Colin Wilson

Johns Hopkins University | JHU · Department of Cognitive Science

Despite the importance of programming to modern society, the cognitive and neural bases of code comprehension are largely unknown. Programming languages might ‘recycle’ neurocognitive mechanisms originally developed for natural languages. Alternatively, comprehension of code could depend on fronto-parietal networks shared with other culturally-inve...

Listeners are highly proficient at adapting to contextual variation when perceiving speech. In the present study, we examined the effects of brief speech and nonspeech contexts on the perception of sibilant fricatives. We explored three theoretically motivated accounts of contextual adaptation, based on phonetic cue calibration, phonetic covariatio...

Listeners are highly proficient at adapting to variation in the speech signal. The present study examined short-term generalized adaptation to sibilant fricatives based on preceding speech and non-speech contexts. We explored three theoretically motivated accounts of generalization: a phonetic cue-based adaptation account, a phonetic covariation-ba...

Processes of talker recognition and adaptation rely on a high degree of inter-talker phonetic variability and systematicity, respectively. While superficially in opposition, talker recognition in part depends on adaptation to the talker at hand. In this talk, we present evidence that talker variability is simultaneously extensive and structured wit...

Stop consonant voice onset time (VOT) was examined in a typological survey of over 100 languages. Within broadly defined laryngeal categories (long-lag, short-lag, and lead voicing), VOT means were found to vary extensively. Importantly, the means for members of the same laryngeal series did not vary independently but instead were highly correlated...

The present study investigates patterns of covariation among acoustic properties of stop consonants in a large multi-talker corpus of American English connected speech. Relations among talker means for different stops on the same dimension (between-category covariation) were considerably stronger than those for different dimensions of the same stop...

The lexicon of a natural language does not contain all of the phonological structures that are grammatical. This presents a fundamental challenge to the learner, who must distinguish linguistically significant restrictions from accidental gaps ( Fischer-Jørgensen 1952 , Halle 1962 , Chomsky and Halle 1965 , Pierrehumbert 1994 , Frisch and Zawaydeh...

Vowel duration is determined by a number of factors in American English (e.g., Klatt, 1976), including the tense vs. lax distinction (e.g., /i/-/ɪ/, /u/-/ʊ/) and the relation between duration and vowel height (e.g., Lehiste, 1970). A large body of research has identified segment-internal factors in data averaged over many speakers (e.g., Crystal an...

Adaptation to the speech of a novel talker can involve at least two types of mechanism: phonetic learning (e.g., Samuel & Kraljic, 2009) and spectral contrast (e.g., Lotto & Kluender, 1998). While phonetic learning persists over long time periods, auditory effects such as spectral contrast have been demonstrated to occur for sounds that are tempora...

Variation across talkers in the acoustic-phonetic realization of speech sounds is a pervasive property of spoken language. The present study provides evidence that variation across talkers in the realization of American English stop consonants is highly structured. Positive voice onset time (VOT) was examined for all six word-initial stop categorie...

After hearing instances of a word initial voiceless stop with lengthened VOT (e.g., long-[ph]), speakers lengthen their VOTs in unheard words beginning with the same stop ([ph]) and, critically, in words beginning with a different stop ([kh]; Nielsen, 2011). This pattern of generalized phonetic imitation has previously been attributed to talker ada...

Previous research has demonstrated that speech perception is highly dependent on preceding acoustic context (e.g., Ladefoged & Broadbent, 1957), and suggested that this reflects adaptation to the long-term average spectrum (LTAS; e.g., Holt, 2006). The present study examined whether adaptation is further enhanced by acoustic-phonetic covariation am...

The spatial prepositions in and on apply to a wide range of containment and support relations, making exhaustive definitions difficult. Theories differ in whether they endorse geometric or functional properties and how these properties are related to meaning and use. This study directly examines the roles of geometric and functional information in...

Recent research has shown that speakers are sensitive to non-contrastive phonetic detail present in nonnative speech (e.g. Escudero et al. 2012; Wilson et al. 2014). Difficulties in interpreting and implementing unfamiliar phonetic variation can lead nonnative speakers to modify second language forms by vowel epenthesis and other changes. These dif...

