Visual and auditory temporal integration in healthy younger and older adults

As people age, they tend to integrate successive visual stimuli over longer intervals than younger adults. It may be expected that temporal integration is affected similarly in other modalities, possibly due to general, age-related cognitive slowing of the brain. However, the previous literature does not provide convincing evidence that this is the case in audition. One hypothesis is that the primacy of time in audition attenuates the degree to which temporal integration in that modality extends over time as a function of age. We sought to settle this issue by comparing visual and auditory temporal integration in younger and older adults directly, achieved by minimizing task differences between modalities. Participants were presented with a visual or an auditory rapid serial presentation task, at 40-100 ms/item. In both tasks, two subsequent targets were to be identified. Critically, these could be perceptually integrated and reported by the participants as such, providing a direct measure of temporal integration. In both tasks, older participants integrated more than younger adults, especially when stimuli were presented across longer time intervals. This difference was more pronounced in vision and only marginally significant in audition. We conclude that temporal integration increases with age in both modalities, but that this change might be slightly less pronounced in audition

Game theoretical semantics for some non-classical logics

Paraconsistent logics are the formal systems in which absurdities do not trivialise the logic. In this paper, we give Hintikka-style game theoretical semantics for a variety of paraconsistent and non-classical logics. For this purpose, we consider Priest’s Logic of Paradox, Dunn’s First-Degree Entailment, Routleys’ Relevant Logics, McCall’s Connexive Logic and Belnap’s four-valued logic. We also present a game theoretical characterisation of a translation between Logic of Paradox/Kleene’s K3 and S5. We underline how non-classical logics require different verification games and prove the correctness theorems of their respective game theoretical semantics. This allows us to observe that paraconsistent logics break the classical bidirectional connection between winning strategies and truth values

Modal Meinongianism: Conceiving the Impossible

Modal Meinongianism—the version of Meinongianism invented by Graham Priest—presupposes that we can think about absolute impossibilities. I defend the view that we can, by tidying up a couple of loose ends in Priest’s arguments to this effect from his book Towards Non-Being

Nonmonotonicity and Knowability: As Knowable as Possible

According to the anti-realistic theory of meaning, everything that is true is knowable. Fitch’s (1963) paradox—based on very standard assumptions made in modal logic—is seen as a challenge to this theory. In this paper I argue that there is something wrong with Fitch’s derivation of the absurdity. Assuming—for the sake of argument— the thesis of anti-realism, I argue with Beall (2000) that this doesn’t lead to disaster in case we allow some contradictions to be true. By making use of a nonmonotonic consequence relation, I show that for all of Tennant’s (1997) so-called ‘Cartesian propositions’ that are true, we can derive that it is true and not false that they are knowable

Talking About Knowledge

In current studies of knowledge at the interface of logic and epistemology, philosophical positions and logical systems lore meet in new ways. In this little piece, a programmatic sequel to van Benthem (2011) and a prequel to Baltag et al. (2015), I add some further perspectives and issues to this mix from dynamic-epistemic logics of information and inquiry. My aim is to show that we can have a yet richer agenda of epistemic themes, and a richer view of the interplay of logic and epistemology, when we make epistemic action a major focus on a par with knowledge or belief per se

Audiovisual Perception of Congruent and Incongruent Dutch Front Vowels

Purpose: Auditory perception of vowels in background noise is enhanced when combined with visually perceived speech features. The objective of this study was to investigate whether the influence of visual cues on vowel perception extends to incongruent vowels, in a manner similar to the McGurk effect observed with consonants. Method: Identification of Dutch front vowels /i, y, e, Y/ that share all features other than height and lip-rounding was measured for congruent and incongruent audiovisual conditions. The audio channel was systematically degraded by adding noise, increasing the reliance on visual cues. Results: The height feature was more robustly carried over through the auditory channel and the lip-rounding feature through the visual channel. Hence, congruent audiovisual presentation enhanced identification, while incongruent presentation led to perceptual fusions and thus decreased identification. Conclusions: Visual cues influence the identification of congruent as well as incongruent audiovisual vowels. Incongruent visual information results in perceptual fusions, demonstrating that the McGurk effect can be instigated by long phonemes such as vowels. This result extends to the incongruent presentation of the visually less reliably perceived height. The findings stress the importance of audiovisual congruency in communication devices, such as cochlear implants and videoconferencing tools, where the auditory signal could be degraded

