Melvin Yap | National University of Singapore (original) (raw)

Papers by Melvin Yap

Behavior Research Methods, 2014

Reading involves a process of matching an orthographic input with stored representations in lexic... more Reading involves a process of matching an orthographic input with stored representations in lexical memory. The masked priming paradigm has become a standard tool for investigating this process. Use of existing results from this paradigm can be limited by the precision of the data and the need for cross-experiment comparisons that lack normal experimental controls. Here, we present a single, large, high-precision, multi-condition experiment to address these problems. Over 1000 participants from 14 sites responded to 840 trials involving 28 different types of orthographically related primes (e.g., castfe-CASTLE) in a lexical decision task, as well as completing measures of spelling and vocabulary. The data 1.4.1

The present study aims to isolate the locus of the frequency effect within the spoken word recogn... more The present study aims to isolate the locus of the frequency effect within the spoken word recognition architecture. By applying the additive factors logic to an auditory lexical decision task where both word frequency and stimulus quality were factorially manipulated, the reaction time data can be analyzed to study processing stages along the time course of spoken word recognition, and determine if frequency has an early or late locus. A significant underadditive interaction of frequency and stimulus quality was obtained. Surprisingly, the typically robust frequency effect was not reliable for words of low stimulus quality. This finding suggests that word frequency influences a relatively late stage in the spoken word recognition process. Implications for extant models of spoken word recognition are discussed.

Psychonomic Bulletin & Review, 2009

Psychonomic bulletin & review, 2011

With a new metric called phonological Levenshtein distance (PLD20), the present study explores th... more With a new metric called phonological Levenshtein distance (PLD20), the present study explores the effects of phonological similarity and word frequency on spoken word recognition, using polysyllabic words that have neither phonological nor orthographic neighbors, as defined by neighborhood density (the N-metric). Inhibitory effects of PLD20 were observed for these lexical hermits: Close-PLD20 words were recognized more slowly than distant PLD20 words, indicating lexical competition. Importantly, these inhibitory effects were found only for low- (not high-) frequency words, in line with previous findings that phonetically related primes inhibit recognition of low-frequency words. These results indicate that the properties of PLD20--a continuous measure of word-form similarity--make it a promising new metric for quantifying phonological distinctiveness in spoken word recognition research.

Psychonomic bulletin & review, 2011

With a new metric called phonological Levenshtein distance (PLD20), the present study explores th... more With a new metric called phonological Levenshtein distance (PLD20), the present study explores the effects of phonological similarity and word frequency on spoken word recognition, using polysyllabic words that have neither phonological nor orthographic neighbors, as defined by neighborhood density (the N-metric). Inhibitory effects of PLD20 were observed for these lexical hermits: Close-PLD20 words were recognized more slowly than distant PLD20 words, indicating lexical competition. Importantly, these inhibitory effects were found only for low- (not high-) frequency words, in line with previous findings that phonetically related primes inhibit recognition of low-frequency words. These results indicate that the properties of PLD20--a continuous measure of word-form similarity--make it a promising new metric for quantifying phonological distinctiveness in spoken word recognition research.

Psychonomic Bulletin & Review, 2009

Behavior Research Methods, 2014

Reading involves a process of matching an orthographic input with stored representations in lexic... more Reading involves a process of matching an orthographic input with stored representations in lexical memory. The masked priming paradigm has become a standard tool for investigating this process. Use of existing results from this paradigm can be limited by the precision of the data and the need for cross-experiment comparisons that lack normal experimental controls. Here, we present a single, large, high-precision, multi-condition experiment to address these problems. Over 1000 participants from 14 sites responded to 840 trials involving 28 different types of orthographically related primes (e.g., castfe-CASTLE) in a lexical decision task, as well as completing measures of spelling and vocabulary. The data 1.4.1

Investigating human cognitive faculties such as language, attention, and memory most often relies... more Investigating human cognitive faculties such as language, attention, and memory most often relies on testing small and homogeneous groups of volunteers coming to research facilities where they are asked to participate in behavioral experiments. We show that this limitation and sampling bias can be overcome by using smartphone technology to collect data in cognitive science experiments from thousands of subjects from all over the world.

