The effects of offline and online prefrontal vs parietal transcranial direct current stimulation (tDCS) on verbal and spatial working memory.

Working memory (WM) is a limited-capacity system or set of processes that enables temporary storage and manipulation of information essential for complex cognitive processes. The WM performance is supported by a widespread neural network in which fronto-parietal functional connections have a pivotal role. Transcranial direct current stimulation (tDCS) is rapidly emerging as a promising tool for understanding the role of various cortical areas and their functional networks on cognitive performance. Here we comprehensively evaluated the effects of tDCS on WM by conducting three cross-over counterbalanced sham-controlled experiments in which we contrasted the effects and interactions of the anodal (i.e. facilitatory) tDCS across anterior-posterior (i.e. DLPFC vs PPC) and left-right (i.e. the lateralization) axes, and across online and offline protocols using both verbal and spatial WM (3-back) tasks as outcomes. In the offline protocols, left DLPFC stimulation affected neither verbal nor spatial WM, while left PPC stimulation increased spatial WM. When applied offline over right DLPFC, tDCS improved verbal WM task and marginally enhanced spatial WM; while when tDCS was applied over the right PPC, facilitatory effects were observed on verbal WM. In the online protocol, tDCS did not modulate WM regardless of the task modality or stimulation loci. In summary, the study did not replicate the left DLPFC tDCS effect on WM, found in some of the previous studies, but demonstrated positive effects of stimulation of the right DLPFC as well as PPC bilaterally. The observed effects varied across modality of the 3-back task, and tDCS protocol applied. The results of this study argue for moving towards targeting the lesser-explored stimulation sites within the fronto-parietal network, such as PPC, to gain a better understanding of the usefulness of tDCS for WM neuromodulation.

Ambulatory assessment of language use: Evidence on the temporal stability of Electronically Activated Recorder and stream of consciousness data.

The ambulatory assessment offers a wide range of methods enabling researchers to investigate psychological, behavioral, emotional, and biological processes. These methods enable us to gather data on individual differences in language use for psychological research. Two studies were conducted with an aim to evaluate and compare the temporal stability of language measures extracted by LIWC software form data obtained by two frequently used methods for assessment of language use, i.e., Electronically Activated Recorder (EAR) and stream of consciousness (SOC) task. Additionally, we examined the amount of variance in language use (assessed by both methods) that can be attributed to intra-individual variability and stable individual differences. Study 1 was focused on investigating language use obtained from 74 respondents using the EAR for 3 consecutive days. Study 2 was conducted on 250 respondents participating in a SOC task where verbal production was collected at ten time points over a 2-month period. Results show that measures obtained using the SOC task have higher temporal stability and consistency, and to a certain extent enable better detection of individual differences. Taking into account certain situational variations improves the reliability of EAR measures.

Transcranial direct current stimulation (tDCS) over parietal cortex improves associative memory.

Associative memory plays a key role in everyday functioning, but it declines with normal ageing as well as due to various pathological states and conditions, thus impairing quality of life. Associative memory enhancement via neurostimulation over frontal areas resulted in limited success, while posterior stimulation sites seemed to be more promising. We hypothesized that anodal transcranial direct current stimulation (tDCS) of parietal areas would lead to higher performance in associative memory due to high connectivity between posterior parietal cortex (PPC) and hippocampus. Forty-two healthy adults participated in two sham-controlled cross-over experiments. Anodal electrode (20 min, 1.5 mA) was placed over P3 in Experiment 1 and over P4 in Experiment 2. During tDCS participants played a simple computer game. After each stimulation session, participants completed parallel forms of an associative memory task (Experiment 1: face-word memory; Experiment 2: object-location memory) and a control task (verbal fluency). In both experiments, associative memory was improved after anodal stimulation compared to sham stimulation, while no differences were observed in the control task. Additionally, memory performance was higher in the second than in the first trial, but the increase in performance between the two trials did not differ between stimulation conditions. It can be concluded that a single-session anodal tDCS over posterior parietal cortex can improve associative memory performance. The specificity, robustness, and reproducibility of the effect suggest that PPC is a promising target for brain stimulation aiming to enhance memory functions.

Pain and executive functions: a unique relationship between Stroop task and experimentally induced pain.

