publications

2026

1. Young and old adult brains experience opposite effects of acute sleep restriction on the functional connectivity network

   Josh Neudorf, Leanne Rokos, Kelly Shen, and 2 more authors

   Imaging Neuroscience, Jun 2026

   Abs DOI

   Chronic, long-term sleep loss is detrimental to brain health and cognitive ability. However, older adults are affected differently by acute, short-term loss of sleep than young and middle-aged adults. Older adults are more resilient to the effects of acute sleep loss and, depending on the cognitive domain, may be completely unaffected while younger adults suffer. To elucidate the brain network responses to sleep loss underlying these cognitive differences between age groups, we investigated the static and dynamic functional connectivity effects of acute sleep restriction (sleep limited to 3 hours) and how these effects differ between younger adults (20-30 years) and older adults (65-75 years). We found a functional connectivity subnetwork that was primarily strengthened in younger adults after acute sleep restriction but weakened in older adults after acute sleep restriction. Similar crossover interactions were consistently observed in further analyses of functional connectivity degree, modularity, and dynamic functional connectivity state fractional occupancy. Our findings demonstrate that the effect of acute sleep restriction on older adults is fundamentally different from younger adults. These results most strongly support the compensation theory of aging, which predicts a fundamental shift in the effects of acute sleep loss, rather than a mere dampening of the sleep benefits experienced by younger adults.

2. Physical activity promotes longitudinal white matter brain adaptations that support fluid intelligence with age

   Josh Neudorf

   May 2026

   ISSN: 2692-8205 Pages: 2026.05.27.728295 Section: New Results

   Abs DOI

   The aging population continues to grow, and along with it the need to better understand the unique characteristics of the aging brain. Despite the cortical thinning and myelin degeneration that occurs in later life, many individuals are resilient to these changes and are relatively spared from cognitive decline (so called “super-agers”). Longitudinal magnetic resonance imaging data from the Human Connectome Project allowed us to probe the underlying white matter connections that are strengthened or pruned to support fluid intelligence in younger and older adults, while also investigating physical activity as a potential behavioural intervention to promote these network reorganizations. Multivariate partial least squares analysis and the recent method of correlational tractography identified parts of the white matter structural connectivity network, measured with diffusion magnetic resonance imaging, where strengthening or pruning were associated with positive fluid intelligence trajectories and promoted by physical activity. This research improves our understanding of how the brain network adapts in later life, identifies physical activity as an accessible intervention to promote this adaptation, and enriches our fundamental models of what the brain’s neural network is capable of.

2025

1. Effects of central vs. peripheral attentional-oculomotor exercise on lexical processing

   Shaylyn Kress, Scott Caron, Josh Neudorf, and 2 more authors

   Quarterly Journal of Experimental Psychology, Jan 2025

   Abs DOI

   Past research from our lab has suggested visual demands in video games serve to exercise attentional-oculomotor (A-O) processing in a manner beneficial to reading. However, testing the effect of video games on reading typically requires long timeframes (e.g., multiweek training or years of accumulated video game experience). The current study manipulated within-experiment peripheral and central demands to evaluate the effects of A-O exercise on task performance. Our study included two tasks: an orthographic lexical decision task (OLDT), designed to optimise orthographic lexical processing, and a novel graphic-based health bar decision task (HBDT). In Experiment 1, the stimuli were presented centrally in one block and peripherally in another block to manipulate A-O exercise. We observed greater improvements in the peripheral-first than the central-first group, particularly for the OLDT. In Experiments 2 and 3, we focused on the OLDT, with the HBDT serving as the A-O exercise task, and observed improvements in both centrally and peripherally trained participants. We additionally observed, through analyses of word and bigram frequency, a double dissociation, whereby increased target word frequency was associated with faster target reaction times and improved error rates, whereas increased foil bigram frequency was associated with slower foil reaction times and worse error rates. Taken together, the experiments demonstrate a mechanism beyond simple task learning that drives reading improvements, and A-O exercise, even if movements are small, appears to play a role in the improvements observed. We suggest future research should further develop this paradigm and examine its utility for reading remediation in dyslexia.

