Perceptual and Motor Skills, 1976, 42, 767-770. @ Perceptual and Motor Skills 1976
CARDIAC CYCLE PHASE A N D MOVEMENT A N D REACTION TIMES MATTI J. SAARI1 AND BRUCE A. PAPPAS Curleton University Summary.-The EKG was recorded while Ss differentially responded to auditory or visual stimuli in a reaction time task. The EKG record was analyzed by dividing each R-R interval encompassing a stimulus presentation into 9 equal phases. Reaction times were determined as a function of the phase encompassing stimulus onset while movement times were determined for the phase in which the response was initiated. Only reaction time significantly varied with cardiac cycle, with reactions during the second phase being slower than later phases.
Lacey and Lacey (1970) have suggested that central nervous system arousal is modified by phasic cardiovascular activity through baroreceptor input to the brainstem areas. This hypothesis was derived from their observation that attending to external stimuli was accompanied by decelerative heart-rate changes while attending to self-generated stimuli was accompanied by heartrate acceleration. In support of the hypothesis, Oswald (1959) observed that afterimages of hallucinations increased in size, intensity, and apparent distance rhythmically with the pulse. Callaway and Layne (1964) reported that patients with transistorized pacemakers had faster reaction times in the latter half of the cardiac cycle than in the earlier half. Requin and his co-workers (Requin, 1965; Requin, Coquery, & Paillard, 1966) also found a relationship between response latencies and cardiac phase. Similarly, Birren, Cardon, and Phillips (1963) found that simple reaction times to auditory stimuli tend to be fastest to stimuli presented during the P wave of the EKG which occurs late in the cardiac cycle. However, not all studies have reported a relationship (Thompson & Botwinick, 1970; Botwinick & Thompson, 1971; Elliott & Graf, 1972; Bonstock & Jarvis, 1970). This study examined the hypothesis that different components of a response may be related to cardiac phase. The dependent variables consisted of the time to raise the responding finger off a button after stimulus onset (reaction time) and then the time to move to one of two other buttons (movement time). Our hypothesis, based on the suggestion that stimulus processing is related to cardiac events (Lacey & Lacey, 1970) and that the motor component of a reaction is programmed prior to the initiation of movement (Henry & Rogers, 1960; Christina, 1973; Norrie, 1974), was that reaction time but not movement time would be correlated with cardiac events. The relationship be'Reprint requests should be sent to Matti J. Saari, Psychology Department, Carleton University, Ottawa, Ontario, Canada K1S 5B6.
768
M. J. SAARI
& B. A. PAPPAS
tween stimulus mode and cardiac phase was also examined in order to determine whether such a correlation might be affected by sensory modality. The stimuli were a 60-Hz tone and a bright diffuse light presented in random order to each subject. The EKG recbrds were scored f o r 9 phases of the cardiac cycle and the median movement and reaction time for each phase was determined for each subject. It was predicted that reaction time would vary with the cardiac phase in a manner analogous to the aortic pressure pulse contour. That is, the higher the pressure, the slower the reaction time. One female and seven male undergraduate students at Carleton University, Ottawa, Ontario, Canada participated in the study. Ss ages ranged from 18 yr. to 21 yr., with 19 gr. being the mode. None had previously participated in reaction time experiments, all were volunteers and received no remuneration. The experiment consisted of three 45-min. sessions with each session separated from the previous one by at least five days and no more than seven days, five days being the modal intersession interval. During each session Ss were presented with 40 light and 40 tone stimuli which varied from 2 to 10 sec. in duration. The interstimulus intervals ranged from 5 to 40 sec. in duration, with the average interstimulus interval being 24.2 sec. The interstimulus intervals were randomly varied in order to reduce the predictability of stimulus onset. The order of the tone and light presentations was also randomized. Since no 'ready' signal was given and the interstimulus interval was randomly varied, the state of cardiovascular preparedness which usually follows a 'ready' signal (Lacey & Lacey, 1970) was avoided. This was done to avoid the possible masking effect of this preparatory response on the cardiac-phase-response-time relationship. The tones were produced by an oscillator circuir which provided a 60-Hz signal which was amplified and then presented through Model SH 650 D Best earphones at about 65 db. A photocell controlled tone onset prevented onset transients. The light stimulus was presented by a 40-w 120-v light bulb in a concave shade placed 15 un. in front of S who wore translucent goggles which diffused the light. Stimulus onset, duration and mode were controlled automatically by a tape reader. Ss were instructed to respond as quickly as possible to both the tones and the lights by pressing on one of the two buttons which were mounted at a 45" angle, 2.5 cm. from a third button on which Ss rested their responding finger between trials. Reaction time was measured as the latency to lift the finger off the third button and movement time was measured from the finger lift to the finger press of the appropriate button. During a particular session S had to respond to one of the two buttons for all the light stimuli and to the other button for all the tone stimuli. These requirements were varied randomly from session to session and from S to S. The buttons were all .8-cm. diameter push buttons which were mounted on a 15-un. by 20-cm. metal surface which was inclined at 20" from the table surface on which the response apparatus was placed. The button on which S's finger rested between responses was located 15 cm. from the base of the metal surface thereby providing a comfortable hand rest for Ss as well as placing the other two buttons within comfortable reach. EKG was recorded on a Beckrnan R411 Dynograph ac a chart speed of 1 0 mm per sec. using the ankles and the wrist of the nonpreferred hand with the non-opposite foot being ground. Stimulus onset, point of response initiation and the response were all marked by event recorders on the chart Timers were used to provide dam on both the movement and reaction time to each stimulus onset.
