The neural substrates of natural reading: a comparison of normal and nonword text using eyetracking and fMRI

A meta-analytical account of the functional lateralization of the reading network

The observation that the neural correlates of reading are left-lateralized is ubiquitous in the cognitive neuroscience and neuropsychological literature. Still, reading is served by a constellation of neural units, and the extent to which these units are consistently left-lateralized is unclear. In this regard, the functional lateralization of the fusiform gyrus is of particular interest, by virtue of its hypothesized role as a "visual word form area". A quantitative Activation Likelihood Estimation meta-analysis was conducted on activation foci from 35 experiments investigating silent reading, and both a whole-brain and a bayesian ROI-based approach were used to assess the lateralization of the data submitted to meta-analysis. Perirolandic areas showed the highest level of left-lateralization, the fusiform cortex and the parietal cortex exhibited only a moderate pattern of left-lateralization, while in the occipital, insular cortices and in the cerebellum the lateralization turned out to be the lowest observed. The relatively limited functional lateralization of the fusiform gyrus was further explored in a regression analysis on the lateralization profile of each study. The functional lateralization of the fusiform gyrus during reading was positively associated with the lateralization of the precentral and inferior occipital gyri and negatively associated with the lateralization of the triangular portion of the inferior frontal gyrus and of the temporal pole. Overall, the present data highlight how lateralization patterns differ within the reading network. Furthermore, the present data highlight how the functional lateralization of the fusiform gyrus during reading is related to the degree of functional lateralization of other language brain areas.

Music literacy improves reading skills via bilateral orthographic development

Considerable evidence suggests that musical education induces structural and functional neuroplasticity in the brain. This study aimed to explore the potential impact of such changes on word-reading proficiency. We investigated whether musical training promotes the development of uncharted orthographic regions in the right hemisphere leading to better reading abilities. A total of 60 healthy, right-handed culturally matched professional musicians and controls took part in this research. They were categorised as normo-typical readers based on their reading speed (syl/sec) and subdivided into two groups of relatively good and poor readers. High density EEG/ERPs were recorded while participants engaged in a note or letter detection task. Musicians were more fluent in word, non-word and text reading tests, and faster in detecting both notes and words. They also exhibited greater N170 and P300 responses, and target-non target differences for words than controls. Similarly, good readers showed larger N170 and P300 responses than poor readers. Increased reading skills were associated to a bilateral activation of the occipito/temporal cortex, during music and word reading. Source reconstruction also showed a reduced activation of the left fusiform gyrus, and of areas devoted to attentional/ocular shifting in poor vs. good readers, and in controls vs. musicians. Data suggest that music literacy acquired early in time can shape reading circuits by promoting the specialization of a right-sided reading area, whose activity was here associated with enhanced reading proficiency. In conclusion, music literacy induces measurable neuroplastic changes in the left and right OT cortex responsible for improved word reading ability.

The effects of rehabilitative interventions on reading disorders caused by homonymous visual field defects: a meta-analysis focusing on improvement in reading speed

INTRODUCTION

Reading disorders caused by homonymous visual field defects (HVFDs) have a significant impact on a patient's quality of life. However, no review has been conducted to evaluate the available evidence on the effects of rehabilitative interventions on reading disorders caused by HVFDs. Thus, the aim of this study was to systematically evaluate the effects of rehabilitative interventions on reading disorders caused by HVFDs.

METHODS

We searched the MEDLINE/PubMed, Cochrane Library, ClinicalTrials.gov, CINAHL, and ScienceDirect databases for relevant articles. Relevant search terms were used to identify reports of randomized controlled trials or randomized crossover trials published between January 1990 and December 2021. Only studies that included reading-speed-related outcomes were analyzed. Risk of bias was assessed using the PEDro scale. Meta-analysis was conducted using a random-effects model, and standardized mean differences (SMD) and 95% confidence intervals (CIs) were calculated. Heterogeneity was assessed using the Ι2 statistic.

RESULTS

Nine studies were included in the meta-analysis. The results showed that rehabilitative interventions significantly improved reading disorders caused by HVFDs (SMD = 0.30; 95% CI 0.08-0.51; P < 0.01; Ι2 = 0.0%). Subgroup analysis showed that reading training significantly improved reading disorders (SMD = 0.35; 95% CI 0.05-0.66; P = 0.02; Ι2 = 0.0%).

CONCLUSION

Reading disorders caused by HVFDs can be improved through rehabilitation. In addition, reading training for the improvement of eye movement and fixation to compensate for foveal and parafoveal visual field defects may improve reading speed.

Perception of color mismatch or conspicuous marginal adaptation in extraoral prostheses with eye-tracking

STATEMENT OF PROBLEM

Color matching and marginal integrity are major challenges when providing extraoral maxillofacial prostheses. Which of the color and marginal harmony features are more important for the extraoral prostheses to be inconspicuous is unclear. Studies on the perception of these prostheses with objective evaluation criteria are lacking.

PURPOSE

The purpose of this observational study was to investigate the significance of color mismatch and conspicuous marginal adaptation in the perception of extraoral maxillofacial prostheses using eye-tracking technology. The secondary aim was to evaluate the perception of extraoral maxillofacial prostheses with regard to the observers' sex.

MATERIAL AND METHODS

Twenty-seven face images, in 3 groups, representing well-fitting orbital prostheses with a color mismatch (IC), prostheses with a good color match but distinct marginal adaptation (IM), and symmetrical face images, were viewed for 5 seconds by 52 laypeople. Time to first fixation (TFF), fixation duration (FD), and fixation count (FC) at defined areas of interest were recorded and analyzed by an eye-tracking device. Because of the nested structure of data, a sex- and age-adjusted random intercept linear mixed effects model was used to assess the difference between IC, IM, and SI. Bonferroni corrected P values were used for pairwise comparisons. The difference between observers' sex was evaluated with random intercept mixed model by adjusting for age for each image. For repeated measurement analysis, the lm4, lmerTest, and emmeans libraries in R version 4.3.1 (R Foundation for Statistical Computing) were used (α=.05 for all tests).

