The impact of atypical text presentation on transposed-word effects

When asked to decide if an ungrammatical sequence of words is grammatically correct or not, readers find it more difficult to do so (longer response times (RTs) and more errors) if the ungrammatical sequence is created by transposing two words from a correct sentence (e.g., the white was cat big) compared with matched ungrammatical sequences where transposing two words does not produce a correct sentence (e.g., the white was cat slowly). Here, we provide a further exploration of transposed-word effects when reading unspaced text in Experiment 1, and when reading from right-to-left ("backwards" reading) in Experiment 2. We found significant transposed-word effects in error rates but not in RTs, a pattern previously found in studies using a one-word-at-a-time sequential presentation. We conclude that the absence of transposed-word effects in RTs in the present study and prior work is due to that atypical nature of the way that text was presented. Under the hypothesis that transposed-word effects at least partly reflect a certain amount of parallel word processing during reading, we further suggest that the ability to process words in parallel would require years of exposure to text in its regular format.

Written Language Acquisition Is Both Shaped by and Has an Impact on Brain Functioning and Cognition

Spoken language is a distinctive trace of our species and it is naturally acquired during infancy. Written language, in contrast, is artificial, and the correspondences between arbitrary visual symbols and the spoken language for reading and writing should be explicitly learned with external help. In this paper, I present several examples of how written language acquisition is both shaped by and has an impact on brain function and cognition. They show in one hand how our phylogenetic legacy influences education and on the other hand how ontogenetic needs for education can rapidly subdue deeply rooted neurocognitive mechanisms. The understanding of this bidirectional influences provides a more dynamic view of how plasticity interfaces phylogeny and ontogeny in human learning, with implications for both neurosciences and education.

A protocol to examine the learning effects of 'multisystem mapping' training combined with post-training sleep consolidation in beginning readers

We have recently used randomized controlled trials to examine the impact of a short neuroscience-informed causal intervention using a targeted training to inhibit a deeply rooted visual mechanism (mirror invariance) that hinders literacy acquisition, combined with post-training sleep (for learning consolidation). Using this training protocol, we have shown unprecedented improvements in visual perception of letters, writing, and a two-fold increase in reading fluency in first graders. Here, we describe this ecologically valid school-based intervention protocol to probe inhibition of mirror invariance for letters, including the detailed training instructions, post-training sleep consolidation, as well as practical tips and potential adaptations to different school sizes.

For complete details on the use and execution of this protocol, please refer to Torres et al., (2021).

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School-based protocol to probe inhibition of mirror invariance for letters

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Gains in visual perception of letters, writing and reading fluency in first graders

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Learning effects sustained for 4 months when sleep followed targeted training

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Simple, ecological and cost-effective 3 weeks intervention to double reading fluency

An ERP investigation of transposed-word effects in same-different matching

Can several words be read in parallel, and if so, how is information about word order encoded under such circumstances? Here we focused on the bottom-up mechanisms involved in word-order encoding under the hypothesis of parallel word processing. We recorded EEG while participants performed a visual same-different matching task with sequences of five words (reference sequence followed by a target sequence each presented for 400 ms). The reference sequence could be grammatically correct or an ungrammatical scrambling of the same words (e.g., he wants these green apples/green wants these he apples). Target sequences for 'different' responses were created by either transposing two words in the reference (e.g., he these wants green apples/green these wants he apples), or by changing two words (e.g., he talks their green apples/green talks their he apples). Different responses were harder to make in the transposition condition, and this transposed-word effect started to emerge around 250 ms post-target onset. The transposed-word effect was first seen on an early onsetting N400 component, with reduced amplitudes (i.e., less negative ERPs) in the transposed condition relative to a two-word replacement condition. A later transposed-word effect was seen on a more temporally widespread positive-going component. Converging behavioral and EEG results showed no effects of reference grammaticality on 'different' responses nor an interaction with transposed-word effects. Our results point to the noisy, bottom-up association of word identities to spatiotopic locations as one means of encoding word order information, and one key source of transposed-word effects.

Neural Representations Behind 'Social Norm' Inferences In Humans

Humans are highly skilled in social reasoning, e.g., inferring thoughts of others. This mentalizing ability systematically recruits brain regions such as Temporo-Parietal Junction (TPJ), Precuneus (PC) and medial Prefrontal Cortex (mPFC). Further, posterior mPFC is associated with allocentric mentalizing and conflict monitoring while anterior mPFC is associated with self-reference (egocentric) processing. Here we extend this work to how we reason not just about what one person thinks but about the abstract shared social norm. We apply functional magnetic resonance imaging to investigate neural representations while participants judge the social congruency between emotional auditory utterances in relation to visual scenes according to how ‘most people’ would perceive it. Behaviorally, judging according to a social norm increased the similarity of response patterns among participants. Multivoxel pattern analysis revealed that social congruency information was not represented in visual and auditory areas, but was clear in most parts of the mentalizing network: TPJ, PC and posterior (but not anterior) mPFC. Furthermore, interindividual variability in anterior mPFC representations was inversely related to the behavioral ability to adjust to the social norm. Our results suggest that social norm inferencing is associated with a distributed and partially individually specific representation of social congruency in the mentalizing network.

