This study examines human and non-human animal communication from a linguistic–semiotic perspective to address the limitations of anthropocentric models that treat language and animal signaling as a strict dichotomy. Existing studies often emphasize human linguistic uniqueness without adequately accounting for semiotic continuities across species. To address this gap, the study conceptualizes communication as a semiotic continuum rather than a binary distinction. Using a qualitative comparative design, the research analyzes multimodal data from human communication and selected animal systems, including honeybee dances, dolphin echolocation, birdsong, and primate alarm calls. Data were examined through a coding framework based on Peircean semiotics and Hockett’s design features to ensure analytical rigor and comparability. The findings indicate that human communication is distinguished by symbolic abstraction, open-ended productivity, recursion, and metacommunication. However, animal communication systems also demonstrate structured, intentional, and adaptive properties shaped by ecological and social demands. Continuities across species include proto-syntactic patterning in primate calls, cultural transmission in birdsong, and multimodal coordination in dolphins and bees. Despite these shared features, animal systems generally lack the generativity and metalinguistic reflexivity characteristic of human language. The study concludes that communication should be understood as a graded semiotic continuum, with human language representing the most elaborated form of meaning-making rather than an isolated system. This reconceptualization contributes to theories of language evolution and broadens semiotic inquiry by situating human communication within a wider ecology of signs.
Psychosocial stress exposure during sensitive periods of development affects brain circuits involved in emotional regulation and contributes to the emergence of mood disorders as well as alterations in peripheral organ function. Most experimental studies have used post-weaning social isolation (SI) spanning the entire adolescent period to model early-life adversity. However, adolescence comprises heterogeneous developmental phases, marked by region-specific brain maturation and dynamic endocrine changes. Exposure to adverse environments during these distinct windows may therefore produce divergent behavioral and physiological outcomes. Yet, the role of developmental timing in determining the susceptibility of peripheral organs to stress remains poorly understood. Here, we assessed the immediate effects of a 10-day acute SI protocol, starting in mid-adolescence (postnatal day [PND] 35) in male NMRI mice, a stage where adolescence overlaps with puberty. We evaluated a on broad range of behavioral outcomes and on peripheral physiology, including renal and hepatic function through blood biochemistry analysis, in order to determine how stress exposure during a specific developmental window impacts both central and peripheral physiological processes. Our results revealed that mice housed in SI exhibited a hyperactivity phenotype and increased anxiety-like and depressive-like states, while cognitive function remained intact. At the peripheral level, SI induced early signs of hepatic stress under basal conditions, reflected by elevated plasma alanine aminotransferase (ALT) levels, without evidence of renal injury. Together, these results highlight the critical importance of developmental timing in shaping stress-related behavioral and peripheral outcomes and suggest that mid-adolescence constitutes a window of heightened vulnerability.
Conditioned inhibition (CI) refers to the learned property of a stimulus to predict the absence of an unconditioned stimulus (US). While excitatory forms of conditioning, like alpha conditioning, appear early in metazoan evolution, evidence of true CI in invertebrates remains scant. In the present study, we employed a negative contingency CI training design with an approach/withdrawal test to identify excitatory components involved in CI-like protocols in Caenorhabditis elegans. By using a joint-presentation procedure and alternating stimulus application sites across blocks, we minimised non-associative sensory effects. A control group was added to further consider context-dependent effects. Our results point to learning effects being consistent with excitatory (alpha) conditioning, as trained behavior was facilitated but did not depend on the conditioned stimulus. This underlines the widespread significance of alpha conditioning in invertebrate learning and its contribution to CI-like processes.
The XXII Biennial ISCP Meeting was held in Bogotá, Colombia, from December 3 to 5, 2025. Leonardo A. Ortega served as the local organizer and President of ISCP. Gabriela E. López-Tolsa served as the Program Chair, and John Solorzano, Aaron Blasidell, Jonathan Buriticá, Brissa Gutiérrez, and Eduardo Reynoso served as part of the Organizing Committee. The symposium, paper, and poster sessions were devoted entirely to the presentation of scientific research and its applications. The conference featured a comprehensive program comprising a total of six invited talks, one symposium, one discussion panel, nine paper sessions, and one poster session. As reflected in the book of abstracts below, the meeting included presentations spanning a broad range of topics and addressing the behavior of numerous species. More than 110 participants from 12 countries across four continents completed registration for the meeting. The presidential address was entitled “Integrating comparative psychology frameworks in the advancement of multilevel health models.”
