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Respiration phase and the cardiac cycle effect
D. Papakostopoulos,
ed. / Psychophysiology
Society abstracts, 1981
273
going to be used for the response execution. 48 subjects participated in this study. Foreperiod duration being 4 set, the warning signal was the sound of a buzzer and the imperative signal was the lighting of a circular display of LEDs. Each subject was submitted to 4 different response conditions, consisting of 40 trials each; pressing a button with the forefinger of his preferred hand, making a plantar flexion with his preferred foot, giving a reaction by means of his voice, and blinking with one eye. All permutations of order of presentation of the response conditions were used such that to each permutation one male and one female subject were assigned. The R-R intervals were computer-analyzed in 18 bins of 500 msec each, the baseline being the average of the R-R intervals in the 6 bins before the warning signal. A response-locked and stimulus-locked analysis were performed, both with two different placements of the bins. The results indicate that the deceleration reaches approximately the same maximal value in the bin around the imperative signal under all response conditions. In all conditions the deceleration reaches its maximum in the bin preceding the response.
RESPIRATION Michael Department
PHASE AND THE CARDIAC CYCLE EFFECT
G.H. COLES of Psycholop,
University of Illinois, Champaign,
IL 61820, U.S.A.
The duration of a cardiac cycle (IBI) can be changed by a stimulus which occurs within that cycle. Furthermore, stimuli presented early in the cycle prolong the cycle more than those occurring later. We have recently shown that this cycle time effect depends on respiratory phase. To some extent these data support the proposition that the cycle time effect is vagally mediated, since it is attenuated during inspiration when the vagal influence on the heart is blocked. However, under some conditions, a strong cycle time effect was observed during inspiration, suggesting possible sympathetic influences. The present study evaluated respiration-cardiac cycle relationships further by classifying respiration into four rather than two phases (early and late inspiration, and early and late expiration). 625 trials of simple, warned reaction time task were given to four male subjects. Warning and respond stimuli were presented at five different delays (0, 150, 300, 450, and 600 msec) from the R wave. The foreperiod was three cardiac cycles. Each delay was given in five randomly ordered blocks of 25 trials each. Respiration phase was established post-hoc from polygraph records.
214
D. Papakostopoulos,
ed. / Psychophysrolom
Society abstracts, 1981
The late expiration phase was associated with a strong cycle time effect for both warning and respond stimuli. A similar effect was observed for early expiration for the respond stimulus only. The only effect for inspiration was a paradoxical increase in acceleration with delay for warning stimuli. These data, which identify respiratory effects more specifically than previously, are discussed in terms of their implications for cardiovascular psychophysiology.
THE EFFECTS OF SPATIAL FREQUENCY OF THE STIMULUS ON THE VEPS R.Y. ERMOLAEV Department
of Psycholoa,
AND ECCENTRICITY
and D. KLEINMAN Durham
Unroersit~v, Durham.
U.K.
The VEPs to tachistoscopically projected circular checkerboard patterns (500 msec exposure) were recorded in six healthy subjects from two sites on the scalp: central occipital 0, and right occipital 0, both referring to a mid-frontal electrode. The three spatial frequencies of the patterns employed in recordings corresponded to check sizes of visual angle 8’, 1’6’, or 32’. Circular patterns subtending 4.5”, 7”, or 8” were used for central retinal stimulation, and rings subtending angles between 4.5” and 8”, or between 7” and 8” were used for stimulation of paracentral areas of retina. All central patterns produced VEPs of typical triphasic structure with clearly distinguishable positive wave at 50-75 msec (PSO) followed by negative wave at about 100 msec (NlOO) and then by positive wave at 150-200 msec (P180). Paracentral stimuli of all spatial frequencies produced a second negative peak at about 130 msec (N130). We found that variation in check size clearly affected NlOO. For central stimuli, the negativity of the earlier part of NlOO increased with smaller check sizes and, in some subjects, reached the peak value at 75 msec. The component P50 which was more prominent over 0, rather than over O,, was also affected by changes in spatial frequency; lower frequencies tended to increase amplitude P50.