Behavior research methods, 2010

Journal of Experimental Psychology: Learning, Memory, and Cognition, 2008

The joint effects of stimulus quality and word frequency in lexical decision were examined in 4 e... more The joint effects of stimulus quality and word frequency in lexical decision were examined in 4 experiments as a function of nonword type (legal nonwords, e.g., BRONE, vs. pseudohomophones, e.g., BRANE). When familiarity was a viable dimension for word-nonword discrimination, as when legal nonwords were used, additive effects of stimulus quality and word frequency were observed in both means and distributional characteristics of the response-time distributions. In contrast, when the utility of familiarity was undermined by using pseudohomophones, additivity was observed in the means but not in distributional characteristics. Specifically, opposing interactive effects in the underlying distribution were observed, producing apparent additivity in means. These findings are consistent with the suggestion that, when familiarity is deemphasized in lexical decision, cascaded processing between letter and word levels is in play, whereas, when familiarity is a viable dimension for word-nonword discrimination, processing is discrete.

The Quarterly Journal of Experimental Psychology, 2011

Psychonomic Bulletin & Review, 2009

Cognitive …, Jan 1, 2010

Using a cross-modal semantic priming paradigm, both experiments of the present study investigated... more Using a cross-modal semantic priming paradigm, both experiments of the present study investigated the link between the mental representations of iconic gestures and words. Two groups of the participants performed a primed lexical decision task where they had to discriminate between visually presented words and nonwords (e.g., flirp). Word targets (e.g., bird) were preceded by video clips depicting either semantically related (e.g., pair of hands flapping) or semantically unrelated (e.g., drawing a square with both hands) gestures. The duration of gestures was on average 3,500 ms in Experiment 1 but only 1,000 ms in Experiment 2. Significant priming effects were observed in both experiments, with faster response latencies for related gesture-word pairs than unrelated pairs. These results are consistent with the idea of interactions between the gestural and lexical representational systems, such that mere exposure to iconic gestures facilitates the recognition of semantically related words.

psych.wustl.edu

Chronometric studies of language and memory processing typically emphasize changes in mean respon... more Chronometric studies of language and memory processing typically emphasize changes in mean response time (RT) 13 performance across conditions. However, changes in mean performance (or the lack thereof) may reflect distinct pat-14 terns at the level of underlying RT distributions. In seven experiments, RT distributional analyses were used to better 15 understand how distributions change across related and unrelated conditions in standard semantic priming paradigms.

Psychonomic bulletin & review, Jan 1, 2011

With a new metric called phonological Levenshtein distance (PLD20), the present study explores th... more With a new metric called phonological Levenshtein distance (PLD20), the present study explores the effects of phonological similarity and word frequency on spoken word recognition, using polysyllabic words that have neither phonological nor orthographic neighbors, as defined by neighborhood density (the N-metric). Inhibitory effects of PLD20 were observed for these lexical hermits: Close-PLD20 words were recognized more slowly than distant PLD20 words, indicating lexical competition. Importantly, these inhibitory effects were found only for low-(not high-) frequency words, in line with previous findings that phonetically related primes inhibit recognition of low-frequency words. These results indicate that the properties of PLD20-a continuous measure of word-form similarity-make it a promising new metric for quantifying phonological distinctiveness in spoken word recognition research.

palm.mindmodeling.org

The effects of orthographic neighborhood density and word frequency in visual word recognition we... more The effects of orthographic neighborhood density and word frequency in visual word recognition were investigated using distributional analyses of response latencies in visual lexical decision. Main effects of density and frequency were observed in mean latencies. Distributional analyses, in addition, revealed a density x frequency interaction: for lowfrequency words, density effects were mediated predominantly by distributional shifting whereas for highfrequency words, density effects were absent except at the slower RTs, implicating distributional skewing. The present findings suggest that density effects in low-frequency words reflect processes involved in early lexical access, while the effects observed in high-frequency words reflect late postlexical checking processes.