Creativity research suggests that creative output can be influenced by extrinsic rewards. Through reinforcement, individual killer whales were trained to produce varied behaviors to a particular cue. The purpose of this study was to opportunistically assess whether or not testing protocols, which varied in reinforcement schedules across four killer whales, influenced the outcomes of four measured constructs of creativity (Fluency, Flexibility, Elaboration, Originality) during the innovate task while under stimulus control. Of the four killer whales, one animal experienced a continuous reinforcement schedule for all test sessions, one experienced a variable reinforcement schedule for all test sessions, and two experienced two types of reinforcement schedules (6 sessions of continuous reinforcement followed by 6 sessions of variable reinforcement). Results suggested that both individuality and reinforcement schedule may have influenced the expression of selected behaviors for some constructs. A prospective study on the influence of reinforcement schedule during testing with larger samples would facilitate a clearer understanding of the mechanisms that influence the different outcomes of creative behavioral expressions. More importantly though, participation in cognitive tasks enables animals to engage in flexible thinking while actively controlling their behavioral choices during interactions with humans, thereby augmenting animal well-being in a positive way.
Siamangs (Symphalangus syndactylus), one of the few singing apes, vocalize loudly, often while they move. We hypothesize that movement and vocalization coordinate, possibly due to vigorous thorax-loading movements such as brachiation affecting vocal-respiratory dynamics. To assess this vocal-motor coordination we recorded more than a hundred stereotypical vocalizations combined with movement from two captive Siamang (isolated from 7 hours of singing). We observed that stereotypical calls coincided with a movement display and were performed by juvenile individuals during solo singing (which allowed for isolation of the calls). Investigating these vocal-motor events, we found that body acceleration estimated using computer vision was statistically associated with the nearest peak in the amplitude envelope of the call, and that body acceleration timeseries contained mutual information about the amplitude envelope timeseries during these events. By confirming via quantitative methods that singing and movement are coordinated, the current report invites further mechanistic investigation on vocal-locomotor coupling in siamang.
Stimulus generalization is a phenomenon in which an animal that is trained to respond to one specific stimulus exhibits a similar but not an identical response when presented with a new similar stimulus. It has been widely demonstrated across a variety of vertebrates. This study investigated stimulus generalization in Western painted turtles (Chrysemys picta), a phenomenon previously rarely studied in turtles. Three turtles were initially trained to criterion in an automated Skinner box on a discrimination task between vertical and horizontal lines. Reward was beef baby food, pumped from a syringe pump. Analysis of the criterion days showed a significant difference between the latencies to the reinforced and unreinforced stimuli, indicating successful discrimination. Following this training, the turtles were tested for stimulus generalization using lines of seven different orientations (from 0 degrees to 90 degrees in 15 degree increments), involving 20 days of testing. The results revealed that response latency varied with the line’s orientation. The fastest latencies were observed for the previously reinforced stimulus and the slowest for the previously unreinforced stimulus, with intermediate response times for the novel intermediate stimuli. This graded pattern formed a generalization gradient, which was best fit by an exponential function (R2 = 0.96). These findings suggest that painted turtles are capable not only of discriminating visual stimuli but also of exhibiting typical stimulus generalization.
The present study aimed to investigate whether children could acquire the oddity concept using olfactory stimuli. To this end, three children aged 3 to 6 years were concurrently trained on multiple odor oddity problems and tested with novel ones. The findings showed that the 6-year-old participant mastered the acquisition training and transferred this experience to the novel oddity problems in the transfer test, suggesting that the child had acquired a relational understanding of the difference between odd and identical odor stimuli. Factors influencing the acquisition of the oddity concept were discussed.
Shadow boxing is the aggressive response of an animal to its reflection. When the species is strong enough to break surfaces (e.g., bear, monkey, woodpecker), this behaviour can lead to human-wildlife conflicts. In this pilot study, we assessed whether shadow boxing is subject to habituation (learning to ignore stimuli) in Southern ground-hornbills (Bucorvus leadbeateri). In the Mirror task, birds were repeatedly exposed to unbreakable mirrors (habituation). Subsequently, one mirror was presented at a different location (test). In the Neophobia task, a food reward was placed next to novel objects. Ground-hornbills did not habituate to the mirrors, but they differed in their levels of neophobia.
This article describes the use of Stickers to generate interest in comparative psychology. It is based on an earlier publication in which users can design their own official United States postage stamps (Abramson & Long, 2012). The company that developed the product no longer manufactures it, so we created a substitute using stickers that can be placed, for instance, on the bottom flap of an envelope. In addition to highlighting aspects of comparative psychology, such as individuals, apparatus, and movements, the stickers can also be used to feature other aspects of psychology. They can also be used as a fundraiser and recruitment tool. Developing the stickers is an excellent student-based project suitable for all courses, including the history of psychology. QR and/or bar codes can be added to link to student-developed resources.
