EXPRESS: Visually Guided Movement with Increasing Time-on-Task: Differential Effects on Movement Preparation and Movement Execution

Top-down cognitive control seems to be sensitive to the detrimental effects of fatigue induced by time-on-task (ToT). The planning and preparation of the motor responses may be especially vulnerable to ToT. Yet, effects of ToT specific to the different phases of movements have received little attention. Therefore, in three experiments, we assessed the effect of ToT on a mouse-pointing task. In Experiment 1, there were 16 possible target positions with variable movement directions. In Experiment 2, the layout of the targets was simplified. In Experiment 3, using cuing conditions we examined whether the effects of ToT on movement preparation and execution were caused by an increased orientation deficit or decreased phasic alertness. In each experiment, initiation of movement (preparatory phase) became slower, movement execution became faster and overall response time remained constant with increasing ToT. There was, however, no significant within-person association between the preparatory and execution phases. In Experiments 1 and 2, we found a decreasing movement time/movement error ratio, suggesting a more impulsive execution of the pointing movement. In addition, ToT was also accompanied with imprecise movement execution as indicated by the increased errors, mainly in Experiment 2. The results of Experiment 3 indicated that ToT did not induce orientation and phasic alerting deficits but rather was accompanied by decreased tonic alertness.

To Be Attentive, Do Not React: Linking Dispositional Mindfulness to Attentional Networks and Vigilance Performance

Objectives: Research addressing the relationship between dispositional mindfulness and objective attention performance remains inconclusive, partly because previous studies used sample sizes possibly leading to underpowered designs. Here, we examined this relationship in a large sample using the ANTI-Vea: a novel cognitive-behavioral task that simultaneously assesses the classical attentional networks—phasic alertness, orienting, executive control—and both the executive and arousal components of vigilance.Methods: Two hundred nineteen meditation-naïve participants completed the study. Correlational analyses using Kendall’s Tau were performed between FFMQ scores and ANTI-Vea outcomes. Additional subsidiary correlations were performed between the FFMQ and two self-report measures assessing subjective attentional control and mind-wandering. Benjamini-Hochberg was applied to control the Type I error rate. The hypotheses and plan of analyses were preregistered at the Open Science Framework.Results: Higher non-reactivity predicted overall faster reaction times and higher accuracy in attentional networks trials. Higher non-reactivity, as well as higher FFMQ total score, predicted faster reaction time and fewer lapses in arousal vigilance trials, the latter also being negatively associated with describe scores. The magnitude of the correlations ranged from τb = .103 to τb = .119. We found no association between FFMQ scores and executive control or executive vigilance.Conclusions: Our results indicate that dispositional mindfulness is linked to improved global attentional and arousal vigilance performance, being non-reactivity to internal experience the key facet driving the association. The absence of association to executive processes is discussed based on the high cognitive demands of the ANTI-Vea task.

The ANTI-Vea task: analyzing the executive and arousal vigilance decrements while measuring the three attentional networks

The vigilance decrement phenomenon has been traditionally studied by simple and monotonous behavioral tasks. Nowadays, however, there is considerable interest in measuring vigilance with more complex tasks, including independent measures of other attentional functions. In the present study, we provide evidence supporting the suitability of the Attentional Networks Test for Interactions and Vigilance – executive and arousal components (ANTI-Vea) as an appropriate method to simultaneously assess multiple attentional and vigilance components. Vigilance was examined as two dissociated components: executive vigilance –as the detection of infrequent signals– and arousal vigilance–as the sustenance of a fast reaction to stimuli without response selection–. Importantly, the executive vigilance decrement was analyzed with a novel methodological approach to particularly determine whether the sensitivity loss effect is influenced by a floor level on the false alarms. As expected, the ANTI-Vea proved to be a task suitable to assess: (a) the main effects and interactions of phasic alertness, orienting, and executive control; (b) the executive vigilance decrement as a progressive change in the response bias; and (c) the arousal vigilance decrement as a progressive slowness and variability in reaction time. We discuss some critical theoretical and empirical implications of measuring vigilance components with the ANTI-Vea task. We expect the present study to provide a suitable method to analyze the vigilance decrement phenomenon when measuring multiple attentional and vigilance functions.

Oculomotor fatigue and neuropsychological assessments mirror multiple sclerosis fatigue

Fatigue is a major complaint in MS. Up to now no objective assessment tools have been established which hampers any treatment approach. Previous work has indicated an association of fatigue with cognitive measures of attention. Oculomotor tests have been established in healthy individuals as a read-out of fatigue, and to some extent in MS patients. Based on these observations we compared two groups of MS patients, one with fatigue (n=28) and one without fatigue (n=21) and a group of healthy subjects (n=15) with a stand- ardised computerised measure of alertness and an oculomotor stress test. Patients with fatigue showed highly significant changes of their saccade dynamics as defined by the Main Sequence and Phase Plane plots: They showed slowing of saccades, the characteristical fatigue double peak, and an asymmetrical phase plane. Oculomotor tests differentiated significantly between fatigue and fatigabiliy in our MS patients. They also showed significantly worse performance in the alertness test as well as in the oculomotor task. Significantly slower reaction times were observed for tonic alertness in 2 series without a cue (p=.025 and p=.037) but not in phasic alertness with a cue (p=.24 and p=.34). Performance was influenced by disability as well as by affective state. We conclude, when controlling for disability and depression, saccadic stress tests and alertness tests could be used as an objective read-out for fatigability and fatigue in MS patients.

Right-lateralized fronto-parietal network and phasic alertness in healthy aging

Phasic alerting cues temporarily increase the brain’s arousal state. In younger and older participants, visual processing speed in a whole report task, estimated based on the theory of visual attention (TVA), is increased in cue compared to no-cue conditions. The present study assessed whether older participants’ ability to profit from warning cues is related to iFC in the cingulo-opercular and/or right fronto-parietal network. We obtained resting-state functional magnetic resonance imaging (rs-fMRI) data from 31 older participants. By combining an independent component analysis and dual regression, we investigated iFC in both networks. A voxel-wise multiple regression in older participants revealed that higher phasic alerting effects on visual processing speed were significantly associated with lower right fronto-parietal network iFC. We then compared healthy older participants to a previously reported sample of healthy younger participants to assess whether behaviour-iFC relationships are age group specific. The comparison revealed that the association between phasic alerting and cingulo-opercular network iFC is significantly lower in older than in younger adults. Additionally, it yielded a stronger association between phasic alerting and right fronto-parietal network iFC in older versus younger participants. The results support a particular role of the right fronto-parietal network in maintaining phasic alerting capabilities in aging.