RESULTS

Significant differences were found between the symmetrical image group and other study groups at the facial prosthesis region in all parameters (each P<.001). Observers first focused on the facial prostheses in IC (0.72 seconds) and in IM (0.789 seconds). Longer fixation durations, 1.909, 1.989 seconds for IC and IM (PIC<.001, PIM<.001), respectively, and a higher fixation count for IC (5.28) (P<.001) and for IM (5.45) (P<.001) were recorded on facial prostheses compared with other areas of interest. Women were more focused on the prosthesis than men in the IC and IM groups considering FD (PIC=.003, PIM<.001) and FC values (PIC=.016, PIM<.001, PSI<.001). Fixation duration for women and men was 2.097 seconds and 1.739 seconds in the IC group, 2.219 seconds and 1.78 seconds in the IM group, and 1.364 seconds and 1.222 seconds in the SI group, respectively.

CONCLUSIONS

Since the color mismatch and distinct marginal adaptation of maxillofacial prostheses were recognized using eye-tracking technology, both features appeared to be equally significant to be considered in fabrication procedures.

Reading Braille by Touch Recruits Posterior Parietal Cortex

Blind readers use a tactile reading system consisting of raised dot arrays: braille/⠃⠗⠇. How do human brains implement reading by touch? The current study looked for signatures of reading-specific orthographic processes in braille, separate from low-level somatosensory responses and semantic processes. Of specific interest were responses in posterior parietal cortices (PPCs), because of their role in high-level tactile perception. Congenitally blind, proficient braille readers read real words and pseudowords by touch while undergoing fMRI. We leveraged the system of contractions in English braille, where one braille cell can represent multiple English print letters (e.g., "ing" ⠬, "one" ⠐⠕), making it possible to separate physical and orthographic word length. All words in the study consisted of four braille cells, but their corresponding Roman letter spellings varied from four to seven letters (e.g., "con-c-er-t" ⠒⠉⠻⠞. contracted: four cells; uncontracted: seven letters). We found that the bilateral supramarginal gyrus in the PPC increased its activity as the uncontracted word length increased. By contrast, in the hand region of primary somatosensory cortex (S1), activity increased as a function of a low-level somatosensory feature: dot-number per word. The PPC also showed greater response to pseudowords than real words and distinguished between real and pseudowords in multivariate-pattern analysis. Parieto-occipital, early visual and ventral occipito-temporal, as well as prefrontal cortices also showed sensitivity to the real-versus-pseudoword distinction. We conclude that PPC is involved in orthographic processing for braille, that is, braille character and word recognition, possibly because of braille's tactile modality.

Beyond Broca's and Wernicke's: Functional Mapping of Ancillary Language Centers Prior to Brain Tumor Surgery

Functional MRI is a well-established tool used for pre-surgical planning to help the neurosurgeon have a roadmap of critical functional areas that should be avoided, if possible, during surgery to minimize morbidity for patients with brain tumors (though this also has applications for surgical resection of epileptogenic tissue and vascular lesions). This article reviews the locations of secondary language centers within the brain along with imaging findings to help improve our confidence in our knowledge on language lateralization. Brief overviews of these language centers and their contributions to the language networks will be discussed. These language centers include primary language centers of "Broca's Area" and "Wernicke's Area". However, there are multiple secondary language centers such as the dorsal lateral prefrontal cortex (DLPFC), frontal eye fields, pre- supplemental motor area (pre-SMA), Basal Temporal Language Area (BTLA), along with other areas of activation. Knowing these foci helps to increase self-assurance when discussing the nature of laterality with the neurosurgeon. By knowing secondary language centers for language lateralization, via fMRI, one can feel confident on providing neurosurgeon colleagues with appropriate information on the laterality of language in preparation for surgery.

The ZuCo benchmark on cross-subject reading task classification with EEG and eye-tracking data

We present a new machine learning benchmark for reading task classification with the goal of advancing EEG and eye-tracking research at the intersection between computational language processing and cognitive neuroscience. The benchmark task consists of a cross-subject classification to distinguish between two reading paradigms: normal reading and task-specific reading. The data for the benchmark is based on the Zurich Cognitive Language Processing Corpus (ZuCo 2.0), which provides simultaneous eye-tracking and EEG signals from natural reading of English sentences. The training dataset is publicly available, and we present a newly recorded hidden testset. We provide multiple solid baseline methods for this task and discuss future improvements. We release our code and provide an easy-to-use interface to evaluate new approaches with an accompanying public leaderboard: www.zuco-benchmark.com.

Perception of orbital epitheses evaluated with eye tracker

PURPOSE

Orbital epitheses replace a missing eyeball and surrounding soft tissue. Perception of epithesis in public gaze and the attention areas on the face are of interest. This study aimed to examine the differences in perception of orbital epitheses by prosthodontists, dentistry students, and laypeople with an objective evaluation tool that utilized eye-tracking technology.

MATERIALS AND METHODS

Twenty-four frontal facial images of 12 patients who had orbital epitheses were viewed by 81 observers (prosthodontists, dentistry students, laypeople) in random order for 5 seconds each. Gaze data were analyzed. Kruskal-Wallis H test with Bonferroni correction was used to compare parameters in groups and areas of interest.

RESULTS

First fixation duration at the mouth for symmetrical images were 0.30, 0.28, and 0.25 seconds for prosthodontists, students, and laypeople, respectively. Fixation duration at the mouth for the laypeople (0.27 second) was shorter than students (0.29 second) and prosthodontists (0.31 second) at symmetrical images. Time to the first fixation to epithesis, nose, and eye was significantly lower than the forehead and mouth for all groups. Fixation count at epithesis was 6.36 for prosthodontists, 5.64 for students, and 5.34 for laypeople.

CONCLUSION

Eyes were of most significant interest for all observer groups in symmetrical images. Individuals dealing with dentistry, especially prosthodontists, paid more attention to the mouth region along with the eyes in symmetrical images, considering fixation duration and fixation count. Attention directed to epithesis by all groups was verified with objective and measurable criteria. Prosthodontists' attention to epithesis and mouth was evident considering the four parameters measured.

