Patterns Of Activity In Cortex Research Articles

Individual differences in prelimbic neural representation of food and cocaine seeking

The prelimbic cortex is involved in operant reward seeking. However, the precise nature of its activity patterns and whether/how they differ between different types of rewards are largely unknown. We use miniscope calcium imaging to observe prelimbic activity during both food and cocaine seeking in freely behaving mice. We find that neurobehavioral representations remain stable across days within individual mice. Unexpectedly, our data reveal significant individual differences: some mice display high similarity in their prelimbic cortex activity patterns for both food and cocaine seeking, while others show no such overlap. These findings suggest that individual differences in the neural mechanisms underlying food and cocaine seeking could be a critical factor to consider when developing future addiction treatment strategies.

The Impact of Sports Participation on College Students' Learning Outcomes: A Mixed Methods Study based on Multiple Campuses

Plato said: In order for humans to have a successful life, God provides two channels-education and sports. We are increasingly seeing that these two channels are complementary and indispensable. Modern neuroscience research shows that sports can have beneficial effects on brain structure and function, epigenetic regulation of brain tissue, cerebral cortex activity patterns and learning-related psychological factors, thereby improving students' cognitive abilities and academic performance. This study aims to explore the multifaceted effects of sports participation on college students' learning outcomes. A mixed research method was used to collect data in three different types of universities, including a questionnaire survey of 500 students and in-depth interviews with 20 students and 10 faculty members. Quantitative analysis showed that moderate sports participation was significantly related to better academic performance, higher mental health and stronger time management skills. However, excessive participation in physical activities may have a negative impact on study time. Qualitative data further revealed how sport participation enhanced students' self-confidence, teamwork and stress management skills. The study also found that the impact of sports participation varies depending on students' personal backgrounds and the characteristics of their universities. Based on the research results, this article puts forward practical suggestions to promote the balanced development of college students, providing a basis for higher education institutions to formulate relevant policies.

Different baseline functional patterns of the frontal cortex in amyotrophic lateral sclerosis patients with Corticospinal tract hyperintensity

Nearly half of the amyotrophic lateral sclerosis (ALS) patients showed hyperintensity of the corticospinal tract (CST+), yet whether brain functional pattern differs between CST+and CST- patients remains obscure. In the current study, 19 ALS CST+, 41 ALS CST- patients and 37 healthy controls (HC) underwent resting state fMRI scans. We estimated local activity and connectivity patterns via the Amplitude of Low Frequency Fluctuations (ALFF) and the Network-Based Statistic (NBS) approaches respectively. The ALS CST+patients did not differ from the CST- patients in amyotrophic lateral sclerosis functional rating scale revised (ALSFRS-R) score and disease duration. ALFF of the superior frontal gyrus (SFG) and the inferior frontal gyrus pars opercularis (OIFG) were highest in the HC and lowest in the ALS CST- patients, resulting in significant group differences (PFWE<0.05). NBS analysis revealed a frontal network consisting of connections between SFG, OIFG, orbital frontal gyrus, middle cingulate cortex and the basal ganglia, which exhibited HC>ALS CST+ > ALS CST- group differences (PFWE=0.037) as well. The ALFF of the OIFG was significantly correlated with ALSFRS-R (R=0.34, P=0.028) and mean connectivity of the frontal network was trend-wise significantly correlated with disease duration (R=-0.31, P=0.052) in the ALS CST- patients. However, these correlations were insignificant in ALS CST+patients (P values > 0.8). In conclusion, The ALS CST+patients exhibited different patterns of baseline functional activity and connectivity in the frontal cortex which may indicate a functional compensatory effect.