Journal of experimental …, Jan 1, 2011

Empirical work and models of visual word recognition have traditionally focused on group-level pe... more Empirical work and models of visual word recognition have traditionally focused on group-level performance. Despite the emphasis on the prototypical reader, there is clear evidence that variation in reading skill modulates word recognition performance. In the present study, we examined differences between individuals who contributed to the English Lexicon Project (http://elexicon.wustl.edu), an online behavioral database containing nearly 4 million word recognition (speeded pronunciation and lexical decision) trials from over 1,200 participants. We observed considerable within-and between-session reliability across distinct sets of items, in terms of overall mean response time (RT), RT distributional characteristics, diffusion model parameters , and sensitivity to underlying lexical dimensions. This indicates reliably detectable individual differences in word recognition performance. In addition, higher vocabulary knowledge was associated with faster, more accurate word recognition performance, attenuated sensitivity to stimuli characteristics, and more efficient accumulation of information. Finally, in contrast to suggestions in the literature, we did not find evidence that individuals were trading-off in their utilization of lexical and nonlexical information.

The Quarterly Journal of …, Jan 1, 2011

PLoS ONE, Jan 1, 2011

Investigating human cognitive faculties such as language, attention, and memory most often relies... more Investigating human cognitive faculties such as language, attention, and memory most often relies on testing small and homogeneous groups of volunteers coming to research facilities where they are asked to participate in behavioral experiments. We show that this limitation and sampling bias can be overcome by using smartphone technology to collect data in cognitive science experiments from thousands of subjects from all over the world. This mass coordinated use of smartphones creates a novel and powerful scientific ''instrument'' that yields the data necessary to test universal theories of cognition. This increase in power represents a potential revolution in cognitive science.

Visual word …

Many disciplines have an agreed-upon knowledge base for study. For cellular neuroscientists, it i... more Many disciplines have an agreed-upon knowledge base for study. For cellular neuroscientists, it is the neuron, for geneticists, it is the genome, for some areas of chemistry, molecular interactions are the primary target. The success in these fields in part appears to be due to the accumulation of a well established set of principles. For example, in each of these domains there is a target knowledge base (i.e., the genome, the periodic table, etc.), which then allows researchers to investigate changes across different contexts and how the system interacts with other systems.

Behavior Research Methods, 2014

Reading involves a process of matching an orthographic input with stored representations in lexic... more Reading involves a process of matching an orthographic input with stored representations in lexical memory. The masked priming paradigm has become a standard tool for investigating this process. Use of existing results from this paradigm can be limited by the precision of the data and the need for cross-experiment comparisons that lack normal experimental controls. Here, we present a single, large, high-precision, multi-condition experiment to address these problems. Over 1000 participants from 14 sites responded to 840 trials involving 28 different types of orthographically related primes (e.g., castfe-CASTLE) in a lexical decision task, as well as completing measures of spelling and vocabulary. The data 1.4.1

The present study aims to isolate the locus of the frequency effect within the spoken word recogn... more The present study aims to isolate the locus of the frequency effect within the spoken word recognition architecture. By applying the additive factors logic to an auditory lexical decision task where both word frequency and stimulus quality were factorially manipulated, the reaction time data can be analyzed to study processing stages along the time course of spoken word recognition, and determine if frequency has an early or late locus. A significant underadditive interaction of frequency and stimulus quality was obtained. Surprisingly, the typically robust frequency effect was not reliable for words of low stimulus quality. This finding suggests that word frequency influences a relatively late stage in the spoken word recognition process. Implications for extant models of spoken word recognition are discussed.

Psychonomic Bulletin & Review, 2009

Psychonomic bulletin & review, 2011

With a new metric called phonological Levenshtein distance (PLD20), the present study explores th... more With a new metric called phonological Levenshtein distance (PLD20), the present study explores the effects of phonological similarity and word frequency on spoken word recognition, using polysyllabic words that have neither phonological nor orthographic neighbors, as defined by neighborhood density (the N-metric). Inhibitory effects of PLD20 were observed for these lexical hermits: Close-PLD20 words were recognized more slowly than distant PLD20 words, indicating lexical competition. Importantly, these inhibitory effects were found only for low- (not high-) frequency words, in line with previous findings that phonetically related primes inhibit recognition of low-frequency words. These results indicate that the properties of PLD20--a continuous measure of word-form similarity--make it a promising new metric for quantifying phonological distinctiveness in spoken word recognition research.

