Cognitive process in high neuroticism: incompatible flexibility in frontal brain region

Objective: This study examines the difference of interference effect in high and low neuroticism. Material and Methods: Low and high groups of neuroticism performed the congruent and incongruent Stroop Colour Word task in the Event Related Potential session. The ERP P300 was extracted and analysed. Results: High neuroticism exhibited larger P300 amplitude than low neuroticism in both congruent and incongruent condition. Conclusion: High neuroticism appraises conflict and non-conflict condition under incompatibility manner driven by prefrontal cortical top–down control. Bangladesh Journal of Medical Science Vol. 21(1) 2022 Page : 129-134

Effects of orthography in the picture-word task: Evidence from Japanese scripts

The picture-word task presents participants with a number of pictured objects together with a written distractor word superimposed upon each picture, and their task is to name the depicted object while ignoring the distractor word. Depending on the specific picture and word combination, various effects, including the identity facilitation effect (e.g., DOG + dog) and the semantic interference effect (e.g., GOAT + cow), are often observed. The response patterns of the picture-word task in terms of naming latencies reflect the mechanisms underlying lexical selection in speech production. Research using this method, however, has typically focused on alphabetic languages, or involved bilingual populations, making it difficult to specifically investigate orthographic effects in isolation. In this paper, we report five experiments investigating the role of orthography in the picture-word task by varying distractor script (using the multiscriptal language Japanese, and pseudohomophonic spellings in English) across three different populations (Japanese monolinguals, Japanese-English bilinguals, and English monolinguals), investigating both the identity facilitation effect and the semantic interference effect. The results generally show that the magnitude of facilitation is affected by orthography even within a single language. The findings and specific patterns of results are discussed in relation to current theories on speech production.

Breakfast and Exercise Improve Academic and Cognitive Performance in Adolescents

This study examined the combined effects of breakfast and exercise on short-term academic and cognitive performance in adolescents. Eighty-two adolescents (64 female), aged 14–19 years, were randomized to four groups over a 4-hour morning: (i) a group who fasted and were sedentary (F-S); (ii) a group who ate breakfast but were sedentary (B-S); (iii) a group who fasted but completed a 30-min exercise bout (F-E); and (iv) a group who ate breakfast and completed a 30-min exercise bout (B-E). Individuals completed academic and cognitive tests over the morning. Adolescents in B-E significantly improved their mathematics score (B-E: 15.2% improvement on correct answers, vs. F-S: 6.7% improvement on correct answers; p = 0.014) and computation time for correct answers (B-E: 16.7% improvement, vs. F-S: 7.4% improvement; p = 0.004) over the morning compared with the F-S group. The B-E group had faster reaction times for congruent, incongruent and control trials of the Stroop Color-Word Task compared with F-S mid-morning (all p < 0.05). Morning breakfast and exercise combine to improve short-term mathematical task performance and speed in adolescents.

The mental representation of non-numerical quantifiers: The Spatial-Linguistic Association of Response Codes (SLARC) effect.

How quantifiers are represented in the human mind is still a topic of intense debate. Seminal studies have addressed the issue of how a subclass of quantifiers, i.e. number words, is spatially coded displaying the SNARC (Spatial-numerical Association of Response Codes) effect; yet, none of these studies have explored the spatial representation of non-numerical quantifiers such as “some” or “many”. The aim of the present study is to investigate whether non-numerical quantifiers are spatially coded in the human mind. We administered two typical comparison tasks to 52 participants: the first task involved non-numerical quantifiers; the second task involved number words. Results showed a response-side compatibility effect for both number words and non-numerical quantifiers, suggesting that both types of quantifiers are encoded in a spatial format; quantifiers referring to “small” quantities are responded to faster with the left hand and quantifiers referring to “large” quantities are responded to faster with the right hand. We labeled this effect for non-numerical quantifiers as the SLARC (Spatial-Linguistic Association of Response Codes) effect. Notably, we found that the SNARC and the SLARC effects were strictly related to each other, namely more a participant was sensitive to the SNARC effect in the number word task, the more a SLARC effect was detectable in the non-numerical quantifier task. These findings add evidence to the tendency of humans to align magnitude information on a mental line that is coded from left to right. This article is in press in The Journal of Experimental Psychology: Learning, Memory and Cognition.