CARDIAC PHASE AND REACTION TIME
RESULTS The raw EKG charts were analyzed by hand by dividing each R-R EKG cycle into 9 equal parts. The EKG cycles which occurred during a stimulus onset for the reaction time and at the initiation of the response for the movement time were analyzed to determine the phase in which the event occurred. The units of analysis were the median movement and reaction time for each cardiac phase for each S over three sessions. The relations between movement and reaction times and cardiac cycle are shown in Fig. 1.
FIG. 1. Mean movement and reaction times as a function of the nine successive phases of the cardiac cycle
Cordioc Phose
An analysis of variance of two within-subject factors (cardiac phase and stimulus modality) was performed on each of the two dependent measures, movement and reaction time. The analyses of variance indicated no significant ( p < .05) interactions for either dependent variable. Although movement times tended to be slowest during the second cardiac phase, the cardiac-phase effect was significant only for the reaction time variable (FsIsa = 2.91, p < .05, MS,,,,, = 5.4). Comparisons of cardiac-phase reaction-time means by Tukey's hsd test (Kirk, 1968) indicated that reaction times were slower ( p < .05) during the second cardiac phase than during the fourth, sixth, and ninth phases. Stimulus modality was also significant only for reaction time (F1,? = 11.56, p < .05, MS,,,,, = 29.5). Average reaction times were 370 msec. f 6.7 msec. and 340 msec. + 6.9 msec. for the light and tone stimuli respectively. No significant relationship was found between movement time and stimulus 13.1 msec. to the light modality. Mean movement times were 270 msec. stimuli and 274 msec. f 12.2 msec. to the tone stimuli. The over-all mean
*
770
M. J. SAARI
& B. A. PAPPAS
reaction time was 355 msec. f 4.9 and the over-all mean movement time was 271 msec. + 8.9. These results confirm earlier findings of a relationship between cardiac phase and reaction time (Callaway & Layne, 1964; Requin, 1965; Phillips, 1963). The nature of this relationship, i.e., reaction times are slower during the second phase than during the fourth, sixth and ninth phases of the R-R cardiac cycle, agrees with the earlier experiments and is congruent with the notion that cyclic fluctuation in blood pressure as a function of the cardiac cycle leads to cyclic fluctuations in behaviour. That only the reaction time was related to the cardiac phase suggests that the cardiac cycle may be more closely correlated with afferent rather than efferent processing within the central nervous system. Similarly, stimulus modality affected only reaction times, which were significantly faster to the auditory stimuli, and not the cardiac-phase-reactiontime relationship. Thus, this relationship may reflect a brain process by which sensory afferents, regardless of modality, are modulated by cardiovascular events. REFERENCES BIRREN, J., WN, P., JR., & PHILLIPS, S. Reaction time as a function of the cardiac
cycle in young adults. Science, 1963, 140, 195-196. & JARVIS, M. Changes in the form of the cerebral evoked response related to the speed of simple reaction time. Electroencephalography and Neurophysiology, 1970, 29, 137-145. BOTWINICK, J., & THOMPSON, L. Cardlac functioning and reaction time in relation to age. Journal of Genetic Psychology. 1971, 119, 127-132. CALLAWAY, E., & LAYNE.R. Interaction between the visual evoked response and two spontaneous biological rhythms: the EEG alpha cycle and the cardiac arousal cycle. Annals of The New York Academy of Sciences, 1964, 112, 421-431. CHRISTINA, R. Influence of enforced motor and sensory sets o n reaction latency and movement soeed. Research Ouarterlr. 1973. 44. 