Fixation disengagement and eye-movement latency

We examined eye-movement latencies to a target that appeared during visual fixation of a stationary stimulus, a moving stimulus, or an extrafoveal stimulus. The stimulus at fixation was turned off either before target onset (gap condition) or after target onset (overlap condition). Consistent with previous research, saccadic latencies were shorter in gap conditions than they were in overlap conditions (the gap effect). In Experiment 1, a gap effect was observed for vergence eye movements. In Experiment 2, a gap effect was observed for saccades directed at a target that appeared during visual pursuit of a moving stimulus. In Experiment 3, a gap effect was observed for saccades directed at a target that appeared during extrafoveal fixation. The present results extend reports of the gap effect for saccadic shifts during visual fixation to (a) vergence shifts during visual fixation, (b) saccadic shifts during smooth visual pursuit, and (c) saccadic shifts during extrafoveal fixation. The present findings are discussed with respect to the incompatible goals of fixation-locking and fixation-shifting oculomotor responses.     

Effectiveness of word order and grammatical marker as syntactic indicators of semantic relations

The effectiveness of word order and grammatical markers as syntactic indicators of semantic relations was explored using an artificial linguistic system. The results showed: (1) semantic interpretation of novel sentences was possible not only for Ss given fixed word order sentences with or without the markers, but also for Ss given the markers in random word order sentences; (2) Ss given neither indicator showed chance performance; (3) word order tended to be more efficient than grammatical markers as clues to semantic relations. The results suggest that the critical condition for language acquisition is the constant covariation of linguistic structure with semantic contexts. A process approach is discussed in accounting for the findings.Half of the data of the present experiment (FP and FA) were collected by Miss Norie Wake for her BA thesis, Okayama University (1978). The other half (RP and RA) were collected by the three juniors for their advanced course of experimental psychology, Okayama University (1979).     

Temporal course of activation of the antecedent by the reflexive in syntactically ambiguous sentences in Japanese

Three experiments examined the temporal course of the activation of an antecedent triggered by a reflexive,jibun, in syntactically ambiguous sentences in Japanese. Twenty-two students in Experiment 1 were tested for sentences where a subject word occupied the first position and an indirect object word the second, with the probe given for each word either immediately after the reflexive or at the end of the sentence. Reaction times (RTs) were faster when the probe was for subject (S-probe) than when it was for indirect object (IO-probe) irrespective of the probe position. Experiment 2 tested 22 students to determine the effect of order of mention of participant on the probe recognition time. RTs were faster for the S-probe than for the IO-probe, although the difference between the two probes was smaller when the probe was given immediately after the reflexive. Experiment 3 tested 22 students to examine the effect of context on an activation pattern. RTs were lower for the S-probe than for the IO-probe, though no difference was found between them for the probe given at the end of the sentence. Findings were interpreted as supporting the single-interpretation model for on-line analysis of syntactically ambiguous sentences and also the immediate-activation model in an assignment of the reflexive to its antecedent.     

Four methods of locating the egocenter: A comparison of their predictive validities and reliabilities

An attempt was made to identify the best method of locating the egocenter by comparing the predictive validity and reliability of the four methods introduced by Fry (1950), Funaishi (1926), Howard and Templeton (1966), and Roelofs (1959). To determine predictive validity, egocenters located by these methods were used to predict the responses of 14 subjects on three visual direction tasks; the correlation between the predicted and the actual responses on each task was computed. To determine reliability, the test-retest stability and the internal consistency were estimated for each method. All of the methods were reliable, but only the Howard and Templeton method predicted the results on all three of the visual direction tasks. The high reliability and predictive validity of the Howard and Templeton method is attributed to its high precision.     

Assessing Representations of Close Relationships Among Chinese and Japanese Adolescents and Young Adults: Commonalities and Differences in the Two Confucian Cultures

This article proposed an affective relationships model with its assessment instrument and examined how Chinese and Japanese adolescents and young adults construct mental representations of their close relationships, and the influence of Confucian cultural beliefs on these representations. The participants were 1,565 students aged 14 to 24 years living in China or Japan. The students were asked about their relationships with four figures: mother, father, closest friend, and romantic partner. We found that: (a) adolescents and young adults in both cultures constructed constellations of relationships containing multiple figures, and they articulated reasons for each figure's significance; and (b) there were between-group differences in the relationships with the father and the romantic partner for Chinese versus Japanese adolescents and young adults. These differences were partly explained by the influence of Confucianism on the Chinese participants’ cultural beliefs that retained the patriarchal values.     

