Visual Perceptual Load Does Not Affect the Frequency Mismatch Negativity

Effect of 24-form simplified Tai Chi on executive inhibitory control of college students: a randomized controlled trial of EEG

Background

College students, undergoing crucial cognitive development, face challenges during the COVID-19 pandemic that impact their executive functions. While existing research indicates positive effects of Tai Chi (TC) on college students' cognitive abilities, there is a scarcity of studies investigating its impact on executive functions and frontal brain activity.

Objective

This study aimed to compare the effects of 24-form simplified TC training on college students' executive functions and frontal brain electrical activity. The hypothesis posited that the TC group would exhibit superior performance compared to the control group during COVID-19 pandemic.

Method

Seventy college students were randomly assigned to either TC group or control group, engaging in 36 sessions (3 sessions per week, 45 min each) over 12 weeks. Executive inhibitory control was assessed using the Stroop Color and Word Test, and resting brain electrical activity in the frontal area was recorded through Electroencephalography.

Result

ACC was influenced by group, group-time interaction, and Stroop task-time interaction. RT was affected by time, task condition, task condition-time interaction, and task condition-group interaction. Notably, the TC group showed improved ACC (from 96.54 ± 3.27% to 98.90 ± 1.32%) and decreased RT (from 0.73 ± 0.12 to 0.66 ± 0.07 s), particularly in the inconsistent task. Regarding EEG band power, significant Group and Time interaction effects were found in F3-θ, F3-α, F3-β, F4-θ, and F4-α. Moreover, within the TC group, significant increases in F3-θ band power (from 4.66 ± 3.55 to 7.71 ± 8.44) and F4-θ band power (from 4.41 ± 2.82 to 8.61 ± 9.51) (10-3·μV·Hz) were noted pre-and post-tests. In the control group, significant decreases were observed in F3-α band power (from 5.18 ± 4.61 to 2.79 ± 2.11) and F4-α band power (from 5.57 ± 6.58 to 2.48 ± 1.95) (10-3·μV·Hz).

Conclusion

The pandemic-induced panic may impact frontal lobe brain activity in college students. TC training not only improves executive inhibitory control but may also enhance localized brain activity, suggesting its potential as a holistic intervention for cognitive and neurological well-being during stressful periods.

Recognition and evaluation of mental workload in different stages of perceptual and cognitive information processing using a multimodal approach

This study explores the effects of different perceptual and cognitive information processing stages on mental workload by assessing multimodal indicators of mental workload such as the NASA-TLX, task performance, ERPs and eye movements. Repeated measures ANOVA of the data showed that among ERP indicators, P1, N1 and N2 amplitudes were sensitive to perceptual load (P-load), P3 amplitude was sensitive to P-load only in the prefrontal region during high cognitive load (C-load) states, and P3 amplitude in the occipital and parietal regions was sensitive to C-load. Among the eye movement indicators, blink frequency was sensitive to P-load in all C-load states, but to C-load in only low P-load states; pupil diameter and blink duration were sensitive to both P-load and C-load. Based on the above indicators, the k-nearest neighbours (KNN) algorithm was used to propose a classification method for the four different mental workload states with an accuracy of 97.89%.Practitioner summary: Based on the results of this study, it is possible to implement the monitoring of mental workload states and optimise brain task allocation in operations involving high mental workload, such as human-computer interaction.

Visual perceptual load and processing of somatosensory stimuli in primary and secondary somatosensory cortices

Load theory assumes that neural activation to distractors in early sensory cortices is modulated by the perceptual load of a main task, regardless of whether task and distractor share the same sensory modality or not. While several studies have investigated the question of load effects on distractor processing in early sensory areas, there is no functional magnetic resonance imaging (fMRI) study regarding load effects on somatosensory stimuli. Here, we used fMRI to investigate effects of visual perceptual load on neural responses to somatosensory stimuli applied to the wrist in a study with 44 participants. Perceptual load was manipulated by an established sustained visual detection task, which avoided simultaneous target and distractor presentations. Load was operationalized by detection difficulty of subtle or clear color changes of one of 12 rotating dots. While all somatosensory stimuli led to activation in somatosensory areas SI and SII, we found no statistically significant difference in brain activation to these stimuli under high compared to low sustained visual load. Moreover, exploratory Bayesian analyses supported the absence of differences. Thus, our findings suggest a resistance of somatosensory processing to at least some forms of visual perceptual load, possibly due to behavioural relevance of discrete somatosensory stimuli and separable attentional resources for the somatosensory and visual modality.

Monetary incentives have only limited effects on auditory distraction: evidence for the automaticity of cross-modal attention capture

The duplex-mechanism account of auditory distraction postulates that two distinct forms of auditory distraction can be distinguished by whether or not they can be cognitively controlled. While the interference-by-process component of auditory distraction is postulated to be automatic and independent of cognitive control, the stimulus-aspecific attention capture by auditory deviants and the stimulus-specific attentional diversion by auditorily presented distractor sentences should be suppressed by increased task engagement. Here we test whether incentive-induced changes in task engagement affect the disruption of serial recall by auditory deviants (Experiment 1) and distractor sentences (Experiment 2). Monetary incentives substantially affected recall performance in both experiments. However, the incentive-induced changes in task engagement had only limited effects on auditory distraction. In Experiment 2, increased task engagement was associated with a small decrease of distraction relative to a quiet condition, but strong effects of auditory distraction on performance persisted in conditions of high task engagement in both experiments. Most importantly, and in contrast to the predictions of the duplex-mechanism account, the effects of stimulus-aspecific attention capture (Experiment 1) and stimulus-specific attentional diversion (Experiment 2) remained unaffected by incentive-induced changes in task engagement. These findings are consistent with an automatic-capture account according to which only the processes responsible for the deliberate memorization of the target items are dependent on controlled mental effort while the attention capture by auditory deviants and the attentional diversion by distractor speech are largely automatic.