July 9, 2003Geoffrey Morgan, 1 Designing, Building, and Testing Behavior Moderators with the ACT-R Cognitive Architecture My Contribution This research is funded by ONR contract #: N

July 9, 2003Geoffrey Morgan, 2 About the author Geoffrey Morgan 20 years old, rising Junior IST Major ISDEV Option This work conducted on a summer residency.

July 9, 2003Geoffrey Morgan, 3 Some definitions Behavior Moderator - Something that changes behaviors, such as stress, alcohol, amphetamines, and caffeine. Cognitive Architecture – Software that allows for intelligent agents to be created capable of memory and learning. ACT-R – A specific cognitive architecture, currently used in academic circles, and with a large community and software library.

July 9, 2003Geoffrey Morgan, 4 Introduction to the project Start Date: January, 2003 Length: 3 years Project is a parallel effort between the ACS lab and BBH. Three studies, one a year: 1)Serial Subtraction 2)Driving Task 3)ARGUS Three Treatments: 1)Placebo 2)200 mg Caffeine 3)400 mg Caffeine

July 9, 2003Geoffrey Morgan, 5 Project Goals Goal: Model caffeine’s effects on human cognition. To achieve goal requires sophisticated study of caffeine’s effects, and then accurate modeling of these effects in a cognitive architecture.

July 9, 2003Geoffrey Morgan, 6 My Progress Developing a comprehensive literature review on the effects of caffeine on cognition. While literature reviews have been written before, this review is not intended for the traditional audience, but for cognitive modelers. These modelers require more than vague assertions, but specific numbers.

July 9, 2003Geoffrey Morgan, 7 Caffeine, a primer Caffeine is ubiquitous. 80% of the world’s population consumes caffeine daily. (James, 1997) Caffeine is addictive, and a drug of abuse. (James, 1997) Caffeine is not a carcinogen. (James, 1997) Caffeine withdrawal effects begin within hours, and include headache, sleepiness, and lethargy. (James, 1997)

July 9, 2003Geoffrey Morgan, 8 Beneficial effects of Caffeine Increased alertness (Smith et al, 1993; Brice and Smith, 2002) Improved dual task performance (Kerr et al. 1991) Superior information encoding (Smith et al. 1999) Improved logical reasoning (Smith et al, 1993) Faster semantic processing (Smith et al, 1993) Quicker simple reaction times (Clubley et al, 1979; Smith et al. 1993) Improved vigilance (Brice and Smith, 2001) However…

July 9, 2003Geoffrey Morgan, 9 A more negative interpretation James (1997) claims that many, if not all, studies that show improvements in performance based upon caffeine have a fundamental flaw. This flaw is based on two facts: –Most of the population is caffeinated daily –Studies, to control caffeine, require caffeine abstinence for a period (6-24 hours) before study.

July 9, 2003Geoffrey Morgan, 10 A more negative interpretation (2) Thus, the performance gains shown in these studies are really just relief from the effects of caffeine withdrawal.

July 9, 2003Geoffrey Morgan, 11 Rebuttal Smith (1995), in response to earlier articles of James, indicates that caffeine withdrawal effects are selective (small number of tasks affected) and are found only in a small number of participants. Therefore, James fundamental flaw speculations and comments are unfounded. Clearly, this debate is still ongoing.

July 9, 2003Geoffrey Morgan, 12 An eye to the future… Literature review requires more work. Review and assimilation. ACT-R model modified to include these effects.

July 9, 2003Geoffrey Morgan, 13 Questions?

July 9, 2003Geoffrey Morgan, 14 References Brice, C., & Smith, A. (2001). The effects of caffeine on simulated driving, subjective alertness and sustained attention. Human Psychopharmacology, 16, Brice, C. F., & Smith, A. P. (2002). Effects on caffeine by mood and performance: a study of realistic consumption. Psychopharmacology. Clubley, M., Bye, C. E., Henson, T. A., Peck, A. W., & Riddington, C. J. (1979). Effects of caffeine alone and in the combination of human performance, subjective effects, and EEG activity. British Journal of Clinical Pharmacology, 7, James, J. E. (1997). Understanding caffeine: A biobehavioral analysis. Sage Publications. Thousand Oaks, California. Kerr, J. S., Sherwood, N., & Hindmarsh, I. (1991). Separate and combined effects of the social drugs on psychomotor performance. Psychopharmacology, 104, Smith, A. P. (1995). Caffeine and psychomotor performance: a reply to James. Addiction, 90 (9), Smith, A. P., Brockman, P., Flynn R., & Thomas, M. (1993). Investigation of the effects of coffee on alertness and performance and mood during the day and night. Neuropsychobiology, 27, Smith, A. P., Clark, R., & Gallagher, J. (1999). Breakfast cereal and caffeinated coffee: effects on working memory, attention, mood and cardiovascular function. Physiological Behavior, 67, 9-17.