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R Borowsky

Publications and source records attributed to R Borowsky.

11 recordsLinked to original sources
PubMed2000

Lexical access codes in visual word recognition: are the joint effects of context and stimulus quality diagnostic?

Is it possible to identify when lexical access in visual word recognition is based on an orthographic code and when it is based on a phonological code? Some researchers have argued that the joint effects of semantic context and stimulus quality in lexical decision are diagnostic. Their argument is that when phonological recoding is employed, it serves to keep the effects of stimulus quality and context from interacting. Semantic context and stimulus quality are therefore predicted to have additive effects on RT. In contrast, when lexical access is not mediated by a phonological recoding stage, then the effect of stimulus quality interacts with context, as commonly seen in the literature. A strong test of these claims was devised in which participants were forced to use phonological recoding for the purpose of lexical access. An interaction between context and stimulus quality was observed. This finding is taken as evidence that the joint effects of semantic context and stimulus quality are not diagnostic with respect to the nature of the lexical access code (i.e., orthographic versus phonological) for readers of English.

Humans↗
PubMed1999

Reading speech and hearing print: constraining models of visual word recognition by exploring connections with speech perception.

Current models of reading and speech perception differ widely in their assumptions regarding the interaction of orthographic and phonological information during language perception. The present experiments examined this interaction through a two-alternative, forced-choice paradigm, and explored the nature of the connections between graphemic and phonemic processing subsystems. Experiments 1 and 2 demonstrated a facilitation-dominant influence (i.e., benefits exceed costs) of graphemic contexts on phoneme discrimination, which is interpreted as a sensitivity effect. Experiments 3 and 4 demonstrated a symmetrical influence (i.e., benefits equal costs) of phonemic contexts on grapheme discrimination, which can be interpreted as either a bias effect, or an equally facilitative/inhibitory sensitivity effect. General implications for the functional architecture of language processing models are discussed, as well as specific implications for models of visual word recognition and speech perception.

Cognition↗
PubMed1998

Evolutionary divergence of AP-PCR (RAPD) patterns.

Rates at which AP-PCR patterns diverge among isolated taxa were examined to test whether they exhibit clocklike regularity. The results showed that rates of divergence differed significantly among the groups examined (primates, antelopes, and Hawaiian Drosophila grimshawi). Therefore, AP-PCR divergence rates cannot be used as a "universal clock" with an invariant rate in all animals. Nevertheless, within each group, a strong relationship existed between degree of AP-PCR pattern divergence and time since separation of isolated taxa. Thus, AP-PCR divergence may prove useful for dating evolutionary events if calibrated within a more limited taxon.

Animals↗
PubMed1998

More than meets the eye: context effects in word identification.

The influence of semantic context on word identification was examined using masked target displays. Related prime words enhanced a signal detection measure of sensitivity in making lexical decisions and in determining whether a probe word matched the target word. When line drawings were used as primes, a similar benefit was obtained with the probe task. Although these results suggest that contextual information affects perceptual encoding, this conclusion is questioned on the grounds that sensitivity in these tasks may be determined by independent contributions of perceptual and contextual information. The plausibility of this view is supported by a simulation of the experiments using a connectionist model in which perceptual and semantic information make independent contributions to word identification. The model also predicts results with two other analytic methods that have been used to argue for priming effects on perceptual encoding.

Adult↗
PubMed1995

Spontaneous melanoma formation in nonhybrid Xiphophorus.

