of Pavlovian biases in behavior. We speculate that this slowing under high stakes might reflect heightened cognitive control, which is however ineffectively used, or reflect positive conditioned suppression, i.e., the interference between goal-directed and consummatory behaviors, a phenomenon previously observed in rodents that might also exist in humans. Pavlovian biases and slowing under high stakes may arise in parallel to each other.


Subject(s)
Conditioning, Classical , Motivation , Reward , Humans , Male , Motivation/physiology , Young Adult , Female , Conditioning, Classical/physiology , Adult , Reaction Time/physiology , Adolescent , Punishment , Reinforcement, Psychology , Psychomotor Performance/physiology
5.
PLoS One ; 19(9): e0308757, 2024.
Article in English | MEDLINE | ID: mdl-39292693

ABSTRACT

Attending to the behaviors of eyewitnesses at police lineups could help to determine whether an eyewitness identification is accurate or mistaken. Eyewitness identification decision processes were explored using augmented reality holograms. Children (n = 143; Mage = 10.79, SD = 1.12 years) and adults (n = 152; Mage = 22.12, SD = 7.47 years) viewed staged crime videos and made identification decisions from sequential lineups. The lineups were presented in augmented reality. Children were less accurate than adults on the lineup task. For adults, fast response times and high post-identification confidence ratings were both reflective of identification accuracy. Fast response times were also reflective of accuracy for children; however, children's confidence ratings did not reflect the likely accuracy of their identifications. A new additional measure, the witness' proximity to the augmented reality lineup, revealed that children who made mistaken identifications moved closer to the lineup than children who correctly identified the person from the crime video. Adults who moved any distance towards the lineup were less accurate than adults who did not move at all, but beyond that, adults' proximity to the lineup was not reflective of accuracy. The findings give further evidence that behavioral indicators of deliberation and information-seeking by eyewitnesses are signals of low lineup identification reliability. The findings also suggest that when assessing the reliability of children's lineup identifications, behavioral measures are more useful than metacognitive reports.


Subject(s)
Augmented Reality , Crime , Reaction Time , Humans , Child , Female , Male , Adult , Young Adult , Adolescent , Mental Recall/physiology , Reproducibility of Results , Recognition, Psychology
6.
PLoS One ; 19(9): e0310502, 2024.
Article in English | MEDLINE | ID: mdl-39292714

ABSTRACT

Biological motion perception is an essential part of the cognitive process. Stress can affect the cognitive process. The present study explored the intrinsic ERP features of the effects of acute psychological stress on biological motion perception. The results contributed scientific evidence for the adaptive behavior changes under acute stress. After a mental arithmetic task was used to induce stress, the paradigm of point-light displays was used to evaluate biological motion perception. Longer reaction time and lower accuracy were found in the inverted walking condition than in the upright walking condition, which was called the "inversion effect". The P2 peak amplitude and the LPP mean amplitude were significantly higher in the local inverted perception than in the local upright walking condition. Compared to the control condition, the stress condition induced lower RT, shorter P1 peak latency of biological motion perception, lower P2 peak amplitude and LPP mean amplitude, and higher N330 peak amplitude. There was an "inversion effect" in biological motion perception. This effect was related to the structural characteristics of biological motion perception but unrelated to the state of acute psychological stress. Acute psychological stress accelerated the reaction time and enhanced attention control of biological motion perception. Attention resources were used earlier, and less attentional investment was made in the early stage of biological motion perception processing. In the late stage, a continuous weakening of inhibition was shown in the parieto-occipital area.


Subject(s)
Motion Perception , Reaction Time , Stress, Psychological , Humans , Motion Perception/physiology , Male , Stress, Psychological/physiopathology , Reaction Time/physiology , Female , Young Adult , Adult , Electroencephalography , Attention/physiology , Evoked Potentials/physiology , Walking/physiology
7.
Sensors (Basel) ; 24(17)2024 Sep 07.
Article in English | MEDLINE | ID: mdl-39275722

