Activity In Occipital Cortex Research Articles

Attentional guidance through object associations in visual cortex

Efficient behavior requires the rapid attentional selection of task-relevant objects. Preparatory activity of target-selective neurons in visual cortex is thought to support attentional selection, guiding spatial attention and favoring processing of target-matching input. However, naturalistic searches are often guided by nontargets, including target-associated “anchor” objects. For instance, when looking for a pen, we may direct our attention to the office desk on which we expect to find it. Here, using fMRI and eye tracking in a context-guided search task, we tested whether preparatory activity in visual cortex reflected the target, the guiding anchor object, or both. Participants learned associations between targets and anchors, reversing across two scene contexts, before searching for these targets. Participants’ first fixations were reliably guided by the associated anchor. Preparatory activity in lateral occipital cortex (LOC) and right intraparietal sulcus (IPS) represented the target-associated anchor rather than the target. These results shed light on the neural basis of context-guided search in structured environments.

Contribution of the lateral occipital and parahippocampal cortices to pattern separation of objects and contexts.

Contextual features are integral to episodic memories; yet, we know little about context effects on pattern separation, a hippocampal function promoting orthogonalization of overlapping memory representations. Recent studies suggested that various extrahippocampal brain regions support pattern separation; however, the specific role of the parahippocampal cortex-a region involved in context representation-in pattern separation has not yet been studied. Here, we investigated the contribution of the parahippocampal cortex (specifically, the parahippocampal place area) to context reinstatement effects on mnemonic discrimination, using functional magnetic resonance imaging. During scanning, participants saw object images on unique context scenes, followed by a recognition task involving the repetitions of encoded objects or visually similar lures on either their original context or a lure context. Context reinstatement at retrieval improved item recognition but hindered mnemonic discrimination. Crucially, our region of interest analyses of the parahippocampal place area and an object-selective visual area, the lateral occipital cortex indicated that while during successful mnemonic decisions parahippocampal place area activity decreased for old contexts compared to lure contexts irrespective of object novelty, lateral occipital cortex activity differentiated between old and lure objects exclusively. These results imply that pattern separation of contextual and item-specific memory features may be differentially aided by scene and object-selective cortical areas.

Alterations in Neural Activation During Facial Emotion Processing in Adolescent Male Participants With Klinefelter Syndrome.

Klinefelter syndrome (KS) is the most common sex-chromosome aneuploidy (47,XXY), affecting 1 in 500 male participants. The phenotype of male participants with KS includes both physical features, such as tall stature and testicular insufficiency, and behavioral alterations, including difficulties in social functioning, anxiety, and depression. Studies examining underlying neural alterations associated with the behavioral phenotype, however, are sparse. We aimed to address this gap in knowledge using functional magnetic resonance imaging in conjunction with an emotion processing paradigm. Functional magnetic resonance imaging was conducted on 38 children and adolescents with KS ( Mage = 12.85, SD = 2.45) and 47 typical developing (control) boys ( Mage = 12.04, SD = 1.82) as they completed a facial emotion processing task. Group differences in activation occurring during the processing of angry versus neutral faces were examined while controlling for age. The results indicated that relative to typically developing boys, boys with KS exhibited anomalous increases in activation of frontal, temporal, and occipital cortices. Within the KS group, secondary analyses indicated that greater activation in these regions was associated with more internalizing symptoms (e.g., anxiety, depression, withdrawn behaviors) and greater social impairments (e.g., social cognition, social communication, social motivation, social communication and interaction, functional communication). The findings from this study indicate a possible neural correlation for difficulties in social and emotional function in KS and add to a growing body of research aimed at increasing our understanding of neural biomarkers in this condition. Future studies that examine the influence of testosterone-replacement therapy on these differences are warranted.

Cognitive stimulation as a mechanism linking socioeconomic status and neural function supporting working memory: a longitudinal fMRI study.

