the audience. We have tried to reveal the dynamics of physiologicaland psychophysiological indicators, typical for the speaker before anthe public. A dominant functional state of the public speaker is astress reaction. Context of public speaking is a complex. It containsfactors: spoken speech, reproduction of information from memory,and the presence of people. So we identified two tasks for theresearch: Identify continuous psychophysiological changes in func-tional state of public speakers; and identify the significance of thevarious components of public speaking context on the functionalstate of the speaker. We used the following methods to assess thefunctional state of the organism. The computer laterometry is ameasurement of the functional hemispheric asymmetry (FHA). Themeasurement is based on the method of dichotic sound stimulation.We estimated level of the FHA by the values of the thresholdinteraural delays [Polevaya, 2013]. The computer campimetry is themeasurement of color discrimination thresholds; wireless cardi-ointervalography is the monitoring of the vegetative regulation, thelevel of resources for adaptation organism. The heart rate variabilityassessed by the frequency-domain indices (TP, LF, HF, LF/HF), usingdynamic spectral analysis. We performed the following experiments:1. Under conditions of natural activity: students were presentingtheir research reports on conferences (25 people aged 13 to25 years). 2. Under conditions of public speaking, simulated in thelaboratory: students were reading texts before the public, and thentell it from memory (16 students aged 17 to 19 years). The results ofour research showed that there is a change in the functional state ofstress in the context of public speaking: the total power of heart ratevariability decreases (mean value before the speech — 1787 ms2,mean value during the speech — 1275 ms2), the index of autonomicbalance increases (mean value before the speech — 3.2; mean valueduring the speech — 4.1); the brain hemispheric asymmetrydecreases (the asymmetry coefficient before the speech — 0.24; theasymmetry coefficient after the speech — 0.14). Decrease in theindex of autonomic balance is because the parameters of parasym-pathetic activation are reduced. This represents the overall reductionof regulatory mechanisms under stress. The results of the laboratoryexperiment did not reproduce the results of measurements, whichwere collected in the context of natural activity, where the factor ofsubjective importance of the event took place for the speakers.

doi:10.1016/j.ijpsycho.2014.08.901

Cardiorespiratory plasticity in children during short periodsof paced breathing

Andrey V. Gorbunova, Maria S. Ogorodnikovab, Vera S. Trubachevab,Vladimir V. Trubachevc, Victor V. SevastyanovcaYoshkar-Ola Ambulance Station, RussiabMari State University, Yoshkar-Ola, RussiacVolga State University of Technology, Yoshkar-Ola, Russia

In order to estimate the effects of slow rhythmic (paced) breathingon cognitive activity observations were made on healthy children aged8–10 years old, boys and girls (N= 63), who haven't experienced anyepisodes of spasmodic (paroxysmal) activity before. An informedconsent was taken from parents, teachers and children in order toparticipate in the study. Observationswere conducted right after classesin a playground environment. The psychologist, the doctor and thephysiologist watched after a child. In a preliminary study 8 childrenwere exposed to short trials, about 1 min long, which showed hightolerance to slow breathing, so after that 90 second periods were used.The duration of the whole breathing session was 17–18min: 3 min forrecording background activity and four 90-second segments forbreathing rates of 12, 8, 7, 6 and 5 times/min (only 8 children);

intertrial interval was 1 min. There was no encounter of any incident offeeling bad, willing to skip the session or refusal among subjects.Children were suggested the following task: “Adults often say whenthey want you to calm down “breathe slowly”. Let's find out if it's true,try to breathe slower”. At the beginning and at the end of session ashort video game was presented to test attention span. Maincharacteristics of HRV and FFT were analyzed with the aid of ANOVA.Upper limits of RR spectra (maximum), accordingly to breathing rate,showed quasilinear growth of responses, peaking at 6 times/mincompared to 12 times/min; index of SDNN was also linearly growingand peaking at 6 times/min (increased 5 times). In figures of RMSSDand NN50 the biggest variance was noted during the first episode ofbreathing 12 times/min. Children who breathed 5 times/min, had thehighest response on the same frequency. Thus, children have similar toadult dynamics of linearly growing spectral extremum and HRV withbreathing rate of 6 times/min. 12 breaths/min caused pronouncedmodulation of RR intervals in HF part of the spectrum (F= 18,p b 0.001). Significant modulation of LF spectrum was registered whilebreathing 8 times/min (F = 37, p b 0.001), going to the peak at 7 and6 breaths/min (F = 54, p b 0.001) and then lowering at 5 breaths/min(F = 17, p b 0.001). LF/HF ratio during 12 breaths/min was less than 1and was highest at 7 breaths/min, increasing 6 times compared tobackground recording, then decreasing slightly at 6 and 5 breaths/min.

doi:10.1016/j.ijpsycho.2014.08.902

Plasticity of cardiorespiratory coupling during visual control ofbreathing rate in athletes and non-athletes of the same age

Vladimir V. Trubacheva, Andrey V. Gorbunovb, Vera S. Trubachevac,Maria S. Nemtsevac, Alexey A. RozhentsovaaVolga State University of Technology, RussiabYoshkar-Ola Ambulance Station, RussiacMari State University, Russia

The aim of this work was to study the influence of paced breathingwith frequencies of 14, 10, 9, 8, 7, 6, 5, and 4 times per minute on heartrate variability (HRV) in HF and LF range of the spectrum of RR-intervalsof athletes (N= 25) and sedentary subjects (N= 15) of the same age(males and females, 21 ± 1.8 years old). Heart rate and breathing wereacquiredwithin 5 minute segments of regular breathing and in 3 minutesegments of paced breathing with intertrial interval of approximately1 min. The subjects were carefully controlling their breathing with theaid of a pacer on the screen (EZ-Air, Thought Technology). Data wasanalyzed with ANOVA. Both athletes and sedentary subjects showedmodulation of RR-intervals in HF band of the spectra when breathingwith 0.23 Hz frequency; when breathing with 0.17 Hz the influence ofbreathing was considerable (F = 13, p b 0.001). Representation ofbreathing at 0.15 Hz on the HF part of the spectrum was not significant,but visible in LF (F = 20, p b 0.001). Sedentary subjects showedinsignificant results at all breathing frequencies (0.23, 0.17, 0.15 Hz).Breathing at 8, 7, 6, 5, and 4 times/min considerablymodulated LF part ofthe spectrum in the athlete group: F8 = 28, F7 = 48, F6 = 51, F5 = 91,F4 = 59. Sedentary subjects also had pronounced slow modulations:F8 = 6, F7 = 7, F6 = 16, F5 = 11, F4 = 12. LF/HF ratio is noticeablyhigher in athletes, than in sedentary subjects (with pace of 8 breaths/min— 12.1 and 8.7; with 6 breaths/min— 9.6 and 5.6; with 4 breaths/min— 18.0 and 12.9). There is higher amount of conscious control of HRautonomic regulation in attentive athletes than in non-athletes.Revelation of RR-interval modulation pattern of HF and LF parts ofthe spectra during paced breathing might be a marker for volitionalcontrol of emotional state and stress coping.

doi:10.1016/j.ijpsycho.2014.08.903

International Journal of Psychophysiology 94 (2014) 120–261 231