ABSTRACT

Sensorimotor disturbances such as disturbed cervical joint position sense (JPS) and reduced reaction time and velocity in fast cervical movements have been demonstrated in people with neck pain. While these sensorimotor functions have been assessed mainly in movement science laboratories, new sensor technology enables objective assessments in the clinic. The aim was to investigate concurrent validity of a VR-based JPS test and a new cervical reaction acuity (CRA) test. Twenty participants, thirteen asymptomatic and seven with neck pain, participated in this cross-sectional study. The JPS test, including outcome measures of absolute error (AE), constant error (CE), and variable error (VE), and the CRA test, including outcome measures of reaction time and maximum velocity, were performed using a VR headset and compared to a gold standard optical motion capture system. The mean bias (assessed with the Bland-Altman method) between VR and the gold standard system ranged from 0.0° to 2.4° for the JPS test variables. For the CRA test, reaction times demonstrated a mean bias of -19.9 milliseconds (ms), and maximum velocity a mean bias of -6.5 degrees per seconds (°/s). The intraclass correlation coefficients (ICCs) between VR and gold standard were good to excellent (ICC 0.835-0.998) for the JPS test, and excellent (ICC 0.931-0.954) for reaction time and maximum velocity for the CRA test. The results show acceptable concurrent validity for the VR technology for assessment of JPS and CRA. A slightly larger bias was observed in JPS left rotation which should be considered in future research.


Subject(s)
Neck Pain , Reaction Time , Humans , Female , Adult , Male , Cross-Sectional Studies , Neck Pain/physiopathology , Neck Pain/diagnosis , Reaction Time/physiology , Cervical Vertebrae/physiology , Young Adult , Virtual Reality , Range of Motion, Articular/physiology , Proprioception/physiology , Movement/physiology , Neck/physiology , Middle Aged
8.
Atten Percept Psychophys ; 86(6): 1872-1882, 2024 Aug.
Article in English | MEDLINE | ID: mdl-39251566

ABSTRACT

A major constraining factor for attentional selection is the similarity between targets and distractors. When similarity is low, target items can be identified quickly and efficiently, whereas high similarity can incur large costs on processing speed. Models of visual search contrast a fast, efficient parallel stage with a slow serial processing stage where search times are strongly modulated by the number of distractors in the display. In particular, recent work has argued that the magnitude of search slopes should be inversely proportional to target-distractor similarity. Here, we assessed the relationship between target-distractor similarity and search slopes. In our visual search tasks, participants detected an oddball color target among distractors (Experiments 1 & 2) or discriminated the direction of a triangle in the oddball color (Experiment 3). We systematically varied the similarity between target and distractor colors (along a circular CIELAB color wheel) and the number of distractors in the search array, finding logarithmic search slopes that were inversely proportional to the number of items in the array. Surprisingly, we also found that searches were highly efficient (i.e., near-zero slopes) for targets and distractors that were extremely similar (≤20° in color space). These findings indicate that visual search is systematically influenced by target-distractor similarity across different processing stages. Importantly, we found that search can be highly efficient and entirely unaffected by the number of distractors despite high perceptual similarity, in contrast to the general assumption that high similarity must lead to slow and serial search behavior.


Subject(s)
Attention , Color Perception , Pattern Recognition, Visual , Humans , Attention/physiology , Color Perception/physiology , Young Adult , Adult , Pattern Recognition, Visual/physiology , Male , Female , Reaction Time
9.
Atten Percept Psychophys ; 86(6): 2013-2028, 2024 Aug.
Article in English | MEDLINE | ID: mdl-39256260

ABSTRACT

The ability to prepare and maintain an optimal level of preparedness for action, across some unknown duration, is critical for human behavior. Temporal preparation has historically been analyzed in the context of reaction time (RT) experiments where the interval varies between the start of the trial, or foreperiod (FP), and the required response. Two main findings have come out of such paradigms: the variable FP effect (longer RTs to shorter vs. longer FPs) and the sequential FP effect (longer RTs when shorter FPs follow longer FPs). Several theoretical views of these FP effects have been proposed with some suggesting a dissociation while others argue for an implicit process driven by memory traces. One possible method to test these views of FP effects is to examine how individual differences in working memory capacity (WMC) moderate such effects. To this end, I reanalyzed data from three studies in which participants completed measures of WMC and a simple RT task with a variable FP. Results suggest that individual differences in WMC were related to the magnitude of the variable FP and the sequential FP effect in two of three individual studies. A "mega-analysis" provided supportive evidence for a relationship between WMC and both forms of FP effects. The present combined experimental-individual differences study provides a novel approach to better understand how and why individuals vary in temporal preparation ability. Through leveraging several large-scale databases unseen in FP research, I provide a new way of understanding FP effects and response timing more generally.


