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Keyboards and cognitive interfaces for dolphins have a long history. Various modalities of communication (visual, acoustic) and triggering mechanisms (physical, infrared, acoustic) have been utilized. Protocols and frameworks (e.g., the model/rival approach) have improved with the adaptation of methodological techniques from primates and birds. This paper reviews the long history of human-dolphin communication studies and the pros and cons of both technology and technique.

Marine mammal behavior and cognition researchers often face a number of challenges, including the research subjects’ lack of interest and verbal abilities, as well as choosing a paradigm with appropriate stimuli for the subjects’ perceptual and cognitive abilities. Researchers who work with human infants often encounter similar challenges when studying infant cognition and have developed strategies to overcome these challenges, including using stimuli that capture the infants’ attention, determining what tasks are age-appropriate, and using conditioned responses to test discrimination abilities. This paper encourages marine mammal researchers to learn from the research paradigms and techniques used in human infant research and alter them appropriately for the intended study subjects. The conditioned head-turn response, Violation-of-Expectation paradigm, and the help/hinder paradigm have all been used in infant cognition research and show great promise for furthering the current understanding of marine mammal behavior and cognition. In addition, studying a subject’s spontaneous behavior can provide valuable insight in areas such as problem solving skills, creativity, and individual differences. Care must be taken to adapt the paradigms and use stimuli to fit each species’ perceptual abilities. For example, avoiding a task that requires color discrimination for species that do not possess color vision or using stimuli that fall within a particular species’ hearing range are necessary steps in designing an ecologically valid and informative study. Adapting paradigms previously used with human infants can help expand the current understanding of marine mammal communication, cognitive abilities, and social behavior.

In the order of cetacean, the ability to detect bioelectric fields has, up to now, only been demonstrated in the Guiana dolphin (Sotalia guianensis) and is suggested to facilitate benthic feeding. As this foraging strategy has also been reported for bottlenose dolphins (Tursiops truncatus), we studied electroreception in this species by combining an anatomical analysis of "vibrissal crypts" as potential electroreceptors from neonate and adult animals with a behavioral experiment. In the latter, four bottlenose dolphins were trained on a go/no-go paradigm with acoustic stimuli and afterward tested for stimulus generalization within and across modalities using acoustic, optical, mechanical, and electric stimuli. While neonates still possess almost complete vibrissal follicles including a hair shaft, hair papilla, and cavernous sinus, adult bottlenose dolphins lack these features. Thus, their "vibrissal crypts" show a similar postnatal morphological transformation from a mechanoreceptor to an electroreceptor as in Sotalia. However, innervation density was high and almost equal in both, neonate as well as adult animals. In the stimulus generalization tests the dolphins transferred the go/no-go response within and across modalities. Although all dolphins responded spontaneously to the first presentation of a weak electric field, only three of them showed perfect transfer in this modality by responding continuously to electric field amplitudes of 1.5 mV cm -1 , successively reduced to 0.5 mV cm -1 . Electroreception can explain short-range prey detection in crater-feeding bottlenose dolphins. The fact that this is the second odontocete species with experimental evidence for electroreception suggests that it might be widespread in this marine mammal group., (© 2021 The Authors. The Anatomical Record published by Wiley Periodicals LLC on behalf of American Association for Anatomy.)

Metacognition-the ability to monitor and control one's own cognition-is a sophisticated ability that reveals humans' reflective mind and consciousness. Researchers have begun to explore whether animals share humans' metacognitive capacity. This article reprises the original study that explored metacognition across species. A captive dolphin performed an auditory pitch-discrimination task using High/Low discrimination responses and an Uncertainty response with which he could decline to complete any trials he chose. He selectively declined the difficult trials near his discriminative threshold-just as humans do. This comparative exploration of metacognition required a trial-intensive titration of perceptual threshold and the training of a distinctive behavioral response. It could not have been conducted in the wild, though the naturalistic observation of dolphin uncertainty behaviors and risk-management strategies would no doubt yield complementary insights. The dolphin study inaugurated a new area of cross-species research. This research area opens a new window on reflective mind in animals, illuminates the phylogenetic emergence of metacognition, and may reveal the antecedents of human consciousness.