Are numerical abilities determined at early age? A brain morphology study in children and adolescents with and without developmental dyscalculia

The intraparietal sulcus (IPS) has been associated with numerical processing. A recent study reported that the IPS sulcal pattern was associated with arithmetic and symbolic number abilities in children and adults. In the present study, we evaluated the link between numerical abilities and the IPS sulcal pattern in children with Developmental Dyscalculia (DD) and typically developing children (TD), extending previous analyses considering other sulcal features and the postcentral sulcus (PoCS). First, we confirm the longitudinal sulcal pattern stability of the IPS and the PoCS. Second, we found a lower proportion of left sectioned IPS and a higher proportion of a double-horizontal IPS shape bilaterally in DD compared to TD. Third, our analyses revealed that arithmetic is the only aspect of numerical processing that is significantly related to the IPS sulcal pattern (sectioned vs not sectioned), and that this relationship is specific to the left hemisphere. And last, correlation analyses of age and arithmetic in children without a sectioned left IPS indicate that although they may have an inherent disadvantage in numerical abilities, these may improve with age. Thus, our results indicate that only the left IPS sulcal pattern is related to numerical abilities and that other factors co-determine numerical abilities.

The benefit of assessing implicit sequence learning in pianists with an eye-tracked serial reaction time task

Playing piano professionally has been shown to benefit implicit motor sequence learning. The aim of the current study was to determine whether this advantage reflects generally enhanced implicit sequence learning unrelated to pianists' higher motor and/or visual-motor coordination abilities. We examined implicit sequence learning using the ocular serial reaction time (O-SRT) task, a manual-free eye-tracked version of the standard SRT, in 29 pianists and 31 controls. Reaction times (RT) and correct anticipations (CA) of several phases describing implicit sequence learning were analyzed. Furthermore, explicit sequence knowledge was compared between the groups, and relationships between implicit sequence learning with explicit sequence knowledge or demographic measures were evaluated. Pianists demonstrated superiority in all critical phases of implicit sequence learning (RT and CA). Moreover, pianists acquired higher explicit sequence knowledge, and only in pianists was explicit sequence knowledge related to implicit sequence learning. Our results demonstrate that pianists' superiority in implicit sequence learning is due to a higher general implicit sequence learning ability. Hence, we can exclude that higher motor and/or visual-motor coordination abilities are related to pianists' higher implicit sequence learning. Furthermore, the significant relationship of implicit sequence learning and explicit sequence knowledge suggests that pianists either used explicit strategies to support implicit sequence learning, had better explicit access to sequence knowledge, or both.

The adapted symbol digit modalities test: Examining the impact of response modality

BACKGROUND

Information processing speed is often impaired in neurological disorders, as well as with healthy aging. Thus, being able to accurately assess information processing speed is of high importance. One of the most commonly used tests to examine information processing speed is the Symbol Digit Modalities Test (SDMT), which has been shown to have good psychometric properties.

OBJECTIVES

The current study aims to examine differences between two response modalities, written and oral, on the performance of an adapted version of the Symbol Digit Modalities Test.

METHODS

Ninety-nine individuals completed two alternate forms of the adapted version of the SDMT (aSDMT). Participants were instructed to complete the five lines of the task as quickly and accurately as possible. On one form participants were instructed to provide their response in writing and on the other one, orally. Form and response modality (oral vs. written) were counterbalanced to control for practice effects.

RESULTS

On average, there was a significant difference between response modalities, such that participants needed more time to respond when the response modality was written. For both response modalities, time to complete each line of stimuli decreased as the task progressed. While changes in response time on the first four lines of stimuli on the oral version were not found, there was a substantial improvement in response time on the fifth line. In contrast, on the written version a gradual learning effect was observed, in which response time was the slowest on the first two lines, an intermediate response time was noted on line 3, and the fastest response time was achieved on lines four and five.

CONCLUSION

The current study demonstrates that response modality, oral versus written, can significantly impact performance efficiency (the length of time it takes to complete a task), but not accuracy (total correct responses), on a new adaptation of the SDMT, the aSDMT.