Subject(s)
Individuality , Memory, Short-Term , Reaction Time , Humans , Memory, Short-Term/physiology , Adult , Young Adult , Male , Female , Psychomotor Performance/physiology , Attention/physiology , Time Perception
10.
Sci Rep ; 14(1): 21498, 2024 09 14.
Article in English | MEDLINE | ID: mdl-39277647

ABSTRACT

As a sport conducted in dynamically changing natural environments, orienteering places high demands on athletes' cognitive processing abilities and visual search efficiency. However, previous studies on orienteering have been primarily limited by the use of fixed stimulus materials on computer screens, which are unable to fully simulate authentic sports scenarios. To better understand the sports expertise of orienteering athletes in terms of their real scene image recognition performance and visual search characteristics, this study recruited 40 orienteering athletes, both experts and novices, as participants. By utilizing eye-tracking technology and setting observation points in real-world scenarios to conduct image recognition task tests, the ecological validity of the experiment was further enhanced. The results showed that the experts demonstrated a high level of accuracy and a short response time, with visual search characteristics including few saccade counts, low fixation frequency, concentrated fixation points, simple and clear fixation paths, and higher visual search efficiency. This study further reveals that long-term specialized training will lead to the formation of a unique cognitive structure related to the specific knowledge and long-term memory required by expert orienteering athletes, thereby promoting the development of expert advantage.


Subject(s)
Athletes , Sports , Humans , Male , Athletes/psychology , Adult , Young Adult , Sports/psychology , Reaction Time/physiology , Female , Athletic Performance/physiology , Athletic Performance/psychology , Pattern Recognition, Visual/physiology , Visual Perception/physiology , Fixation, Ocular/physiology , Eye-Tracking Technology
11.
J Cereb Blood Flow Metab ; 44(9): 1643-1654, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39234985

ABSTRACT

Neuronal activation sequence information is essential for understanding brain functions. Extracting such timing information from blood-oxygenation-level-dependent functional magnetic resonance imaging (fMRI) signals is confounded by local cerebral vascular reactivity (CVR), which varies across brain locations. Thus, detecting neuronal synchrony as well as inferring inter-regional causal modulation using fMRI signals can be biased. Here we used fast fMRI measurements sampled at 10 Hz to measure the fMRI latency difference between visual and sensorimotor areas when participants engaged in a visuomotor task. The regional fMRI timing was calibrated by subtracting the CVR latency measured by a breath-holding task. After CVR calibration, the fMRI signal at the lateral geniculate nucleus (LGN) preceded that at the visual cortex by 496 ms, followed by the fMRI signal at the sensorimotor cortex with a latency of 464 ms. Sequential LGN, visual, and sensorimotor cortex activations were found in each participant after the CVR calibration. These inter-regional fMRI timing differences across and within participants were more closely related to the reaction time after the CVR calibration. Our results suggested the feasibility of mapping brain activity using fMRI with accuracy in hundreds of milliseconds.


Subject(s)
Magnetic Resonance Imaging , Visual Cortex , Humans , Magnetic Resonance Imaging/methods , Male , Female , Adult , Visual Cortex/diagnostic imaging , Visual Cortex/physiology , Brain Mapping/methods , Sensorimotor Cortex/physiology , Sensorimotor Cortex/diagnostic imaging , Reaction Time/physiology , Geniculate Bodies/physiology , Geniculate Bodies/diagnostic imaging , Cerebrovascular Circulation/physiology , Young Adult
12.
Neuroimage ; 299: 120831, 2024 Oct 01.
Article in English | MEDLINE | ID: mdl-39233126

ABSTRACT

One driving factor for attention deployment towards a stimulus is its associated value due to previous experience and learning history. Previous visual search studies found that when looking for a target, distractors associated with higher reward produce more interference (e.g., longer response times). The present study investigated the neural mechanism of such value-driven attention deployment. Specifically, we were interested in which of the three attention sub-processes are responsible for the interference that was repeatedly observed behaviorally: enhancement of relevant information, attentional capture by irrelevant information, or suppression of irrelevant information. We replicated earlier findings showing longer response times and lower accuracy when a target competed with a high-reward compared to a low-reward distractor. We also found a spatial gradient of interference: behavioral performance dropped with increasing proximity to the target. This gradient was steeper for high- than low-reward distractors. Event-related potentials of the EEG signal showed the reason for the reward-induced attentional bias: High-reward distractors required more suppression than low-reward distractors as evident in larger Pd components. This effect was only found for distractors near targets, showing the additional filtering needs required for competing stimuli in close proximity. As a result, fewer attentional resources can be distributed to the target when it competes with a high-reward distractor, as evident in a smaller target-N2pc amplitude. The distractor-N2pc, indicative of attentional capture, was neither affected by distance nor reward, showing that attentional capture alone cannot explain interference by stimuli of high value. In sum our results show that the higher need for suppression of high-value stimuli contributes to reward-modulated attention deployment and increased suppression can prevent attentional capture of high-value stimuli.