The Effects of Transcranial Direct Current Stimulation on Dual-Task Interference Depend on the Dual-Task Content

Recently, some studies revealed that transcranial direct current stimulation (tDCS) reduces dual-task interference. Since there are countless combinations of dual-tasks, it remains unclear whether stable effects by tDCS can be observed on dual-task interference. An aim of the present study was to investigate whether the effects of tDCS on dual-task interference change depend on the dual-task content. We adopted two combinations of dual-tasks, i.e., a word task while performing a tandem task (word-tandem dual-task) and a classic Stroop task while performing a tandem task (Stroop-tandem dual-task). We expected that the Stroop task would recruit the dorsolateral prefrontal cortex (DLPFC) and require involvement of executive function to greater extent than the word task. Subsequently, we hypothesized that anodal tDCS over the DLPFC would improve executive function and result in more effective reduction of dual-task interference in the Stroop-tandem dual-task than in the word-tandem dual-task. Anodal or cathodal tDCS was applied over the DLPFC or the supplementary motor area using a constant current of 2.0 mA for 20 min. According to our results, dual-task interference and the task performances of each task under the single-task condition were not changed after applying any settings of tDCS. However, anodal tDCS over the left DLPFC significantly improved the word task performance immediately after tDCS under the dual-task condition. Our findings suggested that the effect of anodal tDCS over the left DLPFC varies on the task performance under the dual-task condition was changed depending on the dual-task content.

A Neural Marker of Speech Intention: Evidence From Contingent Negative Variation

Purpose This study investigated whether changes in brain activity preceding spoken words can be used as a neural marker of speech intention. Specifically, changes in the contingent negative variation (CNV) were examined prior to speech production in three different study designs to determine a method that maximizes signal detection in a speaking task. Method Electroencephalography data were collected in three different protocols to elicit the CNV in a spoken word task that varied the timing and type of linguistic information. The first protocol provided participants with the word to be spoken before the instruction of whether or not to speak, the second provided both the word and the instruction to speak, and the third provided the instruction to speak before the word. Participants ( N = 18) were split into three groups (one for each protocol) and were instructed to either speak (Go) or refrain from speaking (NoGo) each word according to task instructions. The CNV was measured by analyzing the difference in slope between Go and NoGo trials. Results Statistically significant effects of hemispheric laterality on the CNV slope confirm the third protocol where the participants know they will speak in advance of the word, as the paradigm that reliably elicits a CNV response related to speech intention. Conclusions The maximal CNV response when the instruction is known before the word indicates the neural processing measured in this protocol may reflect a generalized speech intention process in which the speech-language systems become prepared to speak and then execute production once the word information is provided. Further analysis of the optimal protocol identified in this study requires additional experimental investigation to confirm its role in eliciting an objective marker of speech intention. Supplemental Material https://doi.org/10.23641/asha.14111468

Increased Exercise Effort after Artificially-Induced Stress: Laboratory-Based Evidence for the Catharsis Theory of Stress

Background. Evolution prepared humans to deal with physical challenges. Today, people encounter psychosocial stress more than physical stress. However, the physiological response to the contemporary forms of stress is still preserved as the biological evolution’s vestigial heritage. This laboratory investigation aimed to determine whether brief mental stress triggers greater innate (instinctual) effort to ‘let off steam’ than a non-challenging control condition. Method. Using a counterbalanced within-participants laboratory design, 29 young men walked/jogged at voluntary (self-paced) effort after two conditions: a) artificially-induced mental stress comprised by the Stroop Color-Word Task, which lasted for five minutes, and b) a control session, also lasting for five minutes, in which the participants watched a video depicting the world’s ten tallest buildings. Results. The increased arousal after mental stress was carried over into the walk or jog period, and participants worked harder, but they did not perceive exerting greater effort in contrast to the control condition. Conclusions. These results suggest that a ‘flight or fight’ response to psychosocial stress is manifested in the form of subliminal catharsis. While larger-scale studies with more impactful stressors are needed, these preliminary results support the catharsis theory. They might open new research avenues to provide people more physical opportunities for letting off steam before the necessity of treatment with chemical substances or other behavioral therapies. Keywords: cognitive stress, exercise, mental stress, flight or fight, physical activity, psychosocial stress.

