"Alcohol: Effects on Performance"
Alcohol: Effects on Performance Shannon Amerilda Scielzo General Effects • Low doses – Mild euphoria – Anxiolytic effect – reduces the effects of anxiety • Rat studies – reduces inhibitory effects to aversive stimuli – Lower inhibitions – Impaired concentration – Reduced coordination – Impaired reaction time • Medium doses – Slurred – Altered emotions – Sedation • High doses – Breathing difficulty – Vomiting – Unconsciousness • Positive and negative reinforcement General Effects • Effects may be related to: – Age – Gender – Physical condition – Amount of food consumed – Interactions with other drugs • Cells of body affected by destabilization of cell membranes – Alcohol is very small molecule, soluble in lipids – Crosses the blood-brain barrier • Neurochemical effects Neurochemical Effects • NMDA and GABAA receptors • Increased activity of dopaminergic neurons – Indirectly partially through NMDA antagonism – Partially due to reducing the chemical that breaks dopamine down Nucleu Accumbens NMDA Receptors • NMDA receptors – Inverse agonist for receptors – interferes with the effects of glutamate • Glutamate is the most important excitatory neurotransmitter in the brain – NMDA Antagonists produce sedative and anxiolytic effects • Interfere with cognitive performance – Tabakoff and Hoffman (1996) – NMDA antagonists release dopamine • Both positive and negative reinforcements – Loscher, Annies, & Honack (1991) NMDA Receptors • Alcohol disrupts long-term potentiation – Learning – Spatial receptive fields of place cells in the hippocampus • Likely partly explains effects on memory and other cognitive functions GABAA receptors • Alcohol is an indirect agonist to GABA A receptors – CL- – Inhibitory post-synaptic potentials • Neuron less excitable Intake of CL- http://www.thebrain.mcgill.ca/flash/i/i_03/i_03_m/i_03_m_par/i_03_m_par_alcool.html Chronic Alcohol Consumption • NMDA receptors become hypersensitive to glutamate • GABA receptors become desensitized – State of excitation when experiencing alcohol withdrawal • Shaking • Tremors • Sleeping problems • Hallucinations •http://faculty.washington.edu/chudler/alco.html Research on Performance • Effects of alcohol on performance have been recognized for close to 70 years (c.f., Jellinek & McFarland, 1940) • Research thus far suggests effects of alcohol are minimal when stimuli: – Are simple or explicit – Are presented in the absense of competing demands – Involve automatic processes with immediate responses • Casbon, Curtin, Lang, & Patrick (2006) Inattentional Blindness • Random assignment, one drink – Either alcoholic or placebo – 25 second video clip – Gorilla ran through • Alcohol condition twice as likely not to notice the gorilla – Clifsefi, Takarangi, & Bergman (2006) Effects on Driving • High-fidelity driving simulator • Cell phone drivers – Braking reactions delayed – More accidents • Drivers who were intoxicated from ethanol (i.e., BAL of .08). – More aggressive driving style – Followed closer to the vehicle in front – Applied more force while breaking • Strayer, Drews, & Crouch (2006) Effects on Driving: ADHD • Virtual reality driving simulator Alcohol Performance • 2 single, acute doses of alcohol ADHD • Continuous performance test inattention measures and behavioral observations – More affected for ADHD group • Both groups had decreased performance on the driving simulator scores – Barkley, Murphy, O’Connell, Anderson, & Connor (2006) Placebo Effects Anticipated Effects Focus Performance • Placebo participants may focus on attentional cues to compensate for anticipated cognitive impairment • The compensatory strategies may involve a sensitization of evaluative control – Thus, in some situations may result in improved performance • Testa, Fillmore, Jeanette, Abbey, Curtin, Leonard, et al., (2006) Risk-Seeking Behavior • Group decision-making task • 3-person groups that consumed either alcohol or a placebo – Complete a 30-min questionnaire battery – Toss a coin • Either no questionnaires or a 60-minute one • Groups consuming alcohol were more likely to choose the coin toss – Sayette, Kirchner, Moreland, Levine, & Travis (2006) Cognitive Ability Over Time • Light to moderate drinking and cognitive function – 7 or fewer drinks per week – Retired veterans • Current drinkers had significantly better cognitive performance on 3 of 4 tests then non-drinkers • The number of years drinking also contributed unique variance – Reid, Van Ness, Hawkins, Towle, Concato, & Guo (2006) Amount of Drinking Number of years drinking Cognitive Function Alcohol Attentional