Childhood experiences of low socioeconomic status are associated with alterations in neural function in the frontoparietal network and ventral visual stream, which may drive differences in working memory. However, the specific features of low socioeconomic status environments that contribute to these disparities remain poorly understood. Here, we examined experiences of cognitive deprivation (i.e. decreased variety and complexity of experience), as opposed to experiences of threat (i.e. violence exposure), as a potential mechanism through which family income contributes to alterations in neural activation during working memory. As part of a longitudinal study, 148 youth between aged 10 and 13years completed a visuospatial working memory fMRI task. Early childhood low income, chronicity of low income in early childhood, and current income-to-needs were associated with task-related activation in the ventral visual stream and frontoparietal network. The association of family income with decreased activation in the lateral occipital cortex and intraparietal sulcus during working memory was mediated by experiences of cognitive deprivation. Surprisingly, however, family income and deprivation were not significantly related to working memory performance, and only deprivation was associated with academic achievement in this sample. Taken together, these findings suggest that early life low income and associated cognitive deprivation are important factors in neural function supporting working memory.

The Reactivation of working memory representations affects attentional guidance.

Recent studies have suggested that the neural activity that supported working memory (WM) storage is dynamic over time and this dynamic storage decides memory performance. Does the temporal dynamic of the WM representation also affect visual search, and how does it interact with distractor suppression over time? To address these issues, we tracked the time course of the reactivation of WM representations during visual search by analyzing the electroencephalogram (EEG) and event-related optical signals (EROS) in Experiments 1 and 2, respectively, and investigated the interaction between the representation reactivation and distractor suppression in Experiment 3. Participants had to maintain a color in WM under high- or low-precision requirement and perform a subsequent search task. The reactivation of WM representations was defined by the above-chance decoding accuracy. The EEG results showed that compared with the low-precision requirement, WM-matching distractors captured more attention and the WM representation were reactivated more frequently under high-precision requirement. The EROS results showed that compared with the low-precision requirement, the increased activity in occipital cortex in the WM-matching versus WM-mismatching conditions was observed at 224 ms during visual search under high-precision requirement. Regression analysis showed that the representation reactivation during visual search directly predicted the behavioral WM-based attentional capture effect, while the representation reactivation before visual search impacted the WM-based attentional capture effect through the mediation of distractor suppression during visual search. These results suggest that the reactivation of WM representations and distractor suppression collectively determine WM-based attentional capture.

C-reactive protein moderates associations between racial discrimination and ventromedial prefrontal cortex activation during attention to threat in Black American women.

Prior research has shown that racial discrimination (RD) impacts activation in threat network regions, including the ventromedial prefrontal cortex (vmPFC) and middle occipital cortex during attention to threat-relevant stimuli. However, little is known about the biological mechanisms that may modulate these effects; inflammation may be a pathway linking RD and threat network activation. As such, the current study aimed to explore whether systemic inflammation, measured by C-reactive protein (CRP) levels, may moderate the relationship between RD and activation in the vmPFC and middle occipital cortex during attention to threat. Blood samples for inflammatory marker (CRP) assays were obtained from forty Black American women (mean [SD] age, 39.93 [9.97] years; range, 22-58 years) recruited from an ongoing trauma study; participants also viewed threat-relevant stimuli as part of an attention task during fMRI. We found that CRP moderated the relationship between RD and vmPFC activation during attention to threat, such that participants with relatively higher concentrations of CRP ( ≥ 23.97 mg/L) demonstrated significant positive associations between RD and vmPFC activation [β = 0.18, CI (0.04, 0.32), t = 2.65, p = 0.01]. No significant associations were observed for participants who showed moderate (10.89 mg/L) or low (0.20 mg/L) CRP concentrations. CRP did not moderate the relationship between RD and middle occipital cortex activation. Our data present a mechanism through which RD may influence immune system activation and, in turn, threat networkactivation. Inflammation may contribute to brain health vulnerabilities in Black Americans via its effects on threat circuits; this merits further investigation in large-scale studies.

Hypoactive Visual Cortex, Prefrontal Cortex and Insula during Self-Face Recognition in Adults with First-Episode Major Depressive Disorder.

