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Behavioural evidence suggests that cephalopod molluscs may have a form of primary consciousness. First, the linkage of brain to behaviour seen in lateralization, sleep and through a developmental context is similar to that of mammals and birds. Second, cephalopods, especially octopuses, are heavily dependent on learning in response to both visual and(More)
Oculomotor tracking of one's moving hand is considerably more accurate than tracking of an external target undergoing comparable motion. To identify the factors contributing to this enhancement of tracking accuracy, the influence of visual, proprioceptive, and efferent cues on tracking performance was assessed. Related observations were made on the(More)
Oculomotor pursuit can be elicited by moving visual, tactile, proprioceptive, and occasionally auditory targets presented singly. Both the accuracy and amount of pursuit are enhanced if the position of the target is specified by cues from several sensory modalities. When the motion of the target is topologically related to movements of the subject's arm,(More)
Rationale The original call for participation announced the following outline: <<The seven known species of the pygmy squid genus among the smallest living cephalopods. Recent studies revealed that at least some of these miniature squids are extremely short-lived, while they are " maximalists " in terms of their reproductive output. The small adult size and(More)
Continuous ocular and manual tracking of the same visual target moving horizontally in sinusoids at 0.75 Hz was measured by lag, RMS Error, and Gain. The best measures of accuracy of tracking, error and lag, were remarkably similar in the two systems and were affected similarly by presence of a background and changes in predictability of target movement.(More)
During their 3rd week of life, 73 Octopus bimaculoides were observed to test whether discrete behaviors could be grouped reliably to reflect dimensions of temperament. Frequencies of behaviors during Week 3 were subjected to principal-components analysis (PCA), resulting in 4 components (active engagement, arousal/readiness, aggression, and(More)
A taxonomy of the movement patterns of the 8 flexible arms of octopuses is constructed. Components consist of movements of the arm itself, the ventral suckers and their stalks, as well as the relative position of arms and the skin web between them. Within 1 arm, combinations of components result in a variety of behaviors. At the level of all arms, 1 group(More)
An in-depth analysis of eye movements of schizophrenics has demonstrated defects in several oculomotor subsystems, likely due to processing of sensory information and not to problems in the motor system itself. Schizophrenic subjects made more pursuit tracking errors, due to higher RMS errors, larger phase lag, and more saccades in pursuit. When making(More)
Previous behavioral studies in Octopus vulgaris revealed lateralization of eye use. In this study, the authors expanded the scope to investigate arm preferences. The octopus's generalist hunting lifestyle and the structure of their arms suggest that these animals have no need to designate specific arms for specific tasks. However, octopuses also show(More)
Oculomotor tracking of one's unseen hand is greatly enhanced when a positive afterimage of the arm is projected onto its changing apparent position. The "afterimage arm" also influences the perception of real arm motion. The nature of this influence indicates that sense of effort or will derives from spatial computations potentially involving sensory and(More)