Palmar sweating: a quick and simple measure

When Density Affects Task Performance

The effect of density on task performance was examined under three different conditions which varied whether subjects' performance was measured early or late in the crowding experiment. An effect of density on task performance was obtained only when performance was assessed immediately. This result may explain the failure of many studies to find density effects on task performance.

Biosignal analysis to assess mental stress in automatic driving of trucks: palmar perspiration and masseter electromyography

Nowadays insight into human-machine interaction is a critical topic with the large-scale development of intelligent vehicles. Biosignal analysis can provide a deeper understanding of driver behaviors that may indicate rationally practical use of the automatic technology. Therefore, this study concentrates on biosignal analysis to quantitatively evaluate mental stress of drivers during automatic driving of trucks, with vehicles set at a closed gap distance apart to reduce air resistance to save energy consumption. By application of two wearable sensor systems, a continuous measurement was realized for palmar perspiration and masseter electromyography, and a biosignal processing method was proposed to assess mental stress levels. In a driving simulator experiment, ten participants completed automatic driving with 4, 8, and 12 m gap distances from the preceding vehicle, and manual driving with about 25 m gap distance as a reference. It was found that mental stress significantly increased when the gap distances decreased, and an abrupt increase in mental stress of drivers was also observed accompanying a sudden change of the gap distance during automatic driving, which corresponded to significantly higher ride discomfort according to subjective reports.

Differential response to pain by very premature neonates

The ability of very low birth weight (VLBW) premature infants to respond differentially to real versus a sham heelstick conditions was examined in this crossover study. Using a multidimensional assessment of responses of premature infants (n = 48) between 26 and 31 weeks gestational age (GA) at the time of the study, it was found that they respond differentially to real versus sham heelstick both behaviourally and physiologically. The multivariate effect of condition (real/sham) was significant with maximum heart rate and upper facial action (lower facial action was not scored) contributing significantly to the main effect. GA had a main multivariate effect, with the younger infants responding less robustly. The variability outcome measures of heart rate standard deviation and range of transfontanelle intracranial pressure contributed significantly to the main effect of GA, but not to the effect of condition. Young VLBW premature infants are capable of a multidimensional differential response to pain. GA is an important factor to consider when assessing pain in premature infants.

Changes in the number of active sweat glands (palmar sweat index, PSI) during a distressing film

Changes of the number of active palmar sweat glands (palmar sweat index, PSI) as assessed by the plastic finger-print method were studied in two groups of female students (n = 21 each). In both samples experiments involved an initial adaptation period, several relaxation phases and an activation period (presentation of a movie). The film was shown 10 min earlier in Group 1, for which in turn follow-up was twice as long. Prints for determination of PSI were taken every 2.5 min from the forefinger and ring finger of the left hand, and recordings of SCL, SF (number of spontaneous fluctuations) and HR were made during the corresponding intervals. Both within- and between-groups comparisons showed an increase of PSI during the activation period and a decrease afterwards. Similar effects were observed for SCL, SF and affective and somatic arousal assessed by a state questionnaire. A decrease of PSI and parameters of electrodermal activity during the first measurements indicated an initial reaction to the assessment procedure itself. Both within-subject and between-subjects correlations between PSI from both fingers showed high parallel test reliabilities, while correlations with electrodermal variables indicated a common physiological basis.

Changes in the palmar sweat index during mental arithmetic

This study investigated the influence of activation on the number of active sweat glands (palmar sweat index, PSI), as assessed by the plastic impression method. Subjects were 50 male students, assigned to two groups. The experiment involved 5 phases: an initial adaptation for 6 min in both groups (Phase I), 3 relaxation periods for 10 min (Phases II, IV and V in Group 1, Phases II, III and V in Group 2), and 10 min of mental arithmetic (Phase III in Group 1, Phase IV in Group 2). Prints were taken every 2.5 min from the left middle and forefinger, and skin conductance level (SCL), number of spontaneous fluctuations (SF) and heart rate (HR) were recorded for the corresponding intervals. PSI rose significantly during activation conditions and decreased afterwards. Accordingly, during Phase III values were higher in Group 1, whereas during Phase IV they were higher in Group 2. Decrease of PSI during the first measurements indicated that subjects probably react to the assessment procedure itself and that interpretable baseline values can only be obtained after several initial assessments. Correlations between PSI and electrodermal variables proved to be high within subjects, whereas correlations across subjects were lower.

Physiological and subjective stress responses in surgical patients

Autonomic responses, mood and psychological coping were assessed in two groups of orthopaedic patients during hospitalisation for major or minor surgery. Eight patients admitted for total hip replacement and seven patients undergoing knee arthroscopy were seen daily for two days before surgery until discharged from hospital. Mood and coping questionnaires were administered on each session, while pain, heart rate, blood pressure, skin conductance level, palmar sweat prints and forearm EMG were also recorded. Heart rate increased from pre- to post-operative assessments, while skin conductance and palmar sweating fell to low levels on the days immediately following surgery, returning to basal values only after several days. Self ratings of anxiety, fatigue, depression and pain were highest on the immediate post-operative days. Patients utilised the coping factors Rational Cognition and Behavioural Action to the greatest extent, but ratings on coping factors fluctuated little over the study period. The interrelations between these measures and possible explanations of the results are discussed.

Research note: young children's resolution of distress through play

It has been suggested that play is important to the young child as a means of resolving a distressing experience. Pre-school children were observed as they exhibited distress on the first day of school. High- and low-anxiety children were allowed either the opportunity for free play or participation in a story-reading session, each of which was performed in either the presence or absence of peers. The anxious children in the play condition were found to decrease in distress and their play was more solitary and imaginative in nature compared to other conditions.