Do rhesus monkeys (Macaca mulatta) perceive illusory motion?

Abstract

During the last decade, visual illusions have been used repeatedly to understand similarities and differences of visual perception of human and non-human animals. However, nearly all studies have focused only on illusions not related to motion perception and, to date, it is unknown whether non-human primates perceive any kind of motion illusion. In the present study we investigated whether rhesus monkeys (Macaca mulatta) perceived one of the most popular motion illusions in humans, the Rotating Snake illusion (RSI). To this purpose, we set up four experiments. In Experiment 1 subjects initially were trained to discriminate static vs. dynamic arrays. Once reaching the learning criterion, they underwent probe trials in which we presented the RSI and a control stimulus identical in overall configuration with the exception that the order of the luminance sequence was changed in a way that no apparent motion is perceived by humans. The overall performance of monkeys indicated that they spontaneously classified RSI as a dynamic array. Subsequently, we tested adult humans in the same task with the aim of directly comparing the performance of human and non-human primates (Experiment 2). In Experiment 3 we found that monkeys can be successfully trained to discriminate between the RSI and a control stimulus. Experiment 4 showed that a simple change in luminance sequence in the two arrays could not explain the performance reported in Exp. 3. These results suggest that some rhesus monkeys display a human-like perception of this motion illusion, raising the possibility that the neurocognitive systems underlying motion perception may be similar between human and non-human primates.

Visual Illusions: An Interesting Tool to Investigate Developmental Dyslexia and Autism Spectrum Disorder

“…However, illusion classification did not reach a general consensus yet (see Hamburger, 2016 , for a recent review). Measuring a visual illusion, even if it sounds counterintuitive, can be done in a very accurate way in both human and non-human species (e.g., Macknik and Livingstone, 1998 ; Conway et al, 2005 ; Gori et al, 2006 , 2008a , 2010a , b , 2014 ; Fantoni and Pinna, 2008 ; Giora and Gori, 2010 ; Gori and Spillmann, 2010 ; Spillmann et al, 2010 ; Hamburger, 2012 ; Ito, 2012 ; Otero-Millan et al, 2012 ; Shi et al, 2013 ; Agrillo et al, 2015 ). Following the everyman’s perspective, visual illusions could not be considered a good tool for investigating perceptual differences in groups because they are “subjective”.…”

Do domestic dogs (Canis lupus familiaris) perceive the Delboeuf illusion?

“…Most studies have involved non-human primates: rhesus monkeys and baboons, for instance, perceive the Zöllner illusion (Agrillo et al 2014a;Benhar and Samuel 1982); capuchin monkeys are sensitive to the Müller-Lyer illusion (Suganuma et al 2007) and seem to perceive the Solitaire illusion (Parrish et al 2016). Illusory perception of dynamic events has also been found in rhesus monkeys (rotating snakes illusion, Agrillo et al 2015).…”

How Illusory Is the Solitaire Illusion? Assessing the Degree of Misperception of Numerosity in Adult Humans

“…Comparative psychologists have reported that several non-human animals are sensitive to static illusions that produce misperception of size, depth or brightness: chimpanzees and monkeys, for instance, perceive the Delboeuf illusion (Parrish and Beran, 2014; Parrish et al, 2015), chicks perceive the Ebbinghaus illusion (Rosa Salva et al, 2013), baboons perceive the corridor illusion (Barbet and Fagot, 2002) and Zöllner illusion (Benhar and Samuel, 1982), while guppies are sensitive to the brightness illusion (Agrillo et al, 2016). Perception of motion illusions have been reported too, with rhesus monkeys (Agrillo et al, 2015a) and guppies and zebrafish (Gori et al, 2014) showing a human-like perception of the Rotating Snake illusion. These studies suggest perceptual systems may be more shared among vertebrates than previously thought (e.g., Nieder, 2002; Kelley and Kelley, 2014), even though no firm conclusion can be taken at this stage as several illusory phenomena have not been studied in species other than humans, and other illusory stimuli produce different outcomes across species in terms of who sees those illusions (for a review, see Feng et al, 2016).…”