There is a growing body of evidence that a higher level of cognitive inhibition is associated with lower experimental pain sensitivity. However, a systematic examination of the association between executive functions, which include not only inhibition but also updating and shifting, and experimental pain sensitivity is lacking. This study aimed to overcome this limitation by exploring the relationship between a range of executive functions and different measures of experimentally induced cold pain in healthy participants. In a group of 54 healthy participants (age 21-24 years), executive functions (EF) were investigated in a systematic manner following a well-established framework developed by Miyake and collaborators. The investigation included multiple tests of inhibition (Stroop, Stop-signal, and Left-right), updating (Keep-track, Letter-memory, and Spatial n-back), and set-shifting (Plus-minus, Number-letter, and Local-global). The cold pressor test was used to obtain measures of pain threshold (the first sensation of pain), sensitivity to pain (the moment when substantial pain was reported), and pain tolerance (the moment when pain became unbearable). Results showed no relationship between pain measures and measures of updating and shifting. All pain measures were related to Stroop interference inhibition score, but not to other two inhibition tasks. Further analyses confirmed the unique relationship between Stroop-type of inhibition and response to pain. We argue that there is a fundamental relationship between cognitive inhibition and pain experience, which relies on one's ability to suppress automatic processes.

Imageability ratings across languages.

Imageability is a psycholinguistic variable that indicates how well a word gives rise to a mental image or sensory experience. Imageability ratings are used extensively in psycholinguistic, neuropsychological, and aphasiological studies. However, little formal knowledge exists about whether and how these ratings are associated between and within languages. Fifteen imageability databases were cross-correlated using nonparametric statistics. Some of these corresponded to unpublished data collected within a European research network-the Collaboration of Aphasia Trialists (COST IS1208). All but four of the correlations were significant. The average strength of the correlations (rho = .68) and the variance explained (R 2 = 46%) were moderate. This implies that factors other than imageability may explain 54% of the results. Imageability ratings often correlate across languages. Different possibly interacting factors may explain the moderate strength and variance explained in the correlations: (1) linguistic and cultural factors; (2) intrinsic differences between the databases; (3) range effects; (4) small numbers of words in each database, equivalent words, and participants; and (5) mean age of the participants. The results suggest that imageability ratings may be used cross-linguistically. However, further understanding of the factors explaining the variance in the correlations will be needed before research and practical recommendations can be made.

Cross-linguistic adaptations of The Comprehensive Aphasia Test: Challenges and solutions.

Comparative research on aphasia and aphasia rehabilitation is challenged by the lack of comparable assessment tools across different languages. In English, a large array of tools is available, while in most other languages, the selection is more limited. Importantly, assessment tools are often simple translations and do not take into consideration specific linguistic and psycholinguistic parameters of the target languages. As a first step in meeting the needs for comparable assessment tools, the Comprehensive Aphasia Test is currently being adapted into a number of languages spoken in Europe. In this article, some key challenges encountered in the adaptation process and the solutions to ensure that the resulting assessment tools are linguistically and culturally equivalent, are proposed. Specifically, we focus on challenges and solutions related to the use of imageability, frequency, word length, spelling-to-sound regularity and sentence length and complexity as underlying properties in the selection of the testing material.

Noun and verb knowledge in monolingual preschool children across 17 languages: Data from Cross-linguistic Lexical Tasks (LITMUS-CLT).

This article investigates the cross-linguistic comparability of the newly developed lexical assessment tool Cross-linguistic Lexical Tasks (LITMUS-CLT). LITMUS-CLT is a part the Language Impairment Testing in Multilingual Settings (LITMUS) battery (Armon-Lotem, de Jong & Meir, 2015). Here we analyse results on receptive and expressive word knowledge tasks for nouns and verbs across 17 languages from eight different language families: Baltic (Lithuanian), Bantu (isiXhosa), Finnic (Finnish), Germanic (Afrikaans, British English, South African English, German, Luxembourgish, Norwegian, Swedish), Romance (Catalan, Italian), Semitic (Hebrew), Slavic (Polish, Serbian, Slovak) and Turkic (Turkish). The participants were 639 monolingual children aged 3;0-6;11 living in 15 different countries. Differences in vocabulary size were small between 16 of the languages; but isiXhosa-speaking children knew significantly fewer words than speakers of the other languages. There was a robust effect of word class: accuracy was higher for nouns than verbs. Furthermore, comprehension was more advanced than production. Results are discussed in the context of cross-linguistic comparisons of lexical development in monolingual and bilingual populations.