2. Dynamic network features of functional and structural brain networks support visual working memory in aging adults

   Josh Neudorf, Kelly Shen, and Anthony R. McIntosh

   Imaging Neuroscience, May 2025

   Abs DOI

   In this work, we investigated how the relationship between structural connectivity and the dynamics of functional connectivity changes with age to benefit cognitive ability. Visual working memory (VWM) is an important brain function that allows us to maintain a mental representation of the world around us, but its capacity and precision peak by around 20 years old and decrease steadily throughout the rest of our lives. This research examined the functional brain network dynamics associated with VWM throughout the lifespan and found that Default Mode Network and Fronto-Parietal Network states were more well represented in individuals with better VWM. Furthermore, transitions from the Visual/Somatomotor Network state to the Attention Network state were more well represented in older adults, and a network control theory simulation demonstrated that structural connectivity differences supporting this transition were associated with better VWM, especially in middle-aged individuals. The structural connectivity of regions from all states was important for supporting this transition in younger adults, while regions within the Visual/Somatomotor and Attention Network states were more important in older adults. These findings demonstrate that structural connectivity supports flexible, functional dynamics that allow for better VWM with age and may lead to important interventions to uphold healthy VWM throughout the lifespan.

3. Examining Relationships between Functional and Structural Brain Network Architecture, Age, and Attention Skills in Early Childhood

   Leanne Rokos, Signe L. Bray, Josh Neudorf, and 3 more authors

   eNeuro, Jul 2025

   Section: Research Article: New Research

   Abs DOI

   Early childhood is a critical period showing experience-dependent changes in brain structure and function. The complex link between the structural connectivity (SC) and functional connectivity (FC) of the brain is of particular interest. However, its relationship with both age and attention in early childhood is not well understood. In this study, children between the ages of 4 and 7, and at a 1 year follow-up visit, underwent neuroimaging (diffusion-weighted and passive-viewing functional magnetic resonance imaging) and assessments for selective, sustained, and executive attention. We examined regional graph metrics and SC–FC coupling of the structural and functional networks. Partial least squares was used to investigate longitudinal brain measure changes and cross-sectional associations with age and attention. We observed longitudinal changes in functional graph metrics and age-related decreases in SC modularity. Region-wise graph analyses revealed variable brain–behavior relationships across the brain, highlighting regions where structural topology is linked to age and attentional performance. Furthermore, we identified SC as a dominant predictor of age when compared with FC and SC–FC coupling. The findings emphasize how early childhood is a dynamic period where cognitive functioning is intricately and predominantly linked to structural network features.

4. Exploring the interaction of reading and attention through connectivity with the frontal-eye-field

   Shaylyn Kress, Josh Neudorf, Chelsea Ekstrand, and 1 more author

   Neuroscience, Oct 2025

   DOI

2024

1. Reorganization of structural connectivity in the brain supports preservation of cognitive ability in healthy aging

   Josh Neudorf, Kelly Shen, and Anthony R. McIntosh

   Network Neuroscience, Oct 2024

   Abs DOI

   The global population is aging rapidly, and a research question of critical importance is why some older adults suffer tremendous cognitive decline while others are mostly spared. Past aging research has shown that older adults with spared cognitive ability have better local short-range information processing while global long-range processing is less efficient. We took this research a step further to investigate whether the underlying structural connections, measured in vivo using diffusion magnetic resonance imaging (dMRI), show a similar shift to support cognitive ability. We analyzed the structural connectivity streamline probability (representing the probability of connection between regions) and nodal efficiency and local efficiency regional graph theory metrics to determine whether age and cognitive ability are related to structural network differences. We found that the relationship between structural connectivity and cognitive ability with age was nuanced, with some differences with age that were associated with poorer cognitive outcomes, but other reorganizations that were associated with spared cognitive ability. These positive changes included strengthened local intrahemispheric connectivity and increased nodal efficiency of the ventral occipital-temporal stream, nucleus accumbens, and hippocampus for older adults, and widespread local efficiency primarily for middle-aged individuals.We utilized network neuroscience methods to investigate why some older adults suffer tremendous cognitive decline while others are mostly spared. Past functional research found that older adults with spared cognitive ability have better local short-range information processing while global long-range processing is less efficient. We took this research a step further to investigate whether structural connectivity reorganizes to preserve cognitive ability. We analyzed age and fluid intelligence as a function of structural connectivity and regional graph theory measures using partial least squares. Some differences with age were associated with poorer cognitive outcomes, but other reorganizations spared cognitive ability. Beneficial reorganizations included strengthened local intrahemispheric connectivity and increased nodal efficiency of focal regions for older adults, as well as widespread increased local efficiency for middle-aged individuals.

