Is adolescent internet use a risk factor for the development of depression symptoms or vice-versa?

BACKGROUND: The extent to which digital media use by adolescents contributes to poor mental health, or vice-versa, remains unclear. The purpose of the present study is to clarify the strength and direction of associations between adolescent internet use and the development of depression symptoms using a longitudinal modeling approach. We also examine whether associations differ for boys and girls. METHODS: Data are drawn from (N = 1547) participants followed for the Quebec longitudinal Study of Child Development (QLSCD 1998-2020). Youth self-reported internet use in terms of the average hours of use per week at the ages of 13, 15, and 17. Youth also self-reported depression symptoms at the same ages. RESULTS: After testing sex-invariance, random intercepts cross-lagged panel models stratified by sex, revealed that internet use by girls was associated with significant within-person (time-varying) change in depression symptoms. Girl's internet use at age 13 was associated with increased depression symptoms at age 15 (ß = 0.12) and internet use at age 15 increased depression at age 17 (ß = 0.10). For boys, internet use was not associated with significant time varying change in depression symptoms. CONCLUSIONS: The present findings support the hypothesis that internet use by adolescents can represent a significant risk factor for the development of depressive symptoms, particularly in girls.

Landmark-dependent Navigation Strategy Declines across the Human Life-Span: Evidence from Over 37,000 Participants.

Humans show a remarkable capacity to navigate various environments using different navigation strategies, and we know that strategy changes across the life span. However, this observation has been based on studies of small sample sizes. To this end, we used a mobile app-based video game (Sea Hero Quest) to test virtual navigation strategies and memory performance within a distinct radial arm maze level in over 37,000 participants. Players were presented with six pathways (three open and three closed) and were required to navigate to the three open pathways to collect a target. Next, all six pathways were made available and the player was required to visit the pathways that were previously unavailable. Both reference memory and working memory errors were calculated. Crucially, at the end of the level, the player was asked a multiple-choice question about how they found the targets (i.e., a counting-dependent strategy vs. a landmark-dependent strategy). As predicted from previous laboratory studies, we found the use of landmarks declined linearly with age. Those using landmark-based strategies also performed better on reference memory than those using a counting-based strategy. These results extend previous observations in the laboratory showing a decreased use of landmark-dependent strategies with age.

Associations Between Video Game Engagement and ADHD Symptoms in Early Adolescence.

OBJECTIVE: We aim to investigate the direction of causality of the association between adolescent video game playing and later development of ADHD symptoms using a population-based sample of Canadian Youth. METHOD: The present study is based on longitudinal cohort data (N = 1,467). Youth self-reported weekly hours of video game playing as well as ADHD symptoms at both 12 and 13 years of age. RESULTS: Cross-lagged panel model were estimated to examine how adolescent video game playing prospectively contributes to ADHD symptoms while simultaneously considering how adolescent ADHD symptoms may prospectively contribute to videogame playing. Analyses revealed a significant positive association between adolescent video games playing at age 12 and ADHD symptoms at age 13. Youth ADHD symptoms at age 12 did not predict video game use at age 13. CONCLUSION: Our results help clarify the direction of causality of the association between video game playing and ADHD symptoms and provide evidence that video game playing can represent a risk factor for the development of attention problems in early adolescence.

The BDNF val66met polymorphism is associated with decreased use of landmarks and decreased fMRI activity in the hippocampus during virtual navigation.

People can navigate in a new environment using multiple strategies dependent on different memory systems. A series of studies have dissociated between hippocampus-dependent 'spatial' navigation and habit-based 'response' learning mediated by the caudate nucleus. The val66met polymorphism of the brain-derived neurotrophic factor (BDNF) gene leads to decreased secretion of BDNF in the brain, including the hippocampus. Here, we aim to investigate the role of the BDNF val66met polymorphism on virtual navigation behaviour and brain activity in healthy older adults. A total of 139 healthy older adult participants (mean age = 65.8 ± 4.4 years) were tested in this study. Blood samples were collected, and BDNF val66met genotyping was performed. Participants were divided into two genotype groups: val homozygotes and met carriers. Participants were tested on virtual dual-solution navigation tasks in which they could use either a hippocampus-dependent spatial strategy or a caudate nucleus-dependent response strategy to solve the task. A subset of the participants (n = 66) were then scanned in a 3T functional magnetic resonance imaging (fMRI) scanner while engaging in another dual-solution navigation task. BDNF val/val individuals and met carriers did not differ in learning performance. However, the two BDNF groups differed in learning strategy. BDNF val/val individuals relied more on landmarks to remember target locations (i.e., increased use of flexible spatial learning), while met carriers relied more on sequences and patterns to remember target locations (i.e., increased use of inflexible response learning). Additionally, BDNF val/val individuals had more fMRI activity in the hippocampus compared with BDNF met carriers during performance on the navigation task. This is the first study to show in older adults that BDNF met carriers use alternate learning strategies from val/val individuals and to identify differential brain activation of this behavioural difference between the two groups.

