ERP measures of math anxiety:how math anxiety affects working memory and mental calculation tasks?

There have been several attempts to account for the impact of Mathematical Anxiety (MA) on brain activity with variable results. The present study examines the effects of MA on ERP amplitude during performance of simple arithmetic calculations and working memory tasks. Data were obtained from 32 university students as they solved four types of arithmetic problems (one- and two-digit addition and multiplication) and a working memory task comprised of three levels of difficulty (1, 2, and 3-back task). Compared to the Low-MA group, High-MA individuals demonstrated reduced ERP amplitude at frontocentral (between 180-320 ms) and centroparietal locations (between 380-420 ms). These effects were independent of task difficulty/complexity, individual performance, and general state/trait anxiety levels. Results support the hypothesis that higher levels of self-reported MA are associated with lower cortical activation during the early stages of the processing of numeric stimuli in the context of cognitive tasks

Typical and aberrant functional brain flexibility: lifespan development and aberrant organization in traumatic brain injury and dyslexia

Intrinsic functional connectivity networks derived from different neuroimaging methods and connectivity estimators have revealed robust developmental trends linked to behavioural and cognitive maturation. The present study employed a dynamic functional connectivity approach to determine dominant intrinsic coupling modes in resting-state neuromagnetic data from 178 healthy participants aged 8–60 years. Results revealed significant developmental trends in three types of dominant intra- and inter-hemispheric neuronal population interactions (amplitude envelope, phase coupling, and phase-amplitude synchronization) involving frontal, temporal, and parieto-occipital regions. Multi-class support vector machines achieved 89% correct classification of participants according to their chronological age using dynamic functional connectivity indices. Moreover, systematic temporal variability in functional connectivity profiles, which was used to empirically derive a composite flexibility index, displayed an inverse U-shaped curve among healthy participants. Lower flexibility values were found among age-matched children with reading disability and adults who had suffered mild traumatic brain injury. The importance of these results for normal and abnormal brain development are discussed in light of the recently proposed role of cross-frequency interactions in the fine-grained coordination of neuronal population activity

Greater repertoire and temporal variability of cross-frequency coupling (CFC) modes in resting-state neuromagnetic recordings among children with reading difficulties

Cross-frequency, phase-to-amplitude coupling (PAC) between neuronal oscillations at rest may serve as the substrate that supports information exchange between functionally specialized neuronal populations both within and between cortical regions. The study utilizes novel algorithms to identify prominent instantaneous modes of cross-frequency coupling and their temporal stability in resting state magnetoencephalography (MEG) data from 25 students experiencing severe reading difficulties (RD) and 27 age-matched non-impaired readers (NI). Phase coherence estimates were computed in order to identify the prominent mode of PAC interaction for each sensor, sensor pair, and pair of frequency bands (from δ to γ) at successive time windows of the continuous MEG record. The degree of variability in the characteristic frequency-pair PACf1−f2 modes over time was also estimated. Results revealed a wider repertoire of prominent PAC interactions in RD as compared to NI students, suggesting an altered functional substrate for information exchange between neuronal assemblies in the former group. Moreover, RD students showed significant variability in PAC modes over time. This temporal instability of PAC values was particularly prominent: (a) within and between right hemisphere temporo-parietal and occipito-temporal sensors and, (b) between left hemisphere frontal, temporal, and occipito-temporal sensors and corresponding right hemisphere sites. Altered modes of neuronal population coupling may help account for extant data revealing reduced, task-related neurophysiological and hemodynamic activation in left hemisphere regions involved in the reading network in RD. Moreover, the spatial distribution of pronounced instability of cross-frequency coupling modes in this group may provide an explanation for previous reports suggesting the presence of inefficient compensatory mechanisms to support reading

Ακαδημαϊκή αναβλητικότητα και οι συνέπειές της στην ημερήσια σχολική προετοιμασία και το άγχος: Μια έρευνα ποσοτικού ημερολογίου σε μαθητές Δημοτικού