HD-tDCS of primary and higher-order motor cortex affects action word processing

The contribution of action-perception systems of the brain to lexical semantics remains controversial. Here, we used high-definition transcranial direct current stimulation (HD-tDCS) in healthy adults to examine the role of primary (left hand motor area; HMA) and higher-order (left anterior inferior parietal lobe; aIPL) action areas in action-related word processing (action verbs and manipulable nouns) compared to non-action-related control words (non-action verbs and non-manipulable nouns). We investigated stimulation-related effects at three levels of semantic processing: subliminal, implicit, and explicit. Broadly, we found that stimulation of HMA and aIPL resulted in relative facilitation of action-related language processing compared to non-action. HMA stimulation facilitated action verb processing in subliminal and implicit task contexts, suggesting that HMA helps represent action verbs even in semantically shallow tasks. HMA stimulation also facilitated manipulable noun comprehension in an explicit semantic task, suggesting that HMA contributes to manipulable noun comprehension when semantic demands are high. aIPL stimulation facilitated both manipulable noun and action verb processing during an implicit task. We suggest that both HMA and aIPL play a functional role in action semantics. HMA plays a general role in the semantics of actions and manipulable objects, while aIPL is important only when visuo-motor coordination is required for the action.

Brain Responses to Peer Feedback in Social Media Are Modulated by Valence in Late Adolescence

Previous studies have examined the neural correlates of receiving negative feedback from peers during virtual social interaction in young people. However, there is a lack of studies applying platforms adolescents use in daily life. In the present study, 92 late-adolescent participants performed a task that involved receiving positive and negative feedback to their opinions from peers in a Facebook-like platform, while brain activity was measured using functional magnetic resonance imaging (fMRI). Peer feedback was shown to activate clusters in the ventrolateral prefrontal cortex (VLPFC), medial prefrontal cortex (MPFC), superior temporal gyrus and sulcus (STG/STS), and occipital cortex (OC). Negative feedback was related to greater activity in the VLPFC, MPFC, and anterior insula than positive feedback, replicating previous findings on peer feedback and social rejection. Real-life habits of social media use did not correlate with brain responses to negative feedback.

Eye movements during text reading align with the rate of speech production

Across languages, the speech signal is characterized by a predominant modulation of the amplitude spectrum between about 4.3 and 5.5 Hz, reflecting the production and processing of linguistic information chunks (syllables and words) every ~200 ms. Interestingly, ~200 ms is also the typical duration of eye fixations during reading. Prompted by this observation, we demonstrate that German readers sample written text at ~5 Hz. A subsequent meta-analysis of 142 studies from 14 languages replicates this result and shows that sampling frequencies vary across languages between 3.9 Hz and 5.2 Hz. This variation systematically depends on the complexity of the writing systems (character-based versus alphabetic systems and orthographic transparency). Finally, we empirically demonstrate a positive correlation between speech spectrum and eye movement sampling in low-skilled non-native readers, with tentative evidence from post hoc analysis suggesting the same relationship in low-skilled native readers. On the basis of this convergent evidence, we propose that during reading, our brain's linguistic processing systems imprint a preferred processing rate-that is, the rate of spoken language production and perception-onto the oculomotor system.

Individual differences in first-pass fixation duration in reading are related to resting-state functional connectivity

Although there are considerable individual differences in eye movements during text reading, their neural correlates remain unclear. In this study, we investigated the relationship between the first-pass fixation duration (FPFD) in natural reading and resting-state functional connectivity (RSFC) in the brain. We defined the brain regions associated with early visual processing, word identification, attention shifts, and oculomotor control as seed regions. The results showed that individual FPFDs were positively correlated with individual RSFCs between the early visual network, visual word form area, and eye movement control/dorsal attention network. Our findings provide new evidence on the neural correlates of eye movements in text reading and indicate that individual differences in fixation time may shape the RSFC differences in the brain through the time-on-task effect and the mechanism of Hebbian learning.

Neural Correlates of Fixated Low- and High-level Scene Properties during Active Scene Viewing

During real-world scene perception, viewers actively direct their attention through a scene in a controlled sequence of eye fixations. During each fixation, local scene properties are attended, analyzed, and interpreted. What is the relationship between fixated scene properties and neural activity in the visual cortex? Participants inspected photographs of real-world scenes in an MRI scanner while their eye movements were recorded. Fixation-related fMRI was used to measure activation as a function of lower- and higher-level scene properties at fixation, operationalized as edge density and meaning maps, respectively. We found that edge density at fixation was most associated with activation in early visual areas, whereas semantic content at fixation was most associated with activation along the ventral visual stream including core object and scene-selective areas (lateral occipital complex, parahippocampal place area, occipital place area, and retrosplenial cortex). The observed activation from semantic content was not accounted for by differences in edge density. The results are consistent with active vision models in which fixation gates detailed visual analysis for fixated scene regions, and this gating influences both lower and higher levels of scene analysis.

Altered spontaneous neuronal activity and functional connectivity pattern in primary angle-closure glaucoma: a resting-state fMRI study

PURPOSE

To explore the alterations of spontaneous neuronal activity and functional connectivity pattern using fractional amplitude of low-frequency fluctuation (fALFF) and functional connectivity (FC) in patients with primary angle-closure glaucoma (PACG) and fALFF relationship with the glaucoma clinical indices.

MATERIALS AND METHODS

Forty-two PACG patients and 21 normal controls were enrolled in this study. Resting-state functional magnetic resonance imaging was firstly analyzed by fALFF and brain regions with altered fALFF between groups were selected as seeds for the further FC analysis. The relationships between fALFF/FC values of abnormal regions and ophthalmological measures, including mean deviation of visual field (MDVF) and retinal nerve fiber layer (RNFL) thickness, were also analyzed.

RESULTS

Compared with NC, PACG had significant lower fALFF values in the left cuneus, left middle temporal gyrus, right middle temporal gyrus, and right precentral gyrus, while higher fALFF values in the bilateral superior frontal gyrus (P < 0.05 after correction). Furthermore, PACG showed increased FC between left cuneus and bilateral superior frontal gyrus/bilateral posterior cingulate gyrus; between left middle temporal gyrus and bilateral superior frontal gyrus; and between right middle temporal gyrus and bilateral insular (P < 0.05 after correction). In addition, in the PACG group, the mean fALFF values of the left cuneus were positively correlated with MDVF (R = 0.419, P = 0.005) and RNFL thickness (R = 0.322, P = 0.038). Meanwhile, the mean fALFF values of bilateral superior frontal gyrus were negatively correlated with MDVF (R = - 0.454, P = 0.003) and RNFL thickness (R = - 0.556, P < 0.001).

CONCLUSIONS

PACG exhibited abnormal spontaneous neural activity and connectivity in several brain regions mainly associated with visual and visual-related functions. In addition, the fALFF values of the left cuneus and bilateral superior frontal gyrus may be complementary biomarkers for assessing the disease severity.