Grammatical Gender and Mental Representation of Object: The Case of Musical Instruments.

A body of research shows that grammatical gender, although an arbitrary category, is viewed as the system with its own meaning. However, the question remains to what extent does grammatical gender influence shaping our notions about objects when both verbal and visual information are available. Two experiments were conducted. The results obtained in Experiment 1 have shown that grammatical gender as a linguistic property of the pseudo-nouns used as names for musical instruments significantly affects people's representations about these instruments. The purpose of Experiment 2 was to examine how the representation of musical instruments will be shaped in the presence of both language and visual information. The results indicate that the co-existence of linguistic and visual information results in formation of concepts about selected instruments by all available information from both sources, thus suggesting that grammatical gender influences nonverbal concepts' forming, but has no privileged status in the matter.

The consequences of the new European reclassification of non-invasive brain stimulation devices and the medical device regulations pose an existential threat to research and treatment: An invited opinion paper.

A significant amount of European basic and clinical neuroscience research includes the use of transcranial magnetic stimulation (TMS) and low intensity transcranial electrical stimulation (tES), mainly transcranial direct current stimulation (tDCS). Two recent changes in the EU regulations, the introduction of the Medical Device Regulation (MDR) (2017/745) and the Annex XVI have caused significant problems and confusions in the brain stimulation field. The negative consequences of the MDR for non-invasive brain stimulation (NIBS) have been largely overlooked and until today, have not been consequently addressed by National Competent Authorities, local ethical committees, politicians and by the scientific communities. In addition, a rushed bureaucratic decision led to seemingly wrong classification of NIBS products without an intended medical purpose into the same risk group III as invasive stimulators. Overregulation is detrimental for any research and for future developments, therefore researchers, clinicians, industry, patient representatives and an ethicist were invited to contribute to this document with the aim of starting a constructive dialogue and enacting positive changes in the regulatory environment.

Effects of Transcranial Electrical Stimulation on Gambling and Gaming: A Systematic Review of Studies on Healthy Controls, Participants with Gambling/Gaming Disorder, and Substance Use Disorder.

Gambling disorder (GD) and internet gaming disorder (IGD) are formally recognized behavioral addictions with a rapidly growing prevalence and limited treatment options. Recently, transcranial electrical stimulation (tES) techniques have emerged as potentially promising interventions for improving treatment outcomes by ameliorating cognitive functions implicated in addictive behaviors. To systematize the current state of evidence and better understand whether and how tES can influence gambling and gaming-related cognitive processes, we conducted a PRISMA-guided systematic review of the literature, focusing on tES effects on gaming and gambling in a diverse range of population samples, including healthy participants, participants with GD and IGD, as well as participants with substance abuse addictions. Following the literature search in three bibliographic databases (PubMed, Web of Science, and Scopus), 40 publications were included in this review, with 26 conducted on healthy participants, 6 focusing on GD and IGD patients, and 8 including participants with other addictions. Most of the studies targeted the dorsolateral prefrontal cortex, using transcranial direct current stimulation (tDCS), and assessed the effects on cognition, using gaming and gambling computerized cognitive tasks measuring risk taking and decision making, e.g., balloon analogue risk task, Iowa gambling task, Cambridge gambling task, etc. The results indicated that tES could change gambling and gaming task performances and positively influence GD and IGD symptoms, with 70% of studies showing neuromodulatory effects. However, the results varied considerably depending on the stimulation parameters, sample characteristics, as well as outcome measures used. We discuss the sources of this variability and provide further directions for the use of tES in the context of GD and IGD treatment.

Transcranial Electrical Stimulation for Associative Memory Enhancement: State-of-the-Art from Basic to Clinical Research.

