Robots are being extensively used for the purpose of discovering and testing empirical hypotheses about biological sensorimotor mechanisms. We examine here methodological problems that have to be addressed in order to design and perform “good” experiments with these machine models. These problems notably concern the mapping of biological mechanism descriptions into robotic mechanism descriptions; the distinction between theoretically unconstrained “implementation details” and robotic features that carry a modeling weight; the role of preliminary calibration experiments; the monitoring of experimental environments for (...) disturbing factors that affect both modeling features and theoretically unconstrained implementation details of robots. Various assumptions that are gradually introduced in the process of setting up and performing these robotic experiments become integral parts of the background hypotheses that are needed to bring experimental observations to bear on biological mechanism descriptions. (shrink)

Simulation studies have been carried out in robotics for a variety of epistemic and practical purposes. Here it is argued that two broad classes of simulation studies can be identified in robotics research. The first one is exemplified by the use of robotic systems to acquire knowledge on living systems in so-called biorobotics, while the second class of studies is more distinctively connected to cases in which artificial systems are used to acquire knowledge about the behaviour of autonomous mobile robots. (...) The two classes pertain to sub-areas of robotics which are apparently quite distant from one another in terms of goals, methodologies, technologies, and theoretical backgrounds. Still both are concerned with building, running, and experimenting on simulations of other systems. This paper aims to reveal and discuss some methodological commonalities between the two classes of studies. Philosophical literature on simulation methodologies has been traditionally focused on studies carried out in research fields other than robotics: this article may therefore contribute to shedding light on how the concept of simulation is used in robotics, and on the role simulation methodologies play in this research field. (shrink)

A number of research projects have recently taken up the challenge of formulating large-scale models of brain mechanisms at unprecedented levels of detail. These research enterprises have raised lively debates in the press and in the scientific and philosophical literature, some of them revolving around the question whether the incorporation of so many details in a theoretical model and in a computer simulations of it is really needed for the model to be explanatory. Is there a “right” level of detail? (...) In this article I analyse the claim, made by two leading neuroscientists, according to which the content of the why-question addressed and the amount of computational resources available constrains the choice of the most appropriate level of detail in brain modelling. Based on the recent philosophical literature on scientific explanation, I distinguish between two kinds of details, called here mechanistic decomposition and property details, and argue that the nature of the why-question provides only partial constraints to the choice of the most appropriate level of detail under the two interpretations of the term considered here. (shrink)

What can interactive robots offer to the study of social behaviour? Philosophical reflections about the use of robotic models in animal research have focused so far on methods involving robots which do not interact with the target system. Yet, leading researchers have claimed that interactive robots may constitute powerful experimental tools to study collective behaviour. Can they live up to these epistemic expectations? This question is addressed here by focusing on a particular experimental methodology involving interactive robots which has been (...) often adopted in animal research. This methodology is shown to differ from other robot-supported methods for the study of animal behaviour analysed in the philosophical literature, chiefly including the synthetic method. It is also discussed whether biomimicry and acceptability are necessary for an interactive robot to be sensibly used in animal research according to this method. (shrink)

In their theoretical and experimental reflections on the capacities and behaviours of living systems, neuroscientists often formulate generalizations about the behaviour of neural circuits. These generalizations are highly idealized, as they omit reference to the myriads of conditions that could perturb the behaviour of the modelled system in real-world settings. This article analyses an experimental investigation of the behaviour of place cells in the rat hippocampus, in which highly idealized generalizations were tested by comparing predictions flowing from them with real-world (...) experimental results. The aim of the article is to identify under what conditions even single prediction failures regarding the behaviour of single cells sufficed to reject highly idealized generalizations, and under what conditions prima facie counter-examples were deemed to be irrelevant to the testing of highly idealized generalizations. The results of this analysis may contribute to understanding how idealized models are tested experimentally in neuroscience and used to make reliable predictions concerning living systems in real-world settings. (shrink)

Bionic systems, connecting biological tissues with computer or robotic devices through brain–machine interfaces, can be used in various ways to discover biological mechanisms. In this article I outline and discuss a “stimulation-connection” bionics-supported methodology for the study of the brain, and compare it with other epistemic uses of bionic systems described in the literature. This methododology differs from the “synthetic”, simulative method often followed in theoretically driven Artificial Intelligence and cognitive science, even though it involves machine models of biological systems. (...) I also bring the previous analysis to bear on some claims on the epistemic value of bionic technologies made in the recent philosophical literature. I believe that the methodological reflections proposed here may contribute to the piecewise understanding of the many ways bionic technologies can be deployed not only to restore lost sensory-motor functions, but also to discover brain mechanisms. (shrink)

