Abstract not found

We report a quantitative investigation of the visual identification and auditory comprehension deficits of 4 patients who had made a partial recovery from herpes simplex encephalitis. Clinical observations had suggested the selective impairment and selective preservation of certain categories of visual stimuli. In all 4 patients a significant discrepancy between their ability to identify inanimate objects and inability to identify living things and foods was demonstrated. In 2 patients it was possible to compare visual and verbal modalities and the same pattern of dissociation was observed in both. For 1 patient, comprehension of abstract words was significantly superior to comprehension of concrete words. Consistency of responses was recorded within a modality in contrast to a much lesser degree of consistency between modalities. We interpret our findings in terms of category specificity in the organization of meaning systems that are also modality specific semantic systems.

The nature of recollective experience was examined in a recognition memory task. Subjects gave “remember ” judgments to recognized items that were accompanied by conscious recollec-tion and “know ” judgments to items that were recognizedon some other basis. Although a levels-of-processing effect (Experiment 1) and a picture-superiority effect (Experiment 2) were obtained for overall recognition, these effects occurred only for “remember ” judgments, and were reversed for “know ” judgments. In Experiment 3, targets and lures were either preceded by a masked repetition of their own presentation (thought to increase perceptual fluency) or of an unrelated word. The effectof perceptual fluencywas obtained for overall recogrntion and “know ” judgments but not for “remember ” judgments. The data obtained for confidence judgments using the same design (Experiment4) indicated that “remember”/”know ” judgments are not made solely on the basis ofconfidence. Thesedata support the two-factor theories ofrecognition memory by dissociat-ing two forms of recognition, and shed light on the nature of conscious recollection. Consciousness permeates mental activity and yet, with

According to a two-step account of the mere-exposure effect, repeated exposure leads to the subjective feeling of perceptual fluency, which in turn influences liking. If so, perceptual fluency manipulated by means other than repetition should influence liking. In three experiments, effects of perceptual fluency on affective judgments were examined. In Experiment 1, higher perceptual fluency was achieved by presenting a matching rather than nonmatching prime before showing a target picture. Participants judged targets as prettier if preceded by a matching rather than nonmatching prime. In Experiment 2, perceptual fluency was manipulated by figure-ground contrast. Stimuli were judged as more pretty, and less ugly, the higher the contrast. In Experiment 3, perceptual fluency was manipulated by presentation duration. Stimuli shown for a longer duration were liked more, and disliked less. We conclude (a) that perceptual fluency increases liking and (b) that the experience of fluency is affectively positive, and hence attributed to positive but not to negative features, as reflected in a differential impact on positive and negative judgments.

We propose that aesthetic pleasure is a funnction of the perceiver s processing dynam-ics: The more fluently perceivers can process an object, the more positive their aes-thetic response. We review variables known to influence aesthetic judgments, such as figural goodness, figure-ground contrast, stimulus repetition, symmetry, and pro-totvpicalitv, and trace their effects to changes in processing fluency. Other variables that influence processingfluency like visual or semantic priming, similarly increase judgments of aesthetic pleasure. Our proposal provides an integrativeframeworkfor the study of aesthetic pleasure and sheds light on the interplay between early prefer-ences versus cultural influences on taste, preferences for both prototypical and ab-stracted forms, and the relation between beauty and truth. In contrast to theories that trace aesthetic pleasure to objective stimulus features per se, we propose that beauty is grounded in the processing experiences of the perceiver which are in part afunc-tion ofstimulus properties. What is beauty? What makes for a beautiful face, appealing painting, pleasing design, or charming scen-ery? This question has been debated for at least 2,500 years and has been given a wide variety of answers (Feagin, 1995; Tatarkiewicz, 1970). However, one can broadly distinguish three main positions. Many theorists, dating back at least to Plato, saw beauty as a property of an object that produces a plea-surable experience in any suitable perceiver (Tatar-

Intact memory for complex events requires not only memory for particular features (e.g., item, location, color, size), but also intact cognitive processes for binding the features together. Binding provides the memorial experience that certain features belong together. The experiments presented here were designed to explicate these as potentially separable sources of age-associated changes in complex memory—namely, to investigate the possibility that age-related changes in memory for complex events arise from deficits in (1) memory for the kinds of information that comprise complex memories, (2) the processes necessary for binding this information into complex memories, or (3) both of these components. Young and older adults were presented with colored items located within an array. Relative to young adults, older adults had a specific and disproportionate deficit in recognition memory for location, but not for item or for color. Also, older adults consistently demonstrated poorer recognition memory for bound information, especially when all features were acquired intentionally. These feature and binding deficits separately contribute to what have been described as older adults ’ context and source memory impairments.

