Author: admin
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Drugs affect subtypes of Parkinson’s disease differently
In this commentary, I discuss the implications of new work from Hanneke Den Ouden’s lab. The authors subdivided Parkinson’s disease patients into those with and without tremor, and found that learning was affected by dopamine in opposite directions in the two groups!
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Parkinson’s medication has opposite effects on two kinds of motivation
Patients with Parkinson’s disease lack the brain chemical dopamine. Dopamine is thought to signal upcoming rewards, and this might explain why patients on treatment can develop impulse control disorders. My lab is studying two different ways to motivate people. One way is to reward or punish them based on how well they do — like…
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Are working memory and visual search windows into the same neural process?
When you recall an item from memory, a prompt usually brings associated parts of that item into mind. Could this process be the same thing that occurs when you search for a visual target? We tested a neural model designed to perform working memory tasks, to see if it could also perform visual search. The…
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Pupil size betrays contents of working memory
When we hold several things in short-term memory, we can shift our attention internally between different features in memory. For example we might hold two visual objects in memory, and choose to think about one of them. We show that pupils shrink when we are currently thinking of a bright object, in our recent study…
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Dopamine can make our working memory more or less flexible
Dopamine drugs are used to treat Parkinson’s disease, and alter a wide range of brain functions. One role of dopamine might be to make information we are currently holding in mind more stable — we are less likely to get distracted. We showed that this effect is crucially dependent on our initial memory capacity. People…
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Neural model of working memory
Is it possible to account for our patterns of short-term remembering and forgetting, and at the same time, make predictions about what the corresponding neural activity should look like? That is what we tried to do in a recent paper. Our model suggests that neurons in the prefrontal cortex are critical for storing information in…
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Why does it feel effortful to be precise?
Our eye movements are controlled by a relatively simple circuit in the brainstem. Remarkably, it seems to operate with less error when we are motivated by money. We showed that internal feedback gain — a process that stabilises motor plans as they are executed — increases with reward, thus improving the precision of the movement.…