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Psychophysiology in the workplace — Goals and methods
115 prised of two subunits (semantic radical and phonetic remainder). In the first two tasks, a match was defined as identical p h o n e m e sequences ignoring vowel-tone. In task 1, the two characters always shared a subunit (the phonetic remainder). In task 2, the two characters of the pair were completely different. In task 3, a match was defined as identical voweltone, ignoring the p h o n e m e sequence. Enhanced negative components (latency near 400 ms) were observed in ERPs elicited by the second character in non-matching pairs in the three tasks. These components could be similar to N450 described in readers of English. If so, N450 can not be associated with the processing of sublexical phonology, which is absent when reading chinese characters, or with orthographic repetition priming absent in task 2.
S E N S O R I - M O T O R ACTIVITY R E L A T E D TO C A R D I A C PHASE AND HEART RATE Z. Bohdaneck,j, M. Indra and T. Radii Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic Different types of eye-hand tracking and tracing tasks were examined in relation to cardiac activity. During a one-dimensional tracking task, the decrease of error incidence was highly significant 320-380 ms after R-wave, while no such phase-dependence was found in feedback (size of the target or its movement velocity) guided tasks. The tracing of 3 basic geometrical patterns (square, triangle and circle) yielded significant differences in performance with the circle being the most difficult and the square the easiest. Heart rate (HR), however, was lowest for circle and highest for square pattern. H R values decreased when exercising the task. Besides that significantly higher incidence of stimulus segment tracing termination was found within the first half of the cardiac cycle during the second day of tracing only, while this dependence disappeared completely during the fifth day, when the subjects mastered the given tasks. In the auditory-motor task (following rhythmic tones by finger tapping) H R deceleration coincided with movement. The results point to complex ~psychosomatic' relationship between sensory-motor and cardiac activity under physiological conditions.
P S Y C H O P H Y S I O L O G Y IN T H E W O R K P L A C E - G O A L S AND METHODS Wolfram Boucsein Physiological Psychology, University of Wuppertal, Wuppertal, G e r m a n y In recent years, stress induced by mental challenges during work has received considerable attention in psychology and work medicine. Therefore, knowledge about the processes underlying mental activity during work and their impact on psychophysiological systems (including physiological, behaw
ioral and subjective levels) is required for the organization of work settings, as well as for the diagnosis and the prevention of work-related diseases. With computers becoming faster, temporal delays caused by hardware features markedly decreased. However, even today involuntary delays are not unusual in systems where each user has access to big data banks, thus temporarily blocking others. Indeed, temporal delays while working with display units figured out to be most important psychological stress factors at computer workplaces. To systematically test these stress effects, six studies (field and laboratory) were performed with a total of 260 subjects, varying and recording temporal delays at display units in psychophysiological settings. The results are interpreted with respect to a neurophysiological model (a threearousal model using general arousal, emotional arousal and mental arousal) underlying elicitation of the different physiological concomitants of stress at workplaces.
R E S C A L I N G T H E P E A K F O R C E OF I S O M E T R I C RESPONSES Jasper Brener, Suzanne Mitchell and Andrew Slifkin State University of New York, Stony Brook, NY, U S A The Peak Force (PF) of isometric beam presses is determined by two kinematic parameters: the rate of increase in force (dF/dt) and the period over which force is increased (tpf). In experiments with rats, we found that experimentallyimposed increases in the PF criterion for food rewards were precisely tracked by the PF of beam-presses. Kinematic analyses suggested that decreases in reward which result from applying a more stringent PF criterion elicited lengthening of tpf. However, differential reinforcement of higher PFs resulted in learning which was expressed by the upward respecification of the dF/dt parameter of the motor program. These hypotheses were investigated by examining the effects of variations in the PF criterion for reward and the probability of reward on response kinematics. The results suggest that the rescaling of PF is governed by a combination of elicited amplification effects and an automatic tendency to simplify motor responses. Decreases in reward produced by imposing more stringent PF reward criteria elicit increases in PF by lengthening the period of motoneuron recruitment (tpi). If this PF amplification results in an increase in reward, the PF parameter of the motor program is respecified at a higher level. A process of response simplification then follows and results in tpf being restored to its initial value but the pool of motoneurons implicated in generating beam presses being enlarged (an enduring increase in dF/dt).
