593 research outputs found
A longitudinal study of repair strategies in primary progressive aphasia using conversation analysis
Determinants of harassment in online multiplayer games
Objective. Online multiplayer games allow large numbers of participants to play simultaneously online. Unfortunately, this has also given rise to new forms of harassment and abuse. The current study used the criminological framework of Routine Activity Theory to identify possible circumstantial and individual risk factors that predict both general and sexual harassment victimization in this online context.
Method. An online survey of online multiplayer gamers (N = 883) was conducted. Measures included harassment exposure, guardianship, and target suitability. These determinants were used to predict general and sexual harassment victimization in multiple regression analyses. Analyses controlled for social desirability responding.
Results. Both sexual harassment victimization (R² = 63%) and general harassment victimization (R² = 57%) were successfully predicted using the determinants. The gender of the gamer is associated with the type of harassment received; women are more likely to encounter sexual harassment, while men are more likely to be harassed in the general sense. Gaming for fewer hours per week, with mostly or exclusively female avatars, and sharing personal information (e.g. gender) predicts sexual harassment victimization, whereas playing in Player-versus-Player game modes predicts general harassment victimization. Harassing other gamers and associating with harassers predicts both general and sexual harassment.
Conclusions. Our models explained a sizable percentage of the variation in harassment, indicating for the first time that the Routine Activity Theory can be applied to understand online harassment in gaming. Specifically, it was found that different types of in-game exposure predict different types of victimization, that lacking personal self-guardianship predicts sexual harassment and that gender (or revealing gender) is associated with changes in harassment
Design of an ontology for decision support in VR exposure therapy
Virtual Reality (VR) is finding its way into many domains, including healthcare. Therapists greatly benefit from having any scenario in VR at their disposal for exposure therapy. However, adapting the VR environment to the needs of the patient is time-consuming. Therefore, an intelligent decision support system that takes context information into account would be a big improvement for personalised VR therapy. In this paper, a semantic ontology is presented for modelling relevant concepts and relations in the context of anxiety therapy in VR. The necessary knowledge was collected through workshops with therapists, this resulted in a layered ontology. Furthermore, semantic reasoning through logical rules enables deduction of interesting high-level knowledge from low-level data. The presented ontology is a starting point for further research on intelligent adaptation algorithms for personalised VR exposure therapy
The role of the right hemisphere in the recovery of stroke-related aphasia : a systematic review
Quantitative analysis of language production in Parkinson's disease using a cued sentence generation task
The present study examined language production skills in Parkinson's disease (PD) patients. A unique cued sentence generation task was created in order to reduce demands on memory and attention. Differences in sentence production abilities according to disease severity and cognitive impairments were assessed. Language samples were obtained from 20 PD patients and 20 healthy control participants matched for age, sex and educational level. In addition, a cognitive test for verbal memory and resistance to cognitive interference was administered. Statistical comparisons revealed significant language changes in an advanced stage of the disease. Advanced PD patients showed a reduction in lexical diversity in notional verbs, which was absent in nouns. Cognitive dysfunctions such as impaired verbal memory are suggested to contribute to the typical noun/verb dissociation in PD patients. In addition, advanced PD patients produced more semantic perseverations, which may be related to set-switching problems. In conclusion, whether language disturbances in PD are the result of non-linguistic cognitive dysfunctions or reflect pure language deficits exacerbated by cognitive impairments, remains a matter of debate. However, the negative impact of cognitive dysfunctions may be important
Sentence context prevails over word association in aphasia patients with spared comprehension : evidence from N400 event-related potential
