Experience and geometry: controlled-rearing studies with chicks

Animals can reorient making use of the geometric shape of an environment, i.e., using sense and metric properties of surfaces. Animals reared soon after birth either in circular or in rectangular enclosures (and thus affording different experiences with metric properties of the spatial layout) showed similar abilities when tested for spatial reorientation in a rectangular enclosure. Thus, early experience in environments with different geometric characteristics does not seem to affect animals’ ability to reorient using sense and metric information. However, some results seem to suggest that when geometric and non-geometric information are set in conflict, rearing experience could affect the relative dominance of featural (landmark) and geometric information. In three separate experiments, newborn chicks reared either in circular- or in rectangular-shaped home-cages were tested for spatial reorientation in a rectangular enclosure, with featural information provided either by panels at the corners or by a blue-coloured wall. At test, when faced with affine transformations in the arrangement of featural information that contrasted with the geometric information, chicks showed no evidence of any effect of early experience on their relative use of geometric and featural information for spatial reorientation. These findings suggest that, at least for this highly precocial species, the ability to deal with geometry seems to depend more on predisposed mechanisms than on learning and experience after hatching.     

Training generalized spatial skills

Spatial transformation skills are an essential aspect of cognitive ability. These skills can be improved by practice, but such improvement has usually been specific to tasks and stimuli. The present study investigated whether intensive long-term practice leads to change that transcends stimulus and task parameters. Thirty-one participants (14 male, 17 female) were tested on three cognitive tasks: a computerized version of the Shepard-Metzler (1971) mental rotation task (MRT), a mental paper-folding task (MPFT), and a verbal analogies task (VAT). Each individual then participated in daily practice sessions with the MRT or the MPFT over 21 days. Postpractice comparisons revealed transfer of practice gains to novel stimuli for the practiced task, as well as transfer to the other, nonpracticed spatial task. Thus, practice effects were process based, not instance based. Improvement in the nonpracticed spatial task was greater than that in the VAT; thus, improvement was not merely due to greater ease with computerized testing.     

A case of partial biotinidase deficiency associated with autism.

We report the case of a child with partial biotinidase deficiency and autistic developmental disorder. We arrived at the diagnosis of biotinidase deficiency when the child was almost 4 years of age. Consequently, he began cofactor biotin treatment (10 mg daily) which did not resolve his autistic behavior. His younger brother was affected by partial biotinidase deficiency diagnosed at birth through our neonatal screening program. He was precociously treated with cofactor biotin therapy (10 mg daily) and did not show any behavioral abnormality or developmental delay. Since the brain is quite vulnerable to biotin deficiency, delayed biotin therapy could result in neurological damage. Our patient is the first case of partial biotinidase deficiency associated with autism. We hypothesize that the low biotinidase activity could have caused biotin deficiency in his brain and cerebrospinal fluids and consequently serious neurological problems, such as stereotyped and autistic behaviors, which were irreversible in spite of biotin supplementation.     

Detour behaviour in three species of birds: quails (Coturnix sp.), herring gulls (Larus cachinnans) and canaries (Serinus canaria)

Detour behaviour is the ability of an animal to reach a goal stimulus by moving round any interposed obstacle. It has been widely studied and has been proposed as a test of insight learning in several species of mammals, but few data are available in birds. A comparative study in three species of birds, belonging to different eco-ethological niches, allows a better understanding of the cognitive mechanism of such detour behaviour. Young quails (Coturnix sp.), herring gulls (Larus cachinnans) and canaries (Serinus canaria), 1 month old, 10–25 days old and 4–6 months old, respectively, were tested in a detour situation requiring them to abandon a clear view of a biologically interesting object (their own reflection in a mirror) in order to approach that object. Birds were placed in a closed corridor, at one end of which was a barrier through which the object was visible. Four different types of barrier were used: vertical bar, horizontal bar, grid and transparent. Two symmetrical apertures placed midline in the corridor allowed the birds to adopt routes passing around the barrier. After entering the apertures, birds could turn either right or left to re-establish social contact with the object in the absence of any local sensory cues emanating from it. Quails appeared able to solve the task, though their performance depended on the type of barrier used, which appeared to modulate their relative interest in approaching the object or in exploring the surroundings. Young herring gulls also showed excellent abilities to locate spatially the out-of-view object, except when the transparent barrier was used. Canaries, on the other hand, appeared completely unable to solve the detour task, whatever barrier was in use. It is suggested that these species differences can be accounted for in terms of adaptation to a terrestrial or aerial environment.     

Is the face-perception system human-specific at birth?

The present study investigates the human-specificity of the orienting system that allows neonates to look preferentially at faces. Three experiments were carried out to determine whether the face-perception system that is present at birth is broad enough to include both human and nonhuman primate faces. The results demonstrate that the newborns did not show any spontaneous visual preference for the human face when presented simultaneously with a monkey face that shared the same features, configuration, and low-level perceptual properties (Experiment 1). The newborns were, however, able to discriminate between the 2 faces belonging to the 2 different species (Experiment 2). In Experiment 3, the newborns were found to prefer looking at an upright, compared with an inverted, monkey face, as they do for human faces. Overall, the results demonstrate that newborns perceive monkey and human faces in a similar way. These findings are consistent with the hypothesis that the system underlying face preference at birth is broad enough to bias newborns' attention toward both human and nonhuman primate faces.     

Ideal Objects for Set Theory

Journal of Philosophical Logic - In this paper, we argue for an instrumental form of existence, inspired by Hilbert’s method of ideal elements. As a case study, we consider the existence of...     

Staring us in the face? An embodied theory of innate face preference

Human expertise in face perception grows over development, but even within minutes of birth, infants exhibit an extraordinary sensitivity to face‐like stimuli. The dominant theory accounts for innate face detection by proposing that the neonate brain contains an innate face detection device, dubbed ‘Conspec’. Newborn face preference has been promoted as some of the strongest evidence for innate knowledge, and forms a canonical stage for the modern form of the nature–nurture debate in psychology. Interpretation of newborn face preference results has concentrated on monocular stimulus properties, with little mention or focused investigation of potential binocular involvement. However, the question of whether and how newborns integrate the binocular visual streams bears directly on the generation of observable visual preferences. In this theoretical paper, we employ a synthetic approach utilizing robotic and computational models to draw together the threads of binocular integration and face preference in newborns, and demonstrate cases where the former may explain the latter. We suggest that a system‐level view considering the binocular embodiment of newborn vision may offer a mutually satisfying resolution to some long‐running arguments in the polarizing debate surrounding the existence and causal structure of newborns' ‘innate knowledge’ of faces.