Capacity and contextual constraints on product activation: Evidence from task-irrelevant fact retrieval

Three experiments tested the limiting conditions of multiplication facts retrieval in a number-matching task (LeFevre, Bisanz, & Mrkonjic, 1988). By presenting two digits as cue and by requiring participants to decide whether a subsequent numerical target had been present in the pair, we found interference when the target coincided with the product of the cue digits. This was evidence for obligatory activation of multiplication facts. Also, we showed that multiplication facts retrieval occurred even in the absence of any arithmetic context (i.e., a multiplication sign between the cue digits) and did not require processing resources (i.e., the process met the capacity criterion of automaticity; Jonides, 1981), whereas manipulation of the spatial relation between the two operands (cue digits) negatively affected retrieval. The present work appears to be unique in the context of previous similar studies on mental calculation, which invariably adopted an arithmetic task as the primary demand. We identify this difference as the reason for the failure of all previous studies in revealing independence of multiplication facts from attentional resources. Furthermore, we suggest the application of a contextual definition of automaticity to this kind of retrieval, given the fact that it might depend both on association strength and on contextual setting variables.     

Memory deficits in Alzheimer's patients: A comprehensive review

Despite considerable experimental work on Alzheimer's disease (AD), the underlying cognitive mechanisms as well as the precise localization of neuropathological changes critical for memory loss remains undefined. A review of the neuropsychological literature on long-term memory deficits in AD patients suggests that AD patients display (a) a pervasive deficit of explicit memory, (b) a partial deficiency of implicit memory for verbal and visuoperceptual material (as measured by repetition priming procedures), and (c) a substantial sparing of implicit memory for visuomotor skills. The explicit memory loss is likely a result of encoding as well as consolidation difficulties. A faulty lexical-semantic knowledge structure appears responsible for deficient repetition priming effects. Since neuropathological changes diffusely affect the brain of AD patients, establishing a clear relationship between localization of cerebral lesions and memory deficits is particularly difficult. Nevertheless, data suggest that extensive involvement of the hippocampal-amygdala complex plays a major role in explicit memory loss. Damage to associative cortical areas likely is involved in repetition priming deficits. The relative integrity of primary motor and sensory cortical areas and of the basal ganglia likely subsume, by contrast, the normal learning of visuomotor skills.     

Effects of perceptual and conceptual similarity in semantic priming

Summary The study investigates the different contributions to semantic priming of two components of the semantic representation underlying a word. The two components are perceptually based information and conceptually based information. Perceptual information is based on physical attributes such as shape or color, while conceptual information consists of more abstract elements such as functional attributes. The question asked in this study was whether both components would produce an effect in semantic priming. Pairs of words either related because of a conceptual property (banana-apple), a perceptual property (ball-apple), or both because of a perceptual and conceptual property (cherry-apple) were presented as prime and target in a lexical decision and a word-naming task. The results showed independent contributions of perceptual and conceptual attributes to semantic priming.This research was supported by a grant from the Dutch Organization for the Advancement of Pure Research (ZWO). All three authors are senior authors and have contributed to all parts of the project.     

Frequency response characteristics for sinusoidal movement in the fovea and periphery

Threshold sensitivity was measured for sinusoidal movement of bright 1-deg lines against a dark background as a function of oscillation frequency and retinal location. Sensitivity was greatest in the fovea and at a frequency of 1–2 Hz. Peripheral sensitivity was more narrowly tuned than foveal sensitivity. The presence of a stationary reference line affected mainly the foveal sensitivity. The results are interpreted as evidence for both position- and velocity-sensitive mechanisms in the movement detection system.     

A note on some extension results

In this note, a fully modal proof is given of some conservation results proved in a previous paper by arithmetic means. The proof is based on the extendability of Kripke models.     

The lateralization of language comprehension using event-related potentials

Event-Related Potentials were recorded over occipital and parietal scalp from left- and right-handed adults presented with a language and a non-language visual stimulus using a divided field, "oddball" paradigm. The major finding of interest was that the P300 component was larger over the left than the right hemisphere of the right-handers when the language stimulus was presented to the left hemisphere; there were no hemispheric differences for the left-handers, regardless of field of presentation. These results are discussed in the context of developing noninvasive measures to lateralize language function.     

On a unified theory of models and thought experiments in natural sciences

In this paper a unified theory of models and thought experiments is proposed by considering them as fictions, á la Vaihinger. In order to reach this aim, the Hertzian and Botzmannian interpretation of theories as Bilder is reconsidered.     

Toward the neural basis of verbal priming: A cognitive-neuropsychological synthesis

Repetition priming is a mnemonic phenomenon that has attracted considerable attention from neuropsychologists and cognitive scientists. In an attempt at elucidating the putative mechanisms of priming, the present review draws on evidence from both domains. The review is restricted to verbal priming of visually presented stimuli—an area that accounts for the majority of empirical studies of priming. A number of theoretical accounts are presented. The interim conclusion is that neither multiple systems nor unitary system-multiple process theories can adequately explain the data on priming, although both contain many valid components. An integrative model is proposed to improve the explanation of the empirical evidence. The central assertion of the proposed model is that repetition priming depends on perceptual processes that can be mapped on specific neural systems. It is postulated that individual differences in perceptual processing ability predict variability in memory performance. It is proposed that data-driven priming of verbal stimuli critically depends on the activity of primary and secondary visual cortices in the right hemisphere, whereas conceptually-driven priming is hypothesized to rely on the activities of higher order tertiary association cortices in language areas and more anterior neocortical areas.     

Touch dominates haptic estimates of discordant visual-haptic size

Observers (72 college students) estimated the size of plastic squares that they held in their fingers and simultaneously viewed through a reducing lens that halved the squares’ visual size. The squares were grasped from below through a cloth that prevented direct sight of the hand. Each estimate was a match selected later, either haptically or visually, from a set of comparison squares. Vision dominated the visual estimates and touch dominated the haptic estimates, whether or not the observers knew in advance which type of estimate they would be asked to make. Neither modality inherently dominates perceived size.     

Automatic syntactic computation and use of semantic information during sentence comprehension

Summary The paper represents a contribution to the issue of the differential effects of syntactic, semantic and pragmatic information in the process of sentence comprehension. The results of four experiments are reported, in which sentences containing syntactic, semantic and pragmatic violations were presented with different tasks to see how these violations affected language comprehension, how easily they were detected and whether they affected sentence comprehension even when they were not explicitly recognized. The main results can be summarized as follows. First, the most relevant cues used to comprehend a sentence are not so much syntactic, but semantic or pragmatic. Second, with difficult or anomalous linguistic input, syntactic cues become more important. Third, even when the reader is not aware of syntactic violations, these seem to affect his processing of the linguistic input. This suggests the hypothesis of an automatic computation of syntactic information, the output of which is, however, used only when evidence coming from other sources, semantic or pragmatic, is insufficient or not clear enough.