Reorientation Task Research Articles

Spatial reorientation in rats ( Rattus norvegicus): Use of geometric and featural information as a function of arena size and feature location

Rats were used in a spatial reorientation task to assess their ability to use geometric and non-geometric, featural, information. Experimental conditions differed in the size of the arena (small, medium, or large) and whether the food-baited corner was near or far from a visual feature. The main measure was the percentage of trials with first-choice visits to the baited corner (Corner C) and the geometric equivalent corner (Corner R). Regardless of arena size, only the rats in the near-feature condition learned to make more first-choice visits to Corner C than Corner R. However, in this condition, there was a significant trend suggesting an increasing and decreasing use of, respectively, featural and geometric information with increasing arena size. Continued training with the feature removed caused all rats to primarily visit Corners C and R, reflecting the exclusive use of geometric information. However, again, there was a significant trend suggesting a decreasing use of this type of information with increasing arena size. These results were discussed in the framework of data from previous studies assessing reorientation in other species and of an associative-learning model.

Uneven integration for perception and action cues in children's working memory

We examined the development of visual cue integration in a desktop working-memory task using boxes with different visual action cues (opening actions) and perceptual surface cues (colours, monochromatic textures, or images of faces). Children had to recall which box held a hidden toy, based on (a) the action cue, (b) the surface cue, or (c) a conjunction of the two. Results from three experiments show a set of asymmetries in children's integration of action and surface cues. The 18–24-month-olds disregarded colour in conjunction judgements with action; 30–36-month-olds used colour but disregarded texture. Images of faces were not disregarded at either age. We suggest that 18–24-month-olds' disregard of colour, seen previously in reorientation tasks (Hermer & Spelke, 1994), may represent a general phenomenon, likened to uneven integration between the dorsal and ventral streams in early development.

Limitation of the Geometric Module: Evidence from Children's Reorientation Behavior in a Trapezoidal Room

Humans and animals are able to orient themselves to an environment. Previous studies have demonstrated that young children's reorientation behaviors are mainly guided by the geometric information of their environment. Children often reorient themselves according to the shape of the testing room and not in accordance with the room's non-geometric properties. While previous studies typically used rectangular testing rooms that provided unique geometric information, we used a trapezoidal testing room that allowed us to explore the manner in which children use geometric information, including the angle of the corners as well as the dimensions of the walls. In a preliminary experiment, a rectangular testing room (1.9m×1.2m×1.2m) was used. In Experiment 1 (where the participants were children) and Experiment 2 ( where the participants were adults), one of the walls of rectangular room was shortened from 1.2m to 1m to form a trapezoidal testing room. In Experiment 3, the lengths of the two hemlines of the trapezium were altered to 0.9m and 1.5m. Participants included children who were 24 years old and adults (N=20) who were university students. In each experiment, the participants' reorientation abilities were tested through a procedure adapted from Hermer and Spelke (1994, 1996). First, the participants were allowed to observe the environment. Thereafter, they watched the experimenter hide an object in one of the landmark boxes positioned in the four corners of the room. Following one of the two experimental manipulations, the participants were required to retrieve the object. In oriented search trials, the participants retrieved the object after turning 360 degrees in one spot four times, with their eyes open. This served as a control condition that probed whether the participants remembered where the experimenter had hidden the object. In disoriented search trials, the participants retrieved the object after turning 360 degrees, four to six times in one spot, with their eyes closed; this condition was found to induce a state of disorientation in children of this age (Hermer and Spelke, 1996). The results of the preliminary experiment indicated that children search geometrically appropriate locations more often than geometrically inappropriate locations, but did not search proximate locations more often than they do distant locations. In particular, the proportion of the search at the correct corner and at the geometrically equivalent opposite corner (in diagonal direction) did not differ. This result was consistent with the findings of previous studies. When children were tested in a trapezoidal room, they still went to the correct corner or the opposite corner. The video recording revealed that when children faced the two hemlines of the trapezium, they frequently and directly went to the correct corner or the opposite corner. However, when they faced the two lateral walls of the trapezium, they infrequently and indirectly went to the correct corner or the opposite corner. The present study provides converging evidence suggesting that children do not rely solely on geometric information about the dimensions of the walls of their environment. Further, their reorientation behaviors can be affected by egocentric information. It is most probable that children use information of the principal axe of the trapezoidal testing room in the task of reorientation.