Mental navigation in the primate entorhinal cortex

A cognitive map is a suitably structured representation that enables novel computations using previous experience; for example, planning a new route in a familiar space1. Work in mammals has found direct evidence for such representations in the presence of exogenous sensory inputs in both spatial2,3 and non-spatial domains4–10. Here we tested a foundational postulate of the original cognitive map theory1,11: that cognitive maps support endogenous computations without external input. We recorded from the entorhinal cortex of monkeys in a mental navigation task that required the monkeys to use a joystick to produce one-dimensional vectors between pairs of visual landmarks without seeing the intermediate landmarks. The ability of the monkeys to perform the task and generalize to new pairs indicated that they relied on a structured representation of the landmarks. Task-modulated neurons exhibited periodicity and ramping that matched the temporal structure of the landmarks and showed signatures of continuous attractor networks12,13. A continuous attractor network model of path integration14 augmented with a Hebbian-like learning mechanism provided an explanation of how the system could endogenously recall landmarks. The model also made an unexpected prediction that endogenous landmarks transiently slow path integration, reset the dynamics and thereby reduce variability. This prediction was borne out in a reanalysis of firing rate variability and behaviour. Our findings link the structured patterns of activity in the entorhinal cortex to the endogenous recruitment of a cognitive map during mental navigation.

Trying Harder: How Cognitive Effort Sculpts Neural Representations during Working Memory.

While the exertion of mental effort improves performance on cognitive tasks, the neural mechanisms by which motivational factors impact cognition remain unknown. Here, we used fMRI to test how changes in cognitive effort, induced by changes in task difficulty, impact neural representations of working memory (WM). Participants (both sexes) were precued whether WM difficulty would be hard or easy. We hypothesized that hard trials demanded more effort as a later decision required finer mnemonic precision. Behaviorally, pupil size was larger and response times were slower on hard compared with easy trials suggesting our manipulation of effort succeeded. Neurally, we observed robust persistent activity during delay periods in the prefrontal cortex (PFC), especially during hard trials. Yet, details of the memoranda could not be decoded from patterns in prefrontal activity. In the patterns of activity in the visual cortex, however, we found strong decoding of memorized targets, where accuracy was higher on hard trials. To potentially link these across-region effects, we hypothesized that effort, carried by persistent activity in the PFC, impacts the quality of WM representations encoded in the visual cortex. Indeed, we found that the amplitude of delay period activity in the frontal cortex predicted decoded accuracy in the visual cortex on a trial-wise basis. These results indicate that effort-related feedback signals sculpt population activity in the visual cortex, improving mnemonic fidelity.

Investigating the neural basis of schematic false memories by examining schematic and lure pattern similarity

ABSTRACT Schemas allow us to make assumptions about the world based upon previous experiences and aid in memory organisation and retrieval. However, a reliance on schemas may also result in increased false memories to schematically related lures. Prior neuroimaging work has linked schematic processing in memory tasks to activity in prefrontal, visual, and temporal regions. Yet, it is unclear what type of processing in these regions underlies memory errors. The current study examined where schematic lures exhibit greater neural similarity to schematic targets, leading to this memory error, as compared to neural overlap with non-schematic lures, which, like schematic lures, are novel items at retrieval. Results showed that patterns of neural activity in ventromedial prefrontal cortex, medial frontal gyrus, middle temporal gyrus, hippocampus, and occipital cortices exhibited greater neural pattern similarity for schematic targets and schematic lures than between schematic lures and non-schematic lures. As such, results suggest that schematic membership, and not object history, may be more critical to the neural processes underlying memory retrieval in the context of a strong schema.

Motivated with joy or anxiety: Does approach-avoidance goal framing elicit differential reward-network activation in the brain?