WhH subjectsswitch between two tasks, performance is slower after a taskswitch tht after a task repetition. We report five experimentsshperi thp a large part ofth)I "task-sh5S) costs" cannot be attributed to a control operation, needed to configureth cognitive system for th upcoming task (e.g., Rogers & Monsell, 1995). In all experiments subjects switchs between picture-naming and word-reading. We presented di#erent stimulieithl in just one of th two tasks, or inboth ofth9S ShSI#qH(93 were larger for stimuli presented inboth tasks ths forthH3 presented in only one task, even after more the 100 intervening trials between prime and probe events. We suggest (as proposed by Allport & Wylie, 2000)th0 stimuli acquire associationswith th tasks inwh9E th9 occur.Whu th current task activation is weak, as on aswitch of tasks, stimuli can trigger retrieval of th associated, competing task, provoking larger time costs.

In two experiments, eye movements were monitored as participants followed spoken instructions to click on and move pictures with a computer mouse. In Experiment 1, a referent picture (e.g., the picture of a bench) was presented along with three pictures, two of which had names that shared the same initial phonemes as the name of the referent (e.g., bed and bell). Participants were more likely to fixate the picture with the higher frequency name (bed) than the picture with the lower frequency name (bell). In Experiment 2, referent pictures were presented with three unrelated distractors. Fixation latencies to referents with high-frequency names were shorter than those to referents with low-frequency names. The proportion of fixations to the referents and distractors were analyzed in 33-ms time slices to provide fine-grained information about the time course of frequency effects. These analyses established that frequency affects the earliest moments of lexical access and rule out a late-acting, decision-bias locus for frequency. Simulations using models in which frequency operates on resting-activation levels, on connection strengths, and as a postactivation decision bias provided further constraints on the locus of frequency effects. © 2001 Academic Press Key Words: lexical frequency; spoken-word recognition; eye tracking. As the sound pattern of a spoken word unfolds over time, recognition takes place against a backdrop of partially activated alternatives that compete for recognition. The most activated alternatives are those that most closely match the input. For instance, as a listener hears the word cap, lexical representations of words with similar sounds, such as cat, will be briefly activated. This work was supported by NSF Grant SBR-9729095 to Michael K. Tanenhaus and Richard N. Aslin, and an NSF GRF to James S. Magnuson. We thank Ellen Hogan for her help

this article, in conjunction with those developed previously (Plaut et al., 1996; Seidenberg & McClelland, 1989), illustrate how connectionist computational principles---distributed representation, structure-sensitive learning, and interactivity---can provide insight into central empirical phenomena in normal and impaired lexical processing. Moreover, they make it clear that distinctions in the function of the lexical system---as manifest in the behaviour of experimental subjects--- need not re#ect corresponding distinctions in the structure of the system. Thus, networks exhibit word-frequency effects and word/nonword discrimination without word representations, and spelling --sound consistency effects without separate mechanisms for regular and exception items. In this way, gaining insight into the structure and function of the cognitive system by observing its normal and impaired behaviour ---the central goal of cognitive psychology and neuropsycho logy---may depend critically on developing theories and explicit simulations in the context of a speci#c computational framework that relates structure to function

this paper is an attempt to resolve these problems in a satisfactory manner. Although we believe that this algorithm could be seen as an instance of a uniform architecture for parsing and generation--just as the extended Earley parser (Shieber, 1985b) and the bottom-up generator were instances of the generalized Earley deduction architecture---our efforts to date have been aimed foremost toward the development of the algorithm for generation alone. We will mention efforts toward this end in Section 5