Natural Reading in Parkinson's Disease With and Without Mild Cognitive Impairment

Background: Patients with Parkinson’s disease (PD) show eye movement abnormalities and frequently complain about difficulties in reading. So far, it is unclear whether basal ganglia dysfunction or cognitive impairment has a greater impact on eye movements during reading.

Objective: To analyze eye movement behavior during a natural reading task with respect to cognitive state and dopaminergic therapy in PD and healthy controls.

Methods: Eye movements of 59 PD patients and 29 age- and education-matched healthy controls were recorded during mute, self-paced reading of a text. 25 cognitively normal PD patients performed the task additionally in off medication state. Clinical assessment included a comprehensive neuropsychological test battery and the motor section of MDS—Unified Parkinson’s Disease Rating Scale (MDS-UPDRS).

Results: PD-mild cognitive impairment (MCI) was diagnosed in 21 patients. Reading speed was significantly reduced in PD-MCI compared to healthy controls and PD patients without MCI due to higher numbers of progressive saccades. Cognitively intact PD patients showed no significant alterations of reading speed or eye movement pattern during reading. The fixation duration tended to be prolonged in PD compared to healthy controls and decreased significantly after levodopa intake. Scores for executive functions, attention, and language correlated with reading speed in the PD group.

Conclusion: The present study is the first to reveal (1) reduced reading speed with altered reading pattern in PD with MCI and (2) a relevant impact of levodopa on fixation duration during reading in PD. Further research is needed to determine whether therapeutic interventions, e.g., levodopa or neuropsychological training, improve the subjective reading experience for patients with PD.

Distinct individual differences in default mode network connectivity relate to off-task thought and text memory during reading

Often, as we read, we find ourselves thinking about something other than the text; this tendency to mind-wander is linked to poor comprehension and reduced subsequent memory for texts. Contemporary accounts argue that periods of off-task thought are related to the tendency for attention to be decoupled from external input. We used fMRI to understand the neural processes that underpin this phenomenon. First, we found that individuals with poorer text-based memory tend to show reduced recruitment of left middle temporal gyrus in response to orthographic input, within a region located at the intersection of default mode, dorsal attention and frontoparietal networks. Voxels within these networks were taken as seeds in a subsequent resting-state study. The default mode network region (i) had greater connectivity with medial prefrontal cortex, falling within the same network, for individuals with better text-based memory, and (ii) was more decoupled from medial visual regions in participants who mind-wandered more frequently. These findings suggest that stronger intrinsic connectivity within the default mode network is linked to better text processing, while reductions in default mode network coupling to the visual system may underpin individual variation in the tendency for our attention to become disengaged from what we are reading.

Alternating-color words influence Chinese sentence reading: Evidence from neural connectivity

In order to investigate how language and attention systems are affected by word boundary information during reading, we conducted a functional magnetic resonance imaging (fMRI) experiment in which text-color in naturally unspaced Chinese sentences were systematically manipulated in three experimental conditions, that is, text-color alternation consistent or inconsistent with word boundary (i.e., alternating-color word and non-word conditions), as well as a mono-color baseline condition. Twenty college students (14 females; 23.1 years old) were required to silently read 72 sentences during fMRI scanning. We found that the conditions of word boundary modulated the brain connections between the visual word form area (VWFA) and dorsal attention regions, and between the VWFA and language-related regions. These results suggest that the coordination between the VWFA and dorsal attention regions plays an important role in grouping characters and guiding the saccade according to perceptual grouping based on color, and that the connection between VWFA and MTG could be the neural mechanism of lexical access during Chinese text reading.

Brain activity during traditional textbook and audiovisual-3D learning

INTRODUCTION

Audiovisual educational tools have increasingly been used during the past years to complement and compete with traditional textbooks. However, little is known as to how the brain processes didactic information presented in different formats. We directly assessed brain activity during learning using both traditional textbook and audiovisual-3D material.

METHODS

A homogeneous sample of 30 young adults with active study habits was assessed. Educational material on the subject of Cardiology was adapted to be presented during the acquisition of functional MRI.

RESULTS

When tested after image acquisition, participants obtained similar examination scores for both formats. Evoked brain activity was robust during both traditional textbook and audiovisual-3D lessons, but a greater number of brain systems were implicated in the processing of audiovisual-3D information, consistent with its multisource sensory nature. However, learning was not associated with group mean brain activations, but was instead predicted by distinct functional MRI signal changes in the frontal lobes and showed distinct cognitive correlates. In the audiovisual-3D version, examination scores were positively correlated with late-evoked prefrontal cortex activity and working memory, and negatively correlated with language-related frontal areas and verbal memory. As for the traditional textbook version, the fewer results obtained suggested the opposite pattern, with examination scores negatively correlating with prefrontal cortex activity evoked during the lesson.

CONCLUSIONS

Overall, the results indicate that a similar level of knowledge may be achieved via different cognitive strategies. In our experiment, audiovisual learning appeared to benefit from prefrontal executive resources (as opposed to memorizing verbal information) more than traditional textbook learning.

Cortical control of eye movements in natural reading: Evidence from MVPA

Language comprehension during reading requires fine-grained management of saccadic eye movements. A critical question, therefore, is how the brain controls eye movements in reading. Neural correlates of simple eye movements have been found in multiple cortical regions, but little is known about how this network operates in reading. To investigate this question in the present study, participants were presented with normal text, pseudo-word text, and consonant string text in a magnetic resonance imaging (MRI) scanner with eyetracking. Participants read naturally in the normal text condition and moved their eyes "as if they were reading" in the other conditions. Multi-voxel pattern analysis was used to analyze the fMRI signal in the oculomotor network. We found that activation patterns in a subset of network regions differentiated between stimulus types. These results suggest that the oculomotor network reflects more than simple saccade generation and are consistent with the hypothesis that specific network areas interface with cognitive systems.

