title: “Use-It-or-Lose-It”? Interrogating an educational message from teen brain research

authors: Payne, Monica A.

subjects: education

abstract: Recent neuroimaging research has encouraged a fundamental shift in psychological thinking about cognitive development in adolescence. Challenging the existing view that early childhood was the most critical period for intellectually hard-wiring the brain, findings led researchers to speculate that early adolescence might be the more important use-it-or-lose-it period. Despite cautions from critics and some neuroscientists themselves, the new story seems to be following its predecessor in acquiring the status of hard fact. An eclectic sampling of texts examines possible implications of the penetration of this hypothesis into educational discourse. Elements of classism and adultism are identified, and considered with reference to contemporary understandings of adolescence as a period when lifelong habits and lifestyles are established.

text: “Use-It-or-Lose-It”? Interrogating an educational message from teen brain research Recent neuroimaging research has encouraged a fundamental shift in psychological thinking about cognitive development in adolescence. Challenging the existing view that early childhood was the most critical period for intellectually hard-wiring the brain, findings led researchers to speculate that early adolescence might be the more important use-it-or-lose-it period. Despite cautions from critics and some neuroscientists themselves, the new story seems to be following its predecessor in acquiring the status of hard fact. An eclectic sampling of texts examines possible implications of the penetration of this hypothesis into educational discourse. Elements of classism and adultism are identified, and considered with reference to contemporary understandings of adolescence as a period when lifelong habits and lifestyles are established.

year: 2010

title: EEG slow-wave coherence changes in propofol-induced general anesthesia: experiment and theory.

authors: Wang, Kaier

subjects: Turing–Hopf instabilities

abstract: The electroencephalogram (EEG) patterns recorded during general anesthetic-induced coma are closely similar to those seen during slow-wave sleep, the deepest stage of natural sleep; both states show patterns dominated by large amplitude slow waves. Slow oscillations are believed to be important for memory consolidation during natural sleep. Tracking the emergence of slow-wave oscillations during transition to unconsciousness may help us to identify drug-induced alterations of the underlying brain state, and provide insight into the mechanisms of general anesthesia. Although cellular-based mechanisms have been proposed, the origin of the slow oscillation has not yet been unambiguously established. A recent theoretical study by Steyn-Ross et al. (2013) proposes that the slow oscillation is a network, rather than cellular phenomenon. Modeling anesthesia as a moderate reduction in gap-junction interneuronal coupling, they predict an unconscious state signposted by emergent low-frequency oscillations with chaotic dynamics in space and time. They suggest that anesthetic slow-waves arise from a competitive interaction between symmetry-breaking instabilities in space (Turing) and time (Hopf), modulated by gap-junction coupling strength. A significant prediction of their model is that EEG phase coherence will decrease as the cortex transits from Turing-Hopf balance (wake) to Hopf-dominated chaotic slow-waves (unconsciousness). Here, we investigate changes in phase coherence during induction of general anesthesia. After examining 128-channel EEG traces recorded from five volunteers undergoing propofol anesthesia, we report a significant drop in sub-delta band (0.05-1.5 Hz) slow-wave coherence between frontal, occipital, and frontal-occipital electrode pairs, with the most pronounced wake-vs.-unconscious coherence changes occurring at the frontal cortex.

