Microscale Neuronal Activity Collectively Drives Chaotic and Inflexible Dynamics at the Macroscale in Seizures

Neuronal activity propagates through the network during seizures, engaging brain dynamics at multiple scales. Such propagating events can be described through the avalanches framework, which can relate spatiotemporal activity at the microscale with global network properties. Interestingly, propagating avalanches in healthy networks are indicative of critical dynamics, where the network is organised to a phase transition, which optimises certain computational properties. Some have hypothesised that the pathological brain dynamics of epileptic seizures are an emergent property of microscale neuronal networks collectively driving the brain away from criticality. Demonstrating this would provide a unifying mechanism linking microscale spatiotemporal activity with emergent brain dysfunction during seizures. Here, we investigated the effect of drug-induced seizures on critical avalanche dynamics, using in vivo whole-brain 2-photon imaging of GCaMP6s larval zebrafish (males and females) at single neuron resolution. We demonstrate that single neuron activity across the whole brain exhibits a loss of critical statistics during seizures, suggesting that microscale activity collectively drives macroscale dynamics away from criticality. We also construct spiking network models at the scale of the larval zebrafish brain, to demonstrate that only densely connected networks can drive brain-wide seizure dynamics away from criticality. Importantly, such dense networks also disrupt the optimal computational capacities of critical networks, leading to chaotic dynamics, impaired network response properties and sticky states, thus helping to explain functional impairments during seizures. This study bridges the gap between microscale neuronal activity and emergent macroscale dynamics and cognitive dysfunction during seizures.Significance StatementEpileptic seizures are debilitating and impair normal brain function. It is unclear how the coordinated behaviour of neurons collectively impairs brain function during seizures. To investigate this we perform fluorescence microscopy in larval zebrafish, which allows for the recording of whole-brain activity at single-neuron resolution. Using techniques from physics, we show that neuronal activity during seizures drives the brain away from criticality, a regime that enables both high and low activity states, into an inflexible regime that drives high activity states. Importantly, this change is caused by more connections in the network, which we show disrupts the ability of the brain to respond appropriately to its environment. Therefore, we identify key neuronal network mechanisms driving seizures and concurrent cognitive dysfunction.

Daily sensation-seeking and urgency in young adults: Examining associations with alcohol use and self-defined risky behaviors

PURPOSE

To examine the dynamic expression of sensation-seeking and urgency in daily life and the implications for alcohol use and risk-taking during young adulthood.

METHODS

Daily diary surveys were administered to young adults (n = 77) aged 18-25 years every evening for 21 days to assess day's sensation-seeking, urgency, risk-taking, and alcohol use.

RESULTS

Days of higher than usual sensation-seeking are also days of higher than usual risk-taking and are more likely to be alcohol use days than days of lower than usual sensation-seeking. Day's urgency was not associated with day's alcohol use or risk-taking. We extracted 10 themes from self-reports of the day's riskiest behavior: transportation (29.9%), social (22.8%), recreation (17.4%), work (14.8%), school (13.5%), food (9.5%), sleep (9.2%), substance use (5.8%), other (5.2%), and jaywalking (1.5%), and 14.6% of self-reported risky behaviors were considered threatening to safety, health, or wellbeing.

CONCLUSIONS

Risks taken during daily life have mostly positive outcomes and a minority represent threats to safety, health, and wellbeing. Risk-taking and alcohol use in young adult's daily lives is more likely to be driven by the desire to experience novel and exciting experiences than by rash action.

Brain Activity Tracks Population Information Sharing by Capturing Consensus Judgments of Value

Information that is shared widely can profoundly shape society. Evidence from neuroimaging suggests that activity in the ventromedial prefrontal cortex (vmPFC), a core region of the brain's valuation system tracks with this sharing. However, the mechanisms linking vmPFC responses in individuals to population behavior are still unclear. We used a multilevel brain-as-predictor approach to address this gap, finding that individual differences in how closely vmPFC activity corresponded with population news article sharing related to how closely its activity tracked with social consensus about article value. Moreover, how closely vmPFC activity corresponded with population behavior was linked to daily life news experience: frequent news readers tended to show high vmPFC across all articles, whereas infrequent readers showed high vmPFC only to articles that were more broadly valued and heavily shared. Using functional connectivity analyses, we found that superior tracking of consensus value was related to decreased connectivity of vmPFC with a dorsolateral PFC region associated with controlled processing. Taken together, our results demonstrate variability in the brain's capacity to track crowd wisdom about information value, and suggest (lower levels of) stimulus experience and vmPFC-dlPFC connectivity as psychological and neural sources of this variability.

Repetitive negative thinking in daily life and functional connectivity among default mode, fronto-parietal, and salience networks

Repetitive negative thinking (RNT) is a maladaptive response to sadness and a transdiagnostic risk-factor. A critical challenge hampering attempts to promote more adaptive responses to sadness is that the between-person characteristics associated with the tendency for RNT remain uncharacterized. From the perspective of the impaired disengagement hypothesis, we examine between-person differences in blood-oxygen-level-dependent (BOLD) functional networks underlying cognitive conflict signaling, self-referential thought, and cognitive flexibility, and the association between sadness and RNT in daily life. We pair functional magnetic resonance imaging with ambulatory assessments deployed 10 times per day over 4 consecutive days measuring momentary sadness and RNT from 58 participants (40 female, mean age = 36.69 years; 29 remitted from a lifetime episode of Major Depression) in a multilevel model. We show that RNT increases following sadness for participants with higher than average between-network connectivity of the default mode network and the fronto-parietal network. We also show that RNT increases following increases in sadness for participants with lower than average between-network connectivity of the fronto-parietal network and the salience network. We also find that flexibility of the salience network's pattern of connections with brain regions is protective against increases in RNT following sadness. Our findings highlight the importance of functional brain networks implicated in cognitive conflict signaling, self-referential thought, and cognitive flexibility for understanding maladaptive responses to sadness in daily life and provide support for the impaired disengagement hypothesis of RNT.