Long-standing questions in human perception concern the nature of the visual features that underlie letter recognition and the extent to which the visual processing of letters is affected by differences in alphabets and levels of viewer expertise. We examined these issues in a novel approach using a same-different judgment task on pairs of letters...

Language is a collaborative act: To communicate successfully, speakers must generate utterances that are not only semantically valid but also sensitive to the knowledge state of the listener. Such sensitivity could reflect the use of an "embedded listener model," where speakers choose utterances on the basis of an internal model of the listener's c...

Unlabelled: In the multiple object tracking task an observer tracks moving targets within a set of featurally identical objects. Because error rates increase as target load (number of tracked targets) increases, the task is frequently cited as evidence of commodity-like resources that limit attention and working memory, with ongoing debates focuse...

Previous research has demonstrated variation across talkers in the phonetic realization of speech sounds, including vowels (e.g., Peterson and Barney, 1952), fricatives (e.g., Newman et al., 2001) and stop consonants (e.g., Allen et al., 2003; Theodore et al., 2009). The challenge that talker variation presents to perceptual processes may be signif...

Previous research on the perception, recognition, and learning of sounds and words has identified diverse effects of phonetic variation. The present study examined how variation affects cross-language production of consonant clusters. American English speakers shadowed words beginning with nonnative clusters in low- and high-variability conditions....

Talkers differ greatly in the acoustic realization of speech sounds, a source of signal variation that must be overcome by human and machine listeners. The present study examined talker variability in voice onset time (VOT) across the six word-initial stop consonant categories (/ptkbdg/) of American English. Employing a large corpus of productions...

Nonnative sounds and sequences are systematically adapted in both perception and production. For example, American English speakers often modify illegal word-initial clusters by inserting a vocalic transition between the two consonants (e.g., (/bdagu/ → [bədagu]). Previous work on such modifications has for the most part focused on relatively abstr...

Voicing contrasts in stop consonants are expressed by a constellation of acoustic cues. This study focused on a spectral cue present at burst onset in American English labial and coronal stops. Spectral shape was examined for word-initial, prevocalic stops of all three places of articulation in a laboratory production study and a large corpus of co...

Intuitively, extrapolating object trajectories should make visual tracking more accurate. This has proven to be true in many contexts that involve tracking a single item. But surprisingly, when tracking multiple identical items in what is known as "multiple object tracking," observers often appear to ignore direction of motion, relying instead on b...

Background / Purpose: We investigated a well-known configuration effect in spatial working memory to determine whether it could be derived from rational inferences applied to representations of individual objects. Specifically, we employed a spatial change detection task as in Jiang, Olson, and Chun (2000) : participants remembered the positions...

Multiple-object tracking has been an influential paradigm for evaluating attention and working memory limits. Recent work has made the consequences of these limits concrete, employing the Kalman filter—a Bayesian state estimator—as a computational model, and demonstrating how noisy estimates of position lead to target/nontarget confusions. Moreover...

Surprisingly, the rapidly expanding literature on models of color working memory (CWM) has made little contact with research on color perception. With the aim of integrating these literatures, we applied standard color perception methodology to an influential CWM task. First, we scrutinized methodological practice for color rendering. Published CWM...

Background / Purpose: Colour specific variability in colour working memory has been explored in relation to colour categories and borders. Main conclusion: Working memory responses are biased toward focal colours and away from boundary colours.

Working memory for color has been the central focus in an ongoing debate concerning the structure and limits of visual working memory. Within this area, the delayed estimation task has played a key role. An implicit assumption in color working memory research generally, and delayed estimation in particular, is that the fidelity of memory does not d...

Previous research has identified a coronal-to-dorsal 'perceptual assimilation' in which English and French listeners identify Hebrew word-initial /tl/ and /dl/ as beginning with /k/ and /g/, respectively (Hallé and Best, 2007). However, the acoustic-phonetic factors that contribute to this misperception have not been thoroughly identified, and prev...

Intuitively, extrapolating an object’s trajectory should facilitate visual tracking. This intuition has motivated several investigations into whether humans extrapolate when tracking multiple objects. Surprisingly, they appear not to, largely ignoring an object’s motion, and implementing a low-level, spatial memory function instead. Why do humans a...