Psychological research on human motivation repeatedly observed that approach goals (i.e., goals to attain success) increase task enjoyment and intrinsic motivation more strongly than avoidance goals (i.e., goals to avoid failure). The present study sought to address how the reward network in the brain—including the striatum and ventromedial prefrontal cortex—is involved when individuals engage in the same task with a focus on approach or avoidance goals. Participants reported stronger positive emotions when they focused on approach goals, but stronger anxiety and disappointment when they focused on avoidance goals. The fMRI analyses revealed that the reward network in the brain showed similar levels of activity to cues predictive of approach and avoidance goals. In contrast, the two goal states were associated with different patterns of activity in the visual cortex, hippocampus, and cerebellum during success and failure outcomes. Representation similarity analysis further revealed shared and different representations within the striatum and vmPFC between the approach and avoidance goal states, suggesting both the similarity and uniqueness of the mechanisms behind the two goal states. In addition, the distinct patterns of activation in the striatum were associated with distinct subjective experiences participants reported between the approach and the avoidance conditions. These results suggest the importance of examining the pattern of striatal activity in understanding the mechanisms behind different motivational states in humans.

The effects of acute and chronic noise trauma on stimulus-evoked activity across primary auditory cortex layers.

Exposure to intense noise environments is a major cause of sensorineural hearing loss and auditory perception disorders, such as tinnitus and hyperacusis, which may have a central origin. The effects of noise-induced hearing loss on the auditory cortex have been documented in many studies. One limitation of these studies, however, is that the effects of noise trauma have been mostly studied at the granular layer (i.e, the main cortical recipient of thalamic input), while the cortex is a very complex structure, with six different layers each having its own pattern of connectivity and role in sensory processing. The present study aims to investigate the effects of acute and chronic noise trauma on the laminar pattern of stimulus-evoked activity in the primary auditory cortex of the anesthetized guinea pig. We show that acute and chronic noise trauma are both followed by an increase in stimulus-evoked cortical responses, mostly in the granular and supragranular layers. The cortical responses are more monotonic as a function of the intensity level after noise trauma. There was minimal change, if any, in local field potential (LFP) amplitude after acute noise trauma, while LFP amplitude was enhanced after chronic noise trauma. Finally, LFP and the current source density analysis suggest that acute but more specifically chronic noise trauma is associated with the emergence of a new sink in the supragranular layer. This result suggests that supragranular layers become a major input recipient. We discuss the possible mechanisms and functional implications of these changes.NEW & NOTEWORTHY Our study shows that cortical activity is enhanced after trauma and that the sequence of cortical column activation during stimulus-evoked response is altered, i.e. the supragranular layer becomes a major input recipient. We speculate that these large cortical changes may play a key role in the auditory hypersensitivity (hyperacusis) that can be triggered after noise trauma in human subjects.

Feedforward connectivity patterns from visual areas to the front of the brain contain information about sensory stimuli regardless of awareness or report

Current theories of consciousness can be categorized to some extent by their predictions about the putative role of the prefrontal cortex (PFC) in conscious perception. One family of the theories proposes that the PFC is necessary for conscious perception. The other postulates that the PFC is not necessary and that other areas (e.g., posterior cortical areas) are more important for conscious perception. No-report paradigms could potentially arbitrate the debate as they disentangle task reporting from conscious perception. While previous no-report paradigms tend to point to a reduction in PFC activity, they have not examined the critical role of the PFC in “monitoring” or “reading out” the patterns of activity in the sensory cortex to generate conscious perception. To address this, we reanalysed electroencephalography (EEG) data from a no-report inattentional blindness paradigm (Shafto & Pitts, 2015). We examined the role of feedforward input patterns to the PFC from sensory cortices. We employed nonparametric spectral Granger causality and quantified the amount of information that reflected the contents of consciousness using multivariate classifiers. Unexpectedly, regardless of whether the stimulus was consciously seen or not, we found that information relating to the current sensory stimulus was present in the pattern of inputs from visual areas to the PFC. In light of these findings, we suggest various theories of consciousness need to be revised to accommodate the fact that the contents of consciousness are decodable from the input patterns from posterior sensory regions to the PFC, regardless of awareness (or report).

The Role of the Dorsolateral Prefrontal Cortex in Bilingual Language Switching and Non-Linguistic Task-Switching: Evidence from Multi-Voxel Pattern Analysis.