Self-face recognition is a vital aspect of self-referential processing, which is closely related to affective states. However, neuroimaging research on self-face recognition in adults with major depressive disorder is lacking. This study aims to investigate the alteration of brain activation during self-face recognition in adults with first-episode major depressive disorder (FEMDD) via functional magnetic resonance imaging (fMRI); FEMDD (n = 59) and healthy controls (HC, n = 36) who performed a self-face-recognition task during the fMRI scan. The differences in brain activation signal values between the two groups were analyzed, and Pearson correlation analysis was used to evaluate the relationship between the brain activation of significant group differences and the severity of depressive symptoms and negative self-evaluation; FEMDD showed significantly decreased brain activation in the bilateral occipital cortex, bilateral fusiform gyrus, right inferior frontal gyrus, and right insula during the task compared with HC. No significant correlation was detected between brain activation with significant group differences and the severity of depression and negative self-evaluation in FEMDD or HC. The results suggest the involvement of the malfunctioning visual cortex, prefrontal cortex, and insula in the pathophysiology of self-face recognition in FEMDD, which may provide a novel therapeutic target for adults with FEMDD.

Patterns of multiple brain network activation in dot perspective task

In this functional MRI (fMRI) study on 82 healthy adults using the dot perspective task, inconsistency of perspectives was associated with a significant increase of the mean reaction time and number of errors both in Self and Other conditions. Unlike the Arrow (non-mentalizing), the Avatar (mentalizing) paradigm was characterized by the recruitment of parts of the mentalizing and salience networks. These data provide experimental evidence supporting the fMRI distinction between mentalizing and non-mentalizing stimuli. A widespread activation of classical theory of mind (ToM) areas but also of salience network and decision making areas was observed in the Other compared to Self-conditions. Compared to Self-Consistent, Self-Inconsistent trials were related to increased activation in the lateral occipital cortex, right supramarginal and angular gyrus as well as inferior, superior and middle frontal gyri. Compared to the Other-Consistent, Other-Inconsistent trials yielded strong activation in the lateral occipital cortex, precuneus and superior parietal lobule, middle and superior precentral gyri and left frontal pole. These findings reveal that altercentric interference relies on areas involved in self-other distinction, self-updating and central executive functions. In contrast, egocentric interference needs the activation of the mirror neuron system and deductive reasoning, much less related to pure ToM abilities.

Multimodal investigation of melanopsin retinal ganglion cells in Alzheimer's disease.

In Alzheimer's disease (AD), the presence of circadian dysfunction is well-known and may occur early in the disease course. The melanopsin retinal ganglion cell (mRGC) system may play a relevant role in contributing to circadian dysfunction. In this study, we aimed at evaluating, through a multimodal approach, the mRGC system in AD at an early stage of disease. We included 29 mild-moderate AD (70.9 ± 11 years) and 26 (70.5 ± 8 years) control subjects. We performed an extensive neurophtalmological evaluation including optical coherence tomography with ganglion cell layer segmentation, actigraphic evaluation of the rest-activity rhythm, chromatic pupillometry analyzed with a new data-fitting approach, and brain functional MRI combined with light stimuli assessing the mRGC system. We demonstrated a significant thinning of the infero-temporal sector of the ganglion cell layer in AD compared to controls. Moreover, we documented by actigraphy the presence of a circadian-impaired AD subgroup. Overall, circadian measurements worsened by age. Chromatic pupillometry evaluation highlighted the presence of a pupil-light response reduction in the rod condition pointing to mRGC dendropathy. Finally, brain fMRI showed a reduced occipital cortex activation with blue light particularly for the sustained responses. Overall, the results of this multimodal innovative approach clearly document a dysfunctional mRGC system at early stages of disease as a relevant contributing factor for circadian impairment in AD providing also support to the use of light therapy in AD.