Bias Alcohol’s physical Attentional Bias effects Cognitive Performance • Attentional bias only an artifact of impaired cognitive functioning? – Classic Stroop test (a measure of inhibitory control) – Shipley Institute of Living Scale (SILS; a measure of verbal and abstraction ability) • Chronic drinkers vs social drinkers had: – Lower performance on the SILS and Stroop interference – Greater alcohol attentional bias • The authors suggested that excessive drinking sensitizes chronic alcohol users’ attentional responsiveness to alcohol-related stimuli more than alcohol actually affects cognitive functioning – Fadardi, & Cox (2006) Cognitive Control Alcohol Cognitive Control Behavioral Performance • Perseverative behavior - continuation of a behavior when cues are present that it should alter or cease – n-back working memory task • Task complexity • Prepotency of inclinations to respond • Alcohol or no-alcohol conditions – Perseveration of prepotent, task-inappropriate response patterns only under cognitively demanding (heavy memory load) conditions • This effect was evident for both commission errors and omission errors • The authors suggested that alcohol-induced perservation is derived from impairments in cognitive control – Casbon, Curtin, Lang, & Patrick (2006) Perceptual Speed Alcohol Perceptual Speed Task Performance • 4 temporal-factors tests (Pre/post administration – BAC of .11) – Simultaneity – Apparent Movement – Bistable Stroboscopic Motion – Backward Masking • Pre-posttest changes indicated slowed perceptual speed • Perceptual speed was still slowed as BAC decreased – Simultaneity and Backward Masking were still significantly slowed at .096. • Thus, task-performance is likely mediated by the effects of alcohol on perceptual speed – Jones, Chronister, & Kennedy, R. S. (2006) References • Barkley, R. A., Murphy, K. R., O’Connell, T., Anderson, D., & Connor, D. E. (2006). Effects of two doses of alchohol on simulator driving performance in adults with attention deficit/hyperactivity disorder. Neuropsychology, 20(1), 77-87. • Casbon, T. S., Curtin, J. J., Lang, A. R., & Patrick, C. J. (2006). Deleterious effects of alcohol intoxication: Diminished cognitive control and its behavioral consequences. Journal of Abnormal Psychology, 112(3), 476-487. • Carlson, N. R. (1999). Foundations of Physiological Psychology (4th ed.). Allyn & Bacon: Boston. • Clifsefi, S. L., Takarangi, M. K., & Bergman, J. S. (2006). Blind drunk: The effects of alcohol on inattentional blindness. Applied Cognitive Psychology, 20(5), 697-704. • Curtin, J. J., & Fairchild, B. A. (2006). Alcohol and cognitive control: Implications for regulation of behavior during response conflict. Journal of Abnormal Psychology, 112(3), 424-436. • Fadardi, J. S., & Cox, W. M. (2006). Alcohol attentional bias : Drinking salience or cognitive impairment? Psychopharmacology, 185(2), 169-178. References • http://www.thebrain.mcgill.ca/flash/i/i_03/i_03_m/i_03_m_par/i_03_m_pa r_alcool.html • http://faculty.washington.edu/chudler/alco.html • http://www.erowid.org/chemicals/alcohol/alcohol.shtml • http://www.livescience.com/humanbiology/060629_blind_drunk.html • http://www.med.unc.edu/alcohol/cenline/11_1_1.htm • Jones, M. B., Chronister, J. L., & Kennedy, R. S. (2006). Effects of alcohol on perceptual speed. Perceptual and Motor Skills, 87(3), 1247- 1255. • Kirchner, T. R., & Sayette, M. A. (2006). Effects of alcohol on controlled and automatic memory processes. Experimental and Clinical Psychopharmacology, 11(2), 167-175. References • Reid, M. C., Van Ness, P. H., Hawkins, K. A., Towle, V., Concato, J., & Guo, Z. (2006). Light to Moderate Alcohol Consumption Is Associated With Better Cognitive Function Among Older Male Veterans Receiving Primary Care. Journal of Geriatric Psychiatry and Neurology, 19(2), 98-105. • Sayette, M. A., Kirchner, T. R., Moreland, R. L., Levine, J. M., & Travis, T. (2006). Effects of alcohol on risk-seeking behavior: A group level of analysis. Psychology of Addictive Behaviors, 18(2), 190-193. • Strayer, D. L., Drews, F. A., & Crouch, D. J. (2006). A comparison of the cell phone driver and the drunk driver. Human Factors, 48(2), 381-391. • Testa, M., Fillmore, M. T., Jeanette, N., Abbey, A., Curtin, J. J., Leonard, K. E., Mariano, K. A., Thomas, M. C., Nomensen, K. J., George, W. H., VanZile-Tamsen, C., Livingston, J. A., Saenz, C., Buck, P. O., Zawacki, T., Parkhill, M. R., Jacques, A. J., & Hayman, L. (2006). Understanding alcohol expectancy effects: Revisiting the placebo condition. Alcholism: Clinical and Experimental Research, 30(2), 339-348.