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Associative predispositions and flexibility of learned behavior
156 suits are discussed with regard to possible behavioral, cognitive and psycbophysiological mechanisms of hypnotic analgesia.
NEUROCOGNITIVE POTENTIALS, CORTICO-CORTICAL HOMOHEMISPHERIC TWO-WAY CONNECTIONS AND PREFRONTAL CORTEX ABLATION OR DEGENERATION E. Zappoli, A. Versari, M. Bartelli, P.F. Gengomi, M. Mascalchi and D. Poggiolini D e p a r t m e n t of Neurology and Psychiatry, University of Florence, Florence, Italy This report examines the possible role of the bidirectional cortico-cortical connections between temporo-parietal association cortical areas and the frontal ones in the genesis of CNV complexes, especially on the prefrontal regions. With a topographic bit-mapping color imaging method of analysis the multicomponent CNV complex formation was examined in: (1), 4 patients with very extensive right and one with left prefrontal cortex ablation for post-traumatic lesions: (2), One patient with right prefrontal lobectomy for diffuse frontopolar abcess: (3), O n e patient with Pick's disease and another with metachromatic encephalopathy and severe progressive essentially fronto-cortical degeneration. The CNV paradigm was: S1 (0.2 ms, 70 dH SL binaural clicks) - 2 s ISI - $2 (visual signals) - motor response (button press). CNV complex maps were recorded, together with ET and EOG, using 21, 19 or 15 electrodes and linked mastoid reference shunted via a 5 kohm resistor. On the scalp over the ablated or severely-damaged fronto-cortical areas, no consistent CNV complex was recordable. The hypothesis is put forward that an important role is played in the genesis of several CNV components by the bidirectional homohemispheric long and short distance pathways which connect association parieto-temporo-oceipital cortical areas to prefrontal ones, in particular the superior occipito-frontal and longitudinal fasciculi. Differences in latency of 8.5-12.8 ms were measured between the post-warning auditory temporo-parieto-central N100 a-b and the more frontal components (N100 b and c). This time-lapse, roughly measured along the scalp, is probably accounted for by the transcortical conduction time of about 0.5-1 m s / c m . A similar cortico-cortical conduction time through the corpus callosum was recorded on fronto-cortical areas by Cracco and co-workers (1990): about 1 m s / c m measured on the scalp. N u m e r o u s two-way homohemispheric cortico-cortical connections, which occur in part also in the V 1 / V layers of the cerebral cortex and running in this case along all its sulci and fissures, are very long, hence the real conduction velocity along these pathways could be much greater.
ASSOCIATIVE PREDISPOSITIONS AND FLEXIBILITY OF LEARNED BEHAVIOR K. Zielifiski Nencki Institute, Warsaw, Poland Stimuli having no signal value may change on-going animal behavior, either spontaneous or acquired. The character of influence depends on properties of the stimuli and on the experimental situation. Moreover, the effects are subjected to change by successive test trials. Early presentations of visual (house light offset) or auditory (noise) stimuli evoked an orienting response in the rat and attenuation of the rate of bar presses for food, whereas later presentations facilitated this behavior. Since the orienting response to noise habituated rapidly and that to darkness persisted longer, the stimuli differed in their attenuating and facilitatory effects. These unconditioned effects influenced subsequent training of conditioned e n h a n c e m e n t and conditioned suppression. The association of noise with continuous food reinforcement and of darkness with inescapable shock were acquired more readily and showed greater resistance to extinction than the opposite stimulus-reinforcement arrangements. Associative predispositions are especially evident during tests involving change of signalling value of stimuli. These and other data suggest that performance factors contribute substantially to the dichotomy between preparedness and flexibility of learned behavior.
E X A M I N A T I O N OF A D A P T A T I O N L E V E L T H E O R Y BY T H E H E L P OF P300 M E A S U R E M E N T Kazuhiko Yanai a and Yasuhiro Nageishi b a Department of H u m a n Sciences, Kao Institute for Knowledge and Intelligence Sciences, Osaka University, Osaka, Japan and b Department of Behavioral Physiology, Faculty of H u m a n Sciences, Osaka University, Osaka, Japan O n e of ten single digits (0 9) was presented on a video display in random order. Subjects (9 students) were instructed to press a corresponding button to the presentation of digits. The ten digits corresponded to the respective 10 buttons one by one in a 10-choice reaction time (10CRT) task. Two numbers corresponded to each of 5 buttons (digit 1 and 2 corresponded to button 1, etc.) in a 5 C R T task. Odd numbers corresponded to button 1 and even numbers to button 2 in a 2 C R T task. P300 amplitudes were smaller for the numbers near '5' in both 10CRT and 5 C R T tasks in which the digits were related to the number concept', but not in the 2 C R T task in which they were not related to that concept.