Bionic technologies connecting biological nervous systems to computer or robotic devices for therapeutic purposes have been recently claimed to provide novel experimental tools for the investigation of biological mechanisms. This claim is examined here by means of a methodological analysis of bionics-supported experimental inquiries on adaptive sensory-motor behaviours. Two broad classes of bionic systems (regarded here as hybrid simulations of the target biological system) are identified, which differ from each other according to whether a component of the biological target system (...) is replaced by an artificial component, or else a component of an artificial system is replaced by a biological component. The role of these hybrid systems in the modelling of adaptive sensory-motor biological behaviours is discussed with reference to bionics-supported experiments on the mechanisms of body stabilization in lampreys. Methodological problems emerging from these case studies often arise in computer-based and biorobotic simulations of biological behaviours too. Accordingly, the present analysis contributes to identifying a more general regulative methodological framework for the machine-based modelling of biological systems. (shrink)

The advancement of computing technology makes it possible to build extremely accurate digital reconstructions of brain circuits. Are such unprecedented levels of biological accuracy essential for brain simulations to play the roles they are expected to play in neuroscientific research? The main goal of this paper is to clarify this question by distinguishing between various roles played by large-scale simulations in contemporary neuroscience, and by reflecting about what makes a simulation biologically accurate. It is argued that large-scale simulations may play (...) model-oriented and prediction-oriented roles in brain research, and that the concept of biological accuracy can be interpreted as related to the plausibility of the theoretical model implemented in the simulation system, to the accuracy of the computer implementation, and to the level of details of the implemented model. Building on these observations and distinctions, it is argued that biological accuracy is not essential for a computer simulation to play the epistemic roles it is expected to play in brain research. (shrink)

In recent years, a number of research projects have been proposed whose goal is to build large-scale simulations of brain mechanisms at unprecedented levels of biological accuracy. Here it is argued that the roles these simulations are expected to play in neuroscientific research go beyond the “synthetic method” extensively adopted in Artificial Intelligence and biorobotics. In addition we show that, over and above the common goal of simulating brain mechanisms, these projects pursue various modelling ambitions that can be sharply distinguished (...) from one another, and that correspond to conceptually different interpretations of the notion of “biological accuracy”. They include the ambition to reach extremely deep levels in the mechanistic decomposition hierarchy, to simulate networks composed of extremely large numbers of neural units, to build systems able to generate rich behavioural repertoires, to simulate “complex” neuron models, to implement the “best” theories available on brain structure and function. Some questions will be raised concerning the significance of each of these modelling ambitions with respect to the various roles played by simulations in the study of the brain. (shrink)

Robotics and Philosophy of Science What relationship holds between robotics and philosophy of science? Can robotics research contribute to research in philosophy of science? Conversely, can the results achieved by philosophers of science contribute to the progress of research in robotics? This article will deal with both questions based on the distinction between the so-called philosophy of general science and the philosophy of the particular sciences. It will draw relatively pessimistic conclusions about the possibility that robotics research shed light on (...) questions pertaining to the philosophy of general science, and more optimistic conclusions about the potential contribution of robotics research to the philosophy of particular sciences. The normative aspect of philosophy of science is consistent with the possibility that this field of research, taking robotics as its object of study, provides guidelines and regulative methodological principles for engineers and roboticists. Through these considerations, this article attempts to explore a possible field of interaction between philosophy and scientific-technological research, with reference to a discipline that is assuming an increasingly predominant role in many aspects of daily life. (shrink)

In so-called ethorobotics and robot-supported social cognitive neurosciences, robots are used as scientific tools to study animal behavior and cognition. Building on previous epistemological analyses of biorobotics, in this article it is argued that these two research fields, widely differing from one another in the kinds of robots involved and in the research questions addressed, share a common methodology, which significantly differs from the “synthetic method” that, until recently, dominated biorobotics. The methodological novelty of this strategy, the research opportunities that (...) it opens, and the theoretical and technological challenges that it gives rise to, will be discussed with reference to the peculiarities of the two research fields. Some broad methodological issues related to the generalization of results concerning robot-animal interaction to theoretical conclusions on animal-animal interaction will be identified and discussed. (shrink)