Uncovering cortical activations of discourse comprehension and their overlaps with common large-scale neural networks

We conducted a meta-analysis of 78 task-based functional magnetic resonance imaging (fMRI) studies (1976 total participants) to reveal underlying brain activations and their overlap with large-scale neural networks in the brain during general discourse comprehension and its sub-processes. We found that discourse comprehension involved a neural system consisting of widely distributed brain regions that comprised not only the bilateral perisylvian language zones, but also regions in the superior and medial frontal cortex and the medial temporal lobe. Moreover, this neural system can be categorized into several sub-systems representing various sub-processes of discourse comprehension, with the left inferior frontal gyrus and middle temporal gyrus serving as core regions across all sub-processes. At a large-scale network level, we found that discourse comprehension relied most heavily on the default network, particularly on its dorsal medial subsystem. The pattern associated with large-scale network cooperation varied according to the respective sub-processes required. Our results reveal the functional dissociation within the discourse comprehension neural system and highlight the flexible involvements of large-scale networks.

Differential brain mechanisms during reading human vs. machine translated fiction and news texts

Few neuroimaigng studies on reading comprehension have been conducted under natural reading settings. In this study, we showed texts presented in a natural way during functional MRI (fMRI) measurements to reveal brain areas sensitive to reading comprehension. Specifically, this paradigm independently manipulated two holistic features of article style: text genre and translation style, a qualitative index of how typical word choices and arrangements are made in daily use of the language. Specifically, articles from The New York Times (news) and Reader’s Digest (fiction) translated from English to Mandarin Chinese either by human experts or machine (Google Translate) were used to investigate the correlation of brain activity across participants during article reading. We found that bi-hemispheric visual cortex, precuneus, and occipito-parietal junction show significantly correlated hemodynamics across participants regardless of translation style and article genre. Compared to machine translation, reading human expert translation elicited more reliable fMRI signals across participants at precuneus, potentially because narrative representations and contents can be coherently presented over tens of seconds. We also found significantly stronger inter-subject correlated fMRI signals at temporal poles and fusiform gyri in fiction reading than in news reading. This may be attributed to more stable empathy processing across participants in fiction reading. The degree of stability of brain responses across subjects at extra-linguistic areas was found correlated with subjective rating on the text fluency. The functional connectivity between these areas was modulated by text genre and translation style. Taken together, our imaging results suggested stable and selective neural substrates associated with comprehending holistic features of written narratives.

Functional neuroanatomy of the human eye movement network: a review and atlas

The human eye movement network is a complex system that requires the integration of sensory, motor, attentional, and executive processes. Here, we review the neuroanatomy of the eye movement network with an emphasis on functional neuroimaging applications. We consolidate the literature into a concise resource designed to be immediately accessible and applicable to diverse research interests, and present the novel Functional Oculomotor System (FOcuS) Atlas-a tool in stereotaxic space that will simplify and standardize the inclusion of the eye movement network in future functional neuroimaging studies. We anticipate this review and the FOcuS Atlas will facilitate increased examination of the eye movement network across disciplines leading to a thorough understanding of how eye movement network function contributes to higher-order cognition and how it is integrated with other brain networks. Furthermore, functional examination of the eye movement network in patient populations offers the potential for deeper insight into the role of eye movement circuitry in functional network activity, diagnostic assessments, and the indications for augmentative communication systems that rely on eye movement control.

Age-Related Atrophy and Compensatory Neural Networks in Reading Comprehension

OBJECTIVES

Despite changes to brain integrity with aging, some functions like basic language processes remain remarkably preserved. One theory for the maintenance of function in light of age-related brain atrophy is the engagement of compensatory brain networks. This study examined age-related changes in the neural networks recruited for simple language comprehension.

METHODS

Sixty-five adults (native English-speaking, right-handed, and cognitively normal) aged 17-85 years underwent a functional magnetic resonance imaging (fMRI) reading paradigm and structural scanning. The fMRI data were analyzed using independent component analysis to derive brain networks associated with reading comprehension.

RESULTS

Two typical frontotemporal language networks were identified, and these networks remained relatively stable across the wide age range. In contrast, three attention-related networks showed increased activation with increasing age. Furthermore, the increased recruitment of a dorsal attention network was negatively correlated to gray matter thickness in temporal regions, whereas an anterior frontoparietal network was positively correlated to gray matter thickness in insular regions.

CONCLUSIONS

We found evidence that older adults can exert increased effort and recruit additional attentional resources to maintain their reading abilities in light of increased cortical atrophy.

Co-registration of eye movements and neuroimaging for studying contextual predictions in natural reading

Sixteen years ago, Sereno and Rayner (2003. Measuring word recognition in reading: eye movements and event-related potentials. Trends in Cognitive Sciences, 7(11), 489-493) illustrated how "by means of review and comparison" eye movement (EM) and event-related potential (ERP) studies may advance our understanding of visual word recognition. Attempts to simultaneously record EMs and ERPs soon followed. Recently, this co-registration approach has also been transferred to fMRI and oscillatory EEG. With experimental settings close to natural reading, co-registration enables us to directly integrate insights from EM and neuroimaging studies. This should extend current experimental paradigms by moving the field towards studying sentence-level processing including effects of context and parafoveal preview. This article will introduce the basic principles and applications of co-registration and selectively review how this approach may shed light on one of the most controversially discussed issues in reading research, contextual predictions in online language processing.

In situ use of the King-Devick eye tracking test and changes seen with sport-related concussion: saccadic and blinks counts

OBJECTIVES

Sport-related concussion (SRC) can result in impaired oculomotor function. Oculomotor performance, measured utilizing the King-Devick/Eye Tracking test (K-D/ET), is reported to be able to identify sub-optimal brain function. The objectives of the study were to determine the diagnostic accuracy of the K-D/ET in identifying SRC occurring from game participation and to perform a comparative analysis on saccade and blink counts for each K-D card individually and total counts between baseline and post-concussion.

METHODS

Nineteen male Australian Football players were assessed on the K-D/ET test. Those suspected of having SRC secondary to a head impact were also tested.

RESULTS

Participants recorded a slower time on the third (20.2 ± 4.6 s) screen when compared with the first (p = 0.0424) and second (p = 0.0150) screens. The number of blinks was higher on the third (2.9 ± 2.9) when compared with the second (p = 0.0057) screen. There was decrease of the K-D/ET total times between pre- and post-game (p = 0.1769). Participants who sustained a head impact recorded slower mean total K-D time (p = 0.7322), fewer mean total saccades (p = 0.0112), and more mean blinks (p = 0.8678) compared with their baseline scores. The assessment of blinks was the most sensitive measure for potential SRC (0.67). The K-D/ET duration was the most specific measure for potential SRC (0.88). An increase in the number of blinks had a fair specificity of 0.69.

