Biomedical subjects

G McKoon

Publications and source records attributed to G McKoon.

At least 19 recordsLinked to original sources

PubMed2001

Counter model for word identification: reply to Bowers (1999).

The counter model (R. Ratcliff & G. McKoon, 1997) was designed to explain the normal processes of word identification and how they are influenced by a prior encounter with a word. The model accounts for the findings of word identification experiments in which words are flashed briefly. A crucial finding is that prior encounters with words typically lead to biases such that a previously encountered word is more likely to be given as a response. However, for low-frequency words, a prior encounter can improve overall performance (J. S. Bowers, 1999; E. M. Wagenmakers, R. Zeelenberg, & J. G. W. Raaijmakers, 2000). The authors show how the model can explain this result. Also, J. S. Bowers (1999) has claimed that some earlier data concerning dissimilar alternatives in forced-choice experiments that support the counter model are spurious, but the authors show that his claims are incorrect. In sum, the authors argue for a theoretical approach that offers a detailed description of the cognitive processes of word identification and explains performance across tasks, measures, and independent variables.

Bias↗

PubMed2001

A multinomial model for short-term priming in word identification.

A simple multinomial model for short-term priming in perceptual word identification is presented. In the experiments to which the model is applied, prime words are presented just prior to a flashed target word, and subjects must decide which of 2 alternative words matches the target. The model assumes that on some proportion of trials, confusion among the words leads to the decision being based on 1 of the prime words instead of the target. In addition, it is assumed that subjects sometimes discount a prime that matches 1 of the test alternatives and so choose the alternative that does not match. With these assumptions, the model fits the data from 5 experiments (including 4 used to develop the model known as ROUSE [responding optimally with unknown sources of evidence]; D. E. Huber, R. Shiffrin, K. Lyle, & K. Ruys, 2001). The multinomial model fits the data about as well as the ROUSE model and so should lead to further development and critical testing of both models.

Adult↗

PubMed2001

Memory processes and experimental continuity.

What are the memory processes that produce coherent representations of temporally discontinuous experiences? In this article, we describe the memory process of resonance, a process that provides renewed access to long-term memory information that is relevant to cues in working memory. Our experiments demonstrate c parallel waxing and waning of information as a function of relevance to a current episode, a pattern of accessibility of information that contributes to the achievement of continuity across experiences.

Adolescent↗

PubMed2001

The effects of aging on reaction time in a signal detection task.

The effects of aging on response time are examined in 2 simple signal detection tasks with young and older subjects (age 60 years and older). Older subjects were generally slower than young subjects, and standard Brinley plot analyses of response times showed typical results: slopes greater than 1 and (mostly) negative intercepts. R. Ratcliff, D. Spieler, and G. McKoon (2000) showed that the slopes of Brinley plots measure the relative standard deviations of the distributions of response times for older versus young subjects. Applying R. Ratcliff's (1978) diffusion model to fit the response times, their distributions, and response accuracy, it was found that the larger spread in older subjects' response times and their slowness relative to young subjects comes from a 50-ms slowing of the nondecision components of response time and more from conservative settings of response criteria.

Adolescent↗

PubMed2000

A neural network model of implicit memory for object recognition.

People name well-known objects shown in pictures more quickly if they have studied them previously. The most common interpretation of this priming effect is that processing is facilitated by an implicit memory trace in a perceptual representation system. We show that object priming can be explained instead as a bias in information processing, without recourse to an implicit memory system. Assumptions about psychological decision-making processes and bias were added to a neural network model for object identification, and the model accounted for performance both qualitatively and quantitatively in four object identification experiments.

Adult↗

PubMed2000

Explicitly modeling the effects of aging on response time.