The role of functional magnetic resonance imaging in clinically diagnosed cases of migraine

Background: Migraine manifests as recurrent headaches associated with nausea, vomiting, and sensory hypersensitivity. Functional magnetic resonance imaging (fMRI) images activation in different parts of brain either on stimulation or at rest. Aims and Objectives: The aim of the study was to study the fMRI changes in brain in response to visual stimulation in migraine patients with and without aura compared with healthy volunteers. Materials and Methods: A prospective fMRI study was performed in 50 clinically diagnosed cases of migraine and 50 healthy volunteers above 18 years of age on a 3-Tesla MRI scanner. For fMRI, the visual stimulus was presented as a moving black and white checker board pattern. Results: All subjects demonstrated activation in bilateral occipital cortex (predominantly in V1 followed by V2 area). Group analysis of the occipital activation pattern in migraine patients versus control revealed that 56% (28/50) showed significantly increased activation in occipital cortex, 20% (10/50) revealed no significant difference in activation patterns, and 24% of total migraine patients (12/50) had equivocal results. Out of the 28 patients with increased activation in occipital cortex, 14 (50%) revealed increased activation in the left V5 cortex, 8 (28.5%) increased activation in the left V3 cortex, 4 (14.2%) increased activation in both left V3 and V5 cortex, and 2 (7.1%) had increased activation in both right V3 and right V5 areas. Conclusion: The current study revealed increased occipital stimulation mainly in the left V3 and V5 areas in clinically diagnosed cases of migraine in comparison to normal healthy subjects. The study also revealed clinically significant association between increased occipital stimulation and duration of migraine and absence of pharmacological aid.

Brain activity during visuospatial working memory in congenital adrenal hyperplasia.

Patients with congenital adrenal hyperplasia (CAH) require life-long replacement of cortisol. Problems with cognitive function, especially working memory, have previously been identified, but the long-term effects of this disease on brain function are unknown. We investigate brain activity during working memory in CAH compared to controls. Twenty-nine individuals with CAH (17 females) and 40 healthy controls (24 females), 16-33 years, from a single research institute, underwent functional magnetic resonance imaging while doing a verbal and visuospatial working memory task. Individuals with CAH responded faster on the verbal task. Although we found no differences in BOLD response over the whole group, there were significant interactions with sex: CAH males had increased activity in the bilateral lateral superior occipital cortex, left supramarginal and angular gyri, left precuneus, left posterior cingulate cortex and bilateral cerebellum during decoding of the visuospatial task, while females showed decreased activity in these regions. Long-term cortisol imbalances do not seem to have a major impact on the functional brain responses during working memory in CAH. However, activity of the left dorsal visual stream in particular might be affected depending on sex. As the task employed may have been relatively easy, larger studies using more complex tasks are needed to further investigate this.

Occipital cortex activity in response to melanopsin in healthy humans

AbstractPurpose: Melanopsin‐expressing retinal ganglion cells (mRGCs) signal light information to the brain and mediate non‐visual physiologic responses. Animal studies suggest that melanopsin also influences the visual pathway via synaptic contacts in the lateral geniculate nucleus and the superior colliculus. In healthy and blind humans, blue light exposure results in modulation of occipital activity in neuroimaging studies, presumably from melanopsin interaction with photoreceptors. This study examined if melanopsin activation influences the visual evoked potential (VEP).Methods: We recorded VEPs to light flash stimuli to activate cones, rods and melanopsin in 30 healthy volunteers (red: 630 nm, blue: 445 nm, intensities: 0.00003 to 150 cd/m2). Dark adaptation was used to sensitize rods. At 2 log cd/m2, rods are saturated, and bright blue lights are considered more melanopsin activating. Under photopic conditions, red light activates M‐L cones. Amplitude and latency of the N2 and P2 components of the VEP were evaluated.Results: P2 obtained from the melanopsin stimulus presented under dark‐adaptation (MEL1) had the largest amplitude and shortest latency of all VEPs including the melanopsin stimulus presented non‐dark adapted condition (MEL2). There was no difference of N2 between MEL1 and MEL2 conditions. The latency of N2 and P2 from rods was longer than that from MEL1 and MEL2. P2 from MEL2 was equivalent in amplitude and latency to the P2 of the brightest cone stimulus (30 cd/m2 red light).Conclusion: Under non‐dark‐adapted conditions, bright blue light evokes a similar VEP as bright red light, suggesting that cones are the predominant influence in these conditions. However, bright blue light presented under dark adaptation modified the VEP latency and amplitude. As rod VEPs are distinguished by slow latencies, then we propose that these changes arise from mRGCs influence on cone‐mediated visual pathways to the occipital cortex.