CONCLUSION

The rapid number-naming component of the K-D test is an assessment tool which quantifies impairment to oculomotor function and has been validated as a diagnostic tool for SRC. The clinical usefulness of the eye tracking component of the K-D/ET test is that it may be an effective method to assess concussions with the eye tracking component serving as a measure of progression and return to play. However, more research is required at the adult and youth level.

Word Frequency Effects in Naturalistic Reading

Word frequency is a central psycholinguistic variable that accounts for substantial variance in language processing. A number of neuroimaging studies have examined frequency at a single word level, typically demonstrating a strong negative, and sometimes positive correlation between frequency and hemodynamic response. Here, 40 subjects read passages of text in an MRI scanner while their eye movements were recorded. We used fixation-related analysis to identify neural activity tied to the frequency of each fixated word. We found that negative correlations with frequency were reduced, while strong positive correlations were found in the temporal and parietal areas associated with semantics. We propose that the processing cost of low frequency words is reduced due to contextual cues. Meanings of high frequency words are more readily accessed and integrated with context resulting in enhanced processing in the semantic system. The results demonstrate similarities and differences between single word and naturalistic text processing.

The Distinct Roles of Dorsal and Ventral Visual Systems in Naming of Chinese Characters

We aimed to investigate the role of dorsal and ventral visual systems in rapid naming of simple Chinese characters. Twenty college students (10 female; M_age = 22.5 years) were required to covertly read a character- and a cross-matrix during an fMRI experiment. A basic prosaccade and a prosaccade-naming task were also performed to confirm the functional significance of the findings. The results of whole brain analysis showed that both dorsal and ventral visual systems were activated in the character-matrix reading. The cross-matrix scanning elicited weaker activation in the left middle frontal gyrus, superior temporal gyrus, and ventral occipitotemporal cortex. Next, whereas both top-down and bottom-up effective connectivities (ECs) were found between these two systems in the character-matrix reading, only top-down ECs were observed in the cross-matrix scanning. Moreover, in the character-matrix reading, we found a negative correlation between the reaction time of naming in the prosaccade-naming task and the EC strength from visual word form area to superior temporal gyrus and a positive correlation between the reaction time in the basic prosaccade task and the EC strength from middle frontal gyrus to intraparietal sulcus. The cross-matrix scanning did not show any brain-behavior relationship. These results suggest that while the dorsal visual system is mainly engaged in eye-movement control, the ventral system is associated more with orthographic processing and orthography-phonology mapping.

The Fictive Brain: Neurocognitive Correlates of Engagement in Literature

Fiction is vital to our being. Many people enjoy engaging with fiction every day. Here we focus on literary reading as 1 instance of fiction consumption from a cognitive neuroscience perspective. The brain processes which play a role in the mental construction of fiction worlds and the related engagement with fictional characters, remain largely unknown. The authors discuss the neurocognitive poetics model ( Jacobs, 2015a ) of literary reading specifying the likely neuronal correlates of several key processes in literary reading, namely inference and situation model building, immersion, mental simulation and imagery, figurative language and style, and the issue of distinguishing fact from fiction. An overview of recent work on these key processes is followed by a discussion of methodological challenges in studying the brain bases of fiction processing.

A Digital App to Aid Detection, Monitoring, and Management of Dyslexia in Young Children (DIMMAND): Protocol for a Digital Health and Education Solution

Background

Dyslexia, a specific learning difficulty and a disability as defined in the Equality Act 2010, is a lifelong condition that affects a child from the start of education. Dyslexia is characterized by difficulties in language processing (reading, spelling, and writing) which do not correspond with the child’s general intellectual abilities. Although dyslexia cannot be cured, there is a consensus that interventions are more effective and have greater impact the earlier they are administered. Effective interventions start with diagnosis. Currently, formal diagnosis requires an assessment by a dyslexia specialist or educational psychologist. These assessments are expensive and are not easy for a non-specialist teacher or parent to interpret. Consequently, formal assessments are normally performed at a much later age, when interventions are less likely to be effective. Combining the latest in scientific research, expertise of dyslexia practitioners and real-time interactivity facilitated by digital technologies, we aim to provide a cost-effective and convenient solution that focuses on early dyslexia detection and management.

Objective

We discuss the rationale and protocol for the design and development of a digital health solution aimed at improving the early detection, monitoring and management of dyslexia (DIMMAND) in young children (4-8 years). The primary objective is to create a game-based digital solution aimed at children, parents, and teachers that firstly assesses, then monitors and manages progress in a convenient, cost-effective and private environment.

Methods

The proposed solution will be designed and developed in phases. In the initial phase, the full functional specification of the games that constitute the app will be designed, together with the overall architecture of the solution. Prototype proof-of-concept implementation for few of these games, and commercialization strategies will also be developed. The follow-on phases will see the design implemented into a validated solution.

Results

In the initial phase, we worked closely with dyslexia specialists, adult dyslexics, teachers of special-needs children, parents of dyslexic children, and senior dyslexia representatives for large organizations. These interactions provided insights into the range of language difficulties faced by dyslexics, which solutions are used by teachers and professionals, and an overall understanding of the market. We comprehensively defined the ethical, privacy, and data security issues. The detailed design spec of the games, the methodology to be followed to interpret the results, and flow diagrams illustrating how the game screens will be presented was completed. As proof of concept, a few reading, visual, and auditory games were developed and successfully tested by stakeholders on different digital devices. The stakeholders provided regular feedback and confirmed the viability of our game-based solution.

Conclusions

DIMMAND has the potential to provide significant positive health care and economic impact. It is expected to reduce intervention costs, improve dyslexia detection at an early age and aid self-management.

Registered Report Identifier

RR1-10.2196/9583

Left-Lateralized Contributions of Saccades to Cortical Activity During a One-Back Word Recognition Task

Saccadic eye movements are an inherent component of natural reading, yet their contribution to information processing at subsequent fixation remains elusive. Here we use anatomically-constrained magnetoencephalography (MEG) to examine cortical activity following saccades as healthy human subjects engaged in a one-back word recognition task. This activity was compared with activity following external visual stimulation that mimicked saccades. A combination of procedures was employed to eliminate saccadic ocular artifacts from the MEG signal. Both saccades and saccade-like external visual stimulation produced early-latency responses beginning ~70 ms after onset in occipital cortex and spreading through the ventral and dorsal visual streams to temporal, parietal and frontal cortices. Robust differential activity following the onset of saccades vs. similar external visual stimulation emerged during 150-350 ms in a left-lateralized cortical network. This network included: (i) left lateral occipitotemporal (LOT) and nearby inferotemporal (IT) cortex; (ii) left posterior Sylvian fissure (PSF) and nearby multimodal cortex; and (iii) medial parietooccipital (PO), posterior cingulate and retrosplenial cortices. Moreover, this left-lateralized network colocalized with word repetition priming effects. Together, results suggest that central saccadic mechanisms influence a left-lateralized language network in occipitotemporal and temporal cortex above and beyond saccadic influences at preceding stages of information processing during visual word recognition.