Behavioral and event-related potential (ERP) studies on aphasia patients showed that lexical information is not lost but rather its integration into the working context is hampered. Studies have been conducted on the processing of sentence-level information (meaningful versus meaningless) and of word-level information (related versus unrelated) in aphasia patients, but we are not aware of any study that assesses the relationship between the two. In healthy subjects the processing of a single word in a sentence context has been studied using the N400 ERP. It was shown that, even when there is only a weak expectation of a final word in a sentence, this expectation will dominate word relatedness. In order to study the effect of semantic relatedness between words in sentence processing in aphasia patients, we conducted a crossed design ERP study, crossing the factors of word relatedness and sentence congruity. We tested aphasia patients with mild to minimum comprehension deficit and healthy young and older (age-matched with our patients) controls on a semantic anomaly judgment task when simultaneously recording EEG. Our results show that our aphasia patient's N400 amplitudes in response to the sentences of our crossed-design study were similar to those of our age-matched healthy subjects. However, we detected an increase in the N400 ERP latency in those patients, indicating a delay in the integration of the new word into the working context. Additionally, we observed a positive correlation between comprehension level of those patients and N400 effect in response to meaningful sentences without word relatedness contrasted to meaningless sentences without word relatedness
Neurophysiological alterations during phoneme and word processing in the acute stage of aphasia
Only a few studies have investigated neurophysiological substrates of phonological impairment in patients with aphasia (PWA) in the acute stage after stroke (Ilvonen et al., 2003; Nolfe et al., 2006). Behavioral evaluation is often problematic or even impossible in PWA in the acute stage, as some patients cannot be instructed due to severely impaired comprehension, reduced consciousness or confusion. Event-related potentials (ERPS) can circumvent such problems as they have already demonstrated their sensitivity and usefulness in measuring certain language processes in both a healthy and clinical population. The objective of the present study is to investigate neurophysiological substrates of phoneme and word processing in PWA with phonological disorders (PWA-PD) in the acute stage after stroke.
Ten PWA-PD (5 men, 5 women; mean age 69.4 years +/- 3.46) are included and compared to 44 healthy control participants (HC) (20 men, 24 women; mean age 44.46 years +/- 13.76). All patients suffer from a first-ever stroke in the left hemisphere, are right-handed, have Dutch as native language and present with acute phonological disorders as established with the Psycholinguistic Assessment of Language Processing in Aphasia (Bastiaanse et al., 1995). PWA-PD admitted with a recurrent stroke, left handedness, indications for comorbid cognitive disorders and severe hearing deficits are excluded. Phoneme discrimination is studied in a pre-attentive (MMN) and attentive (P300) oddball task with respect to the phonemic contrasts place of articulation (PoA), voicing and manner of articulation (MoA) to explore whether a qualitative pattern of impaired phonemic contrast sensitivity can be determined. Word recognition is studied in a pre-attentive oddball task, which consists of differentiating real words from pseudowords. The electroencephalogram (EEG) is recorded through 23 Ag/AgCl-electrodes using a linked ears reference and an electrode placed on the forehead as ground. Further EEG analysis includes additional filtering, independent component analysis, segmentation, baseline correction and artifact rejection. Statistical analysis is performed on amplitudes and latencies specifically taking into account the large heterogeneity among PWA-PD.
During phoneme discrimination, PWA-PD only show MMN amplitude reductions with voicing as phonemic contrast in the pre-attentive condition, whereas all three phonemic contrasts reveal smaller P300 amplitudes compared to HC in the attentive condition. PWA-PD show a larger response to PoA compared to MoA and voicing in the pre-attentive condition, whereas in the attentive condition only the difference between PoA and voicing remains. During word recognition, PWA-PD and HC display larger responses to pseudowords compared to real words from 100 ms onwards, continuing in the P200 and N400 time windows, despite the fact that responses to pseudowords show longer latencies in PWA-PD. In summary, this demonstrates a distinct pattern of impaired phonemic contrast sensitivity in PWA-PD, with PoA being the most resistant, voicing the most vulnerable and a substantial effect of attention. Moreover, PWA-PD suffer from a delay in lexical access due to a less efficient information transfer, which did not impair the response to pseudowords. For possible clinical implementation of ERPs, pre-attentive tasks seem to be more suitable than attentive tasks in the acute stage of aphasia
Clinical use of event-related potentials in diagnostic and therapeutic evaluation of phonological input processes: a one year follow-up case study
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Phonologically related EEG as a more reliable diagnostic tool in the recovery of aphasia in the different stages after stroke
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