Dr. Shelli Kesler, an Assistant Professor and neuropsychologist at the Stanford University School of Medicine, recently reported that Lumosity training can enhance cognitive performance in patients who have survived breast cancer. The research was published in the peer-reviewed journal Clinical Breast Cancer in the August 2013 issue. Dr. Kesler hypothesized that intensive, targeted cognitive training could enhance higher-level cognitive skills -- referred to in the neuroscience literature as executive functions -- that are known to be impaired in patients who have undergone chemotherapy cancer treatment. The results of this randomized, controlled clinical trial support this hypothesis and demonstrate that cognitive training may be a useful intervention for cancer-related cognitive impairment.
As many as 75% of breast cancer survivors experience long-term cognitive deficits that affect their quality of life. This cancer-related cognitive impairment is sometimes referred to as “chemofog” or “chemobrain.” Expert opinions are mixed regarding the causes of the impairment. The deficits may be attributable to the cancer itself or they may be side effects of the chemical and radiological treatments administered to treat the disease. Either way, these issues often lead patients to complain of memory, attention and other executive functioning problems that can negatively impact their abilities to perform at work or school and generally reduce their quality of life. There is currently no commonly accepted treatment for cancer-related cognitive impairment.
Dr. Kesler recognized that many of the deficits reported by patients with chemobrain are related to executive function abilities that are largely mediated the brain’s frontal lobes. Executive functions include abilities like planning, verbal fluency, focused attention, and set shifting (the ability to switch from an ineffective mental strategy to an effective one). She reasoned that training with Lumosity's targeted exercises could enhance these functions, improving patients’ cognition, thereby benefiting their quality of life.
To test this hypothesis, Dr. Kesler recruited 41 women with a history of chemotherapy treatment for breast cancer to participate in a research study. All participants were at least 18 months post-chemotherapy at the initiation of the study. This is an important feature of the study since since chemobrain typically has a spontaneous recovery period where symptoms show improvements, but this spontaneous recovery has typically run its course by 18 months.
Participants were randomly assigned to either a treatment group in which they received 48 sessions of Lumosity training, each lasting 20-30 minutes, or a control group that did not receive the treatment immediately, but was put on a wait list and received the treatment after the study was completed. Both groups took a battery of cognitive tests before and after the training period to measure whether cognitive performance was affected by the treatment or control participation. The test battery included a series of standard clinical neuropsychological assessments designed to measure executive functions such as cognitive flexibility and verbal fluency as well as processing speed. Participants were also given self-rating scales designed to measure real-world skills such as planning.
The results showed a pattern of greater improvements on assessment scores for the cognitive training group relative to the wait list control group, as shown in the graphs below. Participants who received Lumosity training improved significantly more than the control group on the Wisconsin Card Sort Task (WCST) -- a widely used measure of cognitive flexibility, Symbol Search -- a measure of speed of processing, and Letter Fluency -- a common verbal fluency assessment. Trend level (i.e., not quite statistically significant, but in the right direction) differences were seen on a measure of verbal memory (HVLT-R). In addition, the cognitive training group experienced significant improvements in self-reported planning and monitoring abilities. This pattern of results shows that breast cancer survivors can improve their cognitive abilities and quality of life through cognitive training with Lumosity.
These results are encouraging for cancer survivors struggling to regain their cognitive capacities. They also are consistent with a growing body of literature that shows that with the right kind of intensive, adaptive challenge the brain can change itself to more efficiently process, remember and organize information.
Dr. Kesler continues to pursue investigations into the effects of cognitive training, with the goal of learning more about the brain mechanisms of neuroplasticity that support the positive changes seen in her training studies. Along with the dozens of other university-based researchers conducting independent research with Lumosity as part of the Human Cognition Project, Dr. Kesler is moving the neuroscience of cognitive enhancement forward.