Object expectations alter information use during visual recognition.

Prior expectations influence how we perceive and recognize objects. However, how they do so remains unclear, especially in the case of real-world complex objects. Expectations of objects may affect which features are used to recognize them subsequently. In this study, we used reverse correlation to reveal with high precision how the use of information across time is modulated by real-world object expectations in a visual recognition task. We show that coarse information leads to accurate responses earlier when an object is expected, indicating that observers use diagnostic features earlier in this situation. We also demonstrate an increased variability in the use of coarse information depending on the expected object, indicating that observers adopt a more specialized recognition strategy when they expect a specific object. In summary, our results reveal potential mechanisms underlying the effect of expectations on the recognition of complex objects.

Differential stress response to psychological and physical stressors in children using spatial versus response-dependent navigation strategies.

Previous work from our lab has shown that basal cortisol levels are different between healthy young adults who spontaneously use caudate nucleus-dependent response strategies compared to young adults who use hippocampus-dependent spatial navigation strategies. Young adults who use caudate nucleus dependent strategies display lower basal cortisol levels compared to those who use hippocampus-dependent strategies. In the current study, we assessed navigation strategies in children using a virtual navigation task and measured cortisol at baseline as well as cortisol reactivity to both a psychological and to a physical stressor. Replicating what is observed in adults, we found that children who used caudate nucleus-dependent navigation strategies displayed lower cortisol levels at baseline compared to those who used hippocampus-dependent strategies. The psychological stressor, knowledge that a blood draw would be performed by a nurse, caused a significant increase in cortisol uniquely in response learners. The physical stressor, the actual blood draw, produced a significant increase in cortisol amongst spatial learners that was then comparable to levels observed in response learners. Lower baseline cortisol and higher cortisol psychological stress response observed amongst children who used response strategies may therefore reflect early biological changes during development which may have an impact later in life when considering risk for neuropsychiatric disorders.

Opposing effects of cortisol on learning and memory in children using spatial versus response-dependent navigation strategies.

Previous studies showed that healthy young adults who spontaneously use caudate nucleus-dependent strategies on a virtual navigation task, have significantly lower basal levels of cortisol compared with adults who use hippocampus-dependent spatial navigation strategies. In the current paper, we assessed the relation between basal cortisol levels and learning using a virtual navigation task in children. We show that basal cortisol level has a differential effect on learning and memory between children using spatial and response navigation strategies. Specifically, cortisol was found to be beneficial for learning performance in children using spatial strategies, such that higher levels of cortisol were associated with more efficient learning in a virtual maze. In contrast, cortisol had a deleterious effect on learning the virtual maze in children using response strategies, such that higher cortisol levels were associated with increased spatial working memory errors. Based on these results, individual differences in navigation strategy could help explain contradictory results in the literature showing that cortisol can have either a positive or negative association with learning and memory performance.

Musical training improves the ability to understand speech-in-noise in older adults.

It is well known that hearing abilities decline with age, and one of the most commonly reported hearing difficulties reported in older adults is a reduced ability to understand speech in noisy environments. Older adult musicians have an enhanced ability to understand speech in noise, and this has been associated with enhanced brain responses related to both speech processing and the deployment of attention; however, the causal impact of music lessons in older adults has not yet been demonstrated. To investigate whether a causal relationship exists between short-term musical training and performance on auditory tests in older adults and to determine if musical training can be used to improve hearing in older adult nonmusicians, we conducted a longitudinal training study with random assignment. A sample of older adults was randomly assigned to learn to play piano (Music), to learn to play a visuospatially demanding video game (Video), or to serve as a no-contact control (No-contact). After 6 months, the Music group improved their ability to understand a word presented in loud background noise, whereas the other 2 groups did not. This improvement was related to an increase in positive-going electrical brain activity at fronto-left electrodes 200-1000 ms after the presentation of a word in noise. Source analyses suggest that this activity was due to sources located in the left inferior frontal gyrus and other regions involved in the speech-motor system. These findings support the idea that musical training provides a causal benefit to hearing abilities. Importantly, these findings suggest that musical training could be used as a foundation to develop auditory rehabilitation programs for older adults.

