Many theories have been proposed to explain difficulty with center embedded constructions, most attributing the problem to some kind of limited capacity short-term memory. However, these theories have developed for the most part independently of more traditional memory research, which has focused on uncovering general principles such as chunking and interference. This article attempts to gain some unification with this research by suggesting that an interesting range of core sentence processing phenomena can be explained as interference effects in a sharply limited syntactic working memory. These include difficult and acceptable embeddings, as well as certain limitations on ambiguity resolution, length effects in garden path structures, and the requirement for locality in syntactic structure. The theory takes the form of an architecture for parsing which can index no more than two constituents under the same syntactic relation. A limitation of two or three items shows up in a variety o...

Background: Are the information processing steps that support short-term sensory memory common to all the senses? Systematic, psychophysical comparison requires identical experimental paradigms and closely analogous stimuli, which can be challenging to obtain across modalities. Methodology/Principal Findings: Subjects performed a recognition memory task with auditory and visual stimuli that were comparable in complexity and in their neural representations at early stages of cortical processing. The visual stimuli were static and moving Gaussian-windowed, oriented, sinusoidal gratings (Gabor patches); the auditory stimuli were broadband sounds whose frequency content varied sinusoidally over time (moving ripples). Parallel effects on recognition memory were seen for number of items to be remembered, retention interval, and serial position. Further, regardless of modality, predicting an item’s recognizability requires taking account of (i)the probe’s similarity to the remembered list items (summed similarity), and (ii)the similarity between the items in memory (inter-item homogeneity). A model incorporating both these factors gives a good fit to recognition memory data for both auditory and visual stimuli. In addition, we present the first demonstration of the orthogonality of summed similarity and inter-item homogeneity effects. Conclusions/Significance: These data imply that auditory and visual representations undergo very similar transformations as they are encoded and retrieved from memory. 1

ing away from irrelevant details is a theoretical virtue, but the kinds of abstractions that module geography makes can lead to incorrect inferences from data. That such a possibility exists is clearly demonstrated by the working memory research of Just & Carpenter (1992). Briefly, Just and Carpenter have argued that some garden path effects that were previously interpreted in terms of a syntactically encapsulated module can instead be explained by individual differences in working memory capacity. Such an explanation is not considered in a theoretical framework that systematically ignores the role of memory structures in parsing. This point should be taken regardless of whether one is convinced by the current body of empirical support for this particular model---the fact remains that such an explanation could in principle account for the data, and these alternative explanations are only discovered by developing functionally complete architectures. The next few sections describes what ...

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We examined the time course of threshold reduction in the Gabor lateral masking paradigm (Polat and Sagi 1993). Contrast detection thresholds were measured (2AFC) for a briefly presented (36 msec) foveal Gabor signal (GS), preceded by a presentation (90 msec) of two high-contrast GS flanked masks, with Stimulus Onset Asynchrony (SOA) varying from 0 to 16,290 msec. Using target-to-mask separations of 3 and 12 (=0.15 ffi , GS wavelength), the 3 separated GS masks enhanced target threshold by 0.25 log units at SOA=0 and by 0.17 log units at 2,700 msec. At 12 separation, threshold was enhanced by 0.11 log units at SOA=0 and by 0.14 log units at 2,700 msec. Long-range (12) and short-range (3) enhancements persisted for over 16 seconds. Delayed and simultaneous enhancement depended on the stimulus configuration (maximal for collinear target and masks), local parameters (orientation, spatial frequency, and phase), and the presented eye (dichoptic vs. monoptic). The results suggest that spat...

harmonic relationship of 1:2, with contrasts in a 2:1 relationship. All component contrasts were well above detection threshold; overall stimulus contrast was 0.4. Twenty-seven stimuli were generated from factorial combinations of vertical fundamental frequency, 2, 4 and 6 cycles/image; horizontal frequency, 2, 4, and 6 cycles/image; and phases between vertical components, which were 0, p/4, or p/2. Stimuli were 5 deg in diameter, windowed with a 2-D Gaussian, and were viewed centrally. Mean luminance of the display was fixed at 18.7 cd/m 2 . Figure 2 shows the trial structure. After the last stimulus of any series, a warning tone sounded and then a test stimulus appeared for 1 s. Subjects judged whether the test stimulus had appeared in the series. Half the time it had and half the time it had not. Accuracy and latencies were recorded, and feedback about response correctness was given. Nine subjects gave 1800 trials e

Homogeneity computation: How inter-item similarity in

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