483-487. ELLIOT,R. ~ i m ~ l e v i s u and a l simpG audit&; reaction &me: a comparison. Psychonomic Science, 1968, 10, 335-336. ELLIOT,R., & GRAP.V. Visual sensitivity as a function of phase of cardiac cycle. Psychophysiology, 1972, 9, 357-361. HENRY, F., & ROGERS,D. Increased response latency for complicated movements and a 'memory drum' theory of neuromotor reaction. Research Quarterly, 1960, 31, 448-457. KIRK,R. Experimental design: procedures for the behavioral sciences. Belmont, Calif.: Brooks/Cole, 1968. LACEY, J. I., & LACEY. B. C. Some autonomic-central nervous system interrelationships. In P. Black (Ed.), Physiological correlates o f emotion. New York: Academic Press, 1970. Pp. 205-227. NORRIE, M. Effects of movement complexity o n choice reaction and movement times. Research Q u d e r l y , 1974, 45, 154-161. OSWALD, I. A case of fluccuation of awareness with the pulse. Quarterly Journal of Experimental Psychology, 1959, 11, 45-58. REQUIN,J. RBle de la piriodicite cardiaque dans la latence d'une response motrice simple. Psychologie Prancaise, 1965, 10, 155-163. REQUIN,J., COQUERY,J., & PAILLARD, J. Origine et significauon des fluctuations de I'aaivite nerveuse likes ii griodicitk cardiaque. Cahiers de Psychologie, 1966, 7. 147-153. THOMPSON, L., & BOTWINICK, J. Stimulation in different phases of the cardiac cycle and reaction time. Psychophysiology, 1970, 7, 57-65. Accepted January 26, 1976.
BONSTOCK, H.,
CARDIAC CYCLE PHASE A N D MOVEMENT A N D REACTION TIMES MATTI J. SAARI1 AND BRUCE A. PAPPAS Curleton University Summary.-The EKG was recorded while Ss differentially responded to auditory or visual stimuli in a reaction time task. The EKG record was analyzed by dividing each R-R interval encompassing a stimulus presentation into 9 equal phases. Reaction times were determined as a function of the phase encompassing stimulus onset while movement times were determined for the phase in which the response was initiated. Only reaction time significantly varied with cardiac cycle, with reactions during the second phase being slower than later phases.
Lacey and Lacey (1970) have suggested that central nervous system arousal is modified by phasic cardiovascular activity through baroreceptor input to the brainstem areas. This hypothesis was derived from their observation that attending to external stimuli was accompanied by decelerative heart-rate changes while attending to self-generated stimuli was accompanied by heartrate acceleration. In support of the hypothesis, Oswald (1959) observed that afterimages of hallucinations increased in size, intensity, and apparent distance rhythmically with the pulse. Callaway and Layne (1964) reported that patients with transistorized pacemakers had faster reaction times in the latter half of the cardiac cycle than in the earlier half. Requin and his co-workers (Requin, 1965; Requin, Coquery, & Paillard, 1966) also found a relationship between response latencies and cardiac phase. Similarly, Birren, Cardon, and Phillips (1963) found that simple reaction times to auditory stimuli tend to be fastest to stimuli presented during the P wave of the EKG which occurs late in the cardiac cycle. However, not all studies have reported a relationship (Thompson & Botwinick, 1970; Botwinick & Thompson, 1971; Elliott & Graf, 1972; Bonstock & Jarvis, 1970). This study examined the hypothesis that different components of a response may be related to cardiac phase. The dependent variables consisted of the time to raise the responding finger off a button after stimulus onset (reaction time) and then the time to move to one of two other buttons (movement time). Our hypothesis, based on the suggestion that stimulus processing is related to cardiac events (Lacey & Lacey, 1970) and that the motor component of a reaction is programmed prior to the initiation of movement (Henry & Rogers, 1960; Christina, 1973; Norrie, 1974), was that reaction time but not movement time would be correlated with cardiac events. The relationship be'Reprint requests should be sent to Matti J. Saari, Psychology Department, Carleton University, Ottawa, Ontario, Canada K1S 5B6.
