Pavlov (1935) suggested that those likely to develop neuroses might show ‘overloading inhibition’ when exposed to long lasting or high intensity stimuli. The experiments reported here, done in 2003 and 2004, investigated the hypothesis that absolute sensory threshold was related to how the nervous system processes stimuli of different intensities and to patterns of cutaneous autonomic regulation. With ethical committee permission and informed consent, healthy volunteers of both sexes (18-22 years) were studied. STATISTICA 5.5 was used. General sensitivity of the nervous system (‘force gradient’ (FG); Nesbylitsin, 1969) was assessed by latent period (LP) between the visual stimulus (white square of variable size) and button press. Stimulus size varied randomly (RM) or sequentially (HS); FG was estimated by least squares. Visual threshold following dark adaptation was measured (adaptometer) every 15 s after 1 min pre-adaptation to medium (250 cd m^-2; n=102) or high (1200 cd m^-2; n=96) intensity light. Cutaneous sensitivity was assessed by alternating current (0.1-50 mA; 30 Hz to 30 kHz) on skin of the left forearm, threshold and nature (nociceptive, tactile, anaesthetic) of sensations being reported. Electrodermal properties (static electrical potentials (STEP)), investigated in biologically active zones (BAZ; Podshibiakin, 1960) of facial skin were used to evaluate patterns of autonomic regulation. Potentials were recorded between different BAZ pairs via non-polarisable AgCl electrodes using a millivoltometer with high-input impedance. LP was strongly dependent on the magnitude of stimuli but this differed significantly between RM and HS. With RM only, some subjects had increased LP with the largest stimulus, interpreted as indicating overloading inhibition. Information obtained by factor analysis was taken to indicate different visual sensitivities: early indexes reflecting cone receptors, late indexes reflecting rod properties. Skin threshold was related to the frequency of stimulating current. The higher the frequency, the higher the threshold (Table 1). The type of sensation showed some frequency specificity, but with overlap. At lower frequencies threshold feelings were nociceptive; at higher frequencies they were tactile or anaesthetising. Nociceptive thresholds were usually lower than tactile at the same frequency. Women had higher thresholds at high frequencies (Table 1); men had a more distinct separation of sensations, the border being at a higher frequency (1-3 kHz; n=35) than in women (0.3-1 kHz; n=50), as revealed by factor analysis. STEP was most negative in nasal and most positive in zygomatic BAZ. LP tests with rm were more informative than with HS. Several relationships existed between parameters, but were weak and differed in 2003 and 2004. A linear relation of sensitivity to LP curve slope was supported only for cone sensitivity with medium light pre-adaptation (250 cd m^-2; n=101; 2003) but not with high light pre-adaptation (1200 cd m^-2; n=96; 2004). In other cases we found inverse results, the higher the sensitivity, the steeper the LP curve and the lower the rate of overloading inhibition with large stimuli. Nociceptive threshold (30 Hz) was unrelated to the slope, but was related to STEP in some zones. Conversely, tactile threshold (3 kHz) was unrelated to STEP, but was related to LP curve parameters. STEP was related, in different zones, to slope, levels of visual sensitivity or nociceptive thresholds. We are unclear why some results differed in 2003 and 2004.