Effects of embryonic light stimulation on the ability to discriminate left from right in the domestic chick

Following an early suggestion by Mach [Mach E. The analysis of sensations. Chicago: Open Court Publishing House; 1897 [reprinted by Dover Publications, 1959]] it has been claimed that brain asymmetry would be crucial for biological organisms in order to discriminate left from right. However, direct evidence in support of this hypothesis is scanty. In the animal system model provided by the newly hatched domestic chick ( Gallus gallus) it has been proved feasible to manipulate lateralization on visual tasks by exposing the eggs to light for a brief period before hatching. The light exposure leads to the development of lateralization of some visual functions and generates asymmetry in the thalamofugal visual projections to the forebrain, because the late-stage embryo is turned in the egg so that it occludes its left but not its right eye. Thus, it is possible to obtain organisms with strong (light-incubated chicks, Li-chicks) or weak (dark-incubated chicks, Di-chicks) lateralization. Li- and Di-chicks were trained to discriminate between two small beads for food reward on the basis of their relative left–right position. Li-chicks performed better than Di-chicks. In order to check whether Di-chicks showed a general impairment in discrimination learning, not confined to left–right discrimination only, chicks were tested in a spatial re-orientation task in a square-shaped arena, in which a target located in a corner could be identified using the left–right location of a conspicuous cue (the colour of a wall) which could be used as a landmark. Results showed that Di-chicks were impaired with respect to Li-chicks in use of left–right information for re-orientation, but not in use of the cue as a landmark. These results provide direct evidence that modulation of the strength of visual lateralization may affect left–right discrimination abilities.

Age-related differences during a gaze reorientation task while standing or walking on a treadmill

Falls among adults over the age of 65 years have become a growing concern. Two factors related to high incidence of falls in this group of adults are decreased head stability and impaired balance. Older adults' level of control of head stability or balance is unknown when they must reorient their gaze. In the current study, ten older adults (69 +/- 3.27 years) performed a gaze reorienting task while standing or walking on a treadmill. The task was the same as that used on young adults by Cinelli et al. (2007). The results show that older adults use a different strategy than young adults when reorienting gaze. Shoulder and hip rotations occurred synchronously when standing and were more variable when walking on a treadmill. As well, there was a larger difference between the onset of eye movements and body segment movement in the older adults. These differences can be accounted for by decreases in physiological subsystems. The visual presence of a visual target helped the older adults stabilize their heads-in-space by incorporating information from more than one sensory system.

Learning about environmental geometry: A flaw in Miller and Shettleworth's (2007) operant model.

Many studies have examined how humans and other animals reestablish a sense of direction following disorientation in enclosed environments. Results showing that geometric shape of an enclosure is typically encoded, sometimes to the exclusion of featural cues, have led to suggestions that geometry might be encoded in a dedicated geometric module. Recently, Miller and Shettleworth (2007) proposed that the reorientation task be viewed as an operant task and they presented an associative operant model that appears to account for many empirical findings from reorientation studies. In this paper we show that, although Miller and Shettleworth's insights into the operant nature of the reorientation task may be sound, their mathematical model has a serious flaw. We present simulations to illustrate the implications of the flaw. We also propose that the output of a simple neural network, the perceptron, can be used to conduct operant learning within the reorientation task and can solve the problem in Miller and Shettleworth's model.

Reorientation in the real world: The development of landmark use and integration in a natural environment

An influential series of studies have argued that young children are unable to use landmark information to reorient. However, these studies have used artificial experimental environments that may lead to an underestimation of the children’s ability. We tested whether young children could reorient using landmarks in an ecologically valid setting. Children aged between 3 and 7 years completed a reorientation task in open parkland, and the properties of the search array (size and distinctiveness) were manipulated in a within-subjects design. Responses were recorded using Global Positioning Systems technology. All age groups performed above chance level, demonstrating that young children can reorient using natural landmarks. This behaviour was modulated by the nature of the search array: children were more accurate when the locations were spaced in a large array, and when the search locations were distinctively coloured. This suggests that the integration between landmarks and search locations, at different spatial scales, is a key factor in characterising human reorientation in the real world.