Associative memory (AM) is the ability to bind new information into complex memory representations. Noninvasive brain stimulation (NIBS), especially transcranial electric stimulation (tES), has gained increased interest in research of associative memory (AM) and its impairments. To provide an overview of the current state of knowledge, we conducted a systematic review following PRISMA guidelines covering basic and clinical research. Out of 374 identified records, 41 studies were analyzed-twenty-nine in healthy young adults, six in the aging population, three comparing older and younger adults, as well as two studies on people with MCI, and one in people with Alzheimer's dementia. Studies using transcranial direct current stimulation (tDCS), transcranial alternating current stimulation (tACS) as well as oscillatory (otDCS) and high-definition protocols (HD-tDCS, HD-tACS) have been included. The results showed methodological heterogeneity in terms of study design, stimulation type, and parameters, as well as outcome measures. Overall, the results show that tES is a promising method for AM enhancement, especially if the stimulation is applied over the parietal cortex and the effects are assessed in cued recall paradigms.

Understanding the Male Perspective: Evaluating Quality of Life and Psychological Distress in Serbian Men Undergoing Infertility Treatment.

The experience of an infertility diagnosis and treatment imposes a profound burden on affected individuals, encompassing not only physical and medical aspects but also a plethora of psychological, social, and emotional factors. By employing a multimodal assessment featuring validated self-report questionnaires, physical measurements, and clinical records, the present study aimed to explore the quality of life and psycho-emotional distress of men undergoing infertility treatment in Serbia, thereby addressing the dearth of research on the underrepresented male perspective in this domain. Findings revealed diverse semen abnormalities among participants (n = 96, average age 37.69 ± 5.72), with significant associations between longer treatment durations and reduced sperm motility. The observed rates of men surpassing predetermined DASS-42 questionnaire thresholds for depression, anxiety, and stress in the analyzed cohort were 13.54%, 11.46%, and 22.92%, respectively. Summary scores in conceptual areas comprised in the SF-36 questionnaire ranged from 49.00 ± 6.25 for the mental health dimension to 90.16 ± 17.75 obtained in the physical functioning subscale. Patients with a longer treatment duration demonstrated lower scores in the role emotional domain, indicative of a less favorable emotional state. Expectedly, inverse correlations were found between the SF-36 mental health score and DASS-42 subscales. By addressing the existing knowledge gap and highlighting the unique needs of infertile men, the finding of this study may contribute to a more inclusive and holistic approach to infertility research and management.

Effects of online parietal transcranial electric stimulation on associative memory: a direct comparison between tDCS, theta tACS, and theta-oscillatory tDCS.

Associative memory (AM) is the ability to remember and retrieve multiple items bound together. Previous studies aiming to modulate AM by various transcranial electric stimulation (tES) techniques were inconclusive, although overall suggestive that tES could be a tool for AM enhancement. However, evidence from a direct comparison between different tES techniques is lacking. Here, in a sham-controlled cross-over experiment, we comparatively assessed the effects of three types of tES-anodal tDCS, theta-band transcranial alternating current stimulation (tACS), and theta-oscillatory tDCS (otDCS), delivered over the left posterior parietal cortex, during a short-term digit-color AM task with cued-recall. The effects were tested in 40 healthy young participants while both oscillatory tES were delivered at a previously determined individual theta frequency (4-8 Hz). All three active stimulations facilitated the overall AM performance, and no differences could be detected between them on direct comparison. However, unlike tDCS, the effects of which appeared to stem mainly from the facilitation of low-memory demand trials, both theta-modulated tACS and otDCS primarily promoted AM in high memory demand trials. Comparable yet differential effects of tDCS, theta tACS, and otDCS could be attributed to differences in their presumed modes of action.

Personalized Frequency Modulated Transcranial Electrical Stimulation for Associative Memory Enhancement.

