News & Events

11.06.14

Special Blog Post: An Interview With Anne Marie Brady, Our Most Recent JoVE Winner!

Elucidating Executive Function

The brain is capable of so many things: it can maintain a sense and awareness of one’s surroundings, can initiate motor movements, maintain an active sense of one’s own body positions in space, and produce and comprehend speech, among many other functions.  Furthermore, all of these functions can be traced to specific regions of the brain and specific

An operant chamber setup in Dr. Anne Marie Brady's laboratory.

An operant chamber setup in Dr. Anne Marie Brady’s laboratory.

nerve tracts.

But, did you ever wonder how you maintain attention or solve problems?  These “higher” cognitive processes are actually the main purpose of the frontal lobes of the brain.  This is where attention is maintained or changed, decisions are made, problems are solved, goals are achieved, and behavior is controlled.  It could be argued that this is the region that makes you you.  These abilities are collectively known as “executive functioning.”

Whether you are aware of it or not, your average day requires executive function in all its many forms.  Executive function lacks a formal definition, but is generally understood as the coordination of mental skills responsible for goal-oriented behavior:  working memory, cognitive control or conflict monitoring,  sustained attention, selective attention, and divided attention, decision making and risk assessment, reversal learning and set shifting.  Executive function is disrupted in several different disease states, including Alzheimer’s disease and schizophrenia.

The neurological mechanisms of complex cognitive processes are regularly being elucidated.  Robust preclinical assays are essential so that progress can continue to be made in both drug discovery and refinement of disease models.

We had the opportunity recently to speak with our most recent JoVE contest winner, Dr. Anne Marie Brady of St. Mary’s College of Maryland.  Dr. Brady investigates normal and disease states in rodents using tasks that distinguish between reversal learning and set shifting, both components of executive function and both affected in disease states such as schizophrenia.  Dr. Brady has long had an interest in the complex cognitive processes that the brain is capable of.  Her current work in a developmental model of schizophrenia suggests that the ventral hippocampus lesion model of schizophrenia leads to deficits in set shifting but not reversal learning (Placek et al., 2013).

What was your inspiration in choosing executive function as a research focus? I have always been interested in complex cognitive processes and how they are mediated by the brain, especially the prefrontal cortex which seems to be responsible for the highest cognitive functions of which animals are capable.  I am also interested in neuropsychiatric disease states, such as schizophrenia, drug addiction, and depression, and how cognitive functions are impaired in such conditions.  Executive function is a process which appears to be compromised in many psychopathological states, and there is also evidence for prefrontal abnormalities in these conditions.  So, I suppose it is a matter of all of my interests converging, leading me to study the neurobiological basis of executive function and its disruption in various disease models.

Where do you see this field heading in the future?  I am really excited by the ongoing development and improvement of methods to answer questions related to the neurobiological basis of cognition.  For example, techniques like optogenetics and in vivo electrophysiology will allow us to investigate the neural mechanisms of behavior and cognition on a level of detail that has not been previously possible.  I am particularly encouraged by the *integration* of these techniques with existing, “traditional” behavioral methods – rather than the new techniques *replacing* the existing ones.  Too often, tried-and-true methods are ignored or even abandoned in favor of the newest bells and whistles, but fortunately I don’t see that happening this time.  All of the time and effort that has gone into developing and validating behavioral tasks to measure complex cognitive constructs have laid a solid groundwork for adding new, mechanism-focused technologies as they arise.  I’ve been studying behavior for over 20 years now and it is still fascinating to me – after all, isn’t that why we’re interested in the brain, because of how it controls behavior?

self-admin

A self-administration study in Dr. Brady’s laboratory.

In your JoVE abstract and in recent papers, you focus on set-shifting and reversal learning.  I am curious what other aspects of executive function have been, or are being, elucidated with operant-based studies?  Certainly there are a variety of other operant tasks available to measure different aspects of complex cognitive function that may be included under the umbrella term “executive function.”  There are tasks to assess working memory; tasks for cognitive control or conflict monitoring; for sustained attention, selective attention, and divided attention; for decision-making and risk assessment.

Have you done this kind of research prior to using Med-PC and Med operant chambers?  I have always used Med products, beginning in graduate school.  I have always appreciated the flexibility of the Med-PC programming language, in particular, and the richness of the data collection that is made possible.  I have used Med operant chambers for a variety of more complex applications, including self-administration and simultaneous in vivo microdialysis, and I have found that they are easily adaptable to these different settings.

We wish the Brady laboratory and everyone researching complex cognitive functions the best of luck, and can’t wait to see and hear more from you!

References:

Placek K, Dippel WC, Jones S, Brady AM. Impairments in set-shifting but not reversal learning in the neonatal ventral hippocampal lesion model of schizophrenia: further evidence for medial prefrontal deficits.  Behav Brain Res. 2013 Nov 1;256:405-13. doi: 10.1016/j.bbr.2013.08.034.

 

Remember, you can submit your abstract for consideration for the next contest here: http://www.med-associates.com/jove-contest/

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