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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Electrophysiological evidence for biased competition in V1 for fear expressions.

When multiple stimuli are concurrently displayed in the visual field, they must compete for neural representation at the processing expense of their contemporaries. This biased competition is thought to begin as early as primary visual cortex, and can be driven by salient low-level stimulus features. Stimuli important for an organism's survival, such as facial expressions signaling environmental threat, might be similarly prioritized at this early stage of visual processing. In the present study, we used ERP recordings from striate cortex to examine whether fear expressions can bias the competition for neural representation at the earliest stage of retinotopic visuo-cortical processing when in direct competition with concurrently presented visual information of neutral valence. We found that within 50 msec after stimulus onset, information processing in primary visual cortex is biased in favor of perceptual representations of fear at the expense of competing visual information (Experiment 1). Additional experiments confirmed that the facial display's emotional content rather than low-level features is responsible for this prioritization in V1 (Experiment 2), and that this competition is reliant on a face's upright canonical orientation (Experiment 3). These results suggest that complex stimuli important for an organism's survival can indeed be prioritized at the earliest stage of cortical processing at the expense of competing information, with competition possibly beginning before encoding in V1.

Emotion and action: the effect of fear on saccadic performance.

According to evolutionary accounts, emotions originated to prepare an organism for action (Darwin 1872; Frijda 1986). To investigate this putative relationship between emotion and action, we examined the effect of an emotional stimulus on oculomotor actions controlled by the superior colliculus (SC), which has connections with subcortical structures involved in the perceptual prioritization of emotion, such as the amygdala through the pulvinar. The pulvinar connects the amygdala to cells in the SC responsible for the speed of saccade execution, while not affecting the spatial component of the saccade. We tested the effect of emotion on both temporal and spatial signatures of oculomotor functioning using a gap-distractor paradigm. Changes in spatial programming were examined through saccadic curvature in response to a remote distractor stimulus, while changes in temporal execution were examined using a fixation gap manipulation. We show that following the presentation of a task-irrelevant fearful face, the temporal but not the spatial component of the saccade generation system was affected.

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.

Red diffuse light suppresses the accelerated perception of fear.

Prioritization of affective events may occur via two parallel pathways originating from the retina-a parvocellular (P) pathway projecting to ventral-stream structures responsible for object recognition or a faster and phylogenetically older magnocellular (M) pathway projecting to dorsal-stream structures responsible for localization and action. It has previously been demonstrated that retinal exposure to red diffuse light suppresses M-cell neural activity. We tested whether the fast propagation along the dorsal-action pathway drives an accelerated conduction of fear-based content. Using a visual prior-entry procedure, we assessed accelerated stimulus perception while either suppressing the M pathway with red diffuse light or leaving it unaffected with green diffuse light. We show that the encoding of fearful faces is accelerated, but not when M-channel activity is suppressed, revealing a dissociation that implicates a privileged neural link between emotion and action that begins at the retina.

Capacity limits during perceptual encoding.

When a unique stimulus is embedded in an otherwise homogenous display, it is thought to "pop-out" due to its relative increase in salience. We investigated whether the visual system has the ability to equally prioritize multiple salient pop-out items competing for awareness or whether this early stage of visual processing is constrained by capacity limits. We used signal detection (d') methods to determine if sensitivity to a salient pop-out item decreases as function of the number of total salient items present in the visual display. Participants engaged in a signal detection task where they had to report the presence or absence of a simple display change that involved either a pop-out or a non-salient distractor stimulus. Results across four experiments consistently showed that sensitivity to changes involving pop-out stimuli was significantly reduced after more than one of these items was present in the visual array. Results are discussed in terms of neural models of visual encoding and other known capacity limits during visual processing.

Motivationally significant stimuli show visual prior entry: evidence for attentional capture.

Previous studies that have found attentional capture effects for stimuli of motivational significance do not directly measure initial attentional deployment, leaving it unclear to what extent these items produce attentional capture. Visual prior entry, as measured by temporal order judgments (TOJs), rests on the premise that allocated attention accelerates perception, that is, stimuli that receive attention first are perceived first; thus, this method is a sensitive and direct measure of the time course of initial attentional deployment. The authors demonstrate, using a novel TOJ paradigm without cues, that displays of faces and facial threat show visual prior entry effects, that is, these stimuli are prioritized by the perceptual-attentional system over other stimuli competing for awareness. This study provides direct evidence of the extent to which motivationally significant stimuli capture attention over other concurrently displayed items in the visual array.

Saccadic trajectories receive online correction: evidence for a feedback-based system of oculomotor control.

Although a considerable amount of research has investigated the planning and production of saccadic eye movements, it remains unclear whether (a) central planning processes prior to movement onset largely determine these eye movements or (b) they receive online correction during the actual trajectory. To investigate this issue, the authors measured the spatial position of the eye at specific kinematic markers during saccadic movements (i.e., peak acceleration, peak velocity, peak deceleration, saccade endpoint). In 2 experiments, the authors examined saccades ranging in amplitude from 4 to 20 degrees and computed the variability profiles (SD) of eye position at each kinematic marker and the proportion of explained variance (R2) between each kinematic marker and the saccade endpoint. In Experiment 1, the authors examined differences in the kinematic signature of saccadic online control between eye movements made in gap or overlap conditions. In Experiment 2, the authors examined the online control of saccades made from stored target information after delays of 500, 1,500, and 3,500 ms. Findings evince a robust and consistent feedback-based system of online oculomotor control during saccadic eye movements.

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.

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.