Spatial Reorientation: Effects of Verbal and Spatial Shadowing

ABSTRACT Spatially disoriented adults flexibly conjoin geometric information (macroscopic shape) and nongeometric information (e.g., the color of a wall) to re-establish their bearings. It has been proposed that non-geometric information is incorporated into a geometric frame of reference through the use of spatial language. Support for this assumption comes from dual-task studies in which participants failed to use non-geometric features when they shadowed a verbal message concurrent to the reorientation task. These studies were performed in small rectangular spaces. In contrast, our study was performed in a large square room. Experiment 1 showed that verbal shadowing did not disrupt non-geometric feature use in this environment. In Experiment 2, we found that a spatial shadowing task that required the encoding of frequently changing spatial directions impaired reorientation behavior. Our study shows that nongeometric information can be used for reorientation without recourse to linguistic processes, and suggests that the use of non-geometric features is dependent upon a spatial coding process.

Spatial reorientation: the effects of space size on the encoding of landmark and geometry information

The effects of the size of the environment on animals' spatial reorientation was investigated. Domestic chicks were trained to find food in a corner of either a small or a large rectangular enclosure. A distinctive panel was located at each of the four corners of the enclosures. After removal of the panels, chicks tested in the small enclosure showed better retention of geometrical information than chicks tested in the large enclosure. In contrast, after changing the enclosure from a rectangular-shaped to a square-shaped one, chicks tested in the large enclosure showed better retention of landmark (panels) information than chicks tested in the small enclosure. No differences in the encoding of the overall arrangement of landmarks were apparent when chicks were tested for generalisation in an enclosure differing from that of training in size together with a transformation (affine transformation) that altered the geometric relations between the target and the shape of the environment. These findings suggest that primacy of geometric or landmark information in reorientation tasks depends on the size of the experimental space, likely reflecting a preferential use of the most reliable source of information available during visual exploration of the environment.

Lateralized fish perform better than nonlateralized fish in spatial reorientation tasks

Lines of fish ( Girardinus falcatus) obtained through selective breeding showing different degree and direction of behavioural lateralization in a variety of tasks were tested for their ability for spatial reorientation. In the first experiment, fish were required to reorient themselves after passive disorientation in a rectangular tank in the presence of a salient feature (a blue wall). Lateralized fish proved to be better than nonlateralized fish at using the geometric cues provided by the shape of the tank in order to disambiguate between corners with similar featural information. In the second experiment fish were tested in a square-shaped tank (in order to eliminate any geometric cues) in the presence of salient features (panels) located at the corners. Lateralized fish proved better than nonlateralized fish in using featural cues to reorient themselves. These findings suggest that lateralization may confer advantages in spatial reorientation based on the use of geometric and nongeometric cues.

We Have Never Been Human, or How We Lost Our Humanity: Derrida and Habermas on Cloning