Day versus night consolidation of implicit sequence learning using manual and oculomotor activation versions of the serial reaction time task: reaction time and anticipation measures

This study presents two experiments that explored consolidation of implicit sequence learning based on two dependent variables-reaction time (RT) and correct anticipations to clarify the role of sleep, and whether the manual component is necessary for consolidation processes. Experiment 1 (n = 37) explored the performance of adults using an ocular variant of the serial reaction time task (O-SRT) with manual activation (MA), and Experiment 2 (n = 37) used the ocular activation (OA) version of the task. Each experiment consisted of a Day and a Night group that performed two sessions of the O-SRT with an intervening 12-h offline period (morning/evening in Day group, evening/following morning in Night group). Night offline had an advantage only when manual response was required and when correct anticipations (i.e., accuracy) but not RT (i.e., speed) were measured. We associated this finding with the dual-learning processes required in the MA O-SRT that led to increased sequence specific learning overnight. When using the OA O-SRT, both groups demonstrated similar rates after offline in RT and correct anticipations. We interpreted this finding to reflect stabilization, which confirmed our hypothesis. As expected, all the groups demonstrated reduced performance when another sequence was introduced, thus reflecting sequence-specific learning. This study used a powerful procedure that allows measurement of implicit sequence learning in several ways: by evaluating two different measures (RT, correct anticipations) and by isolating different aspects of the task (i.e., with/without the manual learning component, more/less general skill learning), which are known to affect learning and consolidation.

Oculomotor anticipation reveals a multitude of learning processes underlying the serial reaction time task

Sequence learning is the cognitive faculty enabling everyday skill acquisition. In the lab, it is typically measured in speed of response to sequential stimuli, whereby faster responses are taken to indicate improved anticipation. However, response speed is an indirect measure of anticipation, that can provide only limited information on underlying processes. As a result, little is known about what is learned during sequence learning, and how that unfolds over time. In this work, eye movements that occurred before targets appeared on screen in an ocular serial reaction time (O-SRT) task provided an online indication of where participants anticipated upcoming targets. When analyzed in the context of the stimuli preceding them, oculomotor anticipations revealed several simultaneous learning processes. These processes influenced each other, as learning the task grammar facilitated acquisition of the target sequence. However, they were dissociable, as the grammar was similarly learned whether a repeating sequence inhabited the task or not. Individual differences were found in how the different learning processes progressed, allowing for similar performance to be produced for different latent reasons. This study provides new insights into the processes subserving sequence learning, and a new method for high-resolution study of it.

Implicit sequence learning in individuals with Parkinson's disease: The added value of using an ocular version of the serial reaction time (O-SRT) task

INTRODUCTION

Though the majority of studies reported impaired sequence learning in individuals with Parkinson's disease (PD) tested with the Serial Reaction Time (SRT) task, findings are inconclusive. To elucidate this point, we used an eye tracker in an ocular SRT task version (O-SRT) that in addition to RT, enables extraction of two measures reflecting different cognitive processes, namely, Correct Anticipation (CA) and number of Stucks.

METHODS

Individuals with PD (n = 29) and matched controls (n = 31) were tested with the O-SRT task, consisting of a repeated sequence of six blocks, then a block with an interference sequence followed by an original sequence block.

RESULTS

Unlike controls, patients with PD did not improve in CA rate across learning trials, did not show an increase in RT when presented with the interference sequence, and showed a significantly higher rate of Stucks.

CONCLUSIONS

Low CA rate and high Stucks rate emerge as the cardinal deficits leading to impaired sequence learning following PD. These are viewed as reflecting difficulty in exploration for an efficient learning strategy. This study highlights the advantage in using the O-SRT task, which enables the generation of several informative measures of learning, allowing better characterization of the PD effect on sequence learning.

