Canceling out both the real and the spectral lines

Neglect patients typically show motor perseveration while canceling targets on the ipsilesional side. This behavior can be influenced by the presence vs. absence of targets on the (neglected) contralesional side (). As alternative explanations, the authors proposed (i) directional hypokinesia--the patient cannot perform reaching movements towards detected left-sided targets, and thus carries on canceling on the right side, and (ii) allochiria--the patient misperceives left-sided targets as located on the right side, and cancels them there. We report here data from a patient (EZ) that might confirm the second hypothesis. EZ was presented with 19 displays in which the number and position of cancellation targets on both sides were varied systematically. EZ showed motor perseveration while canceling, but this tendency did not vary across conditions. Interestingly though, EZ also drew cancellation marks in the empty space between the ipsilesional targets, and this phenomenon was significantly more intense when there were more targets on the neglected side. As EZ's comments suggested, such a behavior might reflect the attempt to cancel out delusional targets. Our speculation is that those objects were generated by allochiria.     

Stimulus presentation order in receptive identification tasks: A systematic replication

Conflicting recommendations exist in the literature regarding the optimal order of stimulus presentation when teaching auditory–visual conditional discriminations. The present study examined the generality of a previously demonstrated advantage of presenting the auditory sample before visual comparisons (sample‐first condition) over the reverse sequence (comparison‐first condition). Participants were four typically developing 5‐ and 6‐year‐old boys. The procedures of Petursdottir and Aguilar (2016) were systematically replicated with the addition of a prompted error correction trial following each incorrect response. Overall, there were more instances of quicker mastery in the sample‐first condition (four of seven evaluations) than in the comparison‐first condition (two of seven evaluations). A comparison‐first advantage was associated with slower acquisition in both conditions than in the remaining evaluations, and an analysis of stimulus and position bias yielded tentative evidence for unwanted sources of stimulus control.     

Correction to: Medical Students’ Efforts to Integrate and/or Reclaim Authentic Identity: Insights from a Mask-Making Exercise

Journal of Medical Humanities - The authors would like to correct a misspelling in the name of one of the authors due to a typographical error. The name should read Atur Turakhia, not Artur...     

Civic Stratification, ‘Plastic’ Citizenship and ‘Plastic Subjectivities’ in Greek Immigration Policy

This article critically discusses Greek immigration policy, its adaptation to current social conditions such as the extended stay of undocumented migrants, and political pressures from the EU, with special focus on three groups of migrants: Albanians, ethnic-Greek Albanians (Northern Epirotes) and ethnic-Greeks from former Soviet Union. Taking into account Greek immigration law, its implementation by public authorities and the diversity of immigration status and associated rights accorded to these three groups of migrants, we argue that there is a ‘plastic citizenship’ (from the notion of plasticity) developed, where boundaries are blurred and processes of becoming or not are fluid, changing over time and influenced by notions of who should belong and who should not, who is entitled to what rights and who is not. Plastic citizenship creates plastic subjectivities for migrants in Greece.     

Informal and Absolute Proofs: Some Remarks from a Gödelian Perspective

Topoi - After a brief discussion of Kreisel’s notion of informal rigour and Myhill’s notion of absolute proof, Gödel’s analysis of the subject is presented. It is shown how...     

Gödel,Carnap and the Fregean Heritage

Synthese - Thorough a detailed analysis of version III of Gödel's Is mathematics syntax of language?, we propose a new interpretation of Gödel's criticism against the...     

Conversation and Behavior Games in the Pragmatics of Dialogue

In this article we present the bases for a computational theory of the cognitive processes underlying human communication. The core of the article is devoted to the analysis of the phases in which the process of comprehension of a communicative act can be logically divided: (1) literal meaning, where the reconstruction of the mental states literally expressed by the actor takes place: (2) speaker's meaning, where the partner reconstructs the communicative intentions of the actor; (3) communicative effect, where the partner possibly modifies his own beliefs and intentions; (4) reaction, where the intentions for the generation of the response are produced; and (5) response, where an overt response is constructed. The model appears to be compatible with relevant facts about human behavior. Our hypothesis is that, through communication, an actor tries to exploit the motivational structures of a partner so that the desired goal is generated. A second point is that social behavior requires that cooperation be maintained at some level. In the case of communication, cooperation is, in general, pursued even when the partner does not adhere to the actor's goals, and therefore no cooperation occurs at the behavioral level. This important distinction is reflected in the two kinds of game we introduce to account for communication. The main concept implied in communication is that two agents overtly reach a situation of shared mental states. Our model deals with sharedness through two primitives: shared beliefs and communicative intentions.     

Functional and anatomical profile of visual motion impairments in stroke patients correlate with fMRI in normal subjects

We used six psychophysical tasks to measure sensitivity to different types of global motion in 45 healthy adults and in 57 stroke patients who had recovered from the initial results of the stroke, but a large subset of them had enduring deficits on selective visual motion perception tasks. The patients were divided into four groups on the basis of the location of their cortical lesion: occipito-temporal, occipito-parietal, rostro-dorsal parietal, or frontal-prefrontal. The six tasks were: direction discrimination, speed discrimination, motion coherence, motion discontinuity, two-dimensional form-from-motion, and motion coherence – radial. We found both qualitative and quantitative differences among the motion impairments in the four groups: patients with frontal lesions or occipito-temporal lesions were not impaired on any task. The other two groups had substantial impairments, most severe in the group with occipito-parietal damage. We also tested eight healthy control subjects on the same tasks while they were scanned by functional magnetic resonance imaging. The BOLD signal provoked by the different tasks correlated well with the locus of the lesions that led to impairments among the different tasks. The results highlight the advantage of using psychophysical techniques and a variety of visual tasks with neurological patients to tease apart the contribution of different cortical areas to motion processing.