Increased flanker task and forward digit span performance in caudate-nucleus-dependent response strategies.

One of two memory systems can be used to navigate in a new environment. Hippocampus-dependent spatial strategy consists of creating a cognitive map of an environment and caudate nucleus-dependent response strategy consists of memorizing a rigid sequence of turns. Spontaneous use of the response strategy is associated with greater activity and grey matter within the caudate nucleus while the spatial strategy is associated with greater activity and grey matter in the hippocampus. The caudate nucleus is involved in executive functions such as working memory, cognitive control and certain aspects of attention such as attentional disengaging. This study therefore aimed to investigate whether response learners would display better performance on tests of executive and attention functioning compared to spatial learners. Fifty participants completed the 4/8 virtual maze to assess navigational strategy, the forward and backward visual digit span and the Attention Network Test - Revised to assess both attention disengagement and cognitive control. Results revealed that response learners showed significantly higher working memory capacity, more efficient attention disengagement and better cognitive control. Results suggest that response learners, who putatively display more grey matter and activity in the caudate nucleus, are associated with better working memory span, cognitive control and attentional disengagement.

Caudate nucleus-dependent navigation strategies are associated with increased risk-taking and set-shifting behavior.

When people navigate, they use strategies dependent on one of two memory systems. The hippocampus-based spatial strategy consists of using multiple landmarks to create a cognitive map of the environment. In contrast, the caudate nucleus-based response strategy is based on the memorization of a series of turns. Importantly, response learners display more gray matter and functional activity in the caudate nucleus and less gray matter in the hippocampus. In parallel, the caudate nucleus is involved in decision-making by mediating attention toward rewards and in set-shifting by mediating preparatory actions. The present study, therefore, examined the link between navigational strategy use, that are associated with gray matter differences in the caudate nucleus and hippocampus, and decision-making and set-shifting performance. Fifty-three participants completed the 4 on 8 virtual maze, the Iowa Gambling Task (IGT), the Wisconsin Card Sorting Test-64 (WCST-64), and a task-switching test. The results revealed that people who use response strategies displayed increased risk-taking behavior in the IGT compared to the people using hippocampus-dependent spatial strategies. Response strategy was also associated with enhanced set-shifting performance in the WCST-64 and task-switching test. These results confirm that risk-taking and set-shifting behavior, that are differentially impacted by the caudate nucleus and hippocampus memory systems, can be predicted by navigational strategy.

Autistic traits in neurotypical individuals are associated with increased landmark use during navigation.

People adopt two distinct learning strategies during navigation. "Spatial learners" navigate by building a cognitive map using environmental landmarks, and display more grey matter in the hippocampus. Conversely, "response learners" memorize a series of rigid turns to navigate and display more grey matter in the caudate nucleus of the striatum. Evidence has linked these two structures with autism spectrum disorder (ASD) and autistic traits in non-clinical populations. Both people with ASD and neurotypical people with higher levels of autistic traits have been shown to display more grey matter in the hippocampus and less functional activity in the caudate nucleus. We therefore tested 56 healthy participants who completed the Autism Quotient (AQ) Scale and the 4-on-8 Virtual Maze (4/8 VM), which determines the reliance on landmarks during navigation. We found that people who relied on landmarks during navigation also displayed significantly higher scores on the AQ Scale. Because spatial strategies are associated with increased attention to environmental landmark use and are supported by the hippocampus, our results provide a potential behavioral mechanism linking higher autistic traits (e.g., increased attention to detail and increased sensory processes) to increased hippocampal grey matter.

Playing Super Mario increases oculomotor inhibition and frontal eye field grey matter in older adults.