2023

1. What’s in a game: Video game visual-spatial demand location exhibits a double dissociation with reading speed

   Shaylyn Kress, Josh Neudorf, Braedyn Borowsky, and 1 more author

   Acta Psychologica, Feb 2023

   Abs DOI

   This research sought to clarify the nature of the relationship between video game experience, attention, and reading. Previous studies have suggested playing action video games can improve reading ability in children with dyslexia. Other research has linked video game experience with visual-spatial attention, and visual-spatial attention with reading. We hypothesized that the visual-spatial demands of video games may drive relationships with reading through attentional processing. In this experiment we used a hybrid attention/reading task to explore the relationship between video game visual-spatial demands, reading and attention. We also developed novel visual-spatial demand measures using participants’ top five played video games for an individual-specific measure of visual demands. Peripheral visual demands in video games were associated with faster reading times, while central visual demands were associated with slower reading times for both phonetic decoding and lexical reading. In addition, video game experience in terms of hours spent playing video games each week interacted with the cueing effect size in the lexical reading condition, with experienced video game players exhibiting a larger cueing effect than participants with less video game experience. These results suggest that exposure to peripheral visual spatial demands in video games may be related to both lexical and sublexical reading processes in hybrid attentional reading tasks such as ours with skilled adult readers, which has implications not only for models of how ventral and dorsal stream reading and visual-spatial attention are integrated, but also for the development of dyslexia diagnostics and remediation.

2. Comparing models of information transfer in the structural brain network and their relationship to functional connectivity: diffusion versus shortest path routing

   Josh Neudorf, Shaylyn Kress, and Ron Borowsky

   Brain Structure and Function, Mar 2023

   Number: 2

   Abs DOI

   The relationship between structural and functional connectivity in the human brain is a core question in network neuroscience, and a topic of paramount importance to our ability to meaningfully describe and predict functional outcomes. Graph theory has been used to produce measures based on the structural connectivity network that are related to functional connectivity. These measures are commonly based on either the shortest path routing model or the diffusion model, which carry distinct assumptions about how information is transferred through the network. Unlike shortest path routing, which assumes the most efficient path is always known, the diffusion model makes no such assumption, and lets information diffuse in parallel based on the number of connections to other regions. Past research has also developed hybrid measures that use concepts from both models, which have better predicted functional connectivity from structural connectivity than the shortest path length alone. We examined the extent to which each of these models can account for the structure–function relationship of interest using graph theory measures that are exclusively based on each model. This analysis was performed on multiple parcellations of the Human Connectome Project using multiple approaches, which all converged on the same finding. We found that the diffusion model accounts for much more variance in functional connectivity than the shortest path routing model, suggesting that the diffusion model is better suited to describing the structure–function relationship in the human brain at the macroscale.

3. Cognitive cooperation: Video game experience interacts with reading processes and accounts for interactive attentional cueing effects

   Shaylyn Kress, Josh Neudorf, and Ron Borowsky

   Aug 2023

   Abs DOI

   Video games have been shown to benefit reading and attentional processing, but the precise mechanisms responsible are not yet clear. The goal of this study was to investigate which aspects of reading and attentional processes are related to video game experience. A novel orthographic-phonological lexical decision task was used to test lexical (using exception words) and sublexical (using pseudohomophones) reading processes, while an attentional cueing task with various cue types was used to test exogenous and endogenous attentional orienting processes. The results of the orthographic-phonological lexical decision task indicated that video game experience interacted with target type (exception word vs pseudohomophone), which we suggest may be due to increased involvement of sublexical reading processes. In the attentional cueing task, when video game experience is not considered, we observed an interaction between cue type and cue validity, but when video game experience is accounted for, this interaction is no longer significant. This suggests that video game experience is related to an individual’s attentional processing of different cue types. Finally, we also observed a significant association between performance in the orthographic-phonological lexical decision task and performance in the attentional task, highlighting the overlapping nature of reading and attentional processes. Oculomotor control is proposed as one mechanism which could underly the observed relationships between reading, attention, and video game experience. These findings could aid the development of new reading programs for dyslexia.