Research into the effects of aging on response time has focused on Brinley plots. Brinley plots are constructed by plotting mean response times for older subjects against those for young subjects for a set of experimental conditions. The typical result is a straight line with a slope greater than 1 and a negative intercept. This linear function has been interpreted as showing that aging leads to a general slowing of cognitive processes. In this article, we show that the slope of the Brinley plot is actually a measure of the relative standard deviations of older versus young subjects' response times; it is not a measure of general slowing. We examine current models of the effects of aging on mean response time and show how they might be reinterpreted. We also show how a more comprehensive model, Ratcliff's diffusion model (1978), can account for Brinley plot regularities and, at the same time, provide an account of accuracy rates, the shapes of response time distributions, and the relative speeds of error and correct response times, aspects of the data about which models designed to account for Brinley plots are mute. We conclude by endorsing a research approach that applies explicit models to response time data in aging in order to use the parameters of the model to interpret the effects of aging.

Aging↗

PubMed2000

Modeling the effects of repetition and word frequency in perceptual identification.

The counter model for word identification (Ratcliff & McKoon, 1997) has been challenged by recent empirical findings that performance on low-frequency words improves as the result of repetition of the words. We show that the model can accommodate this learning effect, and that it can do so without jeopardizing its explanations of the effects on word identification of a large number of other variables.

Cues↗

PubMed1999

Connectionist and diffusion models of reaction time.

Two connectionist frameworks, GRAIN (J. L. McClelland, 1993) and brain-state-in-a-box (J. A. Anderson, 1991), and R. Ratcliff's (1978) diffusion model were evaluated using data from a signal detection task. Dependent variables included response probabilities, reaction times for correct and error responses, and shapes of reaction-time distributions. The diffusion model accounted for all aspects of the data, including error reaction times that had previously been a problem for all response-time models. The connectionist models accounted for many aspects of the data adequately, but each failed to a greater or lesser degree in important ways except for one model that was similar to the diffusion model. The findings advance the development of the diffusion model and show that the long tradition of reaction-time research and theory is a fertile domain for development and testing of connectionist assumptions about how decisions are generated over time.

Adult↗

PubMed1998

Memory-based language processing: psycholinguistic research in the 1990s.

There are two main domains of research in psycholinguistics: sentence processing, concerned with how the syntactic structures of sentences are computed, and text processing, concerned with how the meanings of larger units of text are understood. In recent sentence processing research, a new and controversial theme is that syntactic computations may rely heavily on statistical information about the relative frequencies with which different syntactic structures occur in the language. In text processing, recent research has focused on what information the words and ideas of a text evoke from long-term memory quickly, passively, and at low processing cost. Research in both domains has begun to use the information that can be obtained from large corpora of naturally occurring texts.

Humans↗

PubMed1997

Bias in auditory priming.

Priming for previously studied words in an implicit auditory memory task has been interpreted as evidence for a presemantic perceptual representation system that encodes acoustic representations of words (B. A. Church & D. L. Schacter, 1994). In this article, 3 experiments provided evidence that such priming may result instead from a bias to respond with studied words. In forced-choice identification with similar alternative choices, there was no overall improvement in performance due to prior study. Benefits for studied test words were offset by costs for similar but nonstudied test words. Prior study had no effect when forced-choice alternatives were dissimilar. The data are discussed in relation to current models of auditory information processing and a new model (R. Ratcliff & G. McKoon, in press) for priming in visual word identification.

Acoustic Stimulation↗

PubMed1997

A counter model for implicit priming in perceptual word identification.

A model for the identification of briefly presented words is presented. The model accounts for data from naming and forced-choice experiments in which factors such as similarity of alternatives and stimulus presentation time are varied. The model assumes that counts are accumulated in counters that correspond to words and that a word is chosen as a response when the number of counts in its counter exceeds the maximum of the numbers of counts in other counters by a criterial value. Prior exposure to a word causes its counter to attract more counts than it otherwise would, and this yields priming effects. Ten experiments are presented, and the model provides correct predictions for the data. Implications of the model for research in implicit memory are considered.

Analysis of Variance↗

PubMed1996

Separating implicit from explicit retrieval processes in perceptual identification.

Light and Kennison (this issue) proposed that bias effects in the forced-choice perceptual identification of words result from a strategy engaged in by subjects to retrieve explicit information about the words. This article enumerates several problems with this proposal and presents new experimental data against it. It is concluded that subjects do not ordinarily employ an explicit retrieval strategy. The data are discussed in the context of the general problem of separating implicit from explicit influences on performance.

Adolescent↗

PubMed1996

Bias effects in implicit memory tasks.