768
M. J. SAARI
& B. A. PAPPAS
tween stimulus mode and cardiac phase was also examined in order to determine whether such a correlation might be affected by sensory modality. The stimuli were a 60-Hz tone and a bright diffuse light presented in random order to each subject. The EKG recbrds were scored f o r 9 phases of the cardiac cycle and the median movement and reaction time for each phase was determined for each subject. It was predicted that reaction time would vary with the cardiac phase in a manner analogous to the aortic pressure pulse contour. That is, the higher the pressure, the slower the reaction time. One female and seven male undergraduate students at Carleton University, Ottawa, Ontario, Canada participated in the study. Ss ages ranged from 18 yr. to 21 yr., with 19 gr. being the mode. None had previously participated in reaction time experiments, all were volunteers and received no remuneration. The experiment consisted of three 45-min. sessions with each session separated from the previous one by at least five days and no more than seven days, five days being the modal intersession interval. During each session Ss were presented with 40 light and 40 tone stimuli which varied from 2 to 10 sec. in duration. The interstimulus intervals ranged from 5 to 40 sec. in duration, with the average interstimulus interval being 24.2 sec. The interstimulus intervals were randomly varied in order to reduce the predictability of stimulus onset. The order of the tone and light presentations was also randomized. Since no 'ready' signal was given and the interstimulus interval was randomly varied, the state of cardiovascular preparedness which usually follows a 'ready' signal (Lacey & Lacey, 1970) was avoided. This was done to avoid the possible masking effect of this preparatory response on the cardiac-phase-response-time relationship. The tones were produced by an oscillator circuir which provided a 60-Hz signal which was amplified and then presented through Model SH 650 D Best earphones at about 65 db. A photocell controlled tone onset prevented onset transients. The light stimulus was presented by a 40-w 120-v light bulb in a concave shade placed 15 un. in front of S who wore translucent goggles which diffused the light. Stimulus onset, duration and mode were controlled automatically by a tape reader. Ss were instructed to respond as quickly as possible to both the tones and the lights by pressing on one of the two buttons which were mounted at a 45" angle, 2.5 cm. from a third button on which Ss rested their responding finger between trials. Reaction time was measured as the latency to lift the finger off the third button and movement time was measured from the finger lift to the finger press of the appropriate button. During a particular session S had to respond to one of the two buttons for all the light stimuli and to the other button for all the tone stimuli. These requirements were varied randomly from session to session and from S to S. The buttons were all .8-cm. diameter push buttons which were mounted on a 15-un. by 20-cm. metal surface which was inclined at 20" from the table surface on which the response apparatus was placed. The button on which S's finger rested between responses was located 15 cm. from the base of the metal surface thereby providing a comfortable hand rest for Ss as well as placing the other two buttons within comfortable reach. EKG was recorded on a Beckrnan R411 Dynograph ac a chart speed of 1 0 mm per sec. using the ankles and the wrist of the nonpreferred hand with the non-opposite foot being ground. Stimulus onset, point of response initiation and the response were all marked by event recorders on the chart Timers were used to provide dam on both the movement and reaction time to each stimulus onset.
CARDIAC PHASE AND REACTION TIME
RESULTS The raw EKG charts were analyzed by hand by dividing each R-R EKG cycle into 9 equal parts. The EKG cycles which occurred during a stimulus onset for the reaction time and at the initiation of the response for the movement time were analyzed to determine the phase in which the event occurred. The units of analysis were the median movement and reaction time for each cardiac phase for each S over three sessions. The relations between movement and reaction times and cardiac cycle are shown in Fig. 1.