2022

1. Unique, shared, and dominant brain activation in Visual Word Form Area and Lateral Occipital Complex during reading and picture naming

   Josh Neudorf, Layla Gould, Marla J. S. Mickleborough, and 2 more authors

   Neuroscience, Jan 2022

   Abs DOI

   Identifying printed words and pictures concurrently is ubiquitous in daily tasks, and so it is important to consider the extent to which reading words and naming pictures may share a cognitive-neurophysiological functional architecture. Two functional magnetic resonance imaging (fMRI) experiments examined whether reading along the left ventral occipitotemporal region (vOT; often referred to as a visual word form area, VWFA) has activation that is overlapping with referent pictures (i.e., both conditions significant and shared, or with one significantly more dominant) or unique (i.e., one condition significant, the other not), and whether picture naming along the right lateral occipital complex (LOC) has overlapping or unique activation relative to referent words. Experiment 1 used familiar regular and exception words (to force lexical reading) and their corresponding pictures in separate naming blocks, and showed dominant activation for pictures in the LOC, and shared activation in the VWFA for exception words and their corresponding pictures (regular words did not elicit significant VWFA activation). Experiment 2 controlled for visual complexity by superimposing the words and pictures and instructing participants to either name the word or the picture, and showed primarily shared activation in the VWFA and LOC regions for both word reading and picture naming, with some dominant activation for pictures in the LOC. Overall, these results highlight the importance of including exception words to force lexical reading when comparing to picture naming, and the significant shared activation in VWFA and LOC serves to challenge specialized models of reading or picture naming.

2. Structure can predict function in the human brain: a graph neural network deep learning model of functional connectivity and centrality based on structural connectivity

   Josh Neudorf, Shaylyn Kress, and Ron Borowsky

   Brain Structure and Function, Jan 2022

   Number: 1

   Abs DOI

   Although functional connectivity and associated graph theory measures (e.g., centrality; how centrally important to the network a region is) are widely used in brain research, the full extent to which these functional measures are related to the underlying structural connectivity is not yet fully understood. Graph neural network deep learning methods have not yet been applied for this purpose, and offer an ideal model architecture for working with connectivity data given their ability to capture and maintain inherent network structure. Here, we applied this model to predict functional connectivity from structural connectivity in a sample of 998 participants from the Human Connectome Project. Our results showed that the graph neural network accounted for 89% of the variance in mean functional connectivity, 56% of the variance in individual-level functional connectivity, 99% of the variance in mean functional centrality, and 81% of the variance in individual-level functional centrality. These results represent an important finding that functional centrality can be robustly predicted from structural connectivity. Regions of particular importance to the model’s performance as determined through lesioning are discussed, whereby regions with higher centrality have a higher impact on model performance. Future research on models of patient, demographic, or behavioural data can also benefit from this graph neural network method as it is ideally-suited for depicting connectivity and centrality in brain networks. These results have set a new benchmark for prediction of functional connectivity from structural connectivity, and models like this may ultimately lead to a way to predict functional connectivity in individuals who are unable to do fMRI tasks (e.g., non-responsive patients).

2021

1. An fMRI, DTI and neurophysiological examination of atypical organization of motor cortex in ipsilesional hemisphere following post-stroke recovery

   Layla Gould, Shaylyn Kress, Josh Neudorf, and 5 more authors

   Journal of Stroke and Cerebrovascular Diseases, Mar 2021

   Number: 3

   DOI
2. Unmasking the effects of orthography, semantics, and phonology on 2AFC visual word perceptual identification

   Shaylyn Kress, Josh Neudorf, Chelsea Ekstrand, and 1 more author

   Visual Cognition, Nov 2021

   Number: 10 _eprint: https://doi.org/10.1080/13506285.2021.1989099

   Abs DOI

   In the two-alternative forced-choice (2AFC) task, the target stimulus is presented very briefly, and participants must choose which of two options was the presented target. Some past research has assumed that the 2AFC task isolates orthographic effects, despite orthographic, semantic, and phonological differences between the options. If so, performance should not differ between word/nonword pairs and British/American word pairs, the latter of which only differ orthographically. In Experiment 1, accuracy and sensitivity were higher during word/nonword trials than British/American trials when participants did not guess, demonstrating that phonological/semantic processing contributes to performance. Experiment 2 showed that target visibility did not interact with pair type on RT, which suggests phonological/semantic processing did not feed back to orthographic encoding in this task. This study demonstrates the influence of phonological/semantic processing on word perceptual identification, and shows that using British/American word pairs provides a method to isolate orthography in the 2AFC task.

