title: Acute exposure to stress improves performance in trace eyeblink conditioning and spatial learning tasks in healthy men.
abstract: The present study investigated the effects of acute stress exposure on learning performance in humans using analogs of two paradigms frequently used in animals. Healthy male participants were exposed to the cold pressor test (CPT) procedure, i.e., insertion of the dominant hand into ice water for 60 sec. Following the CPT or the control procedure, participants completed a trace eyeblink conditioning task followed by a virtual navigation Morris water task (VNMWT). Hypothalamic-pituitary-adrenocortical (HPA) axis and sympathetic autonomic system (SAS) activity were assessed by measuring salivary cortisol, heart rate, and skin conductance at selected timepoints. Results revealed positive effects of stress on performance in both tasks. The stress group showed significantly more conditioned blinks than the control group during acquisition of trace eyeblink conditioning. The stress group also performed significantly better in the VNMWT than the control group, with the former showing significantly fewer failures to locate the hidden platform in the allotted time and smaller heading errors than the latter. Regression analyses revealed positive relationships between HPA axis and SAS activity during stress and eyeblink conditioning performance. Our results directly extend findings from animal studies and suggest potential physiological mechanisms underlying stress and learning.
authors.affiliation: Section on Developmental Genetic Epidemiology, Mood and Anxiety Disorders Program, National Institute of Mental Health, NIH, Bethesda, Maryland 20892, USA. dunckor@mail.nih.gov
authors.forename: Roman
authors.initials: R
authors.lastname: Duncko
authors.forename: Brian
authors.initials: B
authors.lastname: Cornwell
authors.forename: Lihong
authors.initials: L
authors.lastname: Cui
authors.forename: Kathleen R
authors.initials: KR
authors.lastname: Merikangas
authors.forename: Christian
authors.initials: C
authors.lastname: Grillon
mesh_terms: D000208:Acute Disease; D000328:Adult; D001767:Blinking; D003080:Cold Temperature; D003213:Conditioning, Psychological; D006801:Humans; D007030:Hypothalamo-Hypophyseal System / Q000503:physiopathology; D007101:Immersion; D008297:Male; D018782:Maze Learning; D010913:Pituitary-Adrenal System / Q000503:physiopathology; D012044:Regression Analysis; D013312:Stress, Physiological / Q000209:etiology / Q000503:physiopathology / Q000523:psychology*; D013564:Sympathetic Nervous System / Q000503:physiopathology; D013647:Task Performance and Analysis; D014584:User-Computer Interface