Exploring the Neurocognitive Bases of Statistical Learning

Statistical Learning (SL) involves the extraction of organizing principles from a set of inputs. Recent advances in SL suggest that SL is a componential construct. To better characterize the componential nature of SL, a strategy may be to turn to literature regarding memory and learning. The current study sought to extend the literature by further characterizing the componential nature of. Aim 1 examined the effect of instruction type (explicit, implicit) on direct and indirect (explicit, implicit) indices of visual statistical learning (VSL) performance. Several studies have suggested explicit instructions shift engagement of additional explicit memory resources improving performance. There were no differences in indirect or direct measures of VSL performance. However, the relationship between direct and indirect measures of VSL was affected by instructional condition suggesting the processes underlying VSL may have been affected. Aim 2 examined the relationship between VSL performance and implicit and explicit memory/learning. Further, Aim 2 examined whether instructional condition affected the relationship between VSL and multiple memory systems. The relationship between the direct measure of VSL and explicit and implicit memory was inconsistent. However, the direct measure patterned similarly across explicit and implicit memory (positive relationship, not affected by instructional condition). The relationship between the indirect measures of VSL and multiple memory systems was similarly inconsistent, but had a similar patterning in the significant cases (positive relationship in the explicit condition, but negative relationship in the implicit condition). This suggests the indirect measure of VSL was affected by the instructional condition to differentially emphasize aspects of memory systems. In addition, In recent years, several methodological issues have been identified regarding measures established in the literature. To address the inconsistencies in the findings and these concerns, the psychometric properties of the established measures were examined. Exploratory Aim 3 sought to improve upon the processing of these measures using advanced statistical methods and provide recommendations regarding best practices for individual differences analyses. In Exploratory Aim 4, the first set of results were revisited in an exploratory manner using the insights gained from the updated measures. Implications for the characterization of the componential nature of SL were discussed

Exploring the Neurocognitive Bases of Statistical Learning

Statistical Learning (SL) involves the extraction of organizing principles from a set of inputs. Recent advances in SL suggest that SL is a componential construct. To better characterize the componential nature of SL, a strategy may be to turn to literature regarding memory and learning. The current study sought to extend the literature by further characterizing the componential nature of. Aim 1 examined the effect of instruction type (explicit, implicit) on direct and indirect (explicit, implicit) indices of visual statistical learning (VSL) performance. Several studies have suggested explicit instructions shift engagement of additional explicit memory resources improving performance. There were no differences in indirect or direct measures of VSL performance. However, the relationship between direct and indirect measures of VSL was affected by instructional condition suggesting the processes underlying VSL may have been affected. Aim 2 examined the relationship between VSL performance and implicit and explicit memory/learning. Further, Aim 2 examined whether instructional condition affected the relationship between VSL and multiple memory systems. The relationship between the direct measure of VSL and explicit and implicit memory was inconsistent. However, the direct measure patterned similarly across explicit and implicit memory (positive relationship, not affected by instructional condition). The relationship between the indirect measures of VSL and multiple memory systems was similarly inconsistent, but had a similar patterning in the significant cases (positive relationship in the explicit condition, but negative relationship in the implicit condition). This suggests the indirect measure of VSL was affected by the instructional condition to differentially emphasize aspects of memory systems. In addition, In recent years, several methodological issues have been identified regarding measures established in the literature. To address the inconsistencies in the findings and these concerns, the psychometric properties of the established measures were examined. Exploratory Aim 3 sought to improve upon the processing of these measures using advanced statistical methods and provide recommendations regarding best practices for individual differences analyses. In Exploratory Aim 4, the first set of results were revisited in an exploratory manner using the insights gained from the updated measures. Implications for the characterization of the componential nature of SL were discussed

Individual Differences in Sensitivity to Morphological Structure in Words and Nonwords

Understanding visual word recognition has been a central goal of psycholinguistics from its early beginnings. Examination of the statistical properties of language has uncovered many aspects of words that facilitate recognition. In addition, evidence from both behavior and computational modeling suggests that individual differences in experience and the strength of connections in an individual’s reading network affect the sensitivity to these statistical properties in language. Morphology has special properties in this sense as morphologically related items have statistical regularities across both form and meaning. The current study examined whether individual differences in skill modulate sensitivity to morphological structure. Specifically, we looked at the relationship of three established measures of sensitivity to morphological structure. We used a visual lexical decision task to simultaneously examine sensitivity to morphological structure in nonwords and words. Linear mixed effects modeling was used to assess the main effects of each measure and to extract individual effect slopes to be used in individual differences analysis. Participants also completed an individual skill battery meant to examine language ability. We found that the morphological effects showed systematic variability. As skill increased the nonword complexity effect increased and the morphological effects in words decreased. In addition, the nonword complexity effect in reaction time and the family size effect seem to be indexing opposite ends of the same dimension of variability. Base frequency, while closely related to family size, indexes a separate dimension of variability. Implications for the characterization of each of the effects and possible future directions are discussed

Beyond Panglossian Optimism: Larger N2 Amplitudes Probably Signal a Bilingual Disadvantage in Conflict Monitoring

In this special issue on the brain mechanisms that lead to cognitive benefits of bilingualism we discussed six reasons why it will be very difficult to discover those mechanisms. Many of these problems apply to the article by Fernandez, Acosta, Douglass, Doshi, and Tartar that also appears in the special issue. These concerns include the following: 1) an overly optimistic assessment of the replicability of bilingual advantages in behavioral studies, 2) reliance on risky small samples sizes, 3) failures to match the samples on demographic characteristics such as immigrant status, and 4) language group differences that occur in neural measures (i.e., N2 amplitude), but not in the behavioral data. Furthermore the N2 amplitude measure in general suffers from valence ambiguity: larger N2 amplitudes reported for bilinguals are more likely to reflect poorer conflict resolution rather than enhanced inhibitory control

The Brain Mechanisms Underlying the Cognitive Benefits of Bilingualism may be Extraordinarily Difficult to Discover

The hypothesis that coordinating two or more languages leads to an enhancement in executive functioning has been intensely studied for the past decade with very mixed results. The purpose of this review and analysis is to consider why it has been (and will continue to be) difficult to discover the brain mechanisms underlying any cognitive benefits to bilingualism. Six reasons are discussed: 1) the phenomenon may not actually exist; 2) the cognitive neuroscientists investigating bilingual advantages may have been studying the wrong component of executive functioning; 3) most experiments use risky small numbers of participants and are underpowered; 4) the neural differences between groups do not align with the behavioral differences; 5) neural differences sometimes suffer from valence ambiguity, that is, disagreements whether “more” implies better or worse functioning and 6) neural differences often suffer from kind ambiguity, that is, disagreements regarding what type of mental events the pattern of activation in a region-of-interest actually reflects