2020

1. Brain structural connectivity predicts brain functional complexity: Diffusion tensor imaging derived centrality accounts for variance in fractal properties of functional magnetic resonance imaging signal

   Josh Neudorf, Chelsea Ekstrand, Shaylyn Kress, and 1 more author

   Neuroscience, Jul 2020

   Abs DOI

   The complexity of brain activity has recently been investigated using the Hurst exponent (H), which describes the extent to which functional magnetic resonance imaging (fMRI) blood oxygen-level dependent (BOLD) activity is simple vs. complex. For example, research has demonstrated that fMRI activity is more complex before than after consumption of alcohol and during task than resting state. The measurement of H in fMRI is a novel method that requires the investigation of additional factors contributing to complexity. Graph theory metrics of centrality can assess how centrally important to the brain network each region is, based on diffusion tensor imaging (DTI) counts of probabilistic white matter (WM) tracts. DTI derived centrality was hypothesized to account for the complexity of functional activity, based on the supposition that more sources of information to integrate should result in more complex activity. FMRI BOLD complexity as measured by H was associated with five brain region centrality measures: degree, eigenvector, PageRank, current flow betweenness, and current flow closeness centrality. Multiple regression analyses demonstrated that eigenvector centrality was the most robust predictor of complexity, whereby greater centrality was associated with increased complexity (lower H). Regions known to be highly connected, including the thalamus and hippocampus, notably were among the highest in centrality and complexity. This research has led to a greater understanding of how brain region characteristics such as DTI centrality relate to the novel Hurst exponent approach for assessing brain activity complexity, and implications for future research that employ these measures are discussed.

2. Structural connectivity predicts functional activation during lexical and sublexical reading

   Chelsea Ekstrand, Josh Neudorf, Shaylyn Kress, and 1 more author

   NeuroImage, Sep 2020

   Abs DOI

   A critical question in neuroscience is the extent to which structural connectivity of the brain predicts localization of brain function. Recent research has suggested that anatomical connectivity can predict functional magnetic resonance imaging (fMRI) responses in several cognitive domains, including face, object, scene, and body processing, and development of word recognition skills (Osher et al., 2016; Saygin et al., 2016). However, this technique has not yet been extended to skilled word reading. Thus, we developed a computational model that relates anatomical connectivity (measured using probabilistic tractography) of individual cortical voxels to fMRI responses of the same voxels during lexical and sublexical reading tasks. Our results showed that the model built from structural connectivity was able to accurately predict functional responses of individual subjects based on their structural connectivity alone. This finding was apparent across the cortex, as well as to specific regions of interest associated with reading, language, and spatial attention. Further, we identified the structural connectivity networks associated with different aspects of skilled reading using connectivity analyses, and showed that interconnectivity between left hemisphere language and right hemisphere attentional areas underlies both lexical and sublexical reading. This work has important implications for understanding how structural connectivity contributes to reading and suggests that there is a relationship between skilled reading and neuroanatomical brain connectivity that future research should continue to explore.

3. Language lateralization differences between left and right temporal lobe epilepsy as measured by overt word reading fMRI activation and DTI structural connectivity

   Josh Neudorf, Shaylyn Kress, Layla Gould, and 3 more authors

   Epilepsy & Behavior, Nov 2020

   DOI
4. Atypical language localization in right temporal lobe epilepsy: An fMRI case report

   Layla Gould, Adam Wu, Jose F. Tellez-Zenteno, and 7 more authors

   Epilepsy & Behavior Reports, 2020

   DOI

2019

1. Individual- and area-level socioeconomic inequalities in diabetes mellitus in Saskatchewan between 2007 and 2012: a cross-sectional analysis