Melanoma in hybrids of Xiphophorus is due to the unrestricted activity of a cellular oncogene locus, Tu, encoding the growth factor receptor gene Xmrk. In nonhybrid parental fish, Tu is controlled by a tumor suppressor gene. Thus, its restricted activity leads there only to a nonmalignant, species- and population-specific macromelanophore spot pattern. Prompted by enigmatic reports on nonhybrid Xiphophorus with pigmentation abnormalities resembling melanoma, we have studied pigmentation in descendants of wild-caught fish and purebred laboratory stocks derived from wild populations. Whereas most stocks exhibiting macromelanophore patterns never developed pigmentation abnormalities, an exceptional situation for some nonhybrids was found. In X. variatus carrying the macromelanophore pattern "punctatus-2" and in X. cortezi with "spotted caudal," expressivity of the pigmentation gene ranges from a few black spots to extreme melanosis and eventually to malignant melanoma. In X. maculatus with the mutant pigmentation gene striped" carrying in addition the micromelanophore pattern "anal fin black" or "lower comet," testosterone-dependent melanoma develop originating from the corresponding micromelanophore pattern. The tumors are highly malignant and express a melanoma-associated antigen. Overexpression of the Xmrk oncogene appears as the underlying molecular mechanism for tumor induction. These findings clearly demonstrate that tumors can also develop in purebred wild-type fish. The classical model for formation of hereditary melanoma in Xiphophorus hybrids does not explain the development of melanoma in the absence of hybridization. However, their existence gives additional support to the reasoning that the Xmrk oncogene associated with the macromelanophore locus is potentially injurious.

Animals↗
PubMed1993

Visual word recognition: a multistage activation model.

Although many models of word recognition have postulated loci for the simple effects of Context, Stimulus Quality, and Word Frequency, most of them are problematic in that they do not account for the pattern of joint effects among these factors. The experiments reported here show that, among other things, Word Frequency interacts with Context but is additive with Stimulus Quality in the context of a lexical decision experiment that also produces an interaction between Stimulus Quality and Context. The pattern of joint effects among these factors is accommodated by a multistage activation model that is based on the framework proposed by Besner and Smith (1992a).

Adult↗
PubMed1988

HLA and the probability of paternity.

In cases of disputed paternity, blood tests are often used to obtain an estimate of the probability that the accused male is the true father. The interpretation of the genetic data is usually based upon a statistic called the paternity index. This paper shows that the paternity index method cannot be applied to data from compound loci in the absence of information on linkage phase. Since phenotypic data from compound loci, such as HLA, MNSs, and Rh, are often useful in disputed paternity proceedings, they should be analyzed with available alternative statistics.

Female↗
PubMedDate not supplied

Mapping a cave fish genome: polygenic systems and regressive evolution.

We used random amplified polymorphic DNA (RAPD) fingerprinting to generate anonymous DNA markers in the fish Astyanax mexicanus, a species with both surface and cave populations. Surface individuals are eyed and pigmented; troglobitic forms are blind and depigmented. We hybridized surface fish and Pachon population cave fish and produced a RAPD genomic map 1064 cM in length (about half the total length of the genome) that was used to screen for quantitative trait loci (QTL) for troglomorphic traits. Three QTL for reduced eye size, two for decreased numbers of melanophores, two for condition factor, and the locus for the unifactorial trait, albinism, were mapped. These factors account for an average of 46% of the variance in these traits in the backcross. The results are the first direct demonstration that troglomorphic changes in this population are multifactorial. Two closely linked pairs of QTL were found. Each consisted of a regressive and a constructive trait QTL. These close linkages are unlikely to have occurred by chance (P <.05 for each) and suggest that troglomorphic evolution might be facilitated by pleiotropy or by genetic hitchhiking.

Animals↗
PubMedDate not supplied

Stable association of a pigmentation allele with an oncogene: nonhybrid melanomas in Xiphophorus variatus.

Sex-linked genes in several species of the fish genus Xiphophorus cause macromelanophore pigmentation patterns on the flanks of the fish. Some, but not all, of these patterns can develop into melanomas. The tumorigenic alleles are tightly linked to a supernumerary oncogene sequence, Xmrk. The data show that the association of Xmrk with two of the tumorigenic alleles of X. variatus, P2 and Li, holds over a broad geographic area. From the distribution of the fish and the geology of the area, it is probable that this association is older than the late Tertiary. The persistence of this association suggests that Xmrk confers some benefit on P2-and Li-bearing individuals to offset the deleterious effect. The nature of this benefit remains unknown.

Animals↗