This article addresses prospective and retrospective responsibility issues connected with medical robotics. It will be suggested that extant conceptual and legal frameworks are sufficient to address and properly settle most retrospective responsibility problems arising in connection with injuries caused by robot behaviours (which will be exemplified here by reference to harms occurred in surgical interventions supported by the Da Vinci robot, reported in the scientific literature and in the press). In addition, it will be pointed out that many prospective responsibility (...) issues connected with medical robotics are nothing but well-known robotics engineering problems in disguise, which are routinely addressed by roboticists as part of their research and development activities: for this reason they do not raise particularly novel ethical issues. In contrast with this, it will be pointed out that novel and challenging prospective responsibility issues may emerge in connection with harmful events caused by normal robot behaviours. This point will be illustrated here in connection with the rehabilitation robot Lokomat. (shrink)

Research on hybrid bionic systems (HBSs) is still in its infancy but promising results have already been achieved in laboratories. Experiments on humans and animals show that artificial devices can be controlled by neural signals. These results suggest that HBS technologies can be employed to restore sensorimotor functionalities in disabled and elderly people. At the same time, HBS research raises ethical concerns related to possible exogenous and endogenous limitations to human autonomy and freedom. The analysis of these concerns requires reflecting (...) on the availability of scientific models accounting for key aspects of sensorimotor coordination and plastic adaptation mechanisms in the brain. (shrink)

Abstract. The rapid developments of robotics technologies in the last twenty years of the XX century have greatly encouraged research on the use of robots for surgery, diagnosis, rehabilitation, prosthetics, and assistance to disabled and elderly people. This chapter provides an overview of robotic technologies and systems for health care, focussing on various ethical problems that these technologies give rise to. These problems notably concern the protection of human physical and mental integrity, autonomy, responsibility, ...

Computer simulations are widely used for surrogative reasoning in scientific research. They also play a crucial role in engineering, more specifically in the design of new robotic systems, yet the nature of this role has been little discussed so far in the philosophy of technology literature. The main claim made in this article is that the notion of surrogative reasoning is central to understanding how computer simulations can serve the purpose of designing new robots. More specifically, it is argued that (...) computer simulations can support two forms of surrogative reasoning, which are called model-oriented and prediction-oriented, whose inferential structure is reconstructed to some extent. And it is argued that, when computer simulations are used to design new robots, they are distinctively used in the model-oriented way. By unravelling the structure of the computer simulation-supported methods adopted in robotic design, this article may contribute to a finer-grained understanding of the epistemic processes involved in technological research. (shrink)

Nijhawan argues convincingly that predictive mechanisms are pervasive in the central nervous system (CNS). However, scientific understanding of visual prediction requires one to formulate empirically testable neurophysiological models. The author's suggestions in this direction are to be evaluated on the basis of more realistic experimental methodologies and more plausible assumptions on the hierarchical character of the human visual cortex.

First of all, in this paper we provide some clarifications on the several meanings of the term ‘ethics’, above all in the light of contemporary discussions on this matter. Then we analyze an important ethical concept, i.e. the concept of moral responsibility, for the sake of clarifying some problems concerning the human-robot relationship. Finally, we try to develop a well defined pattern of “ethics of responsibility” in order to give a general background for resolving concrete dilemmas that may arise in (...) the artificial world. (shrink)

Cybernetics promoted machine-supported investigations of adaptive sensorimotor behaviours observed in biological systems. This methodological approach receives renewed attention in contemporary robotics, cognitive ethology, and the cognitive neurosciences. Its distinctive features concern machine experiments, and their role in testing behavioural models and explanations flowing from them. Cybernetic explanations of behavioural events, regularities, and capacities rely on multiply realizable mechanism schemata, and strike a sensible balance between causal and unifying constraints. The multiple realizability of cybernetic mechanism schemata paves the way to principled (...) comparisons between biological systems and machines. Various methodological issues involved in the transition from mechanism schemata to their machine instantiations are addressed here, by reference to a simple sensorimotor coordination task. These concern the proper treatment of ceteris paribus clauses in experimental settings, the significance of running experiments with correct but incomplete machine instantiations of mechanism schemata, and the advantage of operating with real machines ??? as opposed to simulated ones ??? immersed in real environments. (shrink)

The "myside bias'' in evaluating arguments is an empirically well-confirmed phenomenon that consists of overweighting arguments that endorse one's beliefs or attack alternative beliefs while underweighting arguments that attack one's beliefs or defend alternative beliefs. This paper makes two contributions: First, it proposes a probabilistic model that adequately captures three salient features of myside bias in argument evaluation. Second, it provides a Bayesian justification of this model, thus showing that myside bias has a rational Bayesian explanation under certain conditions.