Subject(s)
Attention , Electroencephalography , Evoked Potentials , Reward , Humans , Male , Attention/physiology , Female , Young Adult , Adult , Evoked Potentials/physiology , Reaction Time/physiology , Visual Perception/physiology
13.
Atten Percept Psychophys ; 86(6): 1861-1871, 2024 Aug.
Article in English | MEDLINE | ID: mdl-39254916

ABSTRACT

Variability in the search environment has been shown to affect the capture of attention by salient distractors, as attentional capture is reduced when context variability is low. However, it remains unclear whether this reduction in capture is caused by contextual learning or other mechanisms, grounded in generic context-structure learning. We set out to test this by training participants (n = 200) over two sessions in a visual search task, conducted online, where they gained experience with a small subset of search displays, which significantly reduced capture of attention by colour singletons. In a third session, we then tested participants on a mix of familiar and novel search displays and examined whether this reduction in capture was specific to familiar displays, indicative of contextual cueing effects, or would generalise to novel displays. We found no capture by the singleton in either the familiar or novel condition. Instead, our findings suggested that reduced statistical volatility reduced capture by allowing the development of generic predictions about task-relevant locations and features of the display. These findings add to the current debate about the determinants of capture by salient distractors by showing that capture is also affected by generic task regularities and by the volatility of the learning environment.


Subject(s)
Attention , Color Perception , Cues , Humans , Uncertainty , Female , Male , Young Adult , Adult , Pattern Recognition, Visual , Learning , Adolescent , Orientation , Reaction Time
14.
PLoS One ; 19(9): e0310022, 2024.
Article in English | MEDLINE | ID: mdl-39283871

ABSTRACT

OBJECTIVE: This study aimed to explore the influence of emotional feedback materials on attentional capture at different presentation times and to investigate the mechanisms of positive and negative attentional biases. METHODS: Two experiments were conducted. Experiment 1 recruited 47 participants, and Experiment 2 recruited 46 participants. Emotional facial images and emotional words were used as feedback materials. A learning-testing paradigm was employed to explore the effect of emotional feedback materials on attentional capture at different presentation times (1000 ms/100 ms). RESULTS: We compared the accuracy and reaction times of participants under emotional and neutral conditions at both presentation times. Experiment 1 revealed that participants exhibited a stable positive attentional bias towards emotional facial images. Additionally, under the 100 ms feedback condition, emotional interference on judgment task accuracy was greater than under the 1000 ms feedback condition. Experiment 2 found that under the 100 ms feedback condition, emotional interference on reaction time was greater than under the 1000 ms feedback condition. Comparing the data from both experiments revealed that the processing time for emotional facial images was longer than for emotional words. CONCLUSIONS: (1) Emotional facial images are more effective than emotional words in capturing attention. (2) When positive and negative information with equal arousal levels alternates over a period of time, individuals exhibit a stable positive attentional bias. (3) When there is intense competition for attention and cognitive resources, emotional information is prioritized for processing.


Subject(s)
Attention , Emotions , Reaction Time , Humans , Emotions/physiology , Female , Male , Reaction Time/physiology , Young Adult , Adult , Attention/physiology , Facial Expression , Attentional Bias/physiology
15.
Cereb Cortex ; 34(9)2024 Jul 25.
Article in English | MEDLINE | ID: mdl-39285717

ABSTRACT

In this study, repetitive transcranial magnetic stimulation was applied to either the right inferior frontal junction or the right inferior parietal cortex during a difficult aerial reconnaissance search task to test its capacity to improve search performance. Two stimulation strategies previously found to enhance cognitive performance were tested: The first is called "addition by subtraction," and the second condition utilizes a direct excitatory approach by applying brief trains of high-frequency repetitive transcranial magnetic stimulation immediately before task trials. In a within-subjects design, participants were given active or sham repetitive transcranial magnetic stimulation at either 1 Hz or at 1 Hz above their individual peak alpha frequency (IAF + 1, mean 11.5 Hz), delivered to either the right inferior frontal junction or the right inferior parietal cortex, both defined with individualized peak functional magnetic resonance imaging (fMRI) activation obtained during the visual search task. Results indicated that among the 13 participants who completed the protocol, only active IAF + 1 stimulation to inferior frontal junction resulted in significant speeding of reaction time compared to sham. This site- and frequency-specific enhancement of performance with IAF + 1 repetitive transcranial magnetic stimulation applied immediately prior to task trials provides evidence for the involvement of inferior frontal junction in guiding difficult visual search, and more generally for the use of online repetitive transcranial magnetic stimulation directed at specific functional networks to enhance visual search performance.


