Abstract: Psychopathology, mental illness, and psychiatric treatment are concepts relevant to modern medicine and medical psychology and replete with cumbersome intellectual and literary baggage. They bear the imprint of suppositions, world views, and general beliefs and values exemplified in the science, history, and general culture of Anglo European societies. The study in higher apes of phenomena addressed by such concepts raises conceptual dilemmas, usually termed speciesism and anthropomorphism, not unlike those encountered in comparative human studies of similar phenomena across cultures and historical periods, namely, ethnocentrism and anachronism. The authors' synthesis of literature and their analysis of the implications of higher ape psychopathology represent an epistemically compelling account that broadens the scope of the comparative study of behavioral irregularities, a topic that provides a different slant for examining challenging questions in evolutionary biology and primatology, such as cognition, self awareness, intentional behavior, culture and behavioral traditions, social intelligence, sickness and healing, and altruism. Theoretical and empirical study of this topic expands formulation and can help provide informative answers about human evolution as well as essential features of human psychiatric syndromes, with potential practical implications. The study of psychopathology of higher apes and other non human primates represents an appropriate focus for neuroscience and bio-behavioral sciences.

Abstract: This review examines the biological background to the development of ideas on rapid eye movement sleep (REM sleep), so-called paradoxical sleep (PS), and its relation to dreaming. Aspects of the phenomenon which are discussed include physiological changes and their anatomical location, the effects of total and selective sleep deprivation in the human and animal, and REM sleep behavior disorder, the latter with its clinical manifestations in the human. Although dreaming also occurs in other sleep phases (non-REM or NREM sleep), in the human, there is a contingent relation between REM sleep and dreaming. Thus, REM is taken as a marker for dreaming and as REM is distributed ubiquitously throughout the mammalian class, it is suggested that other mammals also dream. It is suggested that the overall function of REM sleep/dreaming is more important than the content of the individual dream; its function is to place the dreamer protagonist/observer on the topographical world. This has importance for the developing infant who needs to develop a sense of self and separateness from the world which it requires to navigate and from which it is separated for long periods in sleep. Dreaming may also serve to maintain a sense of 'I'ness or “self” in the adult, in whom a fragility of this faculty is revealed in neurological disorders.

Abstract: Two baboons (Papio papio) successfully learned relational matching-to-sample: They picked the choice display that involved the same relation among 16 pictures (same or different) as the sample display, although the sample display shared no pictures with the choice displays. The baboons generalized relational matching behavior to sample displays created from novel pictures. Further experiments varying the number of sample pictures and the mixture of same and different sample pictures suggested that entropy plays a key role in the baboons' conceptual behavior. Two humans (Homo sapiens) were similarly trained and tested; their behavior was both similar to and different from the baboons' behavior. The results suggest that animals other than humans and chimpanzees can discriminate the relation between relations. They further suggest that entropy detection may underlie same-different conceptualization, but that additional processes may participate in human conceptualization.

Abstract: Success in tasks requiring categorization of pictorial stimuli does not prove that a subject understands what the pictures stand for. The ability to achieve representational insight is by no means a trivial one because it exceeds mere detection of 2-D features present in both the pictorial images and their referents. So far, evidence for such an ability in nonhuman species is weak and inconclusive. Here, the authors report evidence of representational insight in pigeons. After being trained on pictures of incomplete human figures, the birds responded significantly more to pictures of the previously missing parts than to nonrepresentative stimuli, which demonstrates that they actually recognized the pictures' representational content.

Abstract: The capacity to construct a cognitive map is hypothesized to rest on two foundations: (1) dead reckoning (path integration); (2) the perception of the direction and distance of terrain features relative to the animal. A map may be constructed by combining these two sources of positional information, with the result that the positions of all terrain features are represented in the coordinate framework used for dead reckoning. When animals need to become reoriented in a mapped space, results from rats and human toddlers indicate that they focus exclusively on the shape of the perceived environment, ignoring non-geometric features such as surface colors. As a result, in a rectangular space, they are misoriented half the time even when the two ends of the space differ strikingly in their appearance. In searching for a hidden object after becoming reoriented, both kinds of subjects search on the basis of the object's mapped position in the space rather than on the basis of its relationship to a goal sign (e.g. a distinctive container or nearby marker), even though they have demonstrably noted the relationship between the goal and the goal sign. When choosing a multidestination foraging route, vervet monkeys look at least three destinations ahead, even though they are only capable of keeping a maximum of six destinations in mind at once.