PHASIC E L E C T R O D E R M A L ACTIVITY A N D C O R T I CAL I N I T I A T I O N M.L. Bringas Vega, M. Rodriguez-Mena and Trinidad Virues Neuroscience Center, Havana, Cuba
S E N S O R I - M O T O R ACTIVITY R E L A T E D TO C A R D I A C PHASE AND HEART RATE Z. Bohdaneck,j, M. Indra and T. Radii Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic Different types of eye-hand tracking and tracing tasks were examined in relation to cardiac activity. During a one-dimensional tracking task, the decrease of error incidence was highly significant 320-380 ms after R-wave, while no such phase-dependence was found in feedback (size of the target or its movement velocity) guided tasks. The tracing of 3 basic geometrical patterns (square, triangle and circle) yielded significant differences in performance with the circle being the most difficult and the square the easiest. Heart rate (HR), however, was lowest for circle and highest for square pattern. H R values decreased when exercising the task. Besides that significantly higher incidence of stimulus segment tracing termination was found within the first half of the cardiac cycle during the second day of tracing only, while this dependence disappeared completely during the fifth day, when the subjects mastered the given tasks. In the auditory-motor task (following rhythmic tones by finger tapping) H R deceleration coincided with movement. The results point to complex ~psychosomatic' relationship between sensory-motor and cardiac activity under physiological conditions.
P S Y C H O P H Y S I O L O G Y IN T H E W O R K P L A C E - G O A L S AND METHODS Wolfram Boucsein Physiological Psychology, University of Wuppertal, Wuppertal, G e r m a n y In recent years, stress induced by mental challenges during work has received considerable attention in psychology and work medicine. Therefore, knowledge about the processes underlying mental activity during work and their impact on psychophysiological systems (including physiological, behaw
ioral and subjective levels) is required for the organization of work settings, as well as for the diagnosis and the prevention of work-related diseases. With computers becoming faster, temporal delays caused by hardware features markedly decreased. However, even today involuntary delays are not unusual in systems where each user has access to big data banks, thus temporarily blocking others. Indeed, temporal delays while working with display units figured out to be most important psychological stress factors at computer workplaces. To systematically test these stress effects, six studies (field and laboratory) were performed with a total of 260 subjects, varying and recording temporal delays at display units in psychophysiological settings. The results are interpreted with respect to a neurophysiological model (a threearousal model using general arousal, emotional arousal and mental arousal) underlying elicitation of the different physiological concomitants of stress at workplaces.
R E S C A L I N G T H E P E A K F O R C E OF I S O M E T R I C RESPONSES Jasper Brener, Suzanne Mitchell and Andrew Slifkin State University of New York, Stony Brook, NY, U S A The Peak Force (PF) of isometric beam presses is determined by two kinematic parameters: the rate of increase in force (dF/dt) and the period over which force is increased (tpf). In experiments with rats, we found that experimentallyimposed increases in the PF criterion for food rewards were precisely tracked by the PF of beam-presses. Kinematic analyses suggested that decreases in reward which result from applying a more stringent PF criterion elicited lengthening of tpf. However, differential reinforcement of higher PFs resulted in learning which was expressed by the upward respecification of the dF/dt parameter of the motor program. These hypotheses were investigated by examining the effects of variations in the PF criterion for reward and the probability of reward on response kinematics. The results suggest that the rescaling of PF is governed by a combination of elicited amplification effects and an automatic tendency to simplify motor responses. Decreases in reward produced by imposing more stringent PF reward criteria elicit increases in PF by lengthening the period of motoneuron recruitment (tpi). If this PF amplification results in an increase in reward, the PF parameter of the motor program is respecified at a higher level. A process of response simplification then follows and results in tpf being restored to its initial value but the pool of motoneurons implicated in generating beam presses being enlarged (an enduring increase in dF/dt).
PHASIC E L E C T R O D E R M A L ACTIVITY A N D C O R T I CAL I N I T I A T I O N M.L. Bringas Vega, M. Rodriguez-Mena and Trinidad Virues Neuroscience Center, Havana, Cuba