If the question of the relation of nature and history is to be seriously posed, then it only offers any chance of solution if it is possible to comprehend historical being in its most extreme historical determinancy, where it is most historical, as natural being, or if it were possible to comprehend nature as an historical being where it seems to rest most deeply in itself as nature. It is no longer simply a matter of conceptualizing the fact of history as natural fact toto caelo (inclusively) under the category of historicity, but rather to retransform the structure of inner-historical events into a structure of natural events. No being underlying or residing within historical being itself is to be understood as ontological, that is, as natural being. The retransformation of concrete history into dialectical nature is the task of the ontological reorientation of the philosophy of history: the idea of natural-history. Theodor W. Adorno1 It is not arbitrary that the chairperson of the President's Council on Bioethics, Leon R. Kass, has turned his attention to the book of Genesis in the so-called Old Testament. Leon Kass, a Straussian neoconservative, who was also influenced by one of Heidegger's children, Hans Jonas, and who often appeals to Heidegger's philosopheme of the Gestell, has been advocating a bio-ethics predicated on a form of philosophical anthropology that seeks its roots in biblical stories about the origins of humanity. Over the last two decades Kass has been arguing against the corrosive, nay apocalyptic, effects of all forms of reproductive technologies. Early in the seventies, he prophesized that in-vitro fertilization would open the way to the end of sex, the family, stable gender roles, and the stability of Western society as such. Artificial reproduction, that is artificial sex, he anticipated, would lead to the "abolition of man," in that memorable phrase popularized by the Christian moralist and writer C. S. Lewis.2 We must forgo discussion of what is real, i.e., natural sex, as opposed to artificial or technologically assisted sex. Even in Genesis we find traces of artificial sex. But this is a discussion for biblical scholars. Early this year, Kass published a gargantuan book entitled The Beginning of Wisdom: Reading Genesis,3 which is a lengthy commentary on Genesis. Above all, however, this book is a philosophical anthropology disguised as biblical exegesis. The goal of the text is to argue that in the allegedly oldest book of Judeo-Christian wisdom literature, we can find insights into what it means to be human, not just spiritually, but also, and most importantly, biologically. In order for Kass to argue that we must reject all forms of technological intervention into human reproduction (although he does waver when it comes to extremely debilitating diseases), he appeals to a basic human nature. In fact, over the last two decades he has been pursuing what was called early in the twentieth century philosophical anthropology.4 The goals of this enterprise are to derive fundamental insights about the structure of the human being from both social and biological aspects of human existence. Thus, from the invariance and pervasiveness of gender roles across history and human groups, philosophical anthropologists want to derive insights about fundamental and inescapable sexual difformism, or an existential analytics that says that human Dasein must come in two, which like electrical plugs, must fit nicely into each other. The philosophical anthropological project, however, is not merely descriptive; it is also and perhaps most importantly, prescriptive. The idea is to read down and backwards into the essential structure of the human being, in order to then derive some ontic-ontologically grounded normative principles. If artificial insemination violates natural sex, then we must proscribe it. If gene therapy circumvents sexual reproduction, then it must be banned, as it violates the most fundamental aspect of human nature, and precisely what makes us human, namely that we are children of "natural" sex. …

Rhesus monkeys use geometric and nongeometric information during a reorientation task.

Rhesus monkeys (Macaca mulata) were subjected to a place finding task in a rectangular room perfectly homogeneous and without distinctive featural information. Results of Experiment 1 show that monkeys rely on the large-scale geometry of the room to retrieve a food reward. Experiments 2 and 3 indicate that subjects use also nongeometric information (colored wall) to reorient. Data of Experiments 4 and 5 suggest that monkeys do not use small angular cues but that they are sensitive to the size of the cues (Experiments 6, 7, and 8). Our findings strengthen the idea that a mechanism based on the geometry of the environment is at work in several mammalian species. In addition, the present data offer new perspectives on spatial cognition in animals that are phylogenetically close to humans. Specifically, the joint use of both geometric and landmark-based cues by rhesus monkeys tends to demonstrate that spatial processing became more flexible with evolution.

Rhesus monkeys use geometric and nongeometric information during a reorientation task.

Rhesus monkeys use geometric and nongeometric information during a reorientation task.

Redirecting Social Studies of Law

The essays in this volume offer a wealth of suggestions for new directions in sociolegal research, not only about the particular subjects they themselves address but also, by analogy, about many others. Here I want to approach the task of theoretical reorientation in a different way. While these essays were in progress I had occasion to attempt a critical overview of recent American scholarship in order to identify the questions posed and assess their strengths and weaknesses. This was in no sense a systematic research effort but merely a reflection upon my experience as editor of this Review from 1976 to 1978, based upon the approximately 500 manuscripts submitted, the nearly 200 books sent for review, the proposals offered for this project, and the papers presented at the second national meeting of the Law and Society Association in Minneapolis in 1978. I would modify these views somewhat in light of work disseminated in other ways or produced during the subsequent two years, but I would not greatly alter them. I offer them here in the hope of stimulating debate on the level of metatheory, for I sense that our field is running so smoothly along familiar tracks that the questions and answers have begun to sound a comfortable, but rather boring, “clackety-clack.”

Casework with Pregnant Women on Methadone Maintenance

Social workers must constantly bear in mind that the client is actively involved in the arduous task of self-rehabilitation and reorientation