Biology subjects

Loconsole, M.

Publications and source records attributed to Loconsole, M..

6 recordsLinked to original sources

bioRxiv2026

Sound-shape correspondences in macaques reveal evolutionary roots of sound symbolism

Humans reliably associate certain speech-like sounds with visual shapes, most notably in the Bouba-Kiki Effect, where rounded and spiky shapes are matched with the sounds Bouba and Kiki, respectively. Although often linked to language and culture, evidence from preverbal infants and domestic chickens suggests that sound-shape correspondences may reflect an experience-independent perceptual bias. However, studies on great apes failed to detect such bias, leaving open the question on its phylogenetic origin. Using a free-choice task, we showed the Bouba-Kiki effect in nine macaques, thus suggesting that such correspondences represent a conserved feature of vertebrate perception that may have provided a scaffold for the later emergence of symbolic communication systems in our species.

animal behavior and cognition↗

bioRxiv2025

Crossmodal pitch-luminance association in tortoises

If you think that high-pitched sounds match bright colours more than dark ones, you are not alone. Spontaneous associations between different sensory modalities --crossmodal associations-- are widely observed in humans. More recently, crossmodal associations have been reported in chimpanzees, monkeys, dogs, chickens, and tortoises, indicating a general cognitive strategy that reflects natural correlations in the environment or similarities in the architecture of the nervous system. Alternatively, or complementarily, crossmodal associations may arise from learning of species-specific occurrences. Recent research on primates has tentatively linked human pitch-luminance associations to the evolution of language. While humans and chimpanzees spontaneously match a high-pitched sound with a white shape and a low-pitched sound with a black shape, baboons and chickens do not exhibit any preferential association. Identifying spontaneous pitch-luminance associations in species that do not rely on vocal communication, such as the solitary Hermanns tortoises, would support the idea of a language-independent phenomenon. To test this idea, we studied tortoises for pitch-luminance associations in a spontaneous food-searching task. After hearing a high-pitched (700 Hz) vs low-pitched (450 Hz) sound, animals could choose to search for food behind either a light- or dark-coloured wall. When hearing the high-pitched sound, tortoises chose the white stimulus, whereas when hearing the low-pitched sound, they chose the black stimulus, similarly to what humans and chimpanzees do. These results demonstrate crossmodal pitch-luminance associations in tortoises. While showing this commonality in the perceptual organization of phylogenetically distant species, we shift the question on whether pitch-luminance associations reflect homology or convergent evolution.

animal behavior and cognition↗

bioRxiv2024

Matching sounds to shapes: Evidence of the Bouba-Kiki effect in naive baby chicks

If you hear the non-words Kiki and Bouba, you may be more likely to associate them with a spiky and a round object, respectively, rather than the opposite. This is a case of sound-symbolism, known as the Bouba-Kiki effect. Studies on four-months infants suggest that this effect might constitute a predisposed perceptual mechanism. However, these studies suffered from the impossibility of ruling out a fast experience-driven origin of the effect resulting from infants speed of learning, their sensitivity to environmental regularities, and the large number of sound-symbolic associations to which they are precociously exposed when interacting with adults. To better describe its ontogeny and fill in this gap, we tested the Bouba-Kiki effect in domestic chicks (Gallus gallus). Being a precocial species, chicks can be tested on the very early days of life, allowing for a virtually total control of their experience before test. Three-day-old chicks (n=42) first learned to circumnavigate a panel to obtain a food reward. Then, they were presented with two identical panels, one depicting a spiky shape, and one depicting a round shape, while hearing either the sound Bouba or Kiki. We recorded which panel chicks chose with either sound, in a total of 24 trials. Chicks preferred the panel with the spiky shape when hearing the Kiki sound, and that with the round shape when hearing the Bouba sound. Results from naive baby chicks hint at a predisposed mechanism for matching the two dimensions of shape and sound that may be widespread across species.

animal behavior and cognition↗

bioRxiv2023

Separate attentional processes in the two visual systems of jumping spiders

1By selectively focusing on a specific portion of the environment, animals can solve the problem of information overload, toning down irrelevant inputs and concentrate only on the relevant ones. This may be of particular relevance for animals such as the jumping spider, which possess a wide visual field of almost 360{degrees} and thus could benefit from a low-cost system for sharpening attention. Jumping spiders have a modular visual system composed of four pairs of eyes, of which only the two frontal eyes (i.e., AMEs) are motile, whereas the other secondary pairs remain immobile. We hypothesized that jumping spiders can exploit both primary and secondary eyes for stimulus detection and attentional shift, with the two systems working synergistically. In Experiment 1 we investigated AMEs attentional responses following a spatial cue presented to the secondary eyes. In Experiment 2, we tested for enhanced attention in the secondary eyes visual field congruent with the direction of the AMEs focus. In both experiments, we observed that animals were faster and more accurate in detecting a target when it appeared in a direction opposite to that of the initial cue. In contrast with our initial hypothesis, these results would suggest that attention is segregated across eyes, while each system works to compensate the other by attending to different spatial locations, rather than sharing a common attentional focus.

animal behavior and cognition↗

bioRxiv2023

Pitch-size crossmodal correspondence in tortoises (Testudo hermanni)

Humans spontaneously match information coming from different senses, what we call crossmodal associations. For instance, high pitch sounds are preferentially associated with small objects, and low pitch sounds with larger ones. While previous studies reported crossmodal associations in mammalian species, evidence for other taxa is scarce, hindering an evolutionary understanding of this phenomenon. Here we provide evidence of pitch-size correspondence in a reptile, the tortoise Testudo hermanni. Tortoises showed a spontaneous preference to associate a small disc (i.e., visual information about size) to a high pitch sound (i.e., auditory information), and a larger disc to a low pitch sound. These results suggest that crossmodal associations may be an evolutionary ancient phenomenon, potentially an organising principle of the vertebrate brain.

animal behavior and cognition↗

bioRxiv2021

Young chicks rely on perceptual grouping to discriminate prime numbers

Grouping sets of elements into smaller, equal-sized, subsets constitutes a perceptual strategy employed by humans and other animals to enhance cognitive performance. We hypothesized that asymmetrical grouping, a characteristic of prime numbers, could provide visual cues enabling discrimination of prime from non-prime numerosities. Newborn chicks were habituated to even numerosities (as sets of elements presented on a screen), and then tested for their spontaneous choice among a prime and a non-prime odd numerosity. Chicks discriminated and preferred the prime over the composite set of elements. We discuss this result in terms of novelty preference. By employing different contrasts (i.e., 7vs.9, 11vs.9, and 13vs.15) we investigated the limits of such mechanism showing that induced grouping positively affects chicks performance.

animal behavior and cognition↗