NEUROCOGNITIVE POTENTIALS, CORTICO-CORTICAL HOMOHEMISPHERIC TWO-WAY CONNECTIONS AND PREFRONTAL CORTEX ABLATION OR DEGENERATION E. Zappoli, A. Versari, M. Bartelli, P.F. Gengomi, M. Mascalchi and D. Poggiolini D e p a r t m e n t of Neurology and Psychiatry, University of Florence, Florence, Italy This report examines the possible role of the bidirectional cortico-cortical connections between temporo-parietal association cortical areas and the frontal ones in the genesis of CNV complexes, especially on the prefrontal regions. With a topographic bit-mapping color imaging method of analysis the multicomponent CNV complex formation was examined in: (1), 4 patients with very extensive right and one with left prefrontal cortex ablation for post-traumatic lesions: (2), One patient with right prefrontal lobectomy for diffuse frontopolar abcess: (3), O n e patient with Pick's disease and another with metachromatic encephalopathy and severe progressive essentially fronto-cortical degeneration. The CNV paradigm was: S1 (0.2 ms, 70 dH SL binaural clicks) - 2 s ISI - $2 (visual signals) - motor response (button press). CNV complex maps were recorded, together with ET and EOG, using 21, 19 or 15 electrodes and linked mastoid reference shunted via a 5 kohm resistor. On the scalp over the ablated or severely-damaged fronto-cortical areas, no consistent CNV complex was recordable. The hypothesis is put forward that an important role is played in the genesis of several CNV components by the bidirectional homohemispheric long and short distance pathways which connect association parieto-temporo-oceipital cortical areas to prefrontal ones, in particular the superior occipito-frontal and longitudinal fasciculi. Differences in latency of 8.5-12.8 ms were measured between the post-warning auditory temporo-parieto-central N100 a-b and the more frontal components (N100 b and c). This time-lapse, roughly measured along the scalp, is probably accounted for by the transcortical conduction time of about 0.5-1 m s / c m . A similar cortico-cortical conduction time through the corpus callosum was recorded on fronto-cortical areas by Cracco and co-workers (1990): about 1 m s / c m measured on the scalp. N u m e r o u s two-way homohemispheric cortico-cortical connections, which occur in part also in the V 1 / V layers of the cerebral cortex and running in this case along all its sulci and fissures, are very long, hence the real conduction velocity along these pathways could be much greater.
ASSOCIATIVE PREDISPOSITIONS AND FLEXIBILITY OF LEARNED BEHAVIOR K. Zielifiski Nencki Institute, Warsaw, Poland Stimuli having no signal value may change on-going animal behavior, either spontaneous or acquired. The character of influence depends on properties of the stimuli and on the experimental situation. Moreover, the effects are subjected to change by successive test trials. Early presentations of visual (house light offset) or auditory (noise) stimuli evoked an orienting response in the rat and attenuation of the rate of bar presses for food, whereas later presentations facilitated this behavior. Since the orienting response to noise habituated rapidly and that to darkness persisted longer, the stimuli differed in their attenuating and facilitatory effects. These unconditioned effects influenced subsequent training of conditioned e n h a n c e m e n t and conditioned suppression. The association of noise with continuous food reinforcement and of darkness with inescapable shock were acquired more readily and showed greater resistance to extinction than the opposite stimulus-reinforcement arrangements. Associative predispositions are especially evident during tests involving change of signalling value of stimuli. These and other data suggest that performance factors contribute substantially to the dichotomy between preparedness and flexibility of learned behavior.
E X A M I N A T I O N OF A D A P T A T I O N L E V E L T H E O R Y BY T H E H E L P OF P300 M E A S U R E M E N T Kazuhiko Yanai a and Yasuhiro Nageishi b a Department of H u m a n Sciences, Kao Institute for Knowledge and Intelligence Sciences, Osaka University, Osaka, Japan and b Department of Behavioral Physiology, Faculty of H u m a n Sciences, Osaka University, Osaka, Japan O n e of ten single digits (0 9) was presented on a video display in random order. Subjects (9 students) were instructed to press a corresponding button to the presentation of digits. The ten digits corresponded to the respective 10 buttons one by one in a 10-choice reaction time (10CRT) task. Two numbers corresponded to each of 5 buttons (digit 1 and 2 corresponded to button 1, etc.) in a 5 C R T task. Odd numbers corresponded to button 1 and even numbers to button 2 in a 2 C R T task. P300 amplitudes were smaller for the numbers near '5' in both 10CRT and 5 C R T tasks in which the digits were related to the number concept', but not in the 2 C R T task in which they were not related to that concept.