Subject(s)
Magnetic Resonance Imaging , Transcranial Magnetic Stimulation , Humans , Transcranial Magnetic Stimulation/methods , Male , Female , Adult , Young Adult , Reaction Time/physiology , Frontal Lobe/physiology , Alpha Rhythm/physiology , Parietal Lobe/physiology , Brain Mapping/methods , Visual Perception/physiology
16.
Air Med J ; 43(5): 401-405, 2024.
Article in English | MEDLINE | ID: mdl-39293916

ABSTRACT

OBJECTIVE: This study aimed to assess whether undertaking retrieval was associated with fatigue independent of sleep and circadian disruption. It also aimed to assess the feasibility of routinely measuring the psychomotor vigilance test (PVT) on neonatal transport. Fatigue is associated with impaired clinician performance and safety. The association between shift work, sleep deprivation, and circadian disruption is well established. No studies have specifically assessed the independent effect of the retrieval environment on fatigue. METHODS: Medical and nursing staff of the neonatal retrieval team were prospectively recruited over a 12-month period. Simple reaction times (RTs) were recorded at the start and end of a day shift using a validated 3-minute PVT. RESULTS: The end-of-shift RT increased (not significant) by 6.38 milliseconds (95% confidence interval [CI], -2.17 to 14.92 milliseconds; P = .149) when retrieval was undertaken. A 1-millisecond increase in RT increased the odds of being in a subjective sleepy category by 0.57% (95% CI, 0.0036-0.0078; P < .001). Consuming caffeine during the shift increased the mean RT by 16.26 milliseconds (95% CI, 4.43-28.1 milliseconds; P < .01). CONCLUSION: The RT of participants exposed to the retrieval environment was not significantly increased. Further studies are needed to consolidate these results as well as to further assess longer-range air medical retrievals.


Subject(s)
Air Ambulances , Psychomotor Performance , Humans , Infant, Newborn , Prospective Studies , Male , Female , Adult , Fatigue , Reaction Time , Western Australia , Sleep Deprivation/psychology , Caffeine , Transportation of Patients
17.
Sci Rep ; 14(1): 21089, 2024 09 10.
Article in English | MEDLINE | ID: mdl-39256417

ABSTRACT

Executive function (EF) has a significant impact on career achievement in adolescence and later adulthood, and there are many factors that influence EF. Cardiorespiratory fitness (CRF) is an important factor in the physical fitness of adolescents and is of great significance to healthy development. However, the current association between CRF and EF in Chinese adolescents is still unclear. For this reason, this study analysed the association between CRF and EF. A three-stage stratified cluster sampling method was used to investigate the demographic information, CRF, EF and multiple covariates of 1245 adolescents in China. One-way analysis of variance and chi-square test were used to compare the EF status of different CRFs. The association between CRF and EF was analysed using multiple linear regression analysis and logistic regression analysis. Multiple linear regression analysis showed that, after adjusting for relevant confounding factors, compared with Chinese adolescents with VO2max < P25, the inhibition function reaction time, 1back reaction time, 2back reaction time, and cognitive flexibility response time of adolescents with VO2max > P75 decreased by 1.41 ms, 238.73 ms, 273.09 ms, 74.14 ms. Logistic regression analysis showed that compared with Chinese adolescents with VO2max > P75, Chinese adolescents with VO2max < P25 developed inhibitory function dysfunction (OR 2.03, 95% CI: 1.29, 3.20), 1back dysfunction (OR 6.26, 95% CI 3.94, 9.97), 2back dysfunction (OR 8.94, 95% CI 5.40, 14.82), cognitive flexibility dysfunction (OR 2.26, 95% CI 1.44, 3.57) The risk was higher (P < 0.01). There is a positive association between CRF and EF in Chinese adolescents. High-grade CRF adolescents have higher EF levels, that is, shorter response times. This study provides reference and lessons for better promoting adolescents' executive function development in the future.


