title: The effects of medial temporal lobe resections on verbal threat and fear conditioning.
abstract: A left hemisphere advantage in the processing of verbal threat has previously been reported, whereas both hemispheres seem equally important in fear conditioning. Here, we compared the effects of unilateral medial temporal lobe (MTL) resections on verbal threat as well as delay and trace fear conditioning. During verbal threat, right and left MTL-resections attenuated fear potentiated startle in comparison with controls. In contrast to previous studies, MTL-resections did not attenuate delay conditioning of skin conductance responses. Left and right resectioned patients did not differ in psychophysiological responses to verbal threat or delay fear conditioning. Trace conditioning was not observed in any group. Results suggest a bilateral MTL hemispheric involvement in the processing of verbal threat, whereas one intact hemisphere seems sufficient for delay conditioning.
authors.affiliation: Department of Psychology, Uppsala University, 751 42 Uppsala, Sweden. Fredrik.ahs@psyk.uu.se
authors.forename: Fredrik
authors.initials: F
authors.lastname: Ahs
authors.forename: Orjan
authors.initials: O
authors.lastname: Frans
authors.forename: Bodil
authors.initials: B
authors.lastname: Tibblin
authors.forename: Eva
authors.initials: E
authors.lastname: Kumlien
authors.forename: Mats
authors.initials: M
authors.lastname: Fredrikson
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001364:Awareness; D003214:Conditioning, Classical; D004576:Electromyography / Q000379:methods; D004597:Electroshock; D004833:Epilepsy, Temporal Lobe / Q000601:surgery; D005239:Fear; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D005712:Galvanic Skin Response / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods; D011930:Reaction Time / Q000502:physiology; D013216:Reflex, Startle / Q000502:physiology; D013702:Temporal Lobe / Q000601:surgery*; D013997:Time Factors; D014706:Verbal Learning / Q000502:physiology*