Crawley Completions of Residuated Lattices and Algebraic Completeness of Substructural Predicate Logics

This paper discusses Crawley completions of residuated lattices. While MacNeille completions have been studied recently in relation to logic, Crawley completions (i.e. complete ideal completions), which are another kind of regular completions, have not been discussed much in this relation while many important algebraic works on Crawley completions had been done until the end of the 70’s. In this paper, basic algebraic properties of ideal completions and Crawley completions of residuated lattices are studied first in their conncetion with the join infinite distributivity and Heyting implication. Then some results on algebraic completeness and conservativity of Heyting implication in substructural predicate logics are obtained as their consequences.     

Spatial distortion induced by imperceptible visual stimuli

Previous studies have explored the effects of attention on spatial representation. Specifically, in the attentional repulsion effect, a transient visual cue that captures attention has been shown to alter the perceived position of a target stimulus to the direction away from the cue. The effect is also susceptible to retrospective influence, that attention appears to attract the target when the cue appears afterwards. This study examined the necessity of visual awareness of the cue in these phenomena. We found that when the cues were rendered invisible by backward visual masks, both repulsion and attraction effects were weakened but still observed. The results suggest that the effects possibly depend on processes that are not necessarily associated with conscious visual awareness of the cues. We conjecture that attentional shift produced by the weak, invisible cues may play a role in spatial distortion; but other possible accounts including non-attentional ones are also discussed.     

Emotional Salience and the Isolation Effect

When a homogeneous list contains a few items that are different from the rest of the items in the list, these isolated items show enhanced recall compared to the same items in a list where these items are not isolated. This phenomenon, known as the isolation effect, has been explained on the basis of isolated items eliciting salience. In this experiment, negative pictures and neutral pictures were isolated at the early and late part of the list. The salience explanation would predict that participants would pay more attention to these isolated items resulting in higher judgments of learning (JOL) ratings compared to the same items in the control list. Negative pictures showed the isolation effect for both early and late isolation; however, for early isolation, JOL was similar between the isolated and non-isolated pictures indicating that the emotional isolation effect does not require emotional salience.     

Studies of interaction between He and elements with mass number 140 in Fe by time-differential perturbed-angular-correlation measurements

Room-temperature time-differential perturbed-angular-correlation (TDPAC) spectra of ¹⁴⁰Ce arising through ¹⁴⁰Ba-¹⁴⁰La from ¹⁴⁰Cs in He-doped Fe, unannealed and annealed in vacuum at various temperatures, were obtained in order to examine whether Ce (or rather, La and Ba) and He form complexes having a definite geometrical structure in Fe, as suggested by first-principles density-functional theory calculations. No clear signal of such complexes was observed in the TDPAC spectra. However, the TDPAC spectra indicate that Ce and He form complexes having a variety of geometrical structures. Comparison with reported TDPAC results on ¹¹¹Cd arising from ¹¹¹In in He-doped stainless steel shows that the parent atoms (La and Ba) of ¹⁴⁰Ce trap He atoms more efficiently than In atoms do, indicating stronger bonding of He to the former atoms, while different from the present case, ¹¹¹Cd (In)–He complexes form a unique geometrical structure.     

Mutual exclusivity in autism spectrum disorders: testing the pragmatic hypothesis

While there is ample evidence that children treat words as mutually exclusive, the cognitive basis of this bias is widely debated. We focus on the distinction between pragmatic and lexical constraints accounts. High-functioning children with autism spectrum disorders (ASD) offer a unique perspective on this debate, as they acquire substantial vocabularies despite impoverished social-pragmatic skills. We tested children and adolescents with ASD in a paradigm examining mutual exclusivity for words and facts. Words were interpreted contrastively more often than facts. Word performance was associated with vocabulary size; fact performance was associated with social-communication skills. Thus mutual exclusivity does not appear to be driven by pragmatics, suggesting that it is either a lexical constraint or a reflection of domain-general learning processes.     