Psychonomic bulletin & review, 2011

With a new metric called phonological Levenshtein distance (PLD20), the present study explores th... more With a new metric called phonological Levenshtein distance (PLD20), the present study explores the effects of phonological similarity and word frequency on spoken word recognition, using polysyllabic words that have neither phonological nor orthographic neighbors, as defined by neighborhood density (the N-metric). Inhibitory effects of PLD20 were observed for these lexical hermits: Close-PLD20 words were recognized more slowly than distant PLD20 words, indicating lexical competition. Importantly, these inhibitory effects were found only for low- (not high-) frequency words, in line with previous findings that phonetically related primes inhibit recognition of low-frequency words. These results indicate that the properties of PLD20--a continuous measure of word-form similarity--make it a promising new metric for quantifying phonological distinctiveness in spoken word recognition research.

Psychonomic Bulletin & Review, 2009

Behavior Research Methods, 2014

Reading involves a process of matching an orthographic input with stored representations in lexic... more Reading involves a process of matching an orthographic input with stored representations in lexical memory. The masked priming paradigm has become a standard tool for investigating this process. Use of existing results from this paradigm can be limited by the precision of the data and the need for cross-experiment comparisons that lack normal experimental controls. Here, we present a single, large, high-precision, multi-condition experiment to address these problems. Over 1000 participants from 14 sites responded to 840 trials involving 28 different types of orthographically related primes (e.g., castfe-CASTLE) in a lexical decision task, as well as completing measures of spelling and vocabulary. The data 1.4.1

Investigating human cognitive faculties such as language, attention, and memory most often relies... more Investigating human cognitive faculties such as language, attention, and memory most often relies on testing small and homogeneous groups of volunteers coming to research facilities where they are asked to participate in behavioral experiments. We show that this limitation and sampling bias can be overcome by using smartphone technology to collect data in cognitive science experiments from thousands of subjects from all over the world.

Behavior research methods, 2010

Journal of Experimental Psychology: Learning, Memory, and Cognition, 2008

The joint effects of stimulus quality and word frequency in lexical decision were examined in 4 e... more The joint effects of stimulus quality and word frequency in lexical decision were examined in 4 experiments as a function of nonword type (legal nonwords, e.g., BRONE, vs. pseudohomophones, e.g., BRANE). When familiarity was a viable dimension for word-nonword discrimination, as when legal nonwords were used, additive effects of stimulus quality and word frequency were observed in both means and distributional characteristics of the response-time distributions. In contrast, when the utility of familiarity was undermined by using pseudohomophones, additivity was observed in the means but not in distributional characteristics. Specifically, opposing interactive effects in the underlying distribution were observed, producing apparent additivity in means. These findings are consistent with the suggestion that, when familiarity is deemphasized in lexical decision, cascaded processing between letter and word levels is in play, whereas, when familiarity is a viable dimension for word-nonword discrimination, processing is discrete.

The Quarterly Journal of Experimental Psychology, 2011

Psychonomic Bulletin & Review, 2009

Cognitive …, Jan 1, 2010

Using a cross-modal semantic priming paradigm, both experiments of the present study investigated... more Using a cross-modal semantic priming paradigm, both experiments of the present study investigated the link between the mental representations of iconic gestures and words. Two groups of the participants performed a primed lexical decision task where they had to discriminate between visually presented words and nonwords (e.g., flirp). Word targets (e.g., bird) were preceded by video clips depicting either semantically related (e.g., pair of hands flapping) or semantically unrelated (e.g., drawing a square with both hands) gestures. The duration of gestures was on average 3,500 ms in Experiment 1 but only 1,000 ms in Experiment 2. Significant priming effects were observed in both experiments, with faster response latencies for related gesture-word pairs than unrelated pairs. These results are consistent with the idea of interactions between the gestural and lexical representational systems, such that mere exposure to iconic gestures facilitates the recognition of semantically related words.

psych.wustl.edu

Chronometric studies of language and memory processing typically emphasize changes in mean respon... more Chronometric studies of language and memory processing typically emphasize changes in mean response time (RT) 13 performance across conditions. However, changes in mean performance (or the lack thereof) may reflect distinct pat-14 terns at the level of underlying RT distributions. In seven experiments, RT distributional analyses were used to better 15 understand how distributions change across related and unrelated conditions in standard semantic priming paradigms.