   Daniel Fuller, Joshua Neudorf, Stuart Lockhart, and 4 more authors

   CMAJ Open, Jan 2019

   Number: 1 Reporter: CMAJ Open

   Abs DOI

   Background: Improving our understanding of social inequalities may improve prevention and treatment efforts for diabetes mellitus. We examined the association between individual- and area-level socioeconomic measures and physician-diagnosed diabetes in Saskatchewan over time. Methods: In this cross-sectional study, we linked health administrative data with individual-level socioeconomic data from the Canadian Community Health Survey and area-level data from the 2006 Canadian census. We used general linear mixed-models regression to analyze the effect of each factor, controlling for geographic and demographic measures. Results: Area-level deprivation was associated with medically diagnosed type 2 diabetes mellitus after adjustment for the individual-level factors of age, sex, household income and education. Individuals residing in areas ranked in the least deprived quintile had a lower likelihood of diabetes than those in the most deprived quintile (odds ratio 0.40, 95% confidence interval 0.18–0.88). However, this disparity existed only in urban areas. This result may reflect less pronounced health inequalities in rural areas, greater socioeconomic heterogeneity, larger geographic units or some combination of these factors. Interpretation: Individual- and area-level socioeconomic factors were associated with the likelihood of medically diagnosed diabetes; however, the strength of this association varied between urban and rural communities. Acknowledgement of area-level deprivation as a modifiable risk factor related to the prevalence of diabetes is important in the development of effective interventions for urban, but not rural, areas.

2. How words and space collide: Lexical and sublexical reading are reliant on separable reflexive and voluntary attention regions in hybrid tasks

   Chelsea Ekstrand, Josh Neudorf, Shaylyn Kress, and 1 more author

   Cortex, Dec 2019

   Reporter: Cortex

   Abs DOI

   Reading ability requires the coordination of many cognitive processes to be effective, including spatial attention. Recent functional magnetic resonance imaging (fMRI) evidence from Ekstrand et al. (2019) suggests that lexical reading is more associated with reflexive attentional orienting regions, whereas sublexical reading is more associated with voluntary attentional orienting regions. The current research sought to further examine the neuroanatomical relationship between reading and attention using a novel experimental design in fMRI. Participants performed four hybrid attentional orienting and reading-aloud tasks, where a reflexive or voluntary spatial cue preceded a lexical or sublexical target. Results indicated that lexical reading resulted in greater activation in the right temporoparietal junction, a reflexive orienting region. Sublexical reading resulted in greater activation in the left inferior frontal gyrus, left fusiform and inferior temporal gyrus, and right superior parietal lobule and intraparietal sulcus (voluntary orienting regions). Further, we found an interaction between reading and attention in the middle occipital gyrus. This study provides the most direct evidence to date that lexical and sublexical reading recruit differential attentional orienting regions during single-word reading in skilled readers. Implications for models of reading and attention, as well as for strategic remediation of their dysfunction, are discussed.

3. Where words and space collide: The overlapping neural activation of lexical and sublexical reading with voluntary and reflexive spatial attention

   Chelsea Ekstrand, Josh Neudorf, Layla Gould, and 2 more authors

   Brain Research, Mar 2019

   Abs DOI

   Recent research has shown a relationship between reading and attention, however the neuroanatomical overlap of these two processes has remained relatively unexplored. Therefore, we sought to investigate the overlapping neural mechanisms of spatial attention and reading using functional magnetic resonance imaging. Participants performed two attentional orienting tasks (reflexive and voluntary), and two overt word-reading tasks (lexical and sublexical). We hypothesized that there would be greater unique activation overlap of reflexive attention with lexical reading, and of voluntary attention with sublexical reading. Results indicated that lexical reading had greater overlapping activation in reflexive orienting areas compared to sublexical reading, suggesting that lexical reading may employ more automatic attentional mechanisms. In contrast, sublexical reading had greater overlapping activation with voluntary attention areas compared to lexical reading, suggesting that phonetic decoding may rely more heavily on voluntary attention. This research broadens our understanding of the neural overlap that underlies the relationship between reading and spatial attention.