Subject(s)
Cardiorespiratory Fitness , Executive Function , Adolescent , Child , Female , Humans , Male , Cardiorespiratory Fitness/physiology , China , East Asian People , Executive Function/physiology , Reaction Time/physiology
18.
J Vis ; 24(9): 17, 2024 Sep 03.
Article in English | MEDLINE | ID: mdl-39325434

ABSTRACT

The flash-lag effect (FLE) occurs when a flash's position seems to be delayed relative to a continuously moving object, even though both are physically aligned. Although several studies have demonstrated that reduced attention increases FLE magnitude, the precise mechanism underlying these attention-dependent effects remains elusive. In this study, we investigated the influence of visual attention on the FLE by manipulating the level of attention allocated to multiple stimuli moving simultaneously in different locations. Participants were cued to either focus on one moving stimulus or split their attention among two, three, or four moving stimuli presented in different quadrants. We measured trial-wise FLE to explore potential changes in the magnitude of perceived displacement and its trial-to-trial variability under different attention conditions. Our results reveal that FLE magnitudes were significantly greater when attention was divided among multiple stimuli compared with when attention was focused on a single stimulus, suggesting that divided attention considerably augments the perceptual illusion. However, FLE variability, measured as the coefficient of variation, did not differ between conditions, indicating that the consistency of the illusion is unaffected by divided attention. We discuss the interpretations and implications of our findings in the context of widely accepted explanations of the FLE within a dynamic environment.


Subject(s)
Attention , Motion Perception , Photic Stimulation , Humans , Attention/physiology , Photic Stimulation/methods , Motion Perception/physiology , Male , Female , Young Adult , Adult , Cues , Optical Illusions/physiology , Reaction Time/physiology
19.
J Vis ; 24(9): 18, 2024 Sep 03.
Article in English | MEDLINE | ID: mdl-39330994

ABSTRACT

Previous studies have elucidated that humans can implicitly process faces faster than they process objects. However, the mechanism through which the brain unconsciously processes ambiguous facial images remains unclear. In our experiment, upright and inverted black-and-white binary face stimuli were presented in a two-alternative forced-choice location discrimination task combined with continuous flash suppression, a technique that suppresses visual stimuli perception using rapidly changing masks. The breaking time (BT) or the time required for a stimulus to be perceptually recognized was recorded for each face stimulus. The results showed that the BT for inverted grayscale images was significantly longer than that for upright grayscale faces, whereas the BT for upright and inverted binary faces did not reach statistical significance. A significant correlation between face likeness and BT was established after evaluating face likeness for each binary face stimulus, with high-face-like binary faces exhibiting shorter BT and low-face-like stimuli resulting in a more prolonged BT. Our results suggest that even an ambiguous object rated highly in face likeness can reduce the BT under implicit processing, indicating the possibility that facial parts such as the eyes and nose are subconsciously detected in ambiguous facial stimuli, enabling facial perception.


Subject(s)
Facial Recognition , Photic Stimulation , Humans , Female , Male , Young Adult , Photic Stimulation/methods , Facial Recognition/physiology , Adult , Reaction Time/physiology , Perceptual Masking/physiology , Face , Pattern Recognition, Visual/physiology , Discrimination, Psychological/physiology
20.
Sci Rep ; 14(1): 22306, 2024 Sep 27.
Article in English | MEDLINE | ID: mdl-39333717

ABSTRACT

Visual search is guided by visual working memory representations (i.e., attentional templates) that are activated prior to search and contain target-defining features (e.g., color). In the present study, we tested whether attentional templates can also contain spatial target properties (knowing where to look for) and whether attentional selection guided by such feature-specific templates is equally efficient than selection that is based on feature-specific templates (knowing what to look for). In every trial, search displays were either preceded by semantic color or location cues, indicating the upcoming target color or location, respectively. Qualitative differences between feature- and location-based template guidance were substantiated in terms of selection efficiency in low-load (one target color/location) versus high-load trials (two target colors/locations). Behavioral and electrophysiological (N2pc) measures of target selection speed and accuracy were combined for converging evidence. In line with previous studies, we found that color search was highly efficient, even under high-low conditions, when multiple attentional templates were activated to guide attentional selection in a spatially global fashion. Importantly, results in the location task almost perfectly mirrored the findings of the color task, suggesting that multiple templates for different target locations were activated concurrently when two possible target locations were task relevant. Our findings align with accounts that assume a common neuronal network during preparation for location and color search, but regard spatial and feature-based selection mechanisms as independent.


Subject(s)
Attention , Memory, Short-Term , Attention/physiology , Humans , Female , Male , Adult , Young Adult , Memory, Short-Term/physiology , Reaction Time/physiology , Visual Perception/physiology , Photic Stimulation , Electroencephalography , Cues , Color Perception/physiology
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