Convergence of spoken and written language processing in the superior temporal sulcus

Spoken and written language processing streams converge in the superior temporal sulcus (STS), but the functional and anatomical nature of this convergence is not clear. We used functional MRI to quantify neural responses to spoken and written language, along with unintelligible stimuli in each modality, and employed several strategies to segregate activations on the dorsal and ventral banks of the STS. We found that intelligible and unintelligible inputs in both modalities activated the dorsal bank of the STS. The posterior dorsal bank was able to discriminate between modalities based on distributed patterns of activity, pointing to a role in encoding of phonological and orthographic word forms. The anterior dorsal bank was agnostic to input modality, suggesting that this region represents abstract lexical nodes. In the ventral bank of the STS, responses to unintelligible inputs in both modalities were attenuated, while intelligible inputs continued to drive activation, indicative of higher level semantic and syntactic processing. Our results suggest that the processing of spoken and written language converges on the posterior dorsal bank of the STS, which is the first of a heterogeneous set of language regions within the STS, with distinct functions spanning a broad range of linguistic processes.

A meta-analysis of functional magnetic resonance imaging studies of eye movements and visual word reading

INTRODUCTION

The pattern of eye movements during reading is substantially correlated with linguistic factors. While there have been a large number of studies on the neural mechanisms of eye movements and word reading separately, a limited number of studies have compared the activation patterns of these two processes and discussed the associations of their corresponding brain regions within the framework of naturalistic reading.

METHODS

This study conducted a meta-analysis of the existing functional magnetic resonance imaging literature on prosaccades and visual word reading using the activation likelihood estimation algorithm.

RESULTS

Our main finding was that, although prosaccades and word reading mainly activated dorsal and ventral brain areas, respectively, they both activated the left precentral gyrus (PreCG), left superior parietal lobe, right PreCG, right lingual gyrus, and bilateral medial frontal gyrus.

CONCLUSION

These findings provide new insights into cognitive processes involved with naturalistic reading, which requires both eye movements and word reading.

Analysis of gaze points for mouth images using an eye tracking system

PURPOSE

We aimed to clarify whether people stare at non-esthetic restorations by analyzing the gaze point of laypersons looking at mouth images with intraoral non-esthetic restoration.

METHODS

The gaze points of 47 laypersons who do not visit dentists were measured using an eye tracker. The stimuli were 18 photographs of mouths with or without a non-esthetic tooth restoration, each randomly shown for 5s. The analysis sites included a tooth with non-esthetic restoration and the same tooth on the opposite side of the mouth. We measured the proportion of participants who first fixated on each analysis site, and total fixation time for each site.

RESULTS

In images without non-esthetic restorations, a similar proportion of participants first fixated on each analysis site. However, more participants first fixated on non-esthetic restorations when the images contained them. Total fixation time for each site did not differ significantly between the left and right sides in the images without non-esthetic restoration (P>0.05). Participants fixated on the non-esthetic restoration significantly more in the images containing them (P<0.01).

CONCLUSIONS

Within the limitations of this study, the present findings suggest that in photographs of the mouth with non-esthetic restoration on either side, the non-esthetic restoration is first gazed before the opposite side. In addition, the non-esthetic restoration is gazed longer than the opposite side, and there was no major difference in the fixation time regarding the state of non-esthetic restoration.

Neural Mechanisms of Dorsal and Ventral Visual Regions during Text Reading

When reading a narrative text, both the dorsal and ventral visual systems are activated. To illustrate the patterns of interactions between the dorsal and ventral visual systems in text reading, we conducted analyses of functional connectivity (FC) and effective connectivity (EC) in a left-hemispheric network for reading-driven functional magnetic resonance imaging (fMRI) and resting-state fMRI (rs-fMRI) data. In reading-driven fMRI (Experiment 1), we found significant FCs among the left middle frontal gyrus (MFG), the left intraparietal sulcus (IPS), and the visual word form area (VWFA), and there were top–down effects from the left MFG to the left IPS, from the left MFG to the VWFA, and from the left IPS to the VWFA. In rs-fMRI (Experiment 2), we identified FCs and ECs for MFG-IPS and IPS-VWFA connections. In addition, the brain–behavior relationship in resting states showed that the dorsal connection was more associated with reading fluency relative to lexical decision. The combination of two experiments revealed that the MFG-IPS and the VWFA-IPS connections were shared connections both in reading-driven fMRI and rs-fMRI, and that the MFG-VWFA was specific connectivity in reading-driven fMRI. These results suggest that top–down effects from the dorsal visual system to ventral visual system play an important role in text reading.

Areas activated during naturalistic reading comprehension overlap topological visual, auditory, and somatotomotor maps

Cortical mapping techniques using fMRI have been instrumental in identifying the boundaries of topological (neighbor-preserving) maps in early sensory areas. The presence of topological maps beyond early sensory areas raises the possibility that they might play a significant role in other cognitive systems, and that topological mapping might help to delineate areas involved in higher cognitive processes. In this study, we combine surface-based visual, auditory, and somatomotor mapping methods with a naturalistic reading comprehension task in the same group of subjects to provide a qualitative and quantitative assessment of the cortical overlap between sensory-motor maps in all major sensory modalities, and reading processing regions. Our results suggest that cortical activation during naturalistic reading comprehension overlaps more extensively with topological sensory-motor maps than has been heretofore appreciated. Reading activation in regions adjacent to occipital lobe and inferior parietal lobe almost completely overlaps visual maps, whereas a significant portion of frontal activation for reading in dorsolateral and ventral prefrontal cortex overlaps both visual and auditory maps. Even classical language regions in superior temporal cortex are partially overlapped by topological visual and auditory maps. By contrast, the main overlap with somatomotor maps is restricted to a small region on the anterior bank of the central sulcus near the border between the face and hand representations of M-I. Hum Brain Mapp 37:2784-2810, 2016. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

