Rain Grant Bosworth

• Doctor of Philosophy
• Professor (Assistant) at Rochester Institute of Technology

Evidence from adult studies of deaf signers supports the dissociation between neural systems involved in processing visual linguistic and non-linguistic body actions. The question of how and when this specialization arises is poorly understood. Visual attention to these forms is likely to change with age and be affected by prior language experience...

The well-known Stroop interference effect has been instrumental in revealing the highly automated nature of lexical processing as well as providing new insights to the underlying lexical organization of first and second languages within proficient bilinguals. The present cross-linguistic study had two goals: 1) to examine Stroop interference for dy...

Children’s gaze behavior reflects emergent linguistic knowledge and real‐time language processing of speech, but little is known about naturalistic gaze behaviors while watching signed narratives. Measuring gaze patterns in signing children could uncover how they master perceptual gaze control during a time of active language learning. Gaze pattern...

Language knowledge, age of acquisition (AoA), and stimulus intelligibility all affect gaze behavior for reading print, but it is unknown how these factors affect "sign-watching" among signers. This study investigated how these factors affect gaze behavior during sign language comprehension in 52 adult signers who acquired American Sign Language (AS...

Careful measurements of the temporal dynamics of speech have provided important insights into phonetic properties of spoken languages, which are important for understanding auditory perception. By contrast, analytic quantification of the visual properties of signed languages is still largely uncharted. Exposure to sign language is a unique experien...

Previous studies using habituation techniques have shown infants as young as three months can discriminate between different faces (Slater et al., 1998; Sangrigoli & De Schonen, 2004; Kelly et al., 2008; Slater et al., 2010). The current study expands upon this literature by tracking the development of face discrimination using an oddball visual st...

The infant brain may be predisposed to identify perceptually salient cues that are common to both signed and spoken languages. Recent theory based on spoken languages has advanced sonority as one of these potential language acquisition cues. Using a preferential looking paradigm with an infrared eye tracker, we explored visual attention of hearing...

Although global motion processing is thought to emerge early in infancy, there is debate regarding the age at which it matures to an adult-like level. In the current study, we address the possibility that the apparent age-related improvement in global motion processing might be secondary to age-related increases in the sensitivity of mechanisms (i....

Background. Motion processing, mediated by the dorsal pathway, is thought to exhibit greater plasticity than ventral pathway functions. This implies both a greater vulnerability in certain developmental disorders and on the flip side, greater compensatory plasticity after sensory deprivation. Although this hypothesis has gathered recent popularity,...

Background: The current study assessed whether contrast sensitivity is affected in preterm infants with a history of spontaneously regressed retinopathy of prematurity (ROP, Stages 1-3). Specifically, we employed luminance (light/dark) and chromatic (red/green) stimuli, which are mediated by the magnocellular (M) and parvocellular (P) subcortical...

Previous studies have asked whether visual sensitivity and attentional processing in deaf signers are enhanced or altered as a result of their different sensory experiences during development, i.e., auditory deprivation and exposure to a visual language. In particular, deaf and hearing signers have been shown to exhibit a right visual field/left he...

In order to investigate the effects of visual experience on early visual development, the current study compared contrast sensitivity across infants born with different levels of moderate-to-late prematurity. Here the logic is that at any given postterm age, the most premature infants will have the oldest postnatal age. Given that postnatal age is...

Aim: Mass educational/entertainment media is currently directed at infants (e.g., "Baby Einstein"), yet the consequences on perceptual development are unknown. Here, we asked whether exposing 3-month-olds to Chromatic (Chrom, red/green) and Luminance (Lum, dark/light) patterns affects their sensitivity to these stimