Neural correlates for perception of companion animal photographs

Abstract

Anthrozoological neuroscience, which we propose as the use of neuroscience techniques to study human-animal interaction, may help to elucidate mechanisms underlying the associated psychological, physiological, and other purported health effects. This preliminary study investigates the neural response to animal photographs in pet owners and non-pet owners, and both attraction and attachment to companion animals as modulators of human perception of companion animal photographs. Thirty male participants, 15 "Pet Owners" (PO) and 15 "Non-Pet Owners" (NPO), viewed photographs of companion animals during functional MRI (fMRI) scans at 3 T and provided ratings of attraction to the animal species represented in the photographs. Fourteen subjects additionally submitted and viewed personal pet photographs during fMRI scans, and completed the Lexington Attachment to Pets Scale (LAPS). PO exhibited greater activation than NPO during the viewing of animal photographs in areas of the insula, and frontal and occipital cortices. Moreover, ratings of attraction to animals correlated positively with neural activation in the cingulate gyrus, precentral gyrus, inferior parietal lobule, and superior temporal gyrus during the viewing of representative photographs. For subjects with household pets, scores on the LAPS correlated positively with neural activation during the viewing of owned pet photographs in the precuneus, cuneus, and superior parietal lobule. Our preliminary findings suggest that human perception of companion animals involve the visual attention network, which may be modulated at the neural level by subjective experiences of attraction or attachment to animals. Our understanding of human-animal interactions through anthrozoological neuroscience may better direct therapeutic applications, such as animal-assisted therapy.

Keywords: Anthrozoological neuroscience; Companion animals; Human-animal interaction; Pet ownership; fMRI.

Fig. 1.

(A) Paradigm A included seven control epochs (nature) and seven experimental epochs (dog, puppy/kitten, fish, small mammal, bird, cat, reptile/amphibian). The order of nature epochs and animal epochs was pseudo-randomized amongst subjects. (B) Paradigm B, if applicable, comprised two control epochs and two experimental epochs. The second experimental epoch comprised personal pet photographs submitted by subjects, and the first experimental epoch comprised unfamiliar animals of matched species. For both paradigms, epochs comprised eight images displayed 2.0 s each, for total epoch durations of 16.0 s.

Fig. 2.

Z-Score Maps Showing Activated Brain Regions in each group, and group differences in brain activations during the viewing of Animal Photographs. (A) Brain regions activated in the Pet Owners. (B) Brain regions activated in Non-Pet Owners. (C) Brain regions with greater activation in Pet Owners than Non-Pet Owners. Bottom numbers represent Z-coordinates of the axial slice. Activated areas are shown with Z> 1.96 and a duster significance threshold of p-(corrected) < 0.05. (See Table 2 for MN1 Coordinates of the cluster maxima, cluster size and significance for these activated brain regions).

Fig. 3.

Stronger Attraction rating, regardless of Pet Ownership status, predicted stronger BOLD Response during the viewing of Paradigm A animal photographs. Z (Gaussianised T/F) statistic images were thresholded using clusters determined by Z > 1.96 and a cluster significance threshold of p-(corrected) < 0.05. Mean Attraction ratings are averaged Likert ratings of “general attraction” to six companion animal species groups (1=no attraction; 10=strong attraction). Scatterplots above and below these Z-maps at specific brain regions show the corresponding subject-level data; BOLD responses are shown as contrast of parameter estimate (COPE) values. Results of the post-hoc regressions are indicated next to the plots (no group or interaction effects were found). See Table 3 for details regarding cluster size and significance.

Fig. 4.

Lexington Attachment to Pets Scale (LAPS) scores correlated with brain activation during the viewing of Paradigm B personal pet photographs. N=14. Z (Gaussianised T/F) statistic images were thresholded using clusters determined by Z > 1.96 and a cluster significance threshold of p < 0.05 (corrected). Bottom numbers represent Z-coordinates of axial slice. See Table 4 for the MNI coordinates of the cluster maxima, cluster size and significance of these brain regions.