A Multitude of Neural Representations Behind Multisensory "Social Norm" Processing

Humans show a unique capacity to process complex information from multiple sources. Social perception in natural environment provides a good example of such capacity as it typically requires the integration of information from different sensory systems, and also from different levels of sensory processing. Here, instead of studying one isolate system and level of representation, we focused upon a neuroimaging paradigm which allows to capture multiple brain representations simultaneously, i.e., low and high-level processing in two different sensory systems, as well as abstract cognitive processing of congruency. Subjects performed social decisions based on the congruency between auditory and visual processing. Using multivoxel pattern analysis (MVPA) of functional magnetic resonance imaging (fMRI) data, we probed a wide variety of representations. Our results confirmed the expected representations at each level and system according to the literature. Further, beyond the hierarchical organization of the visual, auditory and higher order neural systems, we provide a more nuanced picture of the brain functional architecture. Indeed, brain regions of the same neural system show similarity in their representations, but they also share information with regions from other systems. Further, the strength of neural information varied considerably across domains in a way that was not obviously related to task relevance. For instance, selectivity for task-irrelevant animacy of visual input was very strong. The present approach represents a new way to explore the richness of co-activated brain representations underlying the natural complexity in human cognition.

The Effect of Spatial Smoothing on Representational Similarity in a Simple Motor Paradigm

Multi-voxel pattern analyses (MVPA) are often performed on unsmoothed data, which is very different from the general practice of large smoothing extents in standard voxel-based analyses. In this report, we studied the effect of smoothing on MVPA results in a motor paradigm. Subjects pressed four buttons with two different fingers of the two hands in response to auditory commands. Overall, independent of the degree of smoothing, correlational MVPA showed distinctive patterns for the different hands in all studied regions of interest (motor cortex, prefrontal cortex, and auditory cortices). With regard to the effect of smoothing, our findings suggest that results from correlational MVPA show a minor sensitivity to smoothing. Moderate amounts of smoothing (in this case, 1−4 times the voxel size) improved MVPA correlations, from a slight improvement to large improvements depending on the region involved. None of the regions showed signs of a detrimental effect of moderate levels of smoothing. Even higher amounts of smoothing sometimes had a positive effect, most clearly in low-level auditory cortex. We conclude that smoothing seems to have a minor positive effect on MVPA results, thus researchers should be mindful about the choices they make regarding the level of smoothing.

How learning to read changes the cortical networks for vision and language

Does literacy improve brain function? Does it also entail losses? Using functional magnetic resonance imaging, we measured brain responses to spoken and written language, visual faces, houses, tools, and checkers in adults of variable literacy (10 were illiterate, 22 became literate as adults, and 31 were literate in childhood). As literacy enhanced the left fusiform activation evoked by writing, it induced a small competition with faces at this location, but also broadly enhanced visual responses in fusiform and occipital cortex, extending to area V1. Literacy also enhanced phonological activation to speech in the planum temporale and afforded a top-down activation of orthography from spoken inputs. Most changes occurred even when literacy was acquired in adulthood, emphasizing that both childhood and adult education can profoundly refine cortical organization.

Probing the lifetimes of auditory novelty detection processes

Auditory novelty detection can be fractionated into multiple cognitive processes associated with their respective neurophysiological signatures. In the present study we used high-density scalp event-related potentials (ERPs) during an active version of the auditory oddball paradigm to explore the lifetimes of these processes by varying the stimulus onset asynchrony (SOA). We observed that early MMN (90-160 ms) decreased when the SOA increased, confirming the evanescence of this echoic memory system. Subsequent neural events including late MMN (160-220 ms) and P3a/P3b components of the P3 complex (240-500 ms) did not decay with SOA, but showed a systematic delay effect supporting a two-stage model of accumulation of evidence. On the basis of these observations, we propose a distinction within the MMN complex of two distinct events: (1) an early, pre-attentive and fast-decaying MMN associated with generators located within superior temporal gyri (STG) and frontal cortex, and (2) a late MMN more resistant to SOA, corresponding to the activation of a distributed cortical network including fronto-parietal regions.