FIG. 1. Mean movement and reaction times as a function of the nine successive phases of the cardiac cycle
Cordioc Phose
An analysis of variance of two within-subject factors (cardiac phase and stimulus modality) was performed on each of the two dependent measures, movement and reaction time. The analyses of variance indicated no significant ( p < .05) interactions for either dependent variable. Although movement times tended to be slowest during the second cardiac phase, the cardiac-phase effect was significant only for the reaction time variable (FsIsa = 2.91, p < .05, MS,,,,, = 5.4). Comparisons of cardiac-phase reaction-time means by Tukey's hsd test (Kirk, 1968) indicated that reaction times were slower ( p < .05) during the second cardiac phase than during the fourth, sixth, and ninth phases. Stimulus modality was also significant only for reaction time (F1,? = 11.56, p < .05, MS,,,,, = 29.5). Average reaction times were 370 msec. f 6.7 msec. and 340 msec. + 6.9 msec. for the light and tone stimuli respectively. No significant relationship was found between movement time and stimulus 13.1 msec. to the light modality. Mean movement times were 270 msec. stimuli and 274 msec. f 12.2 msec. to the tone stimuli. The over-all mean
*
770
M. J. SAARI
& B. A. PAPPAS
reaction time was 355 msec. f 4.9 and the over-all mean movement time was 271 msec. + 8.9. These results confirm earlier findings of a relationship between cardiac phase and reaction time (Callaway & Layne, 1964; Requin, 1965; Phillips, 1963). The nature of this relationship, i.e., reaction times are slower during the second phase than during the fourth, sixth and ninth phases of the R-R cardiac cycle, agrees with the earlier experiments and is congruent with the notion that cyclic fluctuation in blood pressure as a function of the cardiac cycle leads to cyclic fluctuations in behaviour. That only the reaction time was related to the cardiac phase suggests that the cardiac cycle may be more closely correlated with afferent rather than efferent processing within the central nervous system. Similarly, stimulus modality affected only reaction times, which were significantly faster to the auditory stimuli, and not the cardiac-phase-reactiontime relationship. Thus, this relationship may reflect a brain process by which sensory afferents, regardless of modality, are modulated by cardiovascular events. REFERENCES BIRREN, J., WN, P., JR., & PHILLIPS, S. Reaction time as a function of the cardiac
cycle in young adults. Science, 1963, 140, 195-196. & JARVIS, M. Changes in the form of the cerebral evoked response related to the speed of simple reaction time. Electroencephalography and Neurophysiology, 1970, 29, 137-145. BOTWINICK, J., & THOMPSON, L. Cardlac functioning and reaction time in relation to age. Journal of Genetic Psychology. 1971, 119, 127-132. CALLAWAY, E., & LAYNE.R. Interaction between the visual evoked response and two spontaneous biological rhythms: the EEG alpha cycle and the cardiac arousal cycle. Annals of The New York Academy of Sciences, 1964, 112, 421-431. CHRISTINA, R. Influence of enforced motor and sensory sets o n reaction latency and movement soeed. Research Ouarterlr. 1973. 44. 483-487. ELLIOT,R. ~ i m ~ l e v i s u and a l simpG audit&; reaction &me: a comparison. Psychonomic Science, 1968, 10, 335-336. ELLIOT,R., & GRAP.V. Visual sensitivity as a function of phase of cardiac cycle. Psychophysiology, 1972, 9, 357-361. HENRY, F., & ROGERS,D. Increased response latency for complicated movements and a 'memory drum' theory of neuromotor reaction. Research Quarterly, 1960, 31, 448-457. KIRK,R. Experimental design: procedures for the behavioral sciences. Belmont, Calif.: Brooks/Cole, 1968. LACEY, J. I., & LACEY. B. C. Some autonomic-central nervous system interrelationships. In P. Black (Ed.), Physiological correlates o f emotion. New York: Academic Press, 1970. Pp. 205-227. NORRIE, M. Effects of movement complexity o n choice reaction and movement times. Research Q u d e r l y , 1974, 45, 154-161. OSWALD, I. A case of fluccuation of awareness with the pulse. Quarterly Journal of Experimental Psychology, 1959, 11, 45-58. REQUIN,J. RBle de la piriodicite cardiaque dans la latence d'une response motrice simple. Psychologie Prancaise, 1965, 10, 155-163. REQUIN,J., COQUERY,J., & PAILLARD, J. Origine et significauon des fluctuations de I'aaivite nerveuse likes ii griodicitk cardiaque. Cahiers de Psychologie, 1966, 7. 147-153. THOMPSON, L., & BOTWINICK, J. Stimulation in different phases of the cardiac cycle and reaction time. Psychophysiology, 1970, 7, 57-65. Accepted January 26, 1976.
BONSTOCK, H.,
