Table 2. Summary of the 24 experimental studies included in this systematic review

No.	Study	Participants	Stimulus	Measures	Indicators
1	Tsunetsugu et al. (2002)	10M	Two wooden rooms	BP, Pulse, SD, POMS	Standard: Pulse↓, DBP↓; Designed: Pulse↑; POMS ns
2	Tsunetsugu et al. (2007)	14M	Wood coverage (0%, 45%, 90%)	BP, Pulse, tHb, SD, POMS	45%: comfort↑, DBP↓ 90%: tHb↓, Pulse↑
3	Zhang et al. (2016)	20	Wood vs non-wood offices	POMS, Fatigue	Fatigue↓, TMD↓, comfort↑
4	Nakamura et al. (2019)	28	Wood wall images	oxy-Hb, HRV, POMS2, SD	oxy-Hb↓, naturalness↑, negative mood↓, HRV ns
5	Li et al. (2021)	28	Images 0%–100% wood	Eye-tracking, VAS	40%–60% best
6	Kim et al. (2023)	26	VR café wood levels	ST, SCL, EEG, TSV/VSV	Warmth↑, ST↑, SCL↑, EEG-θ↑
7	Kim et al. (2024)	30	VR café wood × PMV	SCL, HRV, TSV/VSV	Warmth↑, coziness↑; SCL/HRV vary
8	Lee et al. (2025)	26	Real homes wood 0%–90%	HRV, RH	HRV↑ only at 45%; RH fluctuation↓
9	Matsubara and Kawai (2014)	16	Cedar VOC	HRV, Cortisol, VAS	HF↑; cortisol↓ in women; pleasantness↑
10	Azuma et al. (2016)	10	Low cedar odor	HRV, Cortisol, POMS	No significant changes
11	Matsubara and Kawai (2018)	27	Cedar VOC	SAA, Cortisol	SAA↓ (F > M); cortisol suppression in F
12	Skulberg et al. (2019)	30	Pine vs spruce VOC	Symptoms, SCL	No adverse effect
13	Sun et al. (2020)	83	Cedar vs printed sheet	BP, SAA, SCL	BP↓, SAA↓
14	Nakashima (2023)	18	Cedar vs resin hut	ERP	ERP amplitude↑
15	Kishida et al. (2025)	8	Hinoki VOC	EEG, POMS2, ECG	Parasympathetic↑, anger/confusion↓
16	Sakuragawa et al. (2008)	14	Wood vs aluminum	BP, SD	Aluminum BP↑; wood stable, comfort↑
17	Ikei et al. (2018)	26	Hinoki vs marble	oxy-Hb, HRV	Hinoki oxy-Hb↓, HF↑
18	Fell (2010)	119	Wood vs non-wood offices	SCL, SCR	SCL↓, SCR↓, stress↓
19	Burnard and Kutnar (2020)	61	Oak/walnut/control furniture	Cortisol, HR, WHO-5	Cortisol↓ only with oak; walnut ns
20	Ojala et al. (2023)	34	Wood vs control room	HRV, SCL, anxiety	Anxiety↓; HRV/SCL ns
21	Kumpulainen et al. (2024)	43	Wood vs reference room	HRV, BR, mood	LF↑, BR↓, mood↑; HF ns
22	Kutvonen (2024)	42	VR wood + pine odor	HR, stress	Stress↓, HR↓
23	Okamoto et al. (2023)	13	Cedar bedroom	Sleep depth	Sleep depth↑ (12/13)
24	Shima et al. (2025)	30	Walnut visual × Hinoki odor	EEG, POMS2	Anger/confusion↓

↑: increase, ↓: decrease, ns: non-significant.
BP: blood purse, DBP: diastolic blood press, SD: semantic differential, POMS: profile of mood states, tHb: total hemoglobin, TMD: total mood disturbance, oxy-Hb: oxygenated hemoglobin, HRV: heart rate variability, HF: high-frequency component of HRV (parasympathetic activity); VAS: visual analogue scale, ST: skin temperature, SCL: skin conductance level, EEG: electroencephalography, TSV: thermal sensation vote, VSV: visual sensation vote, EEG-θ: theta band activity of EEG, PMV: predicted mean vote, VOC: volatile organic compound, SAA: salivary α-amylase, M: men, F: female, ERP: event-related potential.