
Dr. Robert Dowman
Professor/Chair of Psychology
Psychology Department
173 Science Center
PO Box 5825
Potsdam, NY 13699-5825
Phone: 315-268-3836
Fax: 315-268-7118
E-mail: rdowman@clarkson.edu
Education
Ph.D., Northwestern University, 1984
Courses Taught
Psychology Freshman Seminar, Experimental Psychology, Physiological Psychology, Cognitive Neuroscience.
Research Interests
Electrophysiological studies of attending towards threat
Our work is aimed at understanding how the brain detects a threatening stimulus presented outside the focus of attention and re-directs attention towards it. This fundamental cognitive process is critical to our survival and has been shown to play an important role in the development of anxiety disorders. We study this phenomenon using the somatosensory evoked potential (SEP) elicited by strong electrical stimulation of the sural nerve. The brain electrical activity indexed by the SEP is recorded by electrodes placed on the scalp. The sural nerve electrical stimulus has a number of properties that make it ideal for studying threat. It is strong, has a sudden onset, and produces an unfamiliar paresthesia (prickling/tingling) sensation. We have identified a network of brain areas that are important in detecting and orienting attention towards the threatening sural nerve electrical stimulus. The threatening stimulus is detected by threat feature detectors located in the dorsal posterior insula early in sensory processing (100-180 ms after the stimulus is given). Detection of the threat is monitored by the medial prefrontal cortex (130-200 ms), which in turn signals the lateral prefrontal cortex that on-going tasks need to be interrupted and attention re-directed towards the threat (320-400 ms). Dr. Daniel ben-Avraham of Clarkson's Physics Department and I have developed an artificial neural network model of this system that accounts for the behavioral and electrophysiological data. More importantly, the model has led to new predictions that we will be testing in future experiments. Keegan Lowenstein, Jennifer Quinn, William Gundling, Jennifer Roper, Jasmine Stephens, and Suzanne van Arsdale worked on this project, and gave presentations at Clarkson's SURE conference.
EEG Measure of Pain
Our laboratory, in collaboration with Dr. Stephanie Schuckers of Clarkson's department of Electrical and Computer Engineering, is involved in a study determining whether the electroencephalographic (EEG) activity recorded from the scalp can be used to measure pain. If successful, this project could lead to a much needed objective physiological method of diagnosing and quantifying pain. This would be extremely useful, for example, in patients who are unable to communicate (infants, Alzheimer patients, etc.). We have reliably observed a decrease in the alpha frequency band (8-12 Hz) of the EEG from the scalp that overlies the parietal cortex during the pain condition. The alpha band activity reflects the processing state of the neurons generating it, where large alpha amplitudes indicate the brain area is not processing and small alpha amplitudes indicate the brain is actively processing. Hence, these data are consistent with the parietal cortex's hypothesized role in pain sensation. Future studies will further characterize the changes in alpha band activity to determine whether it can be used to detect clinical pain in patients.
Publications (Last 5 years)
Dowman, R., Rissacher, D., & Schuckers, S. EEG indices of tonic pain-related activity in the somatosensory cortices. Clinical Neurophysiology, 119 (2008) 1201-1212
Dowman, R., & ben-Avraham, D. An artificial neural network model of orienting attention towards threatening somatosensory stimuli. Psychophysiology, 45 (2008) 229-239
Dowman, R. Neural Mechanisms Of Detecting and Orienting Attention Towards Unattended Threatening Somatosensory Target Stimuli. I. Inter-modal effects. Psychophysiology, 44 (2007)407-419.
Dowman, R. Neural Mechanisms Of Detecting and Orienting Attention Towards Unattended Threatening Somatosensory Target Stimuli. II. Intensity Effects. Psychophysiology, 44 (2007) 420-430.
Dowman, R., Darcey, T.M., Barkan, H., Thadani, V. & Roberts, D. Human intracranially-recorded cortical responses evoked by painful electrical stimulation of the sural nerve. NeuroImage, 34(2007) 743-763.
