In vivo functional near-infrared spectroscopy measures mood-modulated cerebral responses to a positive emotional stimulus in sheep

Centre for Proper Housing of Ruminants and Pigs, Federal Veterinary Office, Agroscope Reckenholz-Tänikon Research Station ART, Ettenhausen, Switzerland.
NeuroImage (Impact Factor: 6.36). 01/2011; 54(2):1625-33. DOI: 10.1016/j.neuroimage.2010.08.079
Source: PubMed


The affective state of an animal, which is thought to reflect its welfare, consists of both short-term emotional reactions and long-term general mood. Because this state is generated and processed by the brain, we used non-invasive measurement of such brain activity as a novel indicator variable and investigated the interplay of mood and short-term emotional reactions in animals. We developed a wireless sensor for functional near-infrared spectroscopy (fNIRS), which assesses cortical perfusion changes, and consequently neuronal activity. Mood differences were induced by barren and enriched housing in a total of nine sheep and we observed their brain reaction in response to the positive situation of being groomed. We detected a decrease in cerebral oxyhaemoglobin concentration ([O(2)Hb]) which persisted during grooming. The localisation of the decrease in the brain did not depend on the site where the stimulus was applied. Also, the intensity of the response did not depend on the intensity of the grooming stimulus and a sham stimulus did not evoke an [O(2)Hb] response as seen with a grooming stimulus. Thus, we conclude that the observed haemodynamic brain response was unlikely to reflect pure somato-sensory information. We then found that the amplitude of the [O(2)Hb] response was larger if sheep were in a supposedly more negative mood. This contradicts the common assumption that negative mood generally taints reactions to emotional stimuli. Our results also demonstrate the potential of fNIRS for assessing affective states in freely moving animals.

1 Follower
25 Reads
  • Source
    • "In addition to the go/no-go response, we measured frontal cortical brain activation by using functional near-infrared spectroscopy (fNIRS; Muehlemann, Haensse, & Martin Wolf, 2008; Muehlemann et al., 2011; Vögeli et al., 2014 "
    [Show abstract] [Hide abstract]
    ABSTRACT: Animal welfare concerns have raised an interest in animal affective states. These states also play an important role in the proximate control of behaviour. Due to their potential to modulate short-term emotional reactions, one specific focus is on long-term affective states, that is, mood. These states can be assessed by using non-verbal cognitive judgement bias paradigms. Here, we conducted a spatial variant of such a test on 24 focal animals that were kept under either unpredictable, stimulus-poor or predictable, stimulus-rich housing conditions to induce differential mood states. Based on functional near-infrared spectroscopy, we measured haemodynamic frontal brain reactions during 10s in which the sheep could observe the configuration of the cognitive judgement bias trial before indicating their assessment based on the go/no-go reaction. We used (generalised) mixed-effects models to evaluate the data. Sheep from the unpredictable, stimulus-poor housing conditions took longer and were less likely to reach the learning criterion and reacted slightly more optimistically in the cognitive judgement bias test than sheep from the predictable, stimulus-rich housing conditions. A frontal cortical increase in deoxy-haemoglobin [HHb] and a decrease in oxy-haemoglobin [O2Hb] were observed during the visual assessment of the test situation by the sheep, indicating a frontal cortical brain deactivation. This deactivation was more pronounced with the negativity of the test situation, which was reflected by the provenance of the sheep from the unpredictable, stimulus-poor housing conditions, the proximity of the cue to the negatively reinforced cue location, or the absence of a go reaction in the trial. It seems that (1) sheep from the unpredictable, stimulus-poor in comparison to sheep from the predictable, stimulus-rich housing conditions dealt less easily with the test conditions rich in stimuli, that (2) long-term housing conditions seemingly did not influence mood-which may be related to the difficulty of tracking a constant long-term state in the brain-and that (3) visual assessment of an emotional stimulus leads to frontal brain deactivation in sheep, specifically if that stimulus is negative. Copyright © 2014 Elsevier Inc. All rights reserved.
    Brain and Cognition 02/2015; 93:35-41. DOI:10.1016/j.bandc.2014.11.004 · 2.48 Impact Factor
  • Source
    • "A recent example of this is given by Hesford et al. [3] who describe the use of a wireless NIRS device to monitor tissue oxygenation of the left and right quadriceps muscle in elite speed skaters. Other systems have been developed to provide wireless measurements of cerebral oxygenation and haemodynamics in various subjects, including children and sheep [4] [5] [6] [7]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: We have designed, built and successfully tested a prototype portable and wireless near-infrared spectroscopy system. It takes forward the well-established series of NIRO spectroscopy instruments made by Hamamatsu Photonics (Hamamatsu City, Japan). It uses an identical optical probe, and has a data acquisition rate of 10Hz. It illuminates the tissue with laser diode sources at 3 wavelengths of 775, 810 and 850nm, and detects the reflected light with 2 silicon photodiode detectors at 2 different separations, enabling spatially resolved spectroscopy to be performed. We have tested it with both in vitro and in vivo experiments to establish its basic functionality for use in studies of both brain and muscle.
    Medical Engineering & Physics 05/2013; 35(11). DOI:10.1016/j.medengphy.2013.04.011 · 1.83 Impact Factor
  • Source
    • "We applied functional near-infrared spectroscopy (fNIRS) as described in Muehlemann et al. ([44], Fig. 1). We exposed our goats to external stimuli with presumed emotional content and thus deliberately elicited neuronal activity. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Recent concepts relating to animal welfare accept that animals experience affective states. These are notoriously difficult to measure in non-verbal species, but it is generally agreed that emotional reactions consist of well-coordinated reactions in behaviour, autonomic and brain activation. The aim of the study was to evaluate whether each or a combination of these aspects can differentiate between situations presumed to differ in emotional content. To this end, we repeatedly confronted dwarf goats at short intervals with a covered and an uncovered feed bowl (i.e. presumably frustrating and rewarding situations respectively) whilst simultaneously observing their behaviour, measuring heart-rate and heart-rate variability and haemodynamic changes in the prefrontal cortex using functional near-infrared spectroscopy. When faced with a covered feed bowl, goats occupied themselves at locations away from the bowl and showed increases locomotion, while there was a general increase in prefrontal cortical activity. There was little indication of autonomic changes. In contrast, when feed was accessible, the goats reduced locomotion, focused their behaviour on the feed bowl, showed signs of sympathetically mediated arousal reflecting anticipation and, if any cortical activity at all was present, it was concentrated to the left hemisphere. We thus observed patterns in behaviour, sympathetic reaction and brain activity that distinguished between a situation of frustration and one of reward in dwarf goats. These patterns consisted of a well-coordinated set of reactions appropriate in respect of the emotional content of the stimuli used.
    Behavioural brain research 11/2012; 239(1). DOI:10.1016/j.bbr.2012.10.052 · 3.03 Impact Factor
Show more