The present quantitative diary study examines whether trait academic procrastination shapes the way students perceive their daily academic workload and, in turn, their state (i.e., daily) academic procrastination. This process was expected to determine the extent to which students are satisfied with their preparation for the next day at school and consequently, their anxiety levels at the end of the day. Forty-four elementary school students completed a questionnaire and a diary for five consecutive days over a school week. Results of multilevel analyses confirmed the study hypotheses. Specifically, the positive relationship between trait and state procrastination was supported, while academic workload was found to mediate this relationship. Additionally, daily academic procrastination associated positively to anxiety at the end of the day through its negative link with students’ satisfaction with preparation for the next school day. These findings suggest that even students high in trait academic procrastination exhibit significant within-person variations in daily procrastination, satisfaction with their preparation for the next day at school and anxiety at the end of the day. These daily variations are explained by the daily level of perceived academic workload.Η παρούσα μελέτη ποσοτικού ημερολογίου εξετάζει αν η ακαδημαϊκή αναβλητικότητα, ως σχετικά σταθερό ατομικό χαρακτηριστικό, διαμορφώνει τον τρόπο που οι μαθητές αντιλαμβάνονται το σχολικό φόρτο σε ημερήσιο επίπεδο και εν συνεχεία, την εμφάνιση αναβλητικών συμπεριφορών σε σχέση με την προετοιμασία τους για το σχολείο. Αυτή η διαδικασία προτάθηκε ότι καθορίζει το βαθμό που οι μαθητές είναι ικανοποιημένοι με την προετοιμασία τους για την επόμενη μέρα στο σχολείο και κατ’ επέκταση τα επίπεδα άγχους τους στο τέλος της ημέρας. Σαράντα-τέσσερις μαθητές Δημοτικού συμπλήρωσαν ένα ερωτηματολόγιο και ένα ημερολόγιο για πέντε διαδοχικές ημέρες κατά τη διάρκεια μιας σχολικής εβδομάδας. Τα αποτελέσματα πολύ-επίπεδων αναλύσεων επιβεβαίωσαν τις υποθέσεις της έρευνας. Συγκεκριμένα, βρέθηκε θετική σχέση ανάμεσα στην αναβλητικότητα ως σταθερό χαρακτηριστικό και ως ημερήσια κατάσταση, ενώ επιβεβαιώθηκε και ο διαμεσολαβητικός ρόλος του ημερήσιου σχολικού φόρτου στη σχέση αυτή. Επιπρόσθετα, βρέθηκε ότι η ημερήσια ακαδημαϊκή αναβλητικότητα σχετίζεται θετικά με το ημερήσιο άγχος δια μέσου της αρνητικής της σχέσης με την ικανοποίηση από την προετοιμασία των μαθημάτων για την επόμενη μέρα. Τα αποτελέσματα της έρευνας δείχνουν ότι ακόμα και οι αναβλητικοί μαθητές εμφανίζουν ενδο-ατομικές διακυμάνσεις ως προς τα επίπεδα καταστασιακής ακαδημαϊκής αναβλητικότητας, ικανοποίησης με την προετοιμασία τους για την επόμενη μέρα στο σχολείο και άγχους στο τέλος της ημέρας. Αυτές οι διακυμάνσεις εξηγούνται από τα επίπεδα του ημερήσιου, αντιλαμβανόμενου σχολικού φόρτου

Aberrant resting-state functional brain networks in dyslexia: Symbolic mutual information analysis of neuromagnetic signals

Neuroimaging studies have identified a variety of structural and functional connectivity abnormalities in students experiencing reading difficulties. The present study adopted a novel approach to assess the dynamics of resting-state neuromagnetic recordings in the form of symbolic sequences (i.e., repeated patterns of neuromagnetic fluctuations within and/or between sensors). Participants were 25 students experiencing severe reading difficulties (RD) and 27 agematched non-impaired readers (NI) aged 7-14 years. Sensor-level data were first represented as symbolic sequences in eight conventional frequency bands. Next, dominant types of sensorto- sensor interactions in the form of intra and cross-frequency coupling were computed and subjected to graph modeling to assess group differences in global network characteristics. As a group RD students displayed predominantly within-frequency interactions between neighboring sensors which may reflect reduced overall global network efficiency and cost-efficiency of information transfer. In contrast, sensor networks among NI students featured a higher proportion of cross-frequency interactions. Brain-reading achievement associations highlighted the role of left hemisphere temporo-parietal functional networks, at rest, for reading acquisition and ability