Language and nonverbal auditory processing in the occipital cortex of individuals who are congenitally blind due to anophthalmia

Individuals with congenital blindness due to bilateral anophthalmia offer a unique opportunity to examine cross-modal plasticity in the complete absence of any stimulation of the ‘visual’ pathway even during development in utero. Our previous work has suggested that this complete sensory deafferentation results in different patterns of reorganisation compared with those seen in other early blind populations. Here, we further test the functional specialisation of occipital cortex in six well-studied cases with anophthalmia. Whole brain functional MRI was obtained while these human participants and a group of sighted controls performed two experiments involving phonological and semantic processing of words (verbal experiment) and spatial and identity processing of piano chords (nonverbal experiment). Both experiments were predicted to show a dorsal-ventral difference in activity based on the specific task performed. All tasks evoked activation in occipital cortex in the individuals with anophthalmia but not in the sighted controls. For the verbal experiment, both dorsal and ventral occipital areas were strongly activated by the phonological and semantic tasks in anophthalmia. For the nonverbal experiment, both the spatial and the identity task robustly activated the dorsal occipital area V3a but showed inconsistent activity elsewhere in the occipital lobe. V1 was most strongly activated by the verbal tasks, showing greater activity on the left for the verbal task relative to the nonverbal one. For individual anophthalmic participants, however, activity in V1 was inconsistent across tasks and hemispheres with many participants showing activity levels in the control range, which was not significantly above baseline. Despite the homogeneous nature of the cause of blindness in the anophthalmic group, there remain differences in patterns of activation among the individuals with this condition. Investigation at the case level might further our understanding of how post-natal experiences shape functional reorganisation in deafferented cortex.

Top-down sensory prediction in the infant brain at 6 months is correlated with language development at 12 and 18 months

Previous research has suggested that top-down sensory prediction facilitates, and may be necessary for, efficient transmission of information in the brain. Here we related infants’ vocabulary development to the top-down sensory prediction indexed by occipital cortex activation to the unexpected absence of a visual stimulus previously paired with an auditory stimulus. The magnitude of the neural response to the unexpected omission of a visual stimulus was assessed at the age of 6 months with functional near-infrared spectroscopy (fNIRS) and vocabulary scores were obtained using the MacArthur-Bates Communicative Development Inventory (MCDI) when infants reached the age of 12 months and 18 months, respectively. Results indicated significant positive correlations between this predictive neural signal at 6 months and MCDI expressive vocabulary scores at 12 and 18 months. These findings provide additional and robust support for the hypothesis that top-down prediction at the neural level plays a key role in infants’ language development.

P 58 EEG responses from direct cerebellar activation with Transcranial Magnetic Stimulation

Introduction: Measuring cortical responses from cerebellar stimulation might provide diagnostic biomarkers for the dentato-thalamo-cortical pathway's integrity. Recent studies have investigated the feasibility of delivering cerebellar stimulation through transcranial magnetic stimulation-electroencephalography (TMS-EEG). TMS-EEG presents several potential advantages and could provide more information than previous methods, which rely on motor output measures. However, past TMS-EEG studies were subject to considerable limitations, including contamination of the TMS-evoked potentials by peripherally-evoked potentials (PEPs). Therefore, we aimed to investigate cortical signatures of cerebellar stimulation, while controlling for confounding factors. Methods: We recruited 23 healthy, right-handed volunteers (13 females, mean ± SD age, 22.4±2.2 years). For each, resting motor threshold was used to titrate the intensity necessary to elicit a detectable cerebellar brain inhibition, which was set as the cerebellar TMS-intensity. A total of 280 single TMS pulses were then delivered to the cerebellum, 140 corresponding to REAL and 140 to SHAM condition. SHAM consisted of TMS to the right shoulder, whereas REAL consisted of both TMS to the right cerebellar hemisphere and to the right shoulder. Two further conditions were tested: TMS to the right occipital cortex and TMS to the right trapezius muscle, with otherwise the same parameters of the REAL condition. These conditions aimed to control for confounding factors, respectively collateral occipital cortex activation and PEPs from cerebellar TMS stimulation. EEG-signals of the different conditions were compared with respect to the evoked responses and changes in the time-frequency response via cluster-based t-tests. Results: Comparison of REAL and SHAM revealed significant differences. While some of these differences were explained by the occipital control stimulation, a left-hemispheric prefrontal early positive deflection at 20-26 ms and a left-hemispheric temporal negative deflection peaking at 45 ms (i.e. both contralateral to the cerebellar stimulation) were specific to the cerebellar stimulation. Furthermore, increased frontal theta power immediately after the TMS pulse was specific to the cerebellar stimulation. Conclusions: The investigation of multiple control conditions allowed for unmasking the cortical response resulting specifically from cerebellar TMS. The observed left-hemispheric prefrontal and subsequent temporal cortex responses were only present in conditions involving cerebellar stimulation and could neither be explained by collateral occipital stimulation, nor by a non-specific somatosensory input. These results are anatomically plausible, as targets of the dentato-thalamo-cortical pathway predominantly involve the contralateral prefrontal cortex and structural connectivity between the cerebellum and the contralateral superior temporal sulcus could be demonstrated in past studies.