Associative memory (AM) is the ability to remember the relationship between previously unrelated items. AM is significantly affected by normal aging and neurodegenerative conditions, thus there is a growing interest in applying non-invasive brain stimulation (NIBS) techniques for AM enhancement. A growing body of studies identifies posterior parietal cortex (PPC) as the most promising cortical target for both transcranial magnetic stimulation (TMS) and transcranial electrical stimulation (tES) to modulate a cortico-hippocampal network that underlines AM. In that sense, theta frequency oscillatory tES protocols, targeted towards the hallmark oscillatory activity within the cortico-hippocampal network, are increasingly coming to prominence. To increase precision and effectiveness, the need for EEG guided individualization of the tES protocols is proposed. Here, we present the study protocol in which two types of personalized oscillatory tES-transcranial alternating current stimulation (tACS) and oscillatory transcranial direct current stimulation (otDCS), both frequency-modulated to the individual theta-band frequency (ITF), are compared to the non-oscillatory transcranial direct current stimulation (tDCS) and to the sham stimulation. The study has cross-over design with four tES conditions (tACS, otDCS, tDCS, sham), and the comprehensive set of neurophysiological (resting state EEG and AM-evoked EEG) and behavioral outcomes, including AM tasks (short-term associative memory, face-word, face-object, object-location), as well as measures of other cognitive functions (cognitive control, verbal fluency, and working memory).

Responses at Individual Gamma Frequencies Are Related to the Processing Speed but Not the Inhibitory Control.

The link between the state of networks underlying the generation of periodic responses at gamma ranges and cognitive outcomes is still poorly understood. In this study, we tested the idea that the individual differences in the ability to generate responses to auditory stimulation at gamma frequencies may underlie the individual differences in the inhibitory control. We focused on the processing speed and accuracy in the Bivalent Shape Task (a cognitive inhibition task assessing attentional interference) and explored the relationship with responses at 40 Hz and at individual gamma frequencies (IGFs, assessed utilizing auditory envelope-following responses in 30-60 Hz range). In a sample of 70 subjects, we show that individual measures (phase-locking index and event-related spectral perturbation) of the ability to generate gamma-range activity are not related to the individual differences in inhibitory control but rather reflect basic information processing speed in healthy young subjects. With the individualized approach (at IGFs), the observed associations were found to be somewhat stronger. These findings have important implications for the interpretation of gamma activity in neuropsychiatric disorders.

Determining the Individual Theta Frequency for Associative Memory Targeted Personalized Transcranial Brain Stimulation.

Non-invasive brain stimulation (NIBS) methods have gained increased interest in research and therapy of associative memory (AM) and its impairments. However, the one-size-fits-all approach yields inconsistent findings, thus putting forward the need for electroencephalography (EEG)-guided personalized frequency-modulated NIBS protocols to increase the focality and the effectiveness of the interventions. Still, extraction of individual frequency, especially in the theta band, turned out to be a challenging task. Here we present an approach to extracting the individual theta-band frequency (ITF) from EEG signals recorded during the AM task. The method showed a 93% success rate, good reliability, and the full range of variability of the extracted ITFs. This paper provides a rationale behind the adopted approach and critically evaluates it in comparison to the alternative methods that have been reported in the literature. Finally, we discuss how it could be used as an input parameter for personalized frequency-modulated NIBS approaches-transcranial alternating current stimulation (tACS) and transcranial oscillatory current stimulation (otDCS) directed at AM neuromodulation.

Knowledge, Attitudes, and Practices on Tick-Borne Encephalitis Virus and Tick-Borne Diseases within Professionally Tick-Exposed Persons, Health Care Workers, and General Population in Serbia: A Questionnaire-Based Study.

This study assessed the level of knowledge, attitudes, and practices (KAP) regarding tick-borne encephalitis virus (TBEV) and tick-borne diseases (TBDs) among different groups of people in Serbia. Professionally tick-exposed persons (PTEPs), health care workers (HCWs), and the general population (GP) were subjected to an anonymous, voluntary, online questionnaire using Microsoft Forms. A total of 663 questionnaire responses were collected (February-March 2021), while 642 were included in the analysis. The significant difference in knowledge in TBDs existed between GP and PTEPs, and HCWs (p < 0.001). The perception of risk-to-tick exposure and TBDs was generally high (42.4 (95% CI: 33.6-51.2) within GP, 44.9 (95% CI: 35.8-53.9) within PTEPs and 46.2 (95% CI: 38.0-54.5) within HCWs), while fear was low (13.7 (95% CI: 7.9-19.5) within GP, 12.6 (95% CI: 7.3-19.9) within PTEPs, and 13.5 (95% CI: 7.4-19.5) within HCWs). Protective practices differed across groups (F (2639) = 12.920, p < 0.001, η2 = 0.039), with both PTEPs (t = 3.621, Cohen d = 0.332, p < 0.001) and HCWs (t = 4.644, Cohen d = 0.468, p < 0.001) adhering to more protective practices than the GP, without differences between PTEPs and HCWs (t = 1.256, Cohen d = 0.137, p = 0.421). Further education about TBDs in Serbia is required and critical points were identified in this study.