Early signs of memory impairment among multiple sclerosis patients with clinically isolated syndrome

Abstract. The study investigates primary and secondary verbal memory and motor/executive functions (response inhibition and strategy shifting ability) in multiple sclerosis (MS) patients with clinically isolated syndrome (CIS). We studied 44 CIS patients and compared them to 49 patients with relapsing remitting MS (RR-MS) displaying mild disability and to a large cohort of ageand education level-matched healthy volunteers (n = 230). Results showed that both CIS and RR-MS patients evidenced a disproportionate impairment in the immediate and delayed recall of the second (as compared to the first) of two short narratives of the Logical Memory WMS-III subtest, and reduced performance on the Memory for Digits-Forward. Performance of either group on the executive tasks was not impaired, showing evidence of a reversed speed-accuracy trade-off. Illness duration emerged as a significant predictor of memory and executive task performance. Clinical, psychoemotional, and brain imaging findings were also examined as potential correlates of memory deficits and disease progression among CIS patients. These findings may signify early-onset decline of specific cognitive functions in CIS, which merits regular follow-up assessments and monitoring of psychoemotional adaptation and everyday functioning

The Timing and Strength of Regional Brain Activation Associated with Word Recognition in Children with Reading Difficulties

The study investigates the relative degree and timing of cortical activation across parietal, temporal, and frontal regions during performance of a continuous visual-word recognition task in children who experience reading difficulties (N = 44, RD) and typical readers (N = 40, NI). Minimum norm estimates of regional neurophysiological activity were obtained from magnetoencephalographic recordings. Children with RD showed bilaterally reduced neurophysiological activity in the superior and middle temporal gyri, and increased activity in rostral middle frontal and ventral occipitotemporal cortices, bilaterally. The temporal profile of activity in the RD group, featured near-simultaneous activity peaks in temporal, inferior parietal, and prefrontal regions, in contrast to a clear temporal progression of activity among these areas in the NI group. These results replicate and extend previous MEG and fMRI results demonstrating atypical, latency-dependent attributes of the brain circuit involved in word reading in children with reading difficulties

In search of Matthew effects in reading

The concept of Matthew effects in reading development refers to a longitudinally widening gap between high achievers and low achievers. Various statistical approaches have been proposed to examine this idea. However, little attention has been paid to psychometric issues of scaling. Specifically, interval-level data are required to compare performance differences across performance ranges, but only ordinal-level data are available with current literacy measures. To demonstrate the interpretability problems of contrasting growth slopes, we use data from a longitudinal study of literacy development. We explore the possibility of comparing across ages, matched for performance, and we examine the consequences of nonlinear growth, temporal lag estimates, and individual differences in developmental progression. We conclude that, although conceptually appealing, the widening gap prediction is not empirically testable

Verbal Comprehension Ability in Aphasia: Demographic and Lexical Knowledge Effects

Background. Assessment of sentence-level auditory comprehension can be performed with a variety of tests varying in response requirements. A brief and easy to administer measure, not requiring an overt verbal or a complex motor response, is essential in any test battery for aphasia. Objective. The present study examines the clinical utility of receptive language indices for individuals with aphasia based on the Comprehension of Instructions in Greek (CIG), a variant of the Token Test, and the Greek version of PPVT-R. Methods. Normative data from a large community sample of Greek adults aged 46-80 years was available on both measures. A word-level-independent measure of auditory comprehension was computed as the standard score difference between the two tests and used to compare patients with and without comprehension deficits as indicated by their Boston Diagnostic Aphasia Examination profile. Results and Conclusions. Indices of internal consistency and test-retest reliability were very good. Education and age effects on performance were significant, with the former being stronger. The potential clinical utility of differential ability indices (contrasting sentence-and word-level auditory comprehension tests) is discussed