text: EEG slow-wave coherence changes in propofol-induced general anesthesia: experiment and theory. The electroencephalogram (EEG) patterns recorded during general anesthetic-induced coma are closely similar to those seen during slow-wave sleep, the deepest stage of natural sleep; both states show patterns dominated by large amplitude slow waves. Slow oscillations are believed to be important for memory consolidation during natural sleep. Tracking the emergence of slow-wave oscillations during transition to unconsciousness may help us to identify drug-induced alterations of the underlying brain state, and provide insight into the mechanisms of general anesthesia. Although cellular-based mechanisms have been proposed, the origin of the slow oscillation has not yet been unambiguously established. A recent theoretical study by Steyn-Ross et al. (2013) proposes that the slow oscillation is a network, rather than cellular phenomenon. Modeling anesthesia as a moderate reduction in gap-junction interneuronal coupling, they predict an unconscious state signposted by emergent low-frequency oscillations with chaotic dynamics in space and time. They suggest that anesthetic slow-waves arise from a competitive interaction between symmetry-breaking instabilities in space (Turing) and time (Hopf), modulated by gap-junction coupling strength. A significant prediction of their model is that EEG phase coherence will decrease as the cortex transits from Turing-Hopf balance (wake) to Hopf-dominated chaotic slow-waves (unconsciousness). Here, we investigate changes in phase coherence during induction of general anesthesia. After examining 128-channel EEG traces recorded from five volunteers undergoing propofol anesthesia, we report a significant drop in sub-delta band (0.05-1.5 Hz) slow-wave coherence between frontal, occipital, and frontal-occipital electrode pairs, with the most pronounced wake-vs.-unconscious coherence changes occurring at the frontal cortex.

year: 2014

title: The alienation of the Opuatia block: A GIS case study report written for Counting our Tūpuna

authors: Whitehead, Jesse

abstract: This report provides an analysis and visualisation of the fragmentation and alienation of the Opuatia block (Opuatia hereafter), as well as changes in its ownership and geographic structure since 1866.
The three main aims are to quantify the amount of Opuatia remaining in Ngāti Tiipa ownership at the end of each decade, identifying critical moments in time, and highlighting the processes through which Opuatia was alienated and fragmented. These questions are addressed through a bespoke method that was developed to link data from several sources. These include (but are not limited to) historic records of land alienation, held by the Māori Land Court, and geospatial information available through Land Information New Zealand.
The key findings show that approximately 94% of the original Opuatia has been alienated, with only small parcles of land remaining in Ngāti Tiipa ownership. The late 1890s and early 1900s were a criticial period where over 80% of alienations were carried out. The results inidcate that the Crown was a key driver of this process, directly alienating more than 18,000 acres from Opuatia, much of which was taken on a single day in 1896. Individual settlers were responsible for most other alienations, and some of the same names appear several times in the historical record as settler families alienated clusters of land to build up significant stakes in the area. Finally, another result of this report is the method itself, which outlines an approach for tracing a defined block of land through the Native Land Court and linking this information to geospatial datasets.
The limitations of this report include the poor interoperability of key data sources, and the barriers that this presents to other hapū or organisations who may want to replicate this work. A more detailed investigation of archival records is required to examine the specific reasons behind why each parent block, and the subdivisions with them, was alienated from Ngāti Tiipa ownership.

text: The alienation of the Opuatia block: A GIS case study report written for Counting our Tūpuna This report provides an analysis and visualisation of the fragmentation and alienation of the Opuatia block (Opuatia hereafter), as well as changes in its ownership and geographic structure since 1866.
The three main aims are to quantify the amount of Opuatia remaining in Ngāti Tiipa ownership at the end of each decade, identifying critical moments in time, and highlighting the processes through which Opuatia was alienated and fragmented. These questions are addressed through a bespoke method that was developed to link data from several sources. These include (but are not limited to) historic records of land alienation, held by the Māori Land Court, and geospatial information available through Land Information New Zealand.
The key findings show that approximately 94% of the original Opuatia has been alienated, with only small parcles of land remaining in Ngāti Tiipa ownership. The late 1890s and early 1900s were a criticial period where over 80% of alienations were carried out. The results inidcate that the Crown was a key driver of this process, directly alienating more than 18,000 acres from Opuatia, much of which was taken on a single day in 1896. Individual settlers were responsible for most other alienations, and some of the same names appear several times in the historical record as settler families alienated clusters of land to build up significant stakes in the area. Finally, another result of this report is the method itself, which outlines an approach for tracing a defined block of land through the Native Land Court and linking this information to geospatial datasets.
The limitations of this report include the poor interoperability of key data sources, and the barriers that this presents to other hapū or organisations who may want to replicate this work. A more detailed investigation of archival records is required to examine the specific reasons behind why each parent block, and the subdivisions with them, was alienated from Ngāti Tiipa ownership.

year: 2021