Previous research suggests that bilingual language control requires domain-general cognitive control. Recent research suggests that exploration of individual differences is key for understanding the relationship between bilingual language control and cognitive control. The current study used multi-voxel pattern analysis (MVPA) to examine within-subject patterns of fMRI activity in the dorsolateral prefrontal cortex (DLPFC) during bilingual language switching and non-linguistic task-switching. We hypothesized that bilinguals would have identifiable, within-subject patterns of DLPFC activity for both types of switching and that bilinguals and monolinguals would differ in patterns of DLPFC activity for task-switching. We were unable to identify patterns of DLPFC activity associated with bilingual language switching. Task-switching was related to patterns of left DLPFC activity for both bilinguals and monolinguals, and there were identifiable patterns of right DLPFC activity for the bilinguals only. These findings suggest that the DLPFC is not the key brain structure connecting bilingual language and task-switching.

Cortical thickness moderates intraindividual variability in prefrontal cortex activation patterns of older adults during walking.

Increased intraindividual variability (IIV) in behavioral and cognitive performance is a risk factor for adverse outcomes but research concerning hemodynamic signal IIV is limited. Cortical thinning occurs during aging and is associated with cognitive decline. Dual-task walking (DTW) performance in older adults has been related to cognition and neural integrity. We examined the hypothesis that reduced cortical thickness would be associated with greater increases in IIV in prefrontal cortex oxygenated hemoglobin (HbO2) from single tasks to DTW in healthy older adults while adjusting for behavioral performance. Participants were 55 healthy community-dwelling older adults (mean age = 74.84, standard deviation (SD) = 4.97). Structural MRI was used to quantify cortical thickness. Functional near-infrared spectroscopy (fNIRS) was used to assess changes in prefrontal cortex HbO2 during walking. HbO2 IIV was operationalized as the SD of HbO2 observations assessed during the first 30 seconds of each task. Linear mixed models were used to examine the moderation effect of cortical thickness throughout the cortex on HbO2 IIV across task conditions. Analyses revealed that thinner cortex in several regions was associated with greater increases in HbO2 IIV from the single tasks to DTW (ps < .02). Consistent with neural inefficiency, reduced cortical thickness in the PFC and throughout the cerebral cortex was associated with increases in HbO2 IIV from the single tasks to DTW without behavioral benefit. Reduced cortical thickness and greater IIV of prefrontal cortex HbO2 during DTW may be further investigated as risk factors for developing mobility impairments in aging.

Amplified cortical neural responses as animals learn to use novel activity patterns

Cerebral cortex supports representations of the world in patterns of neural activity, used by the brain to make decisions and guide behavior. Past work has found diverse, or limited, changes in the primary sensory cortex in response to learning, suggesting that the key computations might occur in downstream regions. Alternatively, sensory cortical changes may be central to learning. We studied cortical learning by using controlled inputs we insert: we trained mice to recognize entirely novel, non-sensory patterns of cortical activity in the primary visual cortex (V1) created by optogenetic stimulation. As animals learned to use these novel patterns, we found that their detection abilities improved by an order of magnitude or more. The behavioral change was accompanied by large increases in V1 neural responses to fixed optogenetic input. Neural response amplification to novel optogenetic inputs had little effect on existing visual sensory responses. A recurrent cortical model shows that this amplification can be achieved by a small mean shift in recurrent network synaptic strength. Amplification would seem to be desirable to improve decision-making in a detection task; therefore, these results suggest that adult recurrent cortical plasticity plays a significant role in improving behavioral performance during learning.

Parallel movement planning is achieved via an optimal preparatory state in motor cortex.

How do patterns of neural activity in the motor cortex contribute to the planning of a movement? A recent theory developed for single movements proposes that the motor cortex acts as a dynamical system whose initial state is optimized during the preparatory phase of the movement. This theory makes important yet untested predictions about preparatory dynamics in more complex behavioral settings. Here, we analyze preparatory activity in non-human primates planning not one but two movements simultaneously. As predicted by the theory, we find that parallel planning is achieved by adjusting preparatory activity within an optimal subspace to an intermediate state reflecting a trade-off between the two movements. The theory quantitatively accounts for the relationship between this intermediate state and fluctuations in the animals' behavior down at the trial level. These results uncover a simple mechanism for planning multiple movements in parallel and further point to motor planning as a controlled dynamical process.

