email brody@cshl.edu, phone (516) 367-6902 , fax (516) 367-8389

You look up a number in the phone book, you remember it for a few seconds until you dial it, and then you let it go, forgetting it. This is a classic example of working memory, the ability to keep something in mind for a few seconds. Working memory is thought to be fundamental to many cognitive processes, including, for example, holding a conversation, playing music, or even thinking rationally. What are the neural mechanisms behind it?

In collaboration with experimental neurophysiologists, we have studied responses of prefrontal cortical neurons in monkeys trained to perform a working memory task. Examples of the responses of six such neurons are shown in the figure opposite. The neurons in the middle row are a clear neural correlate of working memory: their firing rate throughout memory periods reflects the remembered stimulus.

The research in my lab focuses on possible mechanisms behind such responses. One approach we are pursuing is to build computational models of networks of neurons that display maintained, stimulus-dependent responses. The models can help us pinpoint the crucial assumptions behind our current hypotheses of how memory activity can arise. The models also make predictions about our capacities to keep sensory stimuli in short-term memory. A second approach we are pursuing is to test these neural network model-based predictions by carrying out psychophysical experiments with humans. Our goal is to bridge the gap between computational neural network-level models and psychophysically tested human behavior.

Please visit the Brody Lab home page.