Respiratory Changes in Response to Cognitive Load: A Systematic Review

Table 1

Characteristics of selected studies ().

	Number of studies	% of studies
Sample
Average size (range)	32 (7–132)
Males	21 (3–64)
Females	20 (1–68)
Characteristics
Male only	14	25.93
Female only	3	5.56
Mixed gender	37	68.52
Mean age in yrs (range)	27.08 (18–80)
Manipulation (type of cognitive task)
Mental arithmetic	17	25.93
Stroop interference	5	9.26
Memory	6	11.11
Reasoning	6	11.11
Psychomotor	5	9.26
Multitasking	14	25.93
Choice reaction time	2	3.70
Attention	9	16.67
Vigilance	2	3.70
Respiratory measures
Respiratory rate (RR)	54	100.00
Tidal volume (TV)	24	44.44
Minute ventilation (MV)	9	16.67
Inspiratory time ()	1	1.85
Expiratory time ()	0	0.00
Inspiratory/expiratory ratio (/)	1	1.85
Mean inspiratory flow rate (TV/)	1	1.85
Inspiratory duty cycle (/)	3	5.56
Expiratory volume ()	1	1.85
Contribution of ribcage breathing to (% RCi)	2	3.70
Sigh rate (SR)	2	3.70
Respiratory variability
Variance of RR (Var (RR))	1	1.85
Coefficient of variation of RR (CV (RR))	3	5.56
Autocorrelation of RR (AR (RR))	3	5.56
Coefficient of variation of TV (CV (TV))	2	3.70
Autocorrelation of TV (AR (TV))	2	3.70
Coefficient of variation of MV (CV (MV))	2	3.70
Autocorrelation of MV (AR (MV))	2	3.70
Partial pressure of end-tidal CO2 (petCO2)	4	7.41
O2 consumption (VO2)	4	7.41
CO2 production (VCO2)	4	7.41
Respiratory exchange ratio (RER)	2	3.70
Apparatus
Spirometry	7	12.96
Respiratory inductive plethysmography	15	27.78
Strain gauge	19	35.19
Impedance plethysmography	4	7.41
Impedance cardiography	3	5.56
Capnography	6	11.11
Metabolic analyzer	2	3.70