Research Issues in Career Development and Transition: An Exploratory Survey of Professionals in the Field

The Research Committee of the Council for Exceptional Children's Division of Career Development and Transition (DCDT) conducted an exploratory study with professionals in the field in an attempt to identify the research issues most important to the field of transition and career development. Twenty-nine items were prioritized as to their importance as research considerations. Results from 201 respondents yielded research priorities in the following areas: teacher training for transition; facilitation of student self-determination and self-esteem; transition plans, goals and objectives, and linkage activities; functional assessment to support transition planning; inclusion of students with special needs in vocational education; and models of K-12 career development and transition planning. Based on these results, recommendations developed by the committee are elaborated and discussed.

Research Translated into Practices for Increasing Student Involvement in Transition-Related Activities

This article describes an empirical investigation of the process and outcomes associated with research-to-practice strategies in three schools during a three and a half-year project. The three interrelated phases of the process were (a) the establishment of an empirical foundation, (b) the design and implementation of school-based interventions, and (c) the evaluation of the effectiveness of the interventions. Findings from each phase are described. The benefits and limitations of research-to-practice strategies as a means to improve practices in local schools is discussed. The critical role of ongoing evaluation throughout the process of translating research into practice also is discussed.

Aligning Transition Services with Secondary Educational Reform: A Position Statement of the Division on Career Development and Transition

Society has witnessed significant improvements in the lives of students receiving transition services over the past 30 years. The field of transition has developed an array of evidence-based interventions and promising practices, however, secondary school reform efforts have often overlooked these approaches for youth without disabilities. If we are to see improvements in postsecondary outcomes for all youth, reform efforts must begin with active participation of both general and special educators and critical home, school, and community stakeholders. In the Division on Career Development for Exceptional Individuals' position paper, we discuss the evolution of transition in light of reform efforts in secondary education. We review and identify secondary educational initiatives that embrace transition principles. Finally, recommendations are provided for advancing alignment of transition services with secondary education reforms.

Secondary special educators' transition involvement

BACKGROUND

Different roles and responsibilities are required of school professionals to facilitate students' successful transition from school to post-school lives. Special educators' involvement in transition services is essential for better post-school outcomes for students with disability.

METHOD

The Transition Involvement Survey with five domains was developed for the study and a total of 343 secondary special educators in the United States participated. MANOVA and post hoc discriminant analysis were used to examine group differences across the five domains.

RESULTS

Special educators rated highly in their involvement in transition planning but less so in other domains. Receiving in-service training was significantly related to educators' transition involvement but receiving pre-service training was found to be only partly related.

CONCLUSION

The gap between special educators' knowledge and involvement in extending transition services affects the provision of services. Recommendations from this study support stronger personnel preparation to improve this situation.

Teacher Candidates' Perceptions of Barriers to Effective Transition Programming

Knowledge, skills, and competencies in transition planning are essential components of preparation programs for special and general educators. This study investigated teacher preparation, implementation of transition services, and perceived gaps in transition service delivery. Candidates in five special education preparation programs completed presemester and postsemester surveys to determine (a) the transition-related knowledge, skills, and competencies that candidates believe they are taught, (b) the transition competency level candidates believe they have, (c) facilitators and barriers to implementing transition practices, and (d) attitudes and perceptions about transition services and the candidates' related preparation. Results indicated that few candidates received any instruction in transition services prior to taking dedicated transition-related coursework. Candidates were not confident about their knowledge and skills in assessment, accountability, postschool outcomes, and student-focused planning and assessment.

A life skills approach to mathematics instruction: preparing students with learning disabilities for the real-life math demands of adulthood

Current mathematics instruction does not address the day-to-day needs of many students with learning disabilities. Although the vast majority of students with learning disabilities are not college bound, much of mathematics instruction provides college preparation. Too often, classes in mathematics ignore the skills needed in home and community and on the job. The present article examines the ways in which general mathematics instruction, focused on daily living skills, can easily be integrated into the classrooms of students with learning disabilities.

Transition in an era of reform

Transition services for students with learning disabilities have not always been a priority in public schools. Although school personnel have long acknowledged the transition needs of students considered to have more severe disabilities, such as mental retardation, physical problems, and emotional disturbance, they do not always consider that students with learning disabilities also need transition programming. The result has been a neglect of these students' transition needs, which has likely contributed to some of the problems experienced by young adults with learning disabilities. This article focuses on the effect of educational reform on transition services for students with learning disabilities. General education reform--fueled by some of the critical reports of the 1980s--inclusion, and some of the more recent efforts to reform public education (namely, Goals 2000) are all discussed as they relate to the transition needs of students with learning disabilities.