Asthma history influences gait performance and associated prefrontal cortex activation patterns in older adults.

Walking and cognition are interrelated due to dependence on shared brain regions that include the prefrontal cortex (PFC). Limited literature indicates that asthma is associated with poor mobility in older adults but the mechanisms underlying this relationship are unknown. Therefore, we tested the hypothesis that asthma history was associated with poor gait performance due to limited attention resources and neural inefficiency. Participants, older adults age ≥ 65years reporting positive (n = 36) and negative (n = 36) history of asthma, walked under single and dual-task conditions with a functional near-infrared-spectroscopy (fNIRS) sensor placed on their forehead to assess task-related changes in PFC oxygenated hemoglobin (HbO2). Results showed that positive asthma history was associated with slower gait and higher fNIRS-derived HbO2 under dual-task walking. These findings suggest that limited attention resources and neural inefficiency underlie the association between asthma and poor walking performance in older adults.

Prefrontal Cortex Brain Activation During Texting and Walking: A Functional Near-Infrared Spectroscopy Feasibility Study

Texting while walking is an increasingly common, potentially dangerous task but its functional brain correlates have yet to be reported. Therefore, we evaluated prefrontal cortex (PFC) activation patterns during single- and dual-task texting and walking in healthy adults. Thirteen participants (29-49years) walked under single- and dual-task conditions involving mobile phone texting or a serial-7s subtraction task, while measuring PFC activation (functional near-infrared spectroscopy) and behavioral task performance (inertial sensors, mobile application). Head lowering during texting increased PFC activation. Texting further increased PFC activation, and decreased gait performance similarly to serial-7 subtraction. Our results support the key role of executive control in texting while walking.

Perspective-taking is associated with increased discriminability of affective states in the ventromedial prefrontal cortex.

Recent work using multivariate-pattern analysis (MVPA) on functional magnetic resonance imaging (fMRI) data has found that distinct affective states produce correspondingly distinct patterns of neural activity in the cerebral cortex. However, it is unclear whether individual differences in the distinctiveness of neural patterns evoked by affective stimuli underlie empathic abilities such as perspective-taking (PT). Accordingly, we examined whether we could predict PT tendency from the classification of blood-oxygen-level-dependent (BOLD) fMRI activation patterns while participants (n = 57) imagined themselves in affectively charged scenarios. We used an MVPA searchlight analysis to map where in the brain activity patterns permitted the classification of four affective states: happiness, sadness, fear and disgust. Classification accuracy was significantly above chance levels in most of the prefrontal cortex and in the posterior medial cortices. Furthermore, participants' self-reported PT was positively associated with classification accuracy in the ventromedial prefrontal cortex and insula. This finding has implications for understanding affective processing in the prefrontal cortex and for interpreting the cognitive significance of classifiable affective brain states. Our multivariate approach suggests that PT ability may rely on the grain of internally simulated affective representations rather than simply the global strength.

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.

Different types of drug abusers prefrontal cortex activation patterns and based on machine-learning classification