4. Interactions of reading and semantics along the ventral visual processing stream

   Josh Neudorf, Chelsea Ekstrand, Shaylyn Kress, and 2 more authors

   Visual Cognition, Jan 2019

   Number: 1 _eprint: https://doi.org/10.1080/13506285.2019.1577319

   Abs DOI

   Converging evidence supports a distributed-plus-hub view of semantic processing, in which there are distributed modular semantic sub-systems (e.g., for shape, colour, and action) connected to an amodal semantic hub. Furthermore, object semantic processing of colour and shape, and lexical reading and identification, are processed mainly along the ventral stream, while action semantic processing occurs mainly along the dorsal stream. In Experiment 1, participants read a prime word that required imagining either the object or action referent, and then named a lexical word target. In Experiments 2 and 3, participants performed a lexical decision task (LDT) with the same targets as in Experiment 1, in the presence of foils that were legal nonwords (NW; Experiment 2) or pseudohomophones (PH; Experiment 3). Semantic priming was similar in effect size regardless of prime type for naming, but was greater for object primes than action primes for the LDT with PH foils, suggesting a shared-stream advantage when the task demands focus on orthographic lexical processing. These experiments extend the distributed-plus-hub model, and provide a novel paradigm for further research.

5. FMRI of shared-stream priming of lexical identification by object semantics along the ventral visual processing stream

   Josh Neudorf, Chelsea Ekstrand, Shaylyn Kress, and 1 more author

   Neuropsychologia, Oct 2019

   Abs DOI

   Distributed sub-systems of the brain’s semantic network have been shown to process semantics associated with visual features of objects (e.g., shape, colour) in the ventral visual processing stream, whereas semantics associated with actions are processed in the dorsal stream. Orthographic lexical processing has also been shown to occur in the ventral stream. Past research from our lab (Neudorf et al., 2019) has demonstrated a temporal (i.e., reaction time) priming advantage for object primes over action primes in the lexical decision task consistent with ventral shared-stream processing of visual feature object semantics and orthographic lexical identification, whereby object primes produced larger priming effects than action primes. The current experiment explored this paradigm using functional magnetic resonance imaging (fMRI) and identified the potential loci of shared-stream processing to regions in the ventral stream just anterior to colour sensitive visual area V4 cortex in the left fusiform gyrus and anterior to lexical and shape sensitive regions in the left fusiform gyrus, as well as in cerebellar lobule VI. Action priming showed more activation than object priming in dorsal stream motion related regions of the right parietal occipital junction, right superior occipital gyrus, and bilateral visual area V3. The fMRI activation observed in this experiment supports the theory that spatially shared-stream activation occurs in the ventral stream during object (but not action) priming of lexical identification, which is consistent with our earlier behavioural research showing that these processes are also temporally shared.

2018

1. Retrieval priming in product verification: Evidence from retrieval-induced forgetting

   Josh Neudorf, Yalin Chen, and Jamie I. D. Campbell

   Journal of Numerical Cognition, Dec 2018

   Number: 3

   DOI

2017

1. More than a feeling: The bidirectional convergence of semantic visual object and somatosensory processing

   Chelsea Ekstrand, Josh Neudorf, Eric Lorentz, and 3 more authors

   Acta psychologica, Oct 2017

   Reporter: Acta psychologica

   Abs DOI

   Prevalent theories of semantic processing assert that the sensorimotor system plays a functional role in the semantic processing of manipulable objects. While motor execution has been shown to impact object processing, involvement of the somatosensory system has remained relatively unexplored. Therefore, we developed two novel priming paradigms. In Experiment 1, participants received a vibratory hand prime (on half the trials) prior to viewing a picture of either an object interacted primarily with the hand (e.g., a cup) or the foot (e.g., a soccer ball) and reported how they would interact with it. In Experiment 2, the same objects became the prime and participants were required to identify whether the vibratory stimulation occurred to their hand or foot. In both experiments, somatosensory priming effects arose for the hand objects, while foot objects showed no priming benefits. These results suggest that object semantic knowledge bidirectionally converges with the somatosensory system.