Perspective: Estrogen and the Risk of Cognitive Decline: A Missing Choline(rgic) Link?

ABSTRACTFactors that influence the risk of neurocognitive decline and Alzheimer's disease (AD) may provide insight into therapies for both disease treatment and prevention. Although age is the most striking risk factor for AD, it is notable that the prevalence of AD is higher in women, representing two-thirds of cases. To explore potential underlying biological underpinnings of this observation, the intent of this article is to explore the interplay between cognitive aging and sex hormones, the cholinergic system, and novel hypotheses related to the essential nutrient choline. Mechanistic evidence points toward estrogen's neuroprotective effects being strongly dependent on its interactions with the cholinergic system, a modulator of attentional functioning, learning, and memory. Estrogen has been shown to attenuate anticholinergic-induced impairments in verbal memory and normalize patterns of frontal and occipital cortex activation, resulting in a more “young adult” phenotype. However, similar to estrogen replacement's effect in cardiovascular diseases, its putative protective effects may be restricted to early postmenopausal women only, a finding supportive of the “critical window hypothesis.” Estrogen's impact on the cholinergic system may act both locally in the brain but also through peripheral tissues. Estrogen is critical for inducing endogenous choline synthesis via the phosphatidylethanolamine N-methyltransferase (PEMT) gene–mediated pathway of phosphatidylcholine (PC) synthesis. PEMT is dramatically induced in response to estrogen, producing not only a PC molecule and source of choline for the brain but also a key source of the long-chain ω-3 fatty acid, DHA. Herein, we highlight novel hypotheses related to hormone replacement therapy and nutrient metabolism aimed at directing future preclinical and clinical investigation.

Brain activation during cognitive reappraisal depending on regulation goals and stimulus valence.

Neural bases of cognitive reappraisal may depend on the direction of regulation (up- or downregulation) and stimulus valence (positive or negative). This study aimed to examine this using a cognitive reappraisal task and conjunction analysis on a relatively large sample of 83 individuals. We identified regions in which activations were common for all these types of emotion regulation. We also investigated differences in brain activation between the ‘decrease’ and ‘increase’ emotional response conditions, and between the regulation of negative and positive emotions. The common activation across conditions involved mainly the prefrontal and temporal regions. Decreasing emotions was associated with stronger involvement of the dorsolateral prefrontal cortex, while increasing with activation of the amygdala and hippocampus. Regulation of negative emotions involved stronger activation of the lateral occipital cortex, while regulation of positive emotions involved stronger activation of the anterior cingulate cortex extending to the medial prefrontal cortex. This study adds to previous findings, not only by doing a conjunction analysis on both emotional valences and regulation goals, but also doing this in a bigger sample size. Results suggest that reappraisal is not a uniform process and may have different neural bases depending on regulation goals and stimulus valence.

Sports in Natural Environment, Sports in Urban Environment: An fMRI Study about Stress and Attention/Awareness.

