Inhibitory Mechanisms in Working Memory

One of the ways in which we are able to maintain goal-directed behavior is by ignoring or suppressing competing goal-irrelevant information in the environment and in memory. Our lab has conducted numerous studies in which we have studied inhibitory mechanisms. For example, our past work has shown the information from an immediately previous event intrudes on memory for a current event even when people are trying to prevent that. We have also shown that active suppression of memories enlists different processes than active suppression of perceptual information. We are currently engaged in several lines of research to continue these investigations and to see how failures of inhibition impair the performance of individuals with ADHD.

Cognitive Control and Self-Regulation

Our lab investigates basic cognitive control processes, model systems in which these processes are altered or impaired, and real-world consequences of such impairment. For example, one line of research focuses on the ability to delay gratification in childhood, how this ability develops across the lifespan, and outcomes associated with failure to delay gratification. Another line of research involves the study of mechanisms to dampen emotional engagement when it is not wanted. We have also studied changes in cognitive control that accompany Major Depressive Disorder and ADHD.


We are studying the efficacy and long-term impact of tDCS (transcranial direct current stimulation) on working memory performance. In one of our studies using a working memory task, we investigate whether experiencing tDCS before, after, or during the task improves working memory capacity, and whether any gains in capacity can be maintained months after the stimulation and training end. We are also studying how tDCS can enhance learning and whether it can dampen distraction from unwanted information. We are also investigating just what happens in the brain when tDCS is applied to the scalp; this work involves providing individuals with tDCS while they are in an MRI scanner, so that we can directly examine the neural consequences of the stimulation.


For some time, we have investigated how cognitive processes change with age. For example, our older work has compared how younger and older individuals differ in their inhibitory skills. More recently, we have embarked on a large program to test how well older individuals, compared to their younger counterparts, benefit from specific cognitive training. And, in this same context, we are investigating whether tDCS can have beneficial effects for learning by older individuals.