The my-side bias is a well-documented cognitive bias in the evaluation of arguments, in which reasoners in a discussion tend to overvalue arguments that confirm their prior beliefs, while undervaluing arguments that attack their prior beliefs. The first part of this paper develops and justifies a Bayesian model of myside bias at the level of individual reasoning. In the second part, this Bayesian model is implemented in an agent-based model of group discussion among myside-biased agents. The agent-based model is then (...) used to perform a number of experiments with the objective to study whether the myside bias hinders or enhances the ability of groups to collectively track the truth, that is, to reach the correct answer to a given binary issue. An analysis of the results suggests the following: First, whether the truth-tracking ability of groups is helped or hindered by myside bias crucially depends on how the strength of myside bias is differentially distributed across subgroups of discussants holding different beliefs. Second, small groups are more likely to track the truth than larger groups, suggesting that increasing group size has a detrimental effect on collective truth-tracking through discussion. (shrink)

Happiness, like other basic emotions, has visual properties that create the conditions for happiness to be perceived in others. This is to say that happiness is perceivable. Its visual properties are to be identified with those facial expressions that are characteristic of happiness. Yet saying that something is perceivable does not suffice for us to conclude that it is perceived. We therefore need to show that happiness is perceived. Empirical evidence suggests that the visual system functions to perceive happiness as (...) well as other basic emotions. Experiences that can be had simply by virtue of how the perceptual system functions are known as observations. I will thus argue that visual experiences in which we become aware of others’ happiness are observations. This approach will provide the necessary conceptual framework to show that we have perceptual knowledge of others’ happiness. (shrink)

BackgroundThe aim of this study was to explore the construct validity and diagnostic properties of the Reading the Mind in the Eyes Test in non-demented patients with amyotrophic lateral sclerosis.MaterialsA total of 61 consecutive patients and 50 healthy controls were administered the 36-item RMET. Additionally, patients underwent a comprehensive assessment of social cognition via the Story-Based Empathy Task, which encompasses three subtests targeting Causal Inference, Emotion Attribution, and Intention Attribution, as well as global cognitive [the Edinburgh Cognitive and Behavioral ALS (...) Screen ] and behavioral screening [the Frontal Behavioral Inventory ; the Dimensional Apathy Scale ; the Beck Depression Inventory ; and the State and Trait Anxiety Inventory-Y]. The construct validity of the RMET was tested by regressing it within a stepwise model that encompassed as predictors the abovementioned cognitive and behavioral measures, covarying for demographic and motor confounders. Receiver-operating characteristics analyses allowed exploring intrinsic and post-test properties of the RMET both in discriminating patients from HCs and in identifying patients with a defective SET-EA performance.ResultsThe RMET was solely predicted by the SET-EA and SET-IA. RMET scores showed high accuracy both in discriminating patients from HCs and in identifying patients with a defective SET-EA score, with adequate-to-optimal both intrinsic and post-test properties.DiscussionThe RMET is a convergently and divergently valid measure of affective social cognition in non-demented ALS patients, also featuring optimal intrinsic and post-test diagnostic properties in both case-control and case-finding scenarios. (shrink)

