SPRING cog control across lifespan Flashcards
steinberg 2013 development of exec function
court argues neurobio immaturity in adolescence so shouldnt be reprimanded for behaviour
early 20s > risk
dual systems model: hightened socioemotional processing thought to tax capacity of limited self reg abilities in young age - inclines adults towards risk and reward
what is pruning
synaptic connections when young - increase till 2-4y
unnecesary connections removed and others strengthened to macimise speed of processing
what is myelination
myelin sheeth improve speed of synaptic transmission via saltatory conduction
blakemore and choudhury 2006 dev of white matter
MRI - steady increase in white mater in throughout hildhood and adol
younger more grey matter
sowell et al 1999 dev white matter
higher white matter in frontal and parietal cortex old>young
young > grey matter - pruning and less developed/prioritized connections
what is grey matter made up of
neuronal cells, dendrites, myelinated and unmyelinated axons
gogtay et al 2005 grey matter maturation
cross sectional longditudinal mri of 13 children every 2 years from 4-21y
grey loss in dorsal, parietal, primary sensory motor then spread to frontal and temporal cortices
follows maturation milestones ie motor and sensory dev early, then speech, lang and spatial, then exec function, thought etc
dlPFC last grey maturation, OF into 21y/o
white linear increase, grey loss region specific
grey vs white matter dev
grey NON LINEAR REGION SPECIFIC
white LINEAR
- grey increase till 12 then decline
grey matter and PFC dev (sowell et al 2001)
inverse relationship
gre decrease density (reduced no synapses) and DLPFC increase vol
dev of EF
basic function areas mature earlier ie motor/sensory - support goal directed beh
EF longer to mature ie spatial orientation and attention (Frontal lobe/DLPFC)
hwang et al 2010 antisaccade task - dev of top down control
antisaccade from target
adults top down control show increase connectivity to downstream cortical and subcortical areas assoc with occulomotor processing + decreases in short range connectivity to parietal/frontal regions
children more parietal and less top down
++ sig decrease in grey matter = more robust prepub increase in white in dPFC
adults better at inhibiting and saccading away and ability to override improves throughout dev
older brain characteristics
older experience greater decline in overall brain volume
exec funciton in aging
performance decreases from 20 y
vocab increase -experince
- ex.f. tasks depend on internal representation, maintenance and updating of context info in exerting control over thought and beh
Fotenos et al 208 brain vol with age
% grey matter + % wm ability sig decreases from 50 years
steeper with age - particularly in areas assoc with exec function and memory tasks
lemaitre et al 2010 PFC with age
healthy brains of 18-87y/o
As ef decrease,age related declines in frontal gyri + PFC thickness, SA and vol
This is the area that is last to develop but also the first to decline – succeptable to brain changes across the lifespan
PARTICULARLY lateral and dorsomedial PFC
age and amyg (van reekum et al)
change in EF also related to ability to suppress amyg activation despite increased cortical activity - greater response to bottom up
increase amyg = decrease EF capabilities
Braver et al 2001 DA and PFC Function
canonical model
DA learn contingencies between stimuli and reward
processing and response to stimuli depend on weighting of reward prediction via DA system- increase DA = increase PFC prioritisation
PFC op down bias of context via mod gated channels
dlPFC reg access to context info
hebb rat studies in cog decline
rat environ stimulation improve neural circuits and maze navigation
smith et al 2009 cog tasks in old age
comp cog training 1 hour a day, 5 days a week for 8 weeks
improve on battery of tests: memory, attention, backward digit, letter no sequencing, verbal learning, delayed recall - NOT AREAS DIRECTLY TRAINED IN - generalised
nouchi et al 2012
nintendo brain training games vs tetris
long and short term interventions
4 hours a day for 5 days or 1 hour a day for 4 weeks
more sig improvement over longer duration with shorter intervals - improved WM on n back and increase in white matter of dlPFC - some only improve in trained domain
-DEPENDS ON THE STRATEGIES USED WITHIN THE TASKS
sandberg 2014 predictors of gain
strategy based intervention on ep memory - recall links between letters and no (ie d=25)
better pre task episodic memory = better improved memory (+ for speed of processing and verbal knowledge )
gain more if already good
colcombe and cramer 2003 aeorbic
meta of aerobic on cog
fitness increase cog with greater influence on ef
why might exercise improve cog
incerase in cerebral blood flow
change in hippocampus
social engagement and interactions
- improve levels of activation, processing of reward, change brain strucure/volume etc?
eaton et al 2006 teens and risk
13000 adolsecents death in uk from motor vehicle crashes, unintentional injury, homicide and suicide
van lejenhorst et al 2010 adolescents and risk in monetary reward
risk increase with increased reward across ages
teen peak in vmPFC and VS in adolescence - greater responsivity to emotionally valent stimuli/rewards
dreyfuss et al 2014 go no go fear
adol specific increase in false alarms to threat stimuli
reflect failure to inhibit response to emotionally valient stimuli in the environment
- processing of neg/threat stimuli assoc with amyg activation (ledoux)
winocur 1998 enrich enviorn
enriched in disadvantaged environ show redution in learn and memory - stay active
smith et al 2009 cog assessments
improvements in memory attention backward digit letter no sequencing delayed word recall
guiney et al 2015 cerebral blood flow on cog
regular physical activity in young adults = greater aeorbic fitness = greater CBF reg and greater cog inhibition
erikson 2011 hipp changes on cog
hipp shrinks into late adulthodo
BUT hipp and MTL increase in volume via exercise
active older adults show improved spatial memory following 2% increase in hipp volume
ONLY SPECIFIC AREAS IMPROVE
