Effect of seated trunk posture on eye blink startle and subjective experience: Comparing flexion, neutral upright posture, and extension of spine

in PLoS ONE (2014), 9(2),

Postures are known to be able to affect emotion and motivation. Much less is known about whether (affective) modulation of eye blink startle occurs following specific postures. The objective of the ... [more ▼]

Postures are known to be able to affect emotion and motivation. Much less is known about whether (affective) modulation of eye blink startle occurs following specific postures. The objective of the current study was to explore this. Participants in the present study were requested to assume three different sitting postures: with the spine flexed (slouched), neutral upright, and extended. Each posture was assumed for four minutes, and was followed by the administration of brief self-report questionnaires before proceeding to the next posture. The same series of postures and measures were repeated prior to ending the experiment. Results indicate that, relative to the other postures, the extended sitting posture was associated with an increased startle, was more unpleasant, arousing, had smaller levels of dominance, induced more discomfort, and was perceived as more difficult. The upright and flexed sitting postures differed in the level of self-reported positive affect, but not in eye blink startle amplitudes. [less ▲]

Accuracy and awareness of perception: Related, yet distinct (commentary on Herbert et al., 2012)

in Biological Psychology (2013), 92(2), 423-427

Herbert and colleagues (2012) state that changes in autonomic activity following a specific type of interoceptive sensation, intensifies general interoceptive awareness. This conclusion is being ... [more ▼]

Herbert and colleagues (2012) state that changes in autonomic activity following a specific type of interoceptive sensation, intensifies general interoceptive awareness. This conclusion is being critically examined and reformulated. A distinction is made between Interoceptive Awareness (IAw) and Interoceptive Accuracy (IAc); awareness not necessarily implying accuracy. Given the heterogeneity of interoceptive sensations, we emphasize to abstain from concluding that heartbeat perception tasks can be considered as a measure of OVERALL IAw or OVERALL IAc until this has been more elaborately investigated. Results are reinterpreted to indicate that homeostatic challenges which lead to an increase in ionotropic cardiac activity, lead to an increased cardioceptive accuracy, and perhaps increased cardioceptive awareness. However, the findings do not provide conclusive evidence that such challenges increase other types of IAc, nor that they increase OVERALL IAw. Furthermore, it remains unclear whether homeostatic challenges leading to negative inotropic cardiac activity, would similarly lead to changes in accuracy of heartbeat perception. [less ▲]