Ninety-one right brain-damaged patients with left neglect and 43 right brain-damaged patients without neglect were asked to extend horizontal segments, either left- or rightward, starting from their right or left endpoints, respectively. Earlier experiments based on similar tasks had shown, in left neglect patients, a tendency to overextend segments toward the left side. This seemingly paradoxical phenomenon was held to undermine current explanations of unilateral neglect. The results of the present extensive research demonstrate that contralesional overextension is also evident in (...) most right brain-damaged patients without contralesional neglect. Furthermore, they show that in a minority of left neglect patients, the opposite behavior, i.e., right overextension can be found. The paper also reports the results of correlational analyses comprising the parameters of line-extension, line-bisection, and cancellation tasks, as well as the parameters relative to the Milner Landmark Task, by which a distinction is drawn between perceptual and response biases in unilateral neglect. A working hypothesis is then advanced about the brain dysfunction underlying neglect and an attempt is made at finding an explanation of neglect and the links between the mechanisms of space representation and consciousness through the study of the changes induced by unilateral brain lesions in the characteristics of space-coding neurons. Abbreviations: C, control group;GN+91,full group of neglect patients;GN+27,group of neglect patients with relative left overextension;GN+14,group of neglect patients with relative right overextension;GN-43,full group of non-neglect patients;GN-9,group of non-neglect patients with relative left overextension; H canc, H cancellation task; LE, left extension; LE/RE, ratio of left-right extension; N+, neglect patients; N-, non-neglect patients; PB Land-M, perceptual bias on Landmark motor task; PB Land-V, perceptual bias on Landmark verbal task; RB Land-M, response bias on Landmark motor task; RB Land-V, response bias on Landmark verbal task; RE, right extension. (shrink)

BackgroundThe present study aimed at assessing the diagnostic properties of the Montreal Cognitive Assessment in non-demented ALS patients and at exploring the MoCA administrability according to motor-functional status.MaterialsN = 348 patients were administered the MoCA and Edinburgh Cognitive and Behavioural ALS Screen. Administrability rates and prevalence of defective MoCA scores were compared across King’s and Milano-Torino clinical stages. Regression models were run to test whether the non-administrability of the MoCA and a defective score on it were predicted, net of the (...) ECAS-Total, by disease duration, ALS Functional Rating Scale-Revised and progression rate, computed as /disease duration. Intrinsic and post-test diagnostics were tested against a below-cut-off ECAS-total score.ResultsThe 79.9% of patients successfully underwent the MoCA, whose administrability rates decreased with advanced clinical stages, at variance with its defective score prevalence. The probability of the FAB not being administrable was predicted only by lower ALSFRS-R-bulbar and-upper-limb scores; no motor features, but the ECAS-Total, predicted a defective MoCA performance. The MoCA showed high accuracy and good intrinsic and post-test properties—being slightly more specific than sensitive.DiscussionIn non-demented ALS patients, the MoCA is featured by optimal diagnostics as a screener for cognitive impairment, especially for ruling-out its occurrence, as long as patients are in the early stages of the disease and have sufficiently spared bulbar and upper-limb functions. (shrink)

BackgroundThis study aimed at standardizing and providing preliminary evidence on the clinical usability of the Italian telephone-based Verbal Fluency Battery, which includes phonemic, semantic and alternate verbal fluency tasks.MethodsThree-hundred and thirty-five Italian healthy participants and 27 individuals with neurodegenerative or cerebrovascular diseases were administered the t-VFB. Switch number and cluster size were computed via latent semantic analyses. HPs underwent the telephone-based Mental State Examination and Backward Digit Span. Construct validity, factorial structure, internal consistency, test-retest and inter-rater reliability and equivalence with (...) the in-person Verbal Fluency tasks were assessed. Norms were derived via Equivalent Scores. Diagnostic accuracy against clinical populations was assessed.ResultsThe majority of t-VFB scores correlated among each other and with the BDS, but not with the MMSE. Switch number correlated with t-PVF, t-SVF, t-AVF scores, whilst cluster size with the t-SVF and t-AVF scores only. The t-VFB was underpinned by a mono-component structure and was internally consistent. Test-retest and inter-rater reliability were optimal. Each t-VFB test was statistically equivalent to its in-person version. Education predicted all t-VFB scores, whereas age t-SVF and t-AVF scores and sex only some t-SVF scores. Diagnostic accuracy against clinical samples was optimal.DiscussionThe t-VFB is a valid, reliable and normed telephone-based assessment tool for language and executive functioning, equivalent to the in-person version; results show promising evidence of its diagnostic accuracy in neurological populations. (shrink)