Aging is associated with cognitive decline and decreased capacity to inhibit distracting information. Video game training holds promise to increase inhibitory mechanisms in older adults. In the current study, we tested the impact of 3D-platform video game training on performance in an antisaccade task and on related changes in grey matter within the frontal eye fields (FEFs) of older adults. An experimental group (VID group) engaged in 3D-platform video game training over a period of 6 months, while an active control group was trained on piano lessons (MUS group), and a no-contact control group did not participate in any intervention (CON group). Increased performance in oculomotor inhibition, as measured by the antisaccade task, and increased grey matter in the right FEF was observed uniquely in the VID group. These results demonstrate that 3D-platform video game training can improve inhibitory control known to decline with age.

Habitual action video game players display increased cortical thickness in the dorsal anterior cingulate cortex.

Action video game players (aVGPs) display increased performance in attention-based tasks and enhanced procedural motor learning. In parallel, the anterior cingulate cortex (ACC) is centrally implicated in specific types of reward-based learning and attentional control, the execution or inhibition of motor commands, and error detection. These processes are hypothesized to support aVGP in-game performance and enhanced learning though in-game feedback. We, therefore, tested the hypothesis that habitual aVGPs would display increased cortical thickness compared with nonvideo game players (nonVGPs). Results showed that the aVGP group (n=17) displayed significantly higher levels of cortical thickness specifically in the dorsal ACC compared with the nonVGP group (n=16). Results are discussed in the context of previous findings examining video game experience, attention/performance, and responses to affective components such as pain and fear.

Playing Super Mario 64 increases hippocampal grey matter in older adults.

Maintaining grey matter within the hippocampus is important for healthy cognition. Playing 3D-platform video games has previously been shown to promote grey matter in the hippocampus in younger adults. In the current study, we tested the impact of 3D-platform video game training (i.e., Super Mario 64) on grey matter in the hippocampus, cerebellum, and the dorsolateral prefrontal cortex (DLPFC) of older adults. Older adults who were 55 to 75 years of age were randomized into three groups. The video game experimental group (VID; n = 8) engaged in a 3D-platform video game training over a period of 6 months. Additionally, an active control group took a series of self-directed, computerized music (piano) lessons (MUS; n = 12), while a no-contact control group did not engage in any intervention (CON; n = 13). After training, a within-subject increase in grey matter within the hippocampus was significant only in the VID training group, replicating results observed in younger adults. Active control MUS training did, however, lead to a within-subject increase in the DLPFC, while both the VID and MUS training produced growth in the cerebellum. In contrast, the CON group displayed significant grey matter loss in the hippocampus, cerebellum and the DLPFC.

Hand position alters vision by modulating the time course of spatial frequency use.

The nervous system gives preferential treatment to objects near the hands that are candidates for action. It is not yet understood how this process is achieved. Here we show evidence for the mechanism that underlies this process having used an experimental technique that maps the use of spatial frequencies (SFs) during object recognition across time. We used this technique to replicate and characterize with greater precision the coarse-to-fine SF sampling observed in previous studies. Then we show that the visual processing of real-world objects near an observer's hands is biased toward the use of low-SF information, around 288 ms. Conversely, high-SF information presented around 113 ms impaired object recognition when objects were presented near the hands. Notably, both of these effects happened relatively late during object recognition and suggest that the modulation of SF use by hand position is at least partly attentional in nature. (PsycINFO Database Record

Electrophysiological evidence for enhanced attentional deployment in spatial learners.

Visual spatial attention is important during navigation processes that rely on a cognitive map, because spatial relationships between environmental landmarks need to be selected, encoded, and learned. People who navigate using this strategy are spatial learners, and this process relies on the hippocampus. Conversely, response learners memorize a series of actions to navigate, which relies on the caudate nucleus. Response learning, which is more efficient, is thought to involve less demanding cognitive operations, and is related to reduced grey matter in the hippocampus. To test if navigational strategy can impact visual attention performance, we investigated if spatial and response learners showed differences in attentional engagement used during a visual spatial task. We tested 40 response learners and 39 spatial learners, as determined by the 4-on-8 Virtual Maze (4/8 VM), on a target detection task designed to elicit an N2pc component (an index visual spatial attention). Spatial learners produced a larger N2pc amplitude during target detection compared to response learners. This relationship might represent an increase in goal-directed attention towards target stimuli or a more global increase in cognitive function that has been previously observed in spatial learners.

Action Video Game Playing Is Reflected In Enhanced Visuomotor Performance and Increased Corticospinal Excitability.