Dowman, R., Glebus, G. & Shinners, L. (2005) Effects of response conflict on pain-evoked medial prefrontal cortex activity. Psychophysiology, 42, 555-558.
Presentations at Scientific Meetings (Last 5 years)
Dowman, R. The neural mechanisms of detecting and orienting attention towards threats to the body, Special Interest Meeting "Symptom Perception and Illness Behaviour", Bellum, Belgium, September 2008.
Dowman, R. An artificial neural network model of orienting attention towards threatening somatosensory stimuli. Society for Psychophysiological Research, 47th Annual Meeting, Savannah Georgia, Oct 17-21 2007.
Rissacher, D., Dowman, R., & Schuckers, S.A.C. Identifying Frequency-Domain Features for an EEG-Based Pain Measurement System. 33rd Annual Northeast Biomedical Engineering Conference, SUNY Stony Brook, New York, March 10-11, 2007.
Dowman, R., Neural processes detecting unattended somatosensory target stimuli. Society for Psychophysiological Research, 46th Annual Meeting, Vancouver B.C. Canada, Oct 25-29 2006.
Dowman, R. (2006) Neural processes detecting unattended somatosensory target stimuli. Society for Psychophysiological Research, 46th Annual Meeting, Vancouver B.C.
Dowman, R., Darcey, T., Barkan, H., Thadani, V. and Roberts, D. Effects of distraction on pain-evoked medial and lateral prefrontal cortex activity. Program No. 50.6.2005. Abstract Viewer/ Itinerary Planner. Washington D.C.: Society for Neuroscience, 2005.
Student Presentations (Last 5 years)
Quinn, J. Dowman, R. Investigation of how the brain orients attention towards threats to the body. Annual Symposium of Undergraduate Research Experiences, Clarkson University, July 2009
Lowenstein, K. Dowman, R. A toolkit for developing neural network models of how the brain detects and orients attention toward threat. Annual Symposium of Undergraduate Research Experiences, Clarkson University, July 2009
Trickey, K., Dowman, R. Threat detection and the orientation of attention toward threatening stimuli. Annual Symposium of Undergraduate Research Experiences, Clarkson University, April 2009
Gundling, W. Dowman R. Spatial attention in response to threat. Annual Symposium of Undergraduate Research Experiences, Clarkson University, August 2009
Lowenstein, K., Dowman, R. Modeling the brain mechanisms of detecting and orienting attention towards threat. Annual Symposium of Undergraduate Research Experiences, Clarkson University, August 2008
Roper, J., Stephens, J., van Arsdale, S., Dowman, R. Developing protocols to study how threats to the body are detected and capture attention. Annual Symposium of Undergraduate Research Experiences, Clarkson University, August 2008
McHugh, C., O'Brien, S., & Dowman, R., and ben-Avraham, D. An artificial neural network model of threat detection. Biomedical Engineering, Science and Technology (BEST) Symposium, Clarkson University, April 2007.
McHugh, C., O'Brien, S., & Dowman, R. An artificial neural network model of threat detection. Annual Symposium of Undergraduate Research Experiences, Clarkson University, April 2007.
Trombley, T., Dowman, R. Brain computer interface control of a robotic arm: Parameters optimizing accuracy. Annual Symposium of Undergraduate Research Experiences, Clarkson University, August 2006.
Lajoie, R., Tucker, S., Gregoire, S., Ingrim, D, Dowman R. Gender differences in altruistic behavior among college students. Annual Symposium of Undergraduate Research Experiences, Clarkson University, April 2006.
Denesha, N., Fraczek, J., Dowman, R. Neural mechanisms of threat detection. Annual Symposium of Undergraduate Research Experiences, Clarkson University, April 2006.
Jodoin, K., Croughan, A., Roberts, V. & Dowman, R. Role of the anterior cingulate cortex in orienting attention towards pain. Annual Symposium of Undergraduate Research Experiences, Clarkson University, April 2005.