2. On the dissociation between reaction time and response duration as a function of lexical and sublexical reading: An examination of phonetic decoding and computational models

   Sarah Wingerak, Josh Neudorf, Layla Gould, and 1 more author

   Visual Cognition, Nov 2017

   Number: 9-10

   Abs DOI

   Neurobiological models of reading account for two ways in which orthography is converted to phonology: (1) familiar words, particularly those with exceptional spelling-sound mappings (e.g., shoe) access their whole-word lexical representations in the ventral visual stream, and (2) orthographically unfamiliar words, particularly those with regular spelling-sound mappings (i.e., pseudohomophones [PHs], which are orthographically novel but sound like real words; e.g., shue) are phonetically decoded via sublexical processing in the dorsal visual stream. The present study used a naming task in order to compare naming reaction time (RT) and response duration (RD) of exception and regular words to their PH counterparts. We replicated our earlier findings with words, and extended them to PH phonetic decoding by showing a similar effect on RT and RD of matched PHs. Given that the shorter RDs for exception words can be attributed to the benefit of whole-word processing in the orthographic word system, and the longer RTs for exception words to the conflict with phonetic decoding, our PH results demonstrate that phonetic decoding also involves top-down feedback from phonological lexical representations (e.g., activated by shue) to the orthographic representations of the corresponding correct word (e.g., shoe). Two computational models were tested for their ability to account for these effects: the DRC and the CDP+. The CDP+ fared best as it was capable of simulating both the regularity and stimulus type effect on RT for both word and PH identification, although not their over-additive interaction. Our results demonstrate that both lexical reading and phonetic decoding elicit a regularity dissociation between RT and RD that provides important constraints to all models of reading, and that phonetic decoding results in top-down feedback that bolsters the orthographic lexical reading process.

2016

1. Classifying the population by socioeconomic factors associated with support for policies to reduce social inequalities in health

   Daniel Fuller, Josh Neudorf, Silvia Bermedo-Carrasco, and 1 more author

   Journal of Public Health, Dec 2016

   Number: 4

   Abs DOI

   To examine citizens’ agreement with policy options to reduce social inequalities in health and socio-demographic factors associated with support for these policies.A random digit dialling sample of 16 125 households with access to a landline telephone was conducted in Saskatoon, Canada in 2013. Saskatoon is located in the Canadian prairies and had a population of 222 189 in 2011. A total of 1002 individuals aged 18 or older answered a questionnaire indicating their support for policies to improve health equity. Socio-demographic variables of interest were household income, education, occupation and ethnicity. Latent class analysis and logistic regression analyses were conducted.The latent class analysis showed that 37% of respondents were in the selective agreement group, while 63% were in the high agreement group. The selective agreement group showed lower policy support compared with the high agreement group, in particular for guaranteed annual income, welfare for adults and parents with children, lower tuition for post-secondary students. In the final logistic regression model, socioeconomic factors associated with the likelihood of being in the selective agreement group were: age ≥40 years, male, Caucasian ethnicity and higher household income.Residents support for policies to reduce poverty and increase funding for education, creation of health promotion and disease prevention programmes. However, support for these policies is different across social groups.

2015

1. The hierarchy of control in the epidemic of farm injury

   James Dosman, Louise Hagel, Nathan King, and 8 more authors

   Journal of Agromedicine, Jul 2015

   Number: 3 Reporter: Journal of Agromedicine

   Abs DOI

   The application of the hierarchy of control (HOC) is a well-established approach to hazard reduction in industrial workplaces. However, it has not been generally applied in farm workplaces. The objective was to determine current practices of farmers in the context of a modified HOC, and the effect of these practices on farm injury outcomes. A self-reported mail survey of 1196 Saskatchewan farm operations was conducted in 2013. Selected survey questions were used as proxy measures of the farm owner-operator’s practices relevant to each of the six steps of increasing importance in a modified HOC: (1) hazard identification; (2) risk assessment; (3) personal protection; (4) administrative controls; (5) engineering controls; and (6) elimination of the hazard. Analysis used basic descriptive statistics and logistic regression to examine associations of interest. When four of the six HOC steps were adhered to, there was a significant protective effect: odds ratio (OR) = 0.32 (95% confidence interval [CI]: 0.14–0.74) for any injury and OR = 0.27 (95% CI: 0.07–0.99) for serious injury in the overall study population. For farm owner-operators utilizing four of the six steps in the modified HOC, there was a significant protective effect for any injury (OR = 0.30, 95% CI: 0.11–0.83). Although there is a considerable absence of use of elements of the HOC among farm operators, for farmers who adhere to these steps, there is a significant reduction in their risk for injury. Prevention strategies that embrace the practice of these principles may be effective in the control of farm workplace injury.