A major focus of recent research in memory has been performance on implicit tasks. The phenomenon of most interest has been repetition priming, the effect that prior exposure to a stimulus has on later perception of the stimulus or on a later decision about the stimulus. Picture naming, word identification, and word production in stem- and fragment-completion tasks all show repetition priming effects. The separation of implicit from explicit memory systems provides one account of this data, but a different theoretical view is proposed here: Repetition-priming effects come about because the processes that perform a task are biased products, temporary modifications of the processes, which influence later processing. The aim of this article is to demonstrate the potential of this view for developing new theories and for prompting new empirical questions.

Auditory Perception↗

PubMed1996

Reliability of prosodic cues for resolving syntactic ambiguity.

Although previous research has shown that listeners can use prosody to resolve syntactic ambiguities in spoken sentences, it is not clear whether naive, untrained speakers in experimental situations ordinarily produce the prosodic cues necessary for disambiguating such sentences. In a series of experiments, the authors found that neither professional nor untrained speakers consistently produced such prosodic cues when simply reading ambiguous sentences in a disambiguating discourse context. Speakers who were aware of the ambiguities and were told to intentionally pronounce the sentences with one meaning of the other, however, did produce sufficient prosodic cues for listeners to identify the intended meanings.

Adult↗

PubMed1996

Pronoun resolution without pronouns: some consequences of memory-based text processing.

A memory-based processing approach to discourse comprehension emphasizes the rapid deployment of information in memory to facilitate understanding of the text that is currently being read. S. B. Greene, R. J. Gerrig, G. McKoon, and R. Ratcliff (1994) demonstrated that when a text described the reunion of 2 characters who had previously discussed a 3rd character, the accessibility of the 3rd character increased, and the use of an unheralded pronoun (R. J. Gerrig, 1986) to refer to that character was felicitous. In experiments in this article, the authors demonstrate that concepts related to the unheralded pronoun also increase in accessibility and that those concepts form associations in memory with concepts present in the discourse at the time the pronoun is used. The authors also show that the increase in accessibility for the referent of the pronoun, as well as the appropriate long-term memory associations, occurs even in the absence of the pronoun.

Attention↗

PubMed1996

Sentential context effects on lexical decisions with a cross-modal instead of an all-visual procedure.

J. L. Nicol and D. Swinney (1989) reported facilitation in a cross-modal lexical-decision task as evidence that implicit objects of verbs (WH-traces) are reinstated during comprehension. G. McKoon and R. Ratcliff (1994) found the same priming effects in the absence of implicit objects, suggesting that the effects are attributable to some factor other than a syntactic process that would fill in implicit objects. J. L. Nicol, J. D. Fodor, and D. Swinney (1994) questioned the relevance of McKoon and Ratcliff's findings because they were obtained with all-visual rather than cross-modal presentation. In 2 experiments, the authors replicated McKoon and Ratcliff's results using cross-modal lexical decision.

Decision Making↗

PubMed1995

Process dissociation, single-process theories, and recognition memory.

According to the assumptions of L. L. Jacoby's (1991) process dissociation method, performance in recognition memory is determined by the combination of an unconscious familiarity process and a conscious intentional recollection process. The process dissociation method is used to produce estimates of the contributions of the 2 components to recognition performance. This article investigates whether the method provides the correct estimates of components if performance actually depends on only a single process or on 2 processes different from those assumed by the method. The SAM model (G. Gillund & R. M. Shiffrin, 1984) was used to produce simulated data based on a single process. Variants of SAM with 2 processes and R. C. Atkinson and J. F. Juola's (1973) 2-process model were used to produce data based on 2 processes.

Cognition↗

PubMed1995

Metaphor-based schemas and text representations: making connections through conceptual metaphors.

Four experiments were conducted to examine the role of metaphor-based schemas in text comprehension and representation. In Experiment 1, schemas facilitated recognition judgements for schema-related sentences that had been presented in a text. Similar facilitation was found for the recognition of individual words in Experiments 2, 3, and 4. The results are interpreted as evidence for the use of metaphor-based schemas to link elements within a text representation.

Humans↗