Developing Intelligence

Archives for February, 2007

Yesterday I was invited to give this 15-minute presentation (PPT, PDF) to LearningRX about recent perspectives on working memory limitations, and their potential for informing cognitive training and enhancement programs. In case you’re curious, here’s a list of references:

Reworking Working Memory

Memory, defined as “any lasting effect of experience,” is an overly broad term. Those with damage to the hippocampus lose their long-term memory but retain the ability to maintain conversations (at least for short periods of time). But new perspectives on the nature of short-term or “working” memory suggests that such a neat division between…

Blogging on the Brain 2/24/07

The story of a patient who awoke after a 20-year coma, induced by traumatic brain injury. Epidemic proportions of TBI in soldiers returning from Iraq: a new problem. Second chance to live: a new blog written by a TBI survivor.

The Development of Prospective Memory

Children are famously bad at remembering to do things – for example, taking out the trash. What exactly is the developmental trajectory of the ability to remember and execute planned actions (known as prospective memory)? Although the effects of traumatic brain injury and old age on prospective memory are becoming elucidated, we have little idea…

Findings in the laboratory do not always apply to the real-world – a myriad of factors can influence real-world phenomena, and scientists actively seek to eliminate many of them in their laboratories. But ecological validity can be particularly difficult to establish in cognitive science, where real-world levels of motivation, stress, and memory load can not…

In the middle of the work day, you realize you’ll need to stop at a store on your way home from work. Your ability to actually do so, hours later, relies on what some psychologists call “prospective memory.” Although prospective memory is clearly important for human intelligence, very little is known about how it works.

The distributions of reaction times are always positively skewed, which seems to reflect two independent processes: a normal gaussian distribution of reaction times, in addition to an exponentially-decaying distribution of a few very long trials. Measures of this reaction time (RT) variability show surprisingly strong correlations with fluid intelligence, and have been interpreted to reflect…

How do the symptoms of ADHD relate to the circuitry underlying executive function and working memory? An in-press article at Neuropsychopharmacology investigates the roles of dopamine and norepinephrine in ADHD, with evidence from both behavioral and simulated experiments. This post will make more sense if you’ve read my previous posts on norepinephrine and dopamine.

Dopamine for Dummies

Dopamine is probably the most studied neurotransmitter, and yet the neuroscience literature contains a huge variety of perspectives on its functional role. This post summarizes a systems-level perspective on the function of dopamine that has motivated several successful drug studies and informed the construction of artificial neural network models. The details of this perspective are…

In a 2006 Psychopharmacology article, Niv et al. suggest that while transient dopamine release is frequently modeled computationally (as encoding reward-prediction error, for example, or as gating information into working memory) the role of more constant dopamine release is not. In the neuroscience literature, these two patterns of release are known as “phasic” and “tonic,”…