Action video game playing is associated with improved visuomotor performance; however, the underlying neural mechanisms associated with this increased performance are not well understood. Using the Serial Reaction Time Task in conjunction with Transcranial Magnetic Stimulation, we investigated if improved visuomotor performance displayed in action video game players (actionVGPs) was associated with increased corticospinal plasticity in primary motor cortex (M1) compared to non-video game players (nonVGPs). Further, we assessed if actionVGPs and nonVGPs displayed differences in procedural motor learning as measured by the SRTT. We found that at the behavioral level, both the actionVGPs and nonVGPs showed evidence of procedural learning with no significant difference between groups. However, the actionVGPs displayed higher visuomotor performance as evidenced by faster reaction times in the SRTT. This observed enhancement in visuomotor performance amongst actionVGPs was associated with increased corticospinal plasticity in M1, as measured by corticospinal excitability changes pre- and post- SRTT and corticospinal excitability at rest before motor practice. Our results show that aVGPs, who are known to have better performance on visual and motor tasks, also display increased corticospinal excitability after completing a novel visuomotor task.

The deployment of visual spatial attention during visual search predicts response time: electrophysiological evidence from the N2pc.

We tracked the deployment of visual spatial attention, as indexed by an electrophysiological event-related potential named the N-2-posterior-contralateral (N2pc). We expected that a stronger and/or earlier deployment of attention would predict faster responses in a visual search task. We tested this hypothesis by sorting the electrophysiological segments into two categories (slow vs. fast) by trial-by-trial response times (RTs), for each participant, on the basis of the median RT within each condition of the experiment. We also classified participants on the basis of overall mean RTs into those faster than the group median and those slower than the group median. The N2pc was larger and earlier for fast responders compared with slow responders. Furthermore, within each of these groups, faster responses were associated with a larger and earlier N2pc. These results provide further evidence that the N2pc is a valid index of the deployment of visual attention, and suggest that a more effective deployment of visual spatial attention (larger and/or earlier N2pc) predicts a faster response, both within and between subjects.

The development of inhibitory saccadic trajectory deviations correlates with measures of antisaccadic inhibition.

Chronological age is related positively to a participant's ability to inhibit distracting information. Inhibition can be measured using the trajectory deviation of a saccade. Saccadic curvature away from distracting visual information is controlled through top-down inhibition mediated by the frontal eye fields. In the present study, we aimed to further test the saccadic trajectory deviation paradigm's sensitivity to the development of frontal inhibitory procuresses by comparing its measure of saccadic inhibition with that of a widely used paradigm, namely, the antisaccade task. We show that the later 'inhibition' phase of the trajectory deviation function correlated strongly with the measure of antisaccadic inhibition obtained in the same individuals. As expected, the earlier 'capture' phase of the trajectory deviation function, which does not represent the involvement of frontal structures, did not correlate with antisaccadic inhibition. Further, both measures of frontal inhibition increased with chronological age.

Habitual action video game playing is associated with caudate nucleus-dependent navigational strategies.

The habitual playing of video games is associated with increased grey matter and activity in the striatum. Studies in humans and rodents have shown an inverse relationship between grey matter in the striatum and hippocampus. We investigated whether action video game playing is also associated with increased use of response learning strategies during navigation, known to be dependent on the caudate nucleus of the striatum, when presented in a dual solution task. We tested 26 action video game players (actionVGPs) and 33 non-action video game players (nonVGPs) on the 4-on-8 virtual maze and a visual attention event-related potential (ERP) task, which elicits a robust N-2-posterior-controlateral (N2pc) component. We found that actionVGPs had a significantly higher likelihood of using a response learning strategy (80.76%) compared to nonVGPs (42.42%). Consistent with previous evidence, actionVGPs and nonVGPs differed in the way they deployed visual attention to central and peripheral targets as observed in the elicited N2pc component during an ERP visual attention task. Increased use of the response strategy in actionVGPs is consistent with previously observed increases in striatal volume in video game players (VGPs). Using response strategies is associated with decreased grey matter in the hippocampus. Previous studies have shown that decreased volume in the hippocampus precedes the onset of many neurological and psychiatric disorders. If actionVGPs have lower grey matter in the hippocampus, as response learners normally do, then these individuals could be at increased risk of developing neurological and psychiatric disorders during their lifetime.