Temporal integration of consecutive tones into synthetic vowels demonstrates perceptual assembly in audition

Temporal integration is the perceptual process combining sensory stimulation over time into longer percepts that can span over 10 times the duration of a minimally detectable stimulus. Particularly in the auditory domain, such "long-term" temporal integration has been characterized as a relatively simple function that acts chiefly to bridge brief input gaps, and which places integrated stimuli on temporal coordinates while preserving their temporal order information. These properties are not observed in visual temporal integration, suggesting they might be modality specific. The present study challenges that view. Participants were presented with rapid series of successive tone stimuli, in which two separate, deviant target tones were to be identified. Critically, the target tone pair would be perceived as a single synthetic vowel if they were interpreted to be simultaneous. During the task, despite that the targets were always sequential and never actually overlapping, listeners frequently reported hearing just one sound, the synthetic vowel, rather than two successive tones. The results demonstrate that auditory temporal integration, like its visual counterpart, truly assembles a percept from sensory inputs across time, and does not just summate time-ordered (identical) inputs or fill gaps therein. This finding supports the idea that temporal integration is a universal function of the human perceptual system

Perceptual restoration of degraded speech is preserved with advancing age

Cognitive skills, such as processing speed, memory functioning, and the ability to divide attention, are known to diminish with aging. The present study shows that, despite these changes, older adults can successfully compensate for degradations in speech perception. Critically, the older participants of this study were not pre-selected for high performance on cognitive tasks, but only screened for normal hearing. We measured the compensation for speech degradation using phonemic restoration, where intelligibility of degraded speech is enhanced using top-down repair mechanisms. Linguistic knowledge, Gestalt principles of perception, and expectations based on situational and linguistic context are used to effectively fill in the inaudible masked speech portions. A positive compensation effect was previously observed only with young normal hearing people, but not with older hearing-impaired populations, leaving the question whether the lack of compensation was due to aging or due to age-related hearing problems. Older participants in the present study showed poorer intelligibility of degraded speech than the younger group, as expected from previous reports of aging effects. However, in conditions that induce top-down restoration, a robust compensation was observed. Speech perception by the older group was enhanced, and the enhancement effect was similar to that observed with the younger group. This effect was even stronger with slowed-down speech, which gives more time for cognitive processing. Based on previous research, the likely explanations for these observations are that older adults can overcome age-related cognitive deterioration by relying on linguistic skills and vocabulary that they have accumulated over their lifetime. Alternatively, or simultaneously, they may use different cerebral activation patterns or exert more mental effort. This positive finding on top-down restoration skills by the older individuals suggests that new cognitive training methods can teach older adults to effectively use compensatory mechanisms to cope with the complex listening environments of everyday life

EVALUATING URBANIZATION, FRAGMENTATION AND LAND USE/LAND COVER CHANGE PATTERN IN ISTANBUL CITY, TURKEY FROM 1971 TO 2002

Sivrikaya, Fatih/0000-0003-0860-6747; Cakir, Gunay/0000-0003-4951-4283; Keles, Sedat/0000-0002-2724-983XWOS: 000261929000006Spatiotemporal analysis of landscape dynamics is crucial in formulating an appropriate set of actions in landscape management. This paper presents a large scale analysis of the spatiotemporal structure of Istanbul, a highly urbanized city in Turkey, from 1971 to 2002 using forest cover type maps analysed with geographical information systems (GIS) and a spatial statistics programme. The quantitative evidence indicated that increasing population and expanding urbanization caused drastic changes to the temporal and spatial dynamics of land use/land cover pattern in Istanbul. There was a net increase of 5387.3ha in total forested areas (1.0 per cent) due to mainly reforestation activities even though the population increased three times over a 31-year period. Increase in number of patches and decrease in mean patch size together demonstrated that the landscape developed into a more fragmented structure that would negatively affect biodiversity and the resilience of the ecosystems. In conclusion, plain increase in forest areas may not always be a favourable situation. The quality, composition and the configuration of forest landscape should also be analysed to present the dynamics of ecosystem in terms of ecological and economical sustainability over a longer time and larger area. Copyright (C) 2008 John Wiley & Sons, Ltd