Age-related EMG variables during maximum voluntary contraction

We studied the neuromuscular adaptation that occurs with aging by comparing changes in surface electromyography (EMG) variables from the tibialis anterior muscle in 12 young (21.4 +/- 1.7 yr. old) and 13 older subjects (70.8 +/- 3.1 yr. old). EMG variables such as the muscle fiber conduction velocity, median frequency, and averaged rectified value were calculated during maximum voluntary contraction for 5-sec. isometric contractions. The dorsiflexion force, muscle fiber conduction velocity, median frequency, and average rectified value during maximum voluntary contraction were significantly smaller in the older than in the younger group (p < .05). These results suggested that the neuromuscular system in older subjects is affected by the selective atrophy of fast twitch fibers and differences in motor unit firing statistics. Our results suggest the utility of applying the EMG observed during maximum voluntary contraction to the noninvasive evaluation of neuromuscular function in elderly persons.     

Kripke Semantics, Undecidability and Standard Completeness for Esteva and Godo's Logic MTL∀

The present paper deals with the predicate version MTL of the logic MTL by Esteva and Godo. We introduce a Kripke semantics for it, along the lines of Ono's Kripke semantics for the predicate version of FL_ew (cf. [O85]), and we prove a completeness theorem. Then we prove that every predicate logic between MTL and classical predicate logic is undecidable. Finally, we prove that MTL is complete with respect to the standard semantics, i.e., with respect to Kripke frames on the real interval [0,1], or equivalently, with respect to MTL-algebras whose lattice reduct is [0,1] with the usual order.     

The pursuit of Leonardo's constraint

Leonardo da Vinci (1452-1519) identified two stimulus situations that cannot be painted faithfully on a canvas: (a) when two objects are located in the same direction with respect to the painter's head, and (b) when parts of a surface are visible to one eye, but occluded from the other eye. He analysed these situations in terms of rays being emitted from the two eyes and, aside from the origin of the rays, the projective geometry he used was correct. His analyses showed that what can be seen from two vantage points cannot be represented on a canvas, because a 'correct' painting must be created from a single 'station point'. He was struck by the consequence of this fact that the depth seen on a canvas cannot match that of viewing the scene with two eyes. Subsequent visual scientists focused on Leonardo's observation about the lack of vivid depth in a picture. We argue that a complete understanding of what we see in the two stimulus situations requires consideration of visual direction in addition to visual depth. More specifically, we argue that the visual directions of the two objects, (a) above, and the visual direction of the monocular areas, (b) above, are dependent upon the constraint that two opaque objects cannot be represented in the same direction. Demonstrations that readers can perform, and that support this argument, are provided on the Perception website at http://www.perceptionweb.com/perc0102/ono.html.     

A new variant of the Ouchi illusion reveals Fourier-component-based processing

We report that anomalous motion illusion in a new variant of the Ouchi figure is well predicted by the strength of its Fourier fundamentals and harmonics. The original Ouchi figure consists of a rectangular checkerboard pattern surrounded by an orthogonal rectangular checkerboard pattern, in which illusory relative motion between the two regions is perceived. Although this illusion has been explained in terms of biases in integrating one-dimensional motion signals to determine the two-dimensional motion direction, the physiological mechanism has not been clarified. With our new stimuli, which consisted of thin lines instead of rectangles, we found that the perceived illusion is drastically reduced when the position of each line element is randomly shifted. This is not predicted by simple models of local motion integration along the visible edges. We demonstrate that the relative amplitude of the relevant Fourier fundamentals and harmonics leads to a quantitative prediction. Our analysis was successfully applied to other variants of the Ouchi figure (Khang and Essock 1997 Perception 26 585-597), closely predicting the reported rating. The results indicate that the underlying physiological mechanism is sensitive to the Fourier components of the stimuli rather than the visible edges.