The model of self-referential truth presented in this paper, named Revision-theoretic supervaluation, aims to incorporate the philosophical insights of Gupta and Belnap’s Revision Theory of Truth into the formal framework of Kripkean fixed-point semantics. In Kripke-style theories the final set of grounded true sentences can be reached from below along a strictly increasing sequence of sets of grounded true sentences: in this sense, each stage of the construction can be viewed as an improvement on the previous ones. I want to (...) do something similar replacing the Kripkean sets of grounded true sentences with revision-theoretic sets of stable true sentences. This can be done by defining a monotone operator through a variant of van Fraassen’s supervaluation scheme which is simply based on ω-length iterations of the Tarskian operator. Clearly, all virtues of Kripke-style theories are preserved, and we can also prove that the resulting set of “grounded” true sentences shares some nice features with the sets of stable true sentences which are provided by the usual ways of formalising revision. What is expected is that a clearer philosophical content could be associated to this way of doing revision; hopefully, a content directly linked with the insights underlying finite revision processes. (shrink)

We examine the relationship between scientific knowledge and the legal system with a focus on the exclusion of expert testimony from trial as ruled by the Daubert standard in the US.We introduce a simple framework to understand and assess the role of judges as “gatekeepers”, monitoring the admission of science in the courtroom. We show how judges face a crucial choice, namely, whether to limit Daubert assessment to the abstract reliability of the methods used by the expert witness or also (...) to check whether the application of those methods was correct. Undesirable outcomes result from both choices, thereby giving rise to the “gatekeeper’s dilemma.” We illustrate the dilemma by analyzing in some detail two well-known cases of Daubert challenges to economic experts. Finally, we present reasons for the absence of straightforward solutions to the dilemma and for its likely endurance. (shrink)

Questo contributo tratta della perifrasi ‘εἶναι + participio’ in greco omerico all’interfaccia fra morfosintassi e semantica. I dati sono analizzati con riferimento al quadro teorico elaborato da Nardi e Romagno (2022), che considerano la perifrasi con εἶναι in greco antico come una categoria prototipica: secondo questa prospettiva, la categoria sovraordinata ‘εἶναι + participio’ include due manifestazioni formalmente diverse ma funzionalmente equivalenti, un costrutto con una copula espressa, cioè una perifrasi vera e propria, e un costrutto senza copula espressa, cioè un (...) participio predicativo (fondamentalmente, un participio che funziona come una forma finita). Questa indagine mira a valutare se si possano individuare fattori che determinano o soggiacciono all’uso di queste costruzioni participiali in greco omerico. L’analisi dei dati raccolti nei poemi omerici mostra che le costruzioni participiali codificano la funzione specifica di significare lo stato, inerente o acquisito, del soggetto del predicato, costituendo pertanto un’alternativa (più o meno libera) al perfetto originario (cfr. Romagno 2005). (shrink)

Aristotle and Eudemus report a Speusippean argument to the effect that defining anything requires knowing everything. Scholars have failed to make sense of this argument. This paper argues that the main preoccupations to which the Puzzle is meant to respond are: (i) to ensure the co-extensiveness of the definition with the definiendum; (ii) to rule out a particular definitional mistake—underdivision. The implications of the Puzzle for Speusippus’ conception of knowledge are further explored.

Summary My paper aims to clarify the subsequent steps of Rome’s encroachment on Etruria in the aftermath of the Pyrrhic War. As is well known, the Latin colony of Cosa was founded in 273 BC on the Tyrrhenian coast to the north of Vulci; moreover, in the years 264–245 BC, four citizen colonies were founded on the Caeretan coast, namely Castrum Novum, Pyrgi, Alsium and Fregenae. Unfortunately, it is not easy to reconstruct precisely what the Roman movements in Etruria were, (...) or how the Etruscans reacted to them. Above all, it is difficult to determine whether a colonial foundation like Cosa – which was contemporary with the establishment of Paestum in Lucania – was part of a broader and coherent strategy that the Romans had been following in their expansion into the Italian peninsula. By evaluating all the available evidence, I will try to demonstrate that the foundation of Cosa depended more upon particular contingencies than upon any preconceived plan for the conquest of Italy. (shrink)

When left-neglect patients are required to extend horizontal segments to double their original length, relative left overextension is frequently observed. Less frequently, relative left underextension may also be found. It was hypothesized that this contrast could depend on the degree of horizontal anisometry of the medium for the representation of spatial properties. The present paper reports an experiment conducted in order to test that hypothesis, on the basis of which left overextension should be larger with shorter than with longer segments (...) and with segments lying in the right rather than in the left hemispace. Although supportive, the results unveiled unexpected complications: the expected effect of line length was found only in neglect patients with frontal damage, while the expected effect of side of presentation was found only in neglect patients without frontal damage. (shrink)