title: A matter of habit? Early life stress and cognitive flexibility in infants

authors: Taylor, Catherine

abstract: The long-term associations between chronic early life stress such as maltreatment, and cognitive functioning are well documented. However, less is known about the relation between early life stress exposure through experiences of more common potentially stressful life events such as parental separation or moving to a new house, and specific aspects of cognitive functioning in the short term. Cognitive flexibility refers to the ability to shift between response strategies and employ alternative strategies. It is an important ability for successful adaption to changing or novel situations. Previous research has shown that under acute stress, 15-month-old infants display elevated levels of rigid behaviour, being less likely to disengage from performing a habitual action that is no longer effective than their non-stressed counterparts. The present study explores the relation between experiences of potentially stressful early life events and infants’ tendency to display this pattern of behaviour that is, cognitive flexibility. Thirty-one 14- to 16-month-old infants participated in an instrumental learning task in their own homes. The task involved the infants initially learning to push two buttons. Each button lit up and produced its own distinct sound when pushed. Next, to establish a habit of button pushing (habit-acquisition), infants were allowed to push one of the buttons until they did not push the button for a period of time (10-s). Finally, at test, infants were given access to both buttons. Pushing the buttons did not result in any light or sound effects. Infants’ behaviour during test was assessed. Increased engagement with the habituated button relative to engagement with both buttons was taken as a measure of reduced cognitive flexibility. Participants’ caregivers indicated the number and severity of any potentially stressful life events that had occurred for the family during the prenatal and postnatal period. Analyses revealed no significant associations between frequency or severity of stressful life events – experienced during the prenatal or postnatal period – and rigid habitual behaviour in infants. This suggests that potentially stressful early life events do not necessarily lead to higher levels of rigid behaviour in infants. Possible explanations of the present findings are discussed.

text: A matter of habit? Early life stress and cognitive flexibility in infants The long-term associations between chronic early life stress such as maltreatment, and cognitive functioning are well documented. However, less is known about the relation between early life stress exposure through experiences of more common potentially stressful life events such as parental separation or moving to a new house, and specific aspects of cognitive functioning in the short term. Cognitive flexibility refers to the ability to shift between response strategies and employ alternative strategies. It is an important ability for successful adaption to changing or novel situations. Previous research has shown that under acute stress, 15-month-old infants display elevated levels of rigid behaviour, being less likely to disengage from performing a habitual action that is no longer effective than their non-stressed counterparts. The present study explores the relation between experiences of potentially stressful early life events and infants’ tendency to display this pattern of behaviour that is, cognitive flexibility. Thirty-one 14- to 16-month-old infants participated in an instrumental learning task in their own homes. The task involved the infants initially learning to push two buttons. Each button lit up and produced its own distinct sound when pushed. Next, to establish a habit of button pushing (habit-acquisition), infants were allowed to push one of the buttons until they did not push the button for a period of time (10-s). Finally, at test, infants were given access to both buttons. Pushing the buttons did not result in any light or sound effects. Infants’ behaviour during test was assessed. Increased engagement with the habituated button relative to engagement with both buttons was taken as a measure of reduced cognitive flexibility. Participants’ caregivers indicated the number and severity of any potentially stressful life events that had occurred for the family during the prenatal and postnatal period. Analyses revealed no significant associations between frequency or severity of stressful life events – experienced during the prenatal or postnatal period – and rigid habitual behaviour in infants. This suggests that potentially stressful early life events do not necessarily lead to higher levels of rigid behaviour in infants. Possible explanations of the present findings are discussed.

year: 2017

title: Compressing semi-structured text using hierarchical phrase identification

authors: Nevill-Manning, Craig G.

subjects: computer science

abstract: Many computer files contain highly-structured, predictable information interspersed with information which has less regularity and is therefore less predictable—such as free text. Examples range from word-processing source files, which contain precisely-expressed formatting specifications enclosing tracts of natural-language text, to files containing a sequence of filled-out forms which have a predefined skeleton clothed with relatively unpredictable entries. These represent extreme ends of a spectrum. Word-processing files are dominated by free text, and respond well to general-purpose compression techniques. Forms generally contain database-style information, and are most appropriately compressed by taking into account their special structure. But one frequently encounters intermediate cases. For example, in many email messages the formal header and the informal free-text content are equally voluminous. Short SGML files often contain comparable amounts of formal structure and informal text. Although such files may be compressed quite well by general-purpose adaptive text compression algorithms, which will soon pick up the regular structure during the course of normal adaptation, better compression can often be obtained by methods that are equipped to deal with both formal and informal structure.

text: Compressing semi-structured text using hierarchical phrase identification Many computer files contain highly-structured, predictable information interspersed with information which has less regularity and is therefore less predictable—such as free text. Examples range from word-processing source files, which contain precisely-expressed formatting specifications enclosing tracts of natural-language text, to files containing a sequence of filled-out forms which have a predefined skeleton clothed with relatively unpredictable entries. These represent extreme ends of a spectrum. Word-processing files are dominated by free text, and respond well to general-purpose compression techniques. Forms generally contain database-style information, and are most appropriately compressed by taking into account their special structure. But one frequently encounters intermediate cases. For example, in many email messages the formal header and the informal free-text content are equally voluminous. Short SGML files often contain comparable amounts of formal structure and informal text. Although such files may be compressed quite well by general-purpose adaptive text compression algorithms, which will soon pick up the regular structure during the course of normal adaptation, better compression can often be obtained by methods that are equipped to deal with both formal and informal structure.

year: 1996

title: Renewal and resistance: Moko in contemporary New Zealand

authors: Nikora, Linda Waimarie

subjects: maori

abstract: Moko is still here, contrary to the widely held belief that the art and custom of moko-Maori skin adornment-had vanished from New Zealand communities. Over the last two decades an increasingly visible number of Maori have revived and renewed the practice, taking colour into their skin. As an indigenous people, re-taking moko confronts and refutes the myth of a 'dying race'. It calls on Maori to recommit to strong Maori identities, customs and traditions and challenges the viewer to re-examine their social representations of moko and moko wearers. This paper reports the resistance strategies of a group of 83 moko wearers. Strategies include (1) educating, representing and reconstructing; (2) invalidating and minimizing representations; (3) building and enhancing social networks; and (4) securing cultural identity and pride. They reflect the celebration of cultural resilience.

text: Renewal and resistance: Moko in contemporary New Zealand Moko is still here, contrary to the widely held belief that the art and custom of moko-Maori skin adornment-had vanished from New Zealand communities. Over the last two decades an increasingly visible number of Maori have revived and renewed the practice, taking colour into their skin. As an indigenous people, re-taking moko confronts and refutes the myth of a 'dying race'. It calls on Maori to recommit to strong Maori identities, customs and traditions and challenges the viewer to re-examine their social representations of moko and moko wearers. This paper reports the resistance strategies of a group of 83 moko wearers. Strategies include (1) educating, representing and reconstructing; (2) invalidating and minimizing representations; (3) building and enhancing social networks; and (4) securing cultural identity and pride. They reflect the celebration of cultural resilience.

year: 2007