Table 2: Contrasts in the spectral power of the EEG signal in selected bands at a priori defined scalp locations related to 6 hypotheses on jhana activity compared with rest, followed by its -test on the null hypothesis that jhana activity is equal to rest activity. All statistics are with degrees of freedom of (1,502). Contrasts labeled simply “jhana” refer to the pooled activity over all recorded jhanas 2–5. In the last (summary) column, all significant differences are in the direction predicted by the 6 hypotheses.

Subjective report during jhanasA priori ROI (scalp electrode locations)Predicted sign of contrast (jhana-rest)Contrast of power in gamma range
Contrast in power of (gamma + beta) − (alpha1 + theta)

(1) “External awareness dims” Visual: BA 17, 19
(O1)(−) Ns −.08
(O2) Ns−.11
Auditory: BA 41, 42
(T3)(−) Ns Ns
(T4) Ns −.10

(2) “Internal verbalization fades”Broca: BA 44, 45
(FC5)(−) Ns−.07
Wernicke: BA 39, 40
(Tp7)(−) Ns Ns

(3) “Altered sense of personal boundaries” Orientation: BA 5, 7
(P1)(−) Ns −.08
(P2) Ns −.12
(P3) Ns −.06
(P4) Ns −.11

(4) “Attention is highly focused” ACC: BA 32, 33
(AFz)(+)+.030 +.12
(Fz)+.014 +.07
(FCz)−.015 Ns

(5) “Ecstatic joy experienced” N Ac (+)(unobservable)(unobservable)
(Fp1)(+)+.104 +.42
(Fp2)+.092 +.35

(6) Less rhythmic movement Somatosens: BA 1, 2, 3
(C3)(−) Ns−.07
(C4) −.013 −.11
Prim motor: BA 4
(FC3)(−) Ns Ns
(FC4) Ns Ns
Cerebellum (−)(unobservable)(unobservable)

BA: Brodmann’s area, NAc: nucleus accumbens, Med OFC: medial orbitofrontal cortex, and ACC: Anterior cingulate cortex.