ed. / Psychophysiology
Society abstracts, 1981
273
going to be used for the response execution. 48 subjects participated in this study. Foreperiod duration being 4 set, the warning signal was the sound of a buzzer and the imperative signal was the lighting of a circular display of LEDs. Each subject was submitted to 4 different response conditions, consisting of 40 trials each; pressing a button with the forefinger of his preferred hand, making a plantar flexion with his preferred foot, giving a reaction by means of his voice, and blinking with one eye. All permutations of order of presentation of the response conditions were used such that to each permutation one male and one female subject were assigned. The R-R intervals were computer-analyzed in 18 bins of 500 msec each, the baseline being the average of the R-R intervals in the 6 bins before the warning signal. A response-locked and stimulus-locked analysis were performed, both with two different placements of the bins. The results indicate that the deceleration reaches approximately the same maximal value in the bin around the imperative signal under all response conditions. In all conditions the deceleration reaches its maximum in the bin preceding the response.
RESPIRATION Michael Department
PHASE AND THE CARDIAC CYCLE EFFECT
G.H. COLES of Psycholop,
University of Illinois, Champaign,
IL 61820, U.S.A.
The duration of a cardiac cycle (IBI) can be changed by a stimulus which occurs within that cycle. Furthermore, stimuli presented early in the cycle prolong the cycle more than those occurring later. We have recently shown that this cycle time effect depends on respiratory phase. To some extent these data support the proposition that the cycle time effect is vagally mediated, since it is attenuated during inspiration when the vagal influence on the heart is blocked. However, under some conditions, a strong cycle time effect was observed during inspiration, suggesting possible sympathetic influences. The present study evaluated respiration-cardiac cycle relationships further by classifying respiration into four rather than two phases (early and late inspiration, and early and late expiration). 625 trials of simple, warned reaction time task were given to four male subjects. Warning and respond stimuli were presented at five different delays (0, 150, 300, 450, and 600 msec) from the R wave. The foreperiod was three cardiac cycles. Each delay was given in five randomly ordered blocks of 25 trials each. Respiration phase was established post-hoc from polygraph records.
214
D. Papakostopoulos,
ed. / Psychophysrolom
Society abstracts, 1981
The late expiration phase was associated with a strong cycle time effect for both warning and respond stimuli. A similar effect was observed for early expiration for the respond stimulus only. The only effect for inspiration was a paradoxical increase in acceleration with delay for warning stimuli. These data, which identify respiratory effects more specifically than previously, are discussed in terms of their implications for cardiovascular psychophysiology.
THE EFFECTS OF SPATIAL FREQUENCY OF THE STIMULUS ON THE VEPS R.Y. ERMOLAEV Department
of Psycholoa,
AND ECCENTRICITY
and D. KLEINMAN Durham
Unroersit~v, Durham.
U.K.
The VEPs to tachistoscopically projected circular checkerboard patterns (500 msec exposure) were recorded in six healthy subjects from two sites on the scalp: central occipital 0, and right occipital 0, both referring to a mid-frontal electrode. The three spatial frequencies of the patterns employed in recordings corresponded to check sizes of visual angle 8’, 1’6’, or 32’. Circular patterns subtending 4.5”, 7”, or 8” were used for central retinal stimulation, and rings subtending angles between 4.5” and 8”, or between 7” and 8” were used for stimulation of paracentral areas of retina. All central patterns produced VEPs of typical triphasic structure with clearly distinguishable positive wave at 50-75 msec (PSO) followed by negative wave at about 100 msec (NlOO) and then by positive wave at 150-200 msec (P180). Paracentral stimuli of all spatial frequencies produced a second negative peak at about 130 msec (N130). We found that variation in check size clearly affected NlOO. For central stimuli, the negativity of the earlier part of NlOO increased with smaller check sizes and, in some subjects, reached the peak value at 75 msec. The component P50 which was more prominent over 0, rather than over O,, was also affected by changes in spatial frequency; lower frequencies tended to increase amplitude P50.