Psychonomic bulletin & review, Jan 1, 2011

With a new metric called phonological Levenshtein distance (PLD20), the present study explores th... more With a new metric called phonological Levenshtein distance (PLD20), the present study explores the effects of phonological similarity and word frequency on spoken word recognition, using polysyllabic words that have neither phonological nor orthographic neighbors, as defined by neighborhood density (the N-metric). Inhibitory effects of PLD20 were observed for these lexical hermits: Close-PLD20 words were recognized more slowly than distant PLD20 words, indicating lexical competition. Importantly, these inhibitory effects were found only for low-(not high-) frequency words, in line with previous findings that phonetically related primes inhibit recognition of low-frequency words. These results indicate that the properties of PLD20-a continuous measure of word-form similarity-make it a promising new metric for quantifying phonological distinctiveness in spoken word recognition research.

palm.mindmodeling.org

The effects of orthographic neighborhood density and word frequency in visual word recognition we... more The effects of orthographic neighborhood density and word frequency in visual word recognition were investigated using distributional analyses of response latencies in visual lexical decision. Main effects of density and frequency were observed in mean latencies. Distributional analyses, in addition, revealed a density x frequency interaction: for lowfrequency words, density effects were mediated predominantly by distributional shifting whereas for highfrequency words, density effects were absent except at the slower RTs, implicating distributional skewing. The present findings suggest that density effects in low-frequency words reflect processes involved in early lexical access, while the effects observed in high-frequency words reflect late postlexical checking processes.

Journal of experimental …, Jan 1, 2011

Empirical work and models of visual word recognition have traditionally focused on group-level pe... more Empirical work and models of visual word recognition have traditionally focused on group-level performance. Despite the emphasis on the prototypical reader, there is clear evidence that variation in reading skill modulates word recognition performance. In the present study, we examined differences between individuals who contributed to the English Lexicon Project (http://elexicon.wustl.edu), an online behavioral database containing nearly 4 million word recognition (speeded pronunciation and lexical decision) trials from over 1,200 participants. We observed considerable within-and between-session reliability across distinct sets of items, in terms of overall mean response time (RT), RT distributional characteristics, diffusion model parameters , and sensitivity to underlying lexical dimensions. This indicates reliably detectable individual differences in word recognition performance. In addition, higher vocabulary knowledge was associated with faster, more accurate word recognition performance, attenuated sensitivity to stimuli characteristics, and more efficient accumulation of information. Finally, in contrast to suggestions in the literature, we did not find evidence that individuals were trading-off in their utilization of lexical and nonlexical information.

The Quarterly Journal of …, Jan 1, 2011

PLoS ONE, Jan 1, 2011

Investigating human cognitive faculties such as language, attention, and memory most often relies... more Investigating human cognitive faculties such as language, attention, and memory most often relies on testing small and homogeneous groups of volunteers coming to research facilities where they are asked to participate in behavioral experiments. We show that this limitation and sampling bias can be overcome by using smartphone technology to collect data in cognitive science experiments from thousands of subjects from all over the world. This mass coordinated use of smartphones creates a novel and powerful scientific ''instrument'' that yields the data necessary to test universal theories of cognition. This increase in power represents a potential revolution in cognitive science.

Visual word …

Many disciplines have an agreed-upon knowledge base for study. For cellular neuroscientists, it i... more Many disciplines have an agreed-upon knowledge base for study. For cellular neuroscientists, it is the neuron, for geneticists, it is the genome, for some areas of chemistry, molecular interactions are the primary target. The success in these fields in part appears to be due to the accumulation of a well established set of principles. For example, in each of these domains there is a target knowledge base (i.e., the genome, the periodic table, etc.), which then allows researchers to investigate changes across different contexts and how the system interacts with other systems.