On the domain-specificity of the visual and non-visual face-selective regions

What happens in our brains when we see a face? The neural mechanisms of face processing - namely, the face-selective regions - have been extensively explored. Research has traditionally focused on visual cortex face-regions; more recently, the role of face-regions outside the visual cortex (i.e., non-visual-cortex face-regions) has been acknowledged as well. The major quest today is to reveal the functional role of each this region in face processing. To make progress in this direction, it is essential to understand the extent to which the face-regions, and particularly the non-visual-cortex face-regions, process only faces (i.e., face-specific, domain-specific processing) or rather are involved in a more domain-general cognitive processing. In the current functional MRI study, we systematically examined the activity of the whole face-network during face-unrelated reading task (i.e., written meaningful sentences with content unrelated to faces/people and non-words). We found that the non-visual-cortex (i.e., right lateral prefrontal cortex and posterior superior temporal sulcus), but not the visual cortex face-regions, responded significantly stronger to sentences than to non-words. In general, some degree of sentence selectivity was found in all non-visual-cortex cortex. Present result highlights the possibility that the processing in the non-visual-cortex face-selective regions might not be exclusively face-specific, but rather more or even fully domain-general. In this paper, we illustrate how the knowledge about domain-general processing in face-regions can help to advance our general understanding of face processing mechanisms. Our results therefore suggest that the problem of face processing should be approached in the broader scope of cognition in general.

Objectifying eye movements during rapid number naming: Methodology for assessment of normative data for the King-Devick test

OBJECTIVE

Concussion is a major public health problem and considerable efforts are focused on sideline-based diagnostic testing to guide return-to-play decision-making and clinical care. The King-Devick (K-D) test, a sensitive sideline performance measure for concussion detection, reveals slowed reading times in acutely concussed subjects, as compared to healthy controls; however, the normal behavior of eye movements during the task and deficits underlying the slowing have not been defined.

METHODS

Twelve healthy control subjects underwent quantitative eye tracking during digitized K-D testing.

RESULTS

The total K-D reading time was 51.24 (±9.7) seconds. A total of 145 saccades (±15) per subject were generated, with average peak velocity 299.5°/s and average amplitude 8.2°. The average inter-saccadic interval was 248.4 ms. Task-specific horizontal and oblique saccades per subject numbered, respectively, 102 (±10) and 17 (±4). Subjects with the fewest saccades tended to blink more, resulting in a larger amount of missing data; whereas, subjects with the most saccades tended to make extra saccades during line transitions.

CONCLUSIONS

Establishment of normal and objective ocular motor behavior during the K-D test is a critical first step towards defining the range of deficits underlying abnormal testing in concussion. Further, it sets the groundwork for exploration of K-D correlations with cognitive dysfunction and saccadic paradigms that may reflect specific neuroanatomic deficits in the concussed brain.

Discrete versus multiple word displays: a re-analysis of studies comparing dyslexic and typically developing children

The study examines whether impairments in reading a text can be explained by a deficit in word decoding or an additional deficit in the processes governing the integration of reading subcomponents (including eye movement programming and pronunciation) should also be postulated. We report a re-analysis of data from eleven previous experiments conducted in our lab where the reading performance on single, discrete word displays as well multiple displays (texts, and in few cases also word lists) was investigated in groups of dyslexic children and typically developing readers. The analysis focuses on measures of time and not accuracy. Across experiments, dyslexic children are slower and more variable than typically developing readers in reading texts as well as vocal reaction time (RTs) to singly presented words; the dis-homogeneity in variability between groups points to the inappropriateness of standard measures of size effect (such as Cohen’s d), and suggests the use of the ratio between groups’ performance. The mean ratio for text reading is 1.95 across experiments. Mean ratio for vocal RTs for singly presented words is considerably smaller (1.52). Furthermore, this latter value is probably an overestimation as considering total reading times (i.e., a measure including also the pronunciation component) considerably reduces the group difference in vocal RTs (1.19 according to Martelli et al., 2014). The ratio difference between single and multiple displays does not depend upon the presence of a semantic context in the case of texts as large ratios are also observed with lists of unrelated words (though studies testing this aspect were few). We conclude that, if care is taken in using appropriate comparisons, the deficit in reading texts or lists of words is appreciably greater than that revealed with discrete word presentations. Thus, reading multiple stimuli present a specific, additional challenge to dyslexic children indicating that models of reading should incorporate this aspect.

Gender and age predict outcomes of cognitive, balance and vision testing in a multidisciplinary concussion center

OBJECTIVE

This study examined components of the Sports Concussion Assessment Tool, 3rd Edition (SCAT3) and a vision-based test of rapid number naming (King-Devick [K-D]) to evaluate sports and non-sports concussion patients in an outpatient, multidisciplinary concussion center. While the Symptom Evaluation, Standardized Assessment of Concussion (SAC), modified Balance Error Scoring System (BESS), and K-D are used typically for sideline assessment, their use in an outpatient clinical setting following concussion has not been widely investigated.

METHODS

K-D, BESS, SAC, and SCAT3 Symptom Evaluation scores were analyzed for 206 patients who received concussion care at the Concussion Center at NYU Langone Medical Center. Patient age, gender, referral data, mechanism of injury, time between concussive event and first concussion center appointment, and the first specialty service to evaluate each patient were also analyzed.

RESULTS

In this cohort, Symptom Evaluation scores showed a higher severity and a greater number of symptoms to be associated with older age (r = 0.31, P = 0.002), female gender (P = 0.002, t-test), and longer time between the concussion event and first appointment at the concussion center (r = 0.34, P = 0.008). Performance measures of K-D and BESS also showed associations of worse scores with increasing patient age (r = 0.32-0.54, P ≤ 0.001), but were similar among males and females and across the spectrum of duration since the concussion event. Patients with greater Symptom Severity Scores also had the greatest numbers of referrals to specialty services in the concussion center (r = 0.33, P = 0.0008). Worse Immediate Memory scores on SAC testing correlated with slower K-D times, potentially implicating the dorsolateral prefrontal cortex as a commonly involved brain structure.

CONCLUSION

This study demonstrates a novel use of sideline concussion assessment tools for evaluation in the outpatient setting, and implicates age and gender as predictors of outcomes for these tests.