Stress can increase reward pursuits: This has traditionally been seen as an attempt to relieve negative affect through the hedonic properties of a reward. However, reward pursuit is not always proportional to the pleasure experienced, because reward processing involves distinct components, including the motivation to obtain a reward (i.e., wanting) and the hedonic pleasure during the reward consumption (i.e., liking). [...] Results showed that compared with participants in the stress-free condition, those in the stress condition mobilized more effort in instrumental action when the reward-associated cue was displayed, even though they did not report the reward as being more pleasurable.
Source: Restoration reveals hidden whale in 17th-century Dutch painting
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| Photograph: Fitzwilliam Museum |
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| Photograph: Fitzwilliam Museum |
It was always a bit of a puzzle what the people clustered on the sands, or peering down from the dunes, were actually looking at on a bleak stretch of windswept Dutch beach. The startling truth has just been revealed, after the conservator Shan Kuang took a delicate scalpel to a painting which has been in the collection of the Fitzwilliam Museum in Cambridge for the past 140 years. She first uncovered a baffling figure of man apparently standing in mid air, and then gradually revealed that he was standing on the great hillock of a beached whale, washed up on the shallows.
The varnish of the beach scene had yellowed and become unsightly, but as she removed it the mid-air man appeared, beside what appeared to be a sail. She could also see that a stretch of the sea was clearly a later addition. There was a long debate among the experts about the potential risk of damaging the painting before she proceeded to remove the overpainting, using a scalpel and solvents, working on tiny areas under a microscope.
Source: Sleep promotes branch-specific formation of dendritic spines after learning (Yang et al., 2014)
How sleep helps learning and memory remains unknown. We report in mouse motor cortex that sleep after motor learning promotes the formation of postsynaptic dendritic spines on a subset of branches of individual layer V pyramidal neurons. New spines are formed on different sets of dendritic branches in response to different learning tasks and are protected from being eliminated when multiple tasks are learned. Neurons activated during learning of a motor task are reactivated during subsequent non–rapid eye movement sleep, and disrupting this neuronal reactivation prevents branch-specific spine formation. These findings indicate that sleep has a key role in promoting learning-dependent synapse formation and maintenance on selected dendritic branches, which contribute to memory storage.
Dr. Robyn Lam, C. Psych.
(supervised practice)
#1001-180 Bloor St. W.
Toronto, ON
M5S 2V6
robyn at robynlam dot ca