This study aimed to explore, on one side, the differences between a group of athletes exercising outdoor (OG) and another group exercising indoor (IG) in stress and awareness, and, on the other side, between-group differences in the fMRI activations during the visualization of natural environment images versus urban images. In addition, we aimed to analyze the associations between the resulting task-related brain activations and stress and attention-awareness in each group separately. All the participants (N = 49; OG = 21, 11 females, mean age = 40, SD = 6.49; and IG = 25, 11 females, mean age = 40; 6.19) underwent an fMRI scan and completed the Perceived Stress Scale and the Mindful Attention Awareness Scale. Besides, we collected a sample of hair cortisol. Participants viewed three types of images: water nature, green nature and urban images. Two-sample t-test with corrected p=0.001 values were carried out. Further correlational analyses were performed to estimate the associations between task-related brain activations and our pyscho-emotional measures in each group. Fisher tests were used to explore for potential between-group differences in the correlational indexes. In OG, compared to IG, we found a higher activation of the middle occipital cortex and a cluster comprising the supplementary motor area (SMA), the premotor cortex and the pre-SMA while viewing green nature images versus urban images. In OG, more than in IG, the higher activation of the left SMA cluster negatively correlated with perceived stress, while in the IG, more than in OG, the higher premotor cortex activation was positively related to the total score on MAAS. No significant association was found with the hair cortisol levels. Exercising outdoor would relate to better psycho-emotional outcomes, also for athletes. On the other side, the exposition to green nature led to higher activation of brain areas related to motor planning, but also to emotion regulation and emotional response.

Transcranial magnetic stimulation entrains alpha oscillatory activity in occipital cortex

Parieto-occipital alpha rhythms (8–12 Hz) underlie cortical excitability and influence visual performance. Whether the synchrony of intrinsic alpha rhythms in the occipital cortex can be entrained by transcranial magnetic stimulation (TMS) is an open question. We applied 4-pulse, 10-Hz rhythmic TMS to entrain intrinsic alpha oscillators targeting right V1/V2, and tested four predictions with concurrent electroencephalogram (EEG): (1) progressive enhancement of entrainment across time windows, (2) output frequency specificity, (3) dependence on the intrinsic oscillation phase, and (4) input frequency specificity to individual alpha frequency (IAF) in the neural signatures. Two control conditions with an equal number of pulses and duration were arrhythmic-active and rhythmic-sham stimulation. The results confirmed the first three predictions. Rhythmic TMS bursts significantly entrained local neural activity. Near the stimulation site, evoked oscillation amplitude and inter-trial phase coherence (ITPC) were increased for 2 and 3 cycles, respectively, after the last TMS pulse. Critically, ITPC following entrainment positively correlated with IAF rather than with the degree of similarity between IAF and the input frequency (10 Hz). Thus, we entrained alpha-band activity in occipital cortex for ~ 3 cycles (~ 300 ms), and IAF predicts the strength of entrained occipital alpha phase synchrony indexed by ITPC.

What Deception Tasks Used in the Lab Really Do: Systematic Review and Meta-analysis of Ecological Validity of fMRI Deception Tasks

Interpretation of the neural findings of deception without considering the ecological validity of the experimental tasks could lead to biased conclusions. In this study we classified the experimental tasks according to their inclusion of three essential components required for ecological validity: intention to lie, social interaction and motivation. First, we carried out a systematic review to categorize fMRI deception tasks and to weigh the degree of ecological validity of each one. Second, we performed a meta-analysis to identify if each type of task involves a different neural substrate and to distinguish the neurocognitive contribution of each component of ecological validity essential to deception. We detected six categories of deception tasks. Intention to lie was the component least frequently included, followed by social interaction. Monetary reward was the most frequent motivator. The results of the meta-analysis, including 59 contrasts, revealed that intention to lie is associated with activation in the left lateral occipital cortex (superior division) whereas the left angular gyrus and right inferior frontal gyrus (IFG) are engaged during lying under instructions. Additionally, the right IFG appears to participate in the social aspect of lying including simulated and real interactions. We found no effect of monetary reward in our analysis. Finally, tasks with high ecological validity recruited fewer brain areas (right insular cortex and bilateral anterior cingulate cortex (ACC)) compared to less ecological tasks, perhaps because they are more natural and realistic, and engage a wide network of brain mechanisms, as opposed to specific tasks that demand more centralized processes.