Genetic studies of reflex epilepsy are conducted primarily on rodent strains in which seizures are triggered by audiogenic stimuli. The genetic aspects of somatosensory epilepsy induced by tactile stimuli remain unclear. Identifying genes that influence the development of seizures evoked by tactile stimuli is important for understanding the underlying mechanisms of somatosensory epilepsy, as well as for its prevention and treatment. This article summarizes previously published results from long-term population and laboratory studies, confirming the assumption of other authors that seizures induced by tactile stimuli are an element of antipredatory behavior that allows the preservation of genes predisposing to somatosensory epilepsy in natural populations. The genetic predisposition of water voles to handling-induced seizures has been shown to be associated with a coat color polymorphism controlled by the agouti locus. Thus, the water vole may become a promising object for genetic studies of somatosensory reflex epilepsy and understanding the evolutionary origins of this disease.
This theoretical and integrative neuroscience review examines the neural mechanisms underlying nonverbal communication, focusing on how the human brain processes body language cues, including posture, gestures, and facial expressions. Drawing from recent advancements in affective neuroscience, social cognition, and neuroimaging research, the article synthesizes findings across multiple disciplines to explain the functional roles of key brain structures, including the amygdala, prefrontal cortex, superior temporal sulcus, and mirror neuron systems, in decoding nonverbal signals. The review highlights how these structures collaborate to interpret social and emotional meaning embedded in nonverbal behavior, with implications for understanding social disorders and improving interpersonal communication. Particular emphasis is placed on studies from the past 10 years to ensure contemporary relevance. This review also addresses theoretical frameworks such as Embodied Simulation Theory to contextualize empirical findings within broader models of brain evolution and communication. By integrating cognitive, affective, and evolutionary perspectives, this paper aims to clarify the neural architecture that supports nonverbal social interaction.
Making an ethogram, a repertoire of the behavior of a species or several related ones, is obviously an important foundation for any theoretical studies of their behavior. In addition, it is useful for conservation, and evolution, and as a basis for good care in captivity. But such a thorough description is neither easy nor quick. This account takes the reader on the author’s journey through lab and field work on seven species and to the struggle to publish results that make up an ethogram of octopuses in the family Octopodidae.
This study aimed to examine whether a lactating Steller sea lion pup (Eumetopias jubatus) could learn the associations between human commands (verbal/ visual) and behavior. A male Steller sea lion pup named Kanata was artificially cared for from the age of 36 hours. When Kanata was three months old, we began behavior-shaping training using milk as a reinforcer. During the training phase, which lasted approximately three months, Kanata learned nine behaviors. The trainers simultaneously presented Kanata with both hand signals and vocal commands to condition each behavior's association with the human commands. In the test phase, we tested the effects of associative learning between the human commands and each behavior in the three conditions. When trainers simultaneously gave him hand signals and vocal commands (Condition 1), Kanata’s performance was significantly higher than for the other conditions (Condition 2: only hand signals and Condition 3: only vocal commands). Additionally, Kanata’s performance was significantly higher in Condition 2 than in Condition 3. Although Kanata’s performance was stable for all commands in both Conditions 1 and 2, it was significantly low for almost all commands in Condition 3. These results provide the first evidence to suggest that a Steller sea lion pup has an excellent ability of associative learning and that he could shape the associations between the human commands and behaviors in both visual and auditory modalities, but his learning association could be dominant in visual information, compared to auditory information.
The bottlenose dolphin (Tursiops truncatus) vocalizations called “burst pulses” exhibit distinct acoustic properties and can potentially be linked to affective states. This study aimed to determine if dolphins produce burst pulses during match-to-sample with both successful and unsuccessful outcomes and to explore any association with positive affect. We observed that burst pulses occurred in 74% of match-to-sample trials (in which the subject views a sample object and selects the match from a group of alternative objects), with a significantly higher frequency during correct responses. Additionally, there was a notable difference in the proportion of burst pulses occurring before versus after the trainer’s bridge, with more burst pulses occurring before the trainer’s bridge. The timing and characteristics of these burst pulses suggest they may be related to the dolphins’ interest and excitement rather than merely a response to reinforcement. These findings provide new insights into the complexity of dolphin vocalizations and their potential connection to affective states.
Several species have demonstrated the ability to cooperate with conspecifics in a lab or zoological setting. The present study sought to replicate previous research (Plotnik et al., 2011) in which pairs of Asian elephants (Elephas maximus) had to simultaneously pull on the ends of a rope in order to bring food rewards within reach. The initial study was conducted in a free-contact setting with Asian elephants, whereas the present study was conducted under a protected-contact management program with ZooTampa at Lowry Park’s herd of six African bush elephants (Loxodonta africana). Trials were deemed successful if the sled was pulled to a distance where both elephants were able to access food that was resting on the sled. Overall, 15 different pairings were tested on the rope-pulling cooperative task while released simultaneously (non-delayed trials). All but one pairing quickly learned that a form of cooperation was necessary to complete the task successfully (p < .05). After non-delayed trials were complete, trials were run with a five-second delay interval for one of the two elephants to assess the elephants’ understanding of the role of a partner in the cooperative task (delayed trials). Four elephants were faced with the decision of waiting for their partner to arrive before pulling their end of the rope, of which two juvenile elephants successfully waited for their partner. This study contributes to the literature of cognition across the elephant taxon.
