creierul de-a lungul anilor - adultii Flashcards
what is adult plasticity
the capacity of the brain to adapt to changing demands by altering its structure
Leads to both change in brain and behaviour and cognition
what is evidence of adult plasticity
adult humans learn new info, skills
Learning involves in crease in synaptic weights between neurones
where are stem cells that give rise to new neurones
hippocampus, only in the inner granular zone of the dentate gyrus
what happens to the neurones that are lost
they are not replaced
the rate of neurones loss is greater than that of gain
how do we examine brain plasticity in humans
examine brain changes in the hippocampus
examine brain changes in response to an environmental benefit or challenge
how have we measured adult plasticity in rats
Adult rats placed in
-enriched environments for 3h for 2w
-in pairs in standard cage
Measured neurogenesis (new neurones produced) and memory
Measured new cells in dentate gyrus
what were the results of the study on adult plasticity in rats
Neurogenesis:
Enriched had more new cells so that enhanced neurogenesis in the dentate gyrus
Memory:
Time spent exploring new or old toys
No group differences at short delay (1h)
After 24 and 48h, enriched rats showed better recognition
how do we investigate adult plasticity in humans
Difficult to deprive ppl of enrichment
So we look for naturalistic factors
what is the role of exercise in humans
87 uni students
measured aerobic fitness
cognition measured on:
-sustained attention
-working memory
RESULTS:
Sustained attention: Faster reaction time for excellent fitness compared to very poor fitness
Working memory: Excellent fitness are more accurate than very poor fitness
Associations between aerobic fitness and cognitive performance were independent of age, sex, IQ
what is effect of music on adult plasticity in humans
26 MALE symphony orchestra musicians
26 non-musicians
Broca’s area inferior frontal gyrus - important for action and spatial information
RESULTS:
Musicians processed music in left, non-music processed in right
Musicians have increased grey matter density in left Broca’s area
What else was found from the study of muscians
significant negative correlation between left inferior frontal gyrus volume and age in controls only
so those that don’t do music, not only they have less matter, but the matter also decreases with age
whereas for musicians, the volume stays consistent with age
so musical training is protective against age-related decline
how do taxi drivers show adult plasticity
hippocampus - important for spatial memory
evidence for plasticity in hippocampus
-MEN London Taxi drivers
-controls who were not taxi drivers
RESULTS:
Taxi drivers had larger grey matter volume in posterior regions - which stores spatial representations
Controls had larger anterior grey matter volumes
how have they investigated associations between time as driver and hippocampal volume
significant correlation between size of hippocampi and time as taxi driver
what are the differences between taxi drivers and controls
bus drivers show same pattern as controls
so they are different to taxi drivers
how were taxi drivers in investigated longitudinally pre and post training
At baseline, no difference between qualifiers and non-qualifiers in age, IQ, memory or brain volume
Qualifiers spent more time training
At follow up, qualifiers were better at a spatial relations test