According to classical arguments, language learning is both facilitated and constrained by cognitive biases. These biases are reflected in linguistic typology-the distribution of linguistic patterns across the world's languages-and can be probed with artificial grammar experiments on child and adult learners. Beginning with a widely successful appr...

In the production of non-native consonant clusters, speakers' systematic errors have been attributed to the influence of native-language phonotactics [Dupoux et al. (1999)]. However, recent models of non-native speech production suggest that speakers are also sensitive to acoustic details [Wilson et al. (2012)]. We examine whether speakers' sensiti...

We use language production data to explore a verb-based hypothesis of spatial language development, demonstrating that: changes in the lexical verb inventory drive development of the spatial language profile; and lexical verbs shape the profile of use for early-acquired basic construction (X is in/on Y).

A recent computational model by Hayes and Wilson (2008) seemingly captures a diverse range of phonotactic phenomena without variables, contrasting with the presumptions of many formal theories. Here, we examine the plausibility of this approach by comparing generalizations of identity restrictions by this architecture and human learners. Whereas hu...

We propose a new approach to metrics based on maxent grammars, which employ weighted constraints and assign well-formedness values to verse lines. Our approach provides an account of metricality and complexity that has a principled mathematical basis and integrates information from all aspects of scansion. Our approach also makes it possible to det...

For many years it has been assumed that when hearing familiar sounds in unfamiliar combinations, listeners will perceive the sounds accurately. In the recent years, this assumption has been challenged [Halle et al. (1998) and Berent et al. (2006)]. The present study investigates what listeners actually hear when presented with familiar consonants i...

The study of phonotactics is a central topic in phonology. We propose a theory of phonotactic grammars and a learning algorithm that con-structs such grammars from positive evidence. Our grammars consist of constraints that are assigned numerical weights according to the principle of maximum entropy. The grammars assess possible words on the basis...

There is an active debate within the field of phonology concerning the cognitive status of substantive phonetic factors such as ease of articulation and perceptual distinctiveness. A new framework is proposed in which substance acts as a bias, or prior, on phonological learning. Two experiments tested this framework with a method in which participa...

Phonological theories and textbook introductions to phonology typically focus on a relatively small set of process types. In the domain of segmental phonology, this set includes deletion and insertion of segments in a restricted range of environments, processes that make one segment more similar (assimilation) or less similar (dissimilation) to ano...

This study examines the influence of wh-gaps on the prosodic contour of spoken utterances. A previous study (Nagel, Shapiro, & Nawy, 1994) claimed that the phonological representation of a sentence containing a filler-gap dependency explicitly encodes the location of the syntactic gap. In support of this hypothesis, Nagel et al. presented evidence...

In this paper, I propose an optimality-theoretic account of the generalisation that deletion processes that apply to intervocalic biconsonantal clusters canonically delete the first consonant (schematically, VC1C2V [rightward arrow] VC2V). The approach to contextual neutralisation proposed here has two main components. First, I follow the licen...

this paper is a formalization of `Shortest Link', which we will call MINLINK, which is simultaneously flexible enough to accomodate the broad cross-linguistic variation in extraction patterns, and strong enough to do the primary work in a wide variety of explanations, including the following general types :

this article.

this paper, we use capital letters such as [O] and [E] to represent vowels whose input specification for [ATR] is irrelevant to the point under discussion, not (as is more common) to represent underspecified vowels.

this paper is a formalization of `Shortest Link', which we will call MINLINK, which is simultaneously flexible

Subsidiary features modulate the degree to which the Obligatory Contour Principle on place (OCP-Place) is violated by homorganic consonants. Statistical analysis of consonant co-occurrence patterns in four unrelated languages, combined with a method of model compar-ison that incorporates Occam's Razor, support a theory in which each place and subsi...

Phonetic variation is sensitive to lexical properties of words, such as frequency and neighborhood density, as well as con-textual properties, such as predictability. Previous studies of lexically-induced variation have observed that both vowels and consonants are phonetically enhanced in words from dense neighborhoods, and have suggested that this...