This paper reviews the effectiveness and application of communication buttons as a means of interaction with domestic dogs (Canis familiaris), based on the personal experiences of users. The results showed that dogs are capable of communicating through buttons, expressing their needs, and forming multi-word phrases. The highest success rate was observed in medium and large breeds between the ages of 6 months and 5 years. Nearly half of the dogs learned to use their first button within a week, although button spamming behavior was also observed in some individuals. Statistical analysis revealed that dogs preferred specific word categories (particularly activity/place and reward), although differences in the intensity of usage between categories were not statistically significant due to high variability within groups. The ability to combine words into more complex expressions was observed in approximately half of the dogs. The findings also suggest that independent button use can sometimes lead to less purposeful patterns, such as repeatedly pressing buttons ("spamming").
In all organisms, fear conditioning is a behavior that would be expected to be adaptive for anticipating dangerous stimuli. It therefore should have been selected for in the course of evolution. Although fear conditioning has been demonstrated in many different species, it had only been shown in one reptile group, lizards, prior to this study. We developed a paradigm to study fear conditioning in painted turtles (Chrysemys picta). In each of two experiments, there were three groups: an Experimental group in which a red light (the conditioned stimulus, or CS) was paired with a footshock (the unconditioned stimulus, or US), an Unpaired control group given unpaired presentations of the red light and footshock, and a CS Only control group presented with the red light only. The experiments differed in the number of days of training: In Experiment 1, the animals were trained for 9 days and were then run on extinction for 6 days. The results appeared to show that turtles in the Experimental group learned to stop moving when the red light came on, but this was not statistically significant. There were significant group differences during extinction, however. It appeared that the behavior was not asymptotic during acquisition, so we ran a second, longer experiment (Experiment 2) for 15 days of acquisition training and 8 or 9 days of extinction. In this experiment, the Experimental group learned to stop moving during the CS during acquisition and reversed that behavior in extinction. These results demonstrate that classical conditioning with footshock is a suitable method for studying fear learning in turtles. Further, they shed light on the evolution of fear behavior. Turtles are closely related to the stem amniotes that gave rise to both mammals and reptiles. Thus, the results demonstrate that fear conditioning is present in turtles and suggest that it was present in the stem amniote ancestors of mammals as well.
In social foraging situations, group members choose between two strategies: (a) actively engage in searching for resource sources (Producing); or (b) join a resource source previously discovered by another group member (Scrounging). Two predictions of the Rate-Maximization Model are: (a) the proportion of producers will be lower in conditions where the group size is larger; and (b) the proportion of producers will be lower in conditions where the number of resources is higher. While these predictions have been tested across various species, the number of studies involving human participants remains relatively low. Using an agent-based model approach, we propose a Direct Interaction Task to study the producer-scrounger game in human participants. In this online behavioral task, a single participant moves freely within the habitat and competes for resources against agents. The study involved 80 university students assigned to one of four conditions that varied by group size (G4, G8) and the number of prey (F5, F15). The results show a decrease in the producer index when the group size was larger; however, no effect was observed for the number of prey. This study highlights the potential for investigating social foraging in controlled environments without extensive physical space.
Animals do not see the external world as it is. Different animals process information in different ways, even when looking at the same object. A visual illusion is a psychological phenomenon by which the eye perceives something as different from what it is. We tested whether a bottlenose dolphin produces the square-diamond illusion to see if it experiences the illusion in the same way as humans. In Experiment 1, two figures (square and diamond) of different sizes were presented in the training session and the subject had to choose the “smaller” figure. In the test session, 22 pairs of squares and diamonds of different areas were presented to see which the subject would choose. When the area difference is large, the percentage of correct responses is high, but when the area difference is small, the percentage of correct responses varies between pairs. When these results were then sorted into “small squares vs. large diamonds” and “small diamonds vs. large squares”, the percentages were significantly high in all pairs in the “small squares vs. large diamonds” group, whereas in the “small diamonds vs. large squares” group, the percentage of correct responses decreased as the difference between the areas of the two figures also decreased. In other words, this result suggests that the illusion may have come into play. Experiment 2 was a square-diamond illusion perception task. Two pairs of squares and diamonds of equal area (225 cm2 and 400 cm2, respectively) were presented and the subject’s choice was then tested. The results showed that the subject chose the square significantly more often than the diamond in both pairs. The square appeared smaller, and the diamond appeared larger to the subject, even though the fact that they had the same area (i.e., it was demonstrated that the square-diamond illusion had occurred), and this study showed that dolphins share the same visual characteristics as humans.