A comparative study on culture-specific and cross-cultural aspects of intercultural relations in Hungary, Serbia, Czech Republic, and Germany.

The ability, will, and belief that it is possible to deal effectively with members of other cultural/ethnic groups are still gaining importance all over the world. However, the majority of studies on intercultural relations focus on Western Europe and the USA, applying constructs and theories that replicate a western-centered worldview. As a consequence, it is unclear whether established measures for intergroup attitudes and intercultural competence may be applied in Eastern European countries and to what extent they display comparable ideas, thoughts, and feelings. The current study thus explores cross-cultural commonalities and differences in established measures of ethnic identity, prejudice, acculturation strategies, intercultural intelligence, and multicultural personality. Therefore, we compare the scale structure, difficulty, and sensitivity in samples from Germany and the Eastern European countries Hungary, Serbia, and the Czech Republic (etic-perspective), as well as the culture-specific conceptions of said concepts (emic-perspective). Results show that the investigated scales do not work comparably across German and Eastern European samples. Differences might be rooted in variations of underlying thinking patterns and connotations of single expressions. Those variations are likely to be related to the constant individual societal and historical developments of cultures, shaping the way individuals think and talk about cultural diversity. Future studies are encouraged to consider culture-specific and generalizable aspects of constructs when conducting cross-cultural research on intercultural relations.

Transcranial Direct Current Stimulation (tDCS) for Memory Enhancement.

Memory enhancement is one of the great challenges in cognitive neuroscience and neurorehabilitation. Among various techniques used for memory enhancement, transcranial direct current stimulation (tDCS) is emerging as an especially promising tool for improvement of memory functions in a non-invasive manner. Here, we present a tDCS protocol that can be applied for memory enhancement in healthy-participant studies as well as in aging and dementia research. The protocol uses weak constant anodal current to stimulate cortical targets within cortico-hippocampal functional network engaged in memory processes. The target electrode is placed either on the posterior parietal cortex (PPC) or the dorsolateral prefrontal cortex (DLPFC), while the return electrode is placed extracranially (i.e., on the contralateral cheek). In addition, we outline a more advanced method of oscillatory tDCS, mimicking a natural brain rhythm to promote hippocampus-dependent memory functions, which can be applied in a personalized and non-personalized manner. We present illustrative results of associative and working memory improvement following single tDCS sessions (20 minutes) in which the described electrode montages were used with current intensities between 1.5 mA and 1.8 mA. Finally, we discuss crucial steps in the protocol and methodological decisions that must be made when designing a tDCS study on memory.

Gamma-Range Auditory Steady-State Responses and Cognitive Performance: A Systematic Review.

The auditory steady-state response (ASSR) is a result of entrainment of the brain's oscillatory activity to the frequency and phase of temporally modulated stimuli. Gamma-range ASSRs are utilized to observe the dysfunctions of brain-synchronization abilities in neuropsychiatric and developmental disorders with cognitive symptoms. However, the link between gamma-range ASSRs and cognitive functioning is not clear. We systematically reviewed existing findings on the associations between gamma-range ASSRs and cognitive functions in patients with neuropsychiatric or developmental disorders and healthy subjects. The literature search yielded 1597 articles. After excluding duplicates and assessing eligibility, 22 articles were included. In healthy participants, the gamma-range ASSR was related to cognitive flexibility and reasoning as measured by complex tasks and behavioral indicators of processing speed. In patients with schizophrenia, the studies that reported correlations found a higher ASSR to be accompanied by better performance on short-term memory tasks, long-term/semantic memory, and simple speeded tasks. The main findings indicate that individual differences in the gamma-range ASSR reflect the level of attentional control and the ability to temporary store and manipulate the information, which are necessary for a wide range of complex cognitive activities, including language, in both healthy and impaired populations.