New insights in implicit sequence learning of adults with traumatic brain injury: As measured by an ocular serial reaction time (O-SRT) task

Objective: We investigated the effect of traumatic brain injury (TBI) on implicit sequence learning (ISL) and its relation with demographic, clinical, and working memory (WM) capacity using an eye-tracked variant of the standard serial reaction time (RT; SRT) task. Besides RT, this ocular SRT (O-SRT) task enables generation of correct anticipations (CA) and stucks, reflecting other critical aspects of ISL. Method: ISL was tested in 26 individuals with TBI and 28 healthy controls using the O-SRT task. Mixed analyses of variance were conducted to analyze RT and CA in three phases: learning, interference, and recovery from interference. The average number of stucks was compared with an independent-samples t test. Finally, Pearson correlation analyses of ISL with demographic, clinical, and WM capacity measures were performed. Results: Based on RT, ISL was impaired in the TBI group. However, CA demonstrated improved learning, but with deficits in the interference and recovery from interference phases. Stucks were more frequent in the TBI group, which affected RT and CA measures. Neither demographic nor clinical factors were associated with ISL. Verbal, but not spatial, WM capacity was impaired in the TBI group, and spatial WM capacity positively correlated with ISL in controls only. Conclusion: We suggest that the high TBI group stuck rate can be attributed to lack of initiative and/or conservative response bias associated with TBI, and view it as a main cause leading to deficits in ISL. Unlike controls, the TBI group could not muster their relatively preserved spatial WM capacity to support their ISL performance. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Direct and indirect measures of context in patients with mild-to-severe traumatic brain injury (TBI): The additive contribution of eye tracking

Introduction: The facilitation of memory for target stimuli due to the similarity of context in the learning and testing phases is known as the "Context-Effect" (CE). Previous studies reported that TBI affects memory for contextual information when tested directly. However, the indirect effect of contextual information on memory of target (i.e., CE) is preserved. Several studies have demonstrated that CE is composed of multiple, distinct cognitive processes. The present study includes four context conditions to enable identification of the exact process affected by TBI. In addition, eye movements were monitored to test three hypotheses: first, that the TBI group's dwell time on target (DTOT) at encoding would be less than that of controls. Second, that DTOT at encoding would be more highly associated with recognition at test for the control group than for the TBI group. Third, that overall DTOT at encoding on new, as compared to old items ("repetition effect"), would be less pronounced for the TBI group as compared to controls. Methods: Twenty-four patients with mild-to-severe TBI and 23 matched controls participated in this study. We presented participants with photographs of male faces shown wearing distinctive, trial-unique hats (yielding specific Target-Context pairing). Eye movements were recorded throughout the test task. Results: Memory for faces following TBI is impaired compared to that of controls. The magnitude and pattern of CE are the same for both groups. The TBI group has a lower DTOT compared to that of controls. However, the relative length of DTOT in the various conditions is similar in both groups. Conclusions: Behavioral results indicate that although the TBI group has impaired memory for faces, the CE pattern is similar to that of controls. Similarly, in terms of eye movements, although the TBI group focuses less on target, relations between the various conditions are similar in both groups.

Developmental dyscalculia: a dysconnection syndrome?

Numerical understanding is important for everyday life. For children with developmental dyscalculia (DD), numbers and magnitudes present profound problems which are thought to be based upon neuronal impairments of key regions for numerical understanding. The aim of the present study was to investigate possible differences in white matter fibre integrity between children with DD and controls using diffusion tensor imaging. White matter integrity and behavioural measures were evaluated in 15 children with developmental dyscalculia aged around 10 years and 15 matched controls. The main finding, obtained by a whole brain group comparison, revealed reduced fractional anisotropy in the superior longitudinal fasciculus in children with developmental dyscalculia. In addition, a region of interest analysis exhibited prominent deficits in fibres of the superior longitudinal fasciculus adjacent to the intraparietal sulcus, which is thought to be the core region for number processing. To conclude, our results outline deficient fibre projection between parietal, temporal and frontal regions in children with developmental dyscalculia, and therefore raise the question of whether dyscalculia can be seen as a dysconnection syndrome. Since the superior longitudinal fasciculus is involved in the integration and control of distributed brain processes, the present results highlight the importance of considering broader domain-general mechanisms in the diagnosis and therapy of dyscalculia.