Assessment of animal internal “state” – which includes hormonal, disease, nutritional, and emotional states – is normally considered the province of laboratory work, since its determination in animals in the wild is considered more difficult. However, we show that accelerometers attached externally to animals as diverse as elephants, cockroaches, and humans display consistent signal differences in micro‐movement that are indicative of internal state. Originally used to elucidate the behavior of wild animals, accelerometers also have great potential for highlighting animal actions, which are considered as responses stemming from the interplay between internal state and external environment. Advances in accelerometry may help wildlife managers understand how internal state is linked to behavior and movement, and thus clarify issues ranging from how animals cope with the presence of newly constructed roads to how diseased animals might change movement patterns and therefore modulate disease spread.

BackgroundWe are increasingly using recording devices with multiple sensors operating at high frequencies to produce large volumes of data which are problematic to interpret. A particularly challenging example comes from studies on animals and humans where researchers use animal-attached accelerometers on moving subjects to attempt to quantify behaviour, energy expenditure and condition.ResultsThe approach taken effectively concatinated three complex lines of acceleration into one visualization that highlighted patterns that were otherwise not obvious. The summation of data points within sphere facets and presentation into histograms on the sphere surface effectively dealt with data occlusion. Further frequency binning of data within facets and representation of these bins as discs on spines radiating from the sphere allowed patterns in dynamic body accelerations (DBA) associated with different postures to become obvious.MethodWe examine the extent to which novel, gravity-based spherical plots can produce revealing visualizations to incorporate the complexity of such multidimensional acceleration data using a suite of different acceleration-derived metrics with a view to highlighting patterns that are not obvious using current approaches. The basis for the visualisation involved three-dimensional plots of the smoothed acceleration values, which then occupied points on the surface of a sphere. This sphere was divided into facets and point density within each facet expressed as a histogram. Within each facet-dependent histogram, data were also grouped into frequency bins of any desirable parameters, most particularly dynamic body acceleration (DBA), which were then presented as discs on a central spine radiating from the facet. Greater radial distances from the sphere surface indicated greater DBA values while greater disc diameter indicated larger numbers of data points with that particular value.ConclusionsWe indicate how this approach links behaviour and proxies for energetics and can inform our identification and understanding of movement-related processes, highlighting subtle differences in movement and its associated energetics. This approach has ramifications that should expand to areas as disparate as disease identification, lifestyle, sports practice and wild animal ecology.UCT Science Faculty Animal Ethics 2014/V10/PR (valid until 2017).Electronic supplementary materialThe online version of this article (doi:10.1186/s40462-016-0088-3) contains supplementary material, which is available to authorized users.

Two prime issues can detrimentally affect animals that have been equipped with tags; (i) the effect of the capture and restraint process and (ii) the effect of the tag itself. This work examines some of the issues surrounding quantification of tag effects on wild animals for both restrained and free-living animals. A new method to quantify stress effects based on monitoring ventilation rates in relation to activity is suggested for restrained animals which may help improve the practice of handling animals. It is also suggested that various metrics, many derived from accelerometers, can be examined in tagged wild animals to examine the change in behaviours over time with a view to having a better understanding of welfare issues, assuring the quality of recorded data and informing best practice. This article is protected by copyright. All rights reserved.

The recreational use of various stimulant drugs has been implicated in the development of movement disorders through dysregulation of the dopaminergic and serotoninergic neurotransmitter systems. The present study investigated psychomotor differences in current and former recreational stimulant drug users compared with nonusing controls. Sixty participants comprised 3 groups: 20 current stimulant drug users (CSUs; 11 men, aged 31.4 ± 9.1 years), 20 former stimulant drug users (FSUs; 5 men, aged 39.1 ± 8.5 years), and 20 nonuser controls (NUCs; 5 men, aged 35.7 ± 6.4 years). Psychomotor arm steadiness for each participant was assessed with a wrist-attached accelerometer during 5 arm positions with eyes open and then eyes closed. Arm-drop of arm position was indicated by the arm longitudinal rotation axis (ALoRA), and tremor was indicated by the overall vector of dynamic body acceleration (VeDBA). Overall, CSUs performed the most poorly on ALoRA (P < .05) and VeDBA indices (P < .05), and FSUs perform almost as poorly on VeDBA indices (P < .05) compared with NUCs. It was concluded that stimulant drug use, primarily MDMA and amphetamines, may result in acute stimulant-induced tremor as well as long-term proprioceptive deficits in terms of arm-droop.

Background: The mood and psychomotor effects of caffeine are well documented; however, many previous studies assessing these factors have been carried out on habitual consumers of caffeine. Thus, it is difficult to discern whether beneficial findings are due to the positive effects of caffeine or the reversal of negative withdrawal symptoms. Aims: The current placebo-controlled balanced-crossover study aimed to investigate the acute effects of caffeine on mood and psychomotor performance in both moderate consumers and minimal/nonconsumers of caffeine. Materials and Methods: Following overnight caffeine abstinence (*12 hours), 15 moderate consumers (mean 316.2 mg/day) and 14 minimal/nonconsumers (mean 37.07 mg/day) received a beverage containing either 150 mg caffeine or a matched placebo at ‡ 48 hours apart. Mood and psychomotor assessments were carried out at baseline and 30 minutes postdrink. Bond-Lader visual analogue scales (VAS) and caffeine research VAS were used to assess mood, while three simple motion tasks (using an accelerometer device to record dynamic bodily movement) were used to assess psychomotor control. Results: Baseline differences after a night's abstinence were observed for only two outcome measures, with moderate consumers reporting significantly worse headaches and experiencing more tremors on accelerometer Task 2 (holding both arms out to the sides). Following caffeine, ratings of alertness and jitteriness significantly increased and ratings of calmness significantly decreased. Furthermore, accelerometer Task 2 revealed a significant increase in tremor following caffeine compared to when following placebo. It was concluded that these results do not support the withdrawal reversal hypothesis of caffeine consumption but are more indicative of a net effect of caffeine consumption.