Drug addiction can cause abnormal brain activation changes, which are the root cause of drug craving and brain function errors. This study enrolled drug abusers to determine the effects of different drugs on brain activation. A functional near-infrared spectroscopy (fNIRS) device was used for the research. This study was designed with an experimental paradigm that included the induction of resting and drug addiction cravings. We collected the fNIRS data of 30 drug users, including 10 who used heroin, 10 who used Methamphetamine, and 10 who used mixed drugs. First, using Statistical Analysis, the study analyzed the activations of eight functional areas of the left and right hemispheres of the prefrontal cortex of drug addicts who respectively used heroin, Methamphetamine, and mixed drugs, including Left/Right-Dorsolateral prefrontal cortex (L/R-DLPFC), Left/Right-Ventrolateral prefrontal cortex (L/R-VLPFC), Left/Right-Frontopolar prefrontal cortex (L/R-FPC), and Left/Right Orbitofrontal Cortex (L/R-OFC). Second, referencing the degrees of activation of oxyhaemoglobin concentration (HbO[Formula: see text], the study made an analysis and got the specific activation patterns of each group of the addicts. Finally, after taking out data which are related to the addicts who recorded high degrees of activation among the three groups of addicts, and which had the same channel numbers, the paper classified the different drug abusers using the data as the input data for Convolutional Neural Networks (CNNs). The average three-class accuracy is 67.13%. It is of great significance for the analysis of brain function errors and personalized rehabilitation.

Changes in the spatiotemporal pattern of spontaneous activity across a cortical column after noise trauma.

In the auditory modality, noise trauma has often been used to investigate cortical plasticity as it causes cochlear hearing loss. One limitation of these past studies, however, is that the effects of noise trauma have been mostly documented at the granular layer, which is the main cortical recipient of thalamic inputs. Importantly, the cortex is composed of six different layers each having its own pattern of connectivity and specific role in sensory processing. The present study aims at investigating the effects of acute and chronic noise trauma on the laminar pattern of spontaneous activity (SA) in primary auditory cortex (A1) of the anesthetized guinea pig. We show that spontaneous activity is dramatically altered across cortical layers after acute and chronic noise-induced hearing loss. First, spontaneous activity was globally enhanced across cortical layers, both in terms of firing rate and amplitude of spike-triggered average of local field potentials. Second, current source density on (spontaneous) spike-triggered average of local field potentials indicates that current sinks develop in the supra- and infragranular layers. These latter results suggest that supragranular layers become a major input recipient and the propagation of spontaneous activity over a cortical column is greatly enhanced after acute and chronic noise-induced hearing loss. We discuss the possible mechanisms and functional implications of these changes.NEW & NOTEWORTHY The present study investigates the effects of acute and chronic noise trauma on the laminar pattern of spontaneous activity in the primary auditory cortex. Our study is first to report that noise trauma alters the sequence of cortical column activation during ongoing activity. In particular, we show that the supragranular layer becomes a major input recipient and the synaptic activity in the infragranular layers is enhanced.

Cognitive Reserve Moderates the Efficiency of Prefrontal Cortex Activation Patterns of Gait in Older Adults.

Cognitive reserve (CR) protects against cognitive decline, but whether CR influences the efficiency of cortical control of gait has not been reported. The current study addressed this important gap in the literature. Specifically, we determined the role of CR in moderating the efficiency of functional near-infrared spectroscopy (fNIRS)-derived oxygenated hemoglobin (HbO2) in the prefrontal cortex (PFC) assessed during active walking. We hypothesized that higher CR would be associated with more efficient brain activation patterns. Participants were 55 (mean age = 74.84; %female = 49.1) older adults who underwent the combined walking/fNIRS protocol and had magnetic resonance imaging data. We used an established dual-task walking paradigm that consisted of 3 task conditions: single-task walk (STW), single-task alpha (STA, cognitive task), and dual-task walk (DTW). Using the residual approach, CR was derived from a word-reading test score by removing variance accounted for by sociodemographic variables, tests of current cognitive functions, and a measure of structural brain integrity. CR moderated the change in fNIRS-derived HbO2 in the PFC across tasks. Higher CR was associated with smaller increases in fNIRS-derived HbO2 from the single tasks to dual-task walking (CR × DTW compared with STW: estimate = 0.183; p < .001; CR × DTW compared with STA: estimate = 0.257; p < .001). The moderation effect of CR remained significant when adjusting for multiple covariates and concurrent moderation effects of measures of gait performance, current cognitive functions, and structural integrity of the brain. The current study provided first evidence that higher CR was associated with better neural efficiency of walking in older adults.