Correlating cognition and cortical excitability with pain in fibromyalgia: a case control study

Background Fibromyalgia is a chronic pain disorder characterized by widespread musculoskeletal symptoms, primarily attributed to sensitization of somatosensory system carrying pain. Few reports have investigated the impact of fibromyalgia symptoms on cognition, corticomotor excitability, sleepiness, and the sleep quality — all of which can deteriorate the quality of life in fibromyalgia. However, the existing reports are underpowered and have conflicting directions of findings, limiting their generalizability. Therefore, the present study was designed to compare measures of cognition, corticomotor excitability, sleepiness, and sleep quality using standardized instruments in the recruited patients of fibromyalgia with pain-free controls. Methods Diagnosed cases of fibromyalgia were recruited from the Rheumatology department for the cross-sectional, case-control study. Cognition (Mini-Mental State Examination, Stroop color-word task), corticomotor excitability (Resting motor threshold, Motor evoked potential amplitude), daytime sleepiness (Epworth sleepiness scale), and sleep quality (Pittsburgh sleep quality index) were studied according to the standard procedure. Results Thirty-four patients of fibromyalgia and 30 pain-free controls were recruited for the study. Patients of fibromyalgia showed decreased cognitive scores (p = 0.05), lowered accuracy in Stroop color-word task (for color: 0.02, for word: 0.01), and prolonged reaction time (< 0.01, < 0.01). Excessive daytime sleepiness in patients were found (< 0.01) and worsened sleep quality (< 0.01) were found. Parameters of corticomotor excitability were comparable between patients of fibromyalgia and pain-free controls. Conclusions Patients of fibromyalgia made more errors, had significantly increased reaction time for cognitive tasks, marked daytime sleepiness, and impaired quality of sleep. Future treatment strategies may include cognitive deficits and sleep disturbances as an integral part of fibromyalgia management.

Excitability of the Ipsilateral Primary Motor Cortex During Unilateral Goal-Directed Movement

IntroductionPrevious transcranial magnetic stimulation (TMS) studies have revealed that the activity of the primary motor cortex ipsilateral to an active hand (ipsi-M1) plays an important role in motor control. The aim of this study was to investigate whether the ipsi-M1 excitability would be influenced by goal-directed movement and laterality during unilateral finger movements.MethodTen healthy right-handed subjects performed four finger tapping tasks with the index finger: (1) simple tapping (Tap) task, (2) Real-word task, (3) Pseudoword task, and (4) Visually guided tapping (VT) task. In the Tap task, the subject performed self-paced simple tapping on a touch screen. In the real-word task, the subject tapped letters displayed on the screen one by one to create a Real-word (e.g., apple). Because the action had a specific purpose (i.e., creating a word), this task was considered to be goal-directed as compared to the Tap task. In the Pseudoword task, the subject tapped the letters to create a pseudoword (e.g., gdiok) in the same manner as in the Real-word task; however, the word was less meaningful. In the VT task, the subject was required to touch a series of illuminated buttons. This task was considered to be less goal-directed than the Pseudoword task. The tasks were performed with the right and left hand, and a rest condition was added as control. Single- and paired-pulse TMS were applied to the ipsi-M1 to measure corticospinal excitability and short- and long-interval intracortical inhibition (SICI and LICI) in the resting first dorsal interosseous (FDI) muscle.ResultsWe found the smaller SICI in the ipsi-M1 during the VT task compared with the resting condition. Further, both SICI and LICI were smaller in the right than in the left M1, regardless of the task conditions.DiscussionWe found that SICI in the ipsi-M1 is smaller during visual illumination-guided finger movement than during the resting condition. Our finding provides basic data for designing a rehabilitation program that modulates the M1 ipsilateral to the moving limb, for example, for post-stroke patients with severe hemiparesis.