Shortening of subjective tone intervals followed by repetitive tone stimuli

Accumulated evidence shows that a subjective time interval is lengthened by preceding or concurrent presentation of flickers or repetitive tone stimuli that have been hypothesized to increase the frequency of pulse generation by a brain pacemaker. In the present study, we presented a series of repetitive tone stimuli after an interval that started and ended with tone markers. We found that subjective perception of the preceding interval was not lengthened but shortened by the tone stimuli that followed the interval. The perceived duration decreased as the frequency of the repetitive tone stimuli increased. The effect disappeared when the repetitive tone stimuli were delivered with a delay of 500 msec after the test interval or when continuous sound was delivered instead of delivering a rapid series of tones. On the basis of the results, we propose that the pulse count accumulated during a test interval was normalized by the clock frequency just after the test interval in a postdictive manner.     

The effect of perceived motion-in-depth on time perception

The present study examined the effect of perceived motion-in-depth on temporal interval perception. We required subjects to estimate the length of a short empty interval starting from the offset of a first marker and ending with the onset of a second marker. The size of the markers was manipulated so that the subjects perceived a visual object as approaching or receding. We demonstrated that the empty intervals between markers was perceived as taking shorter to view when the object was perceived as approaching than when it was perceived as receding. We found in addition that the motion-in-depth effect disappeared when the shape continuity between the first and second marker was broken or when the object approached but missed the face. We conclude that anticipated collision of an approaching object altered perception of an empty interval.     

Psychological Essentialism at the Explicit and Implicit Levels: The Unique Status of Social Categories

Psychological essentialism refers to a naive theory concerning fundamental elements that bring a category into its existence. The present study examined the structure of this lay theory as well as its implicitness, with a special focus on social categories. In Study 1, Japanese college students rated a number of categories that were natural‐kind, social, or human artifacts, in terms of different elements of essentialist beliefs. A factor analysis revealed that entitativity and naturalness are the common underlying dimensions across these category domains. We also identified some natural‐kind and human artifact categories that can be used as two extreme referent points for the examination of naturalness perceived in a whole array of social categories. Study 2 assessed implicit and automatic judgments on naturalness using a go/no‐go task, and compared them to explicit judgments. Unlike natural kinds and artifacts, social categories were essentialized to a greater extent at the implicit level. These results suggest a dual process of intuitive and deliberate cognition, particularly involving social categories, with implications concerning the bases of stereotypes and prejudices.     

Intertrial temporal contextual cuing: association across successive visual search trials guides spatial attention

Contextual cuing refers to the facilitation of performance in visual search due to the repetition of the same displays. Whereas previous studies have focused on contextual cuing within single-search trials, this study tested whether 1 trial facilitates visual search of the next trial. Participants searched for a T among Ls. In the training phase, the spatial layout on trial N=1 was predictive of the target location on trial N. In the testing phase, the predictive value was removed. Results revealed an intertrial temporal contextual cuing effect: Search speed became progressively shorter in the training phase, but it significantly lengthened during testing. The authors conclude that the visual system is capable of retaining spatial contextual memory established earlier to facilitate perception.     

Motion parallax driven by head movements: conditions for visual stability, perceived depth, and perceived concomitant motion

Yoking the movement of the stimulus on the screen to the movement of the head, we examined visual stability and depth perception as a function of head-movement velocity and parallax. In experiment 1, for different head velocities, observers adjusted the parallax to find (a) the depth threshold and (b) the concomitant-motion threshold. Between these thresholds, depth was seen with no perceived motion. In experiment 2, for different head velocities, observers adjusted the parallax to produce the same perceived depth. A slower head movement required a greater parallax to produce the same perceived depth as faster head movements. In experiment 3, observers reported the perceived depth for different parallax magnitudes. Perceived depth covaried with smaller parallax without motion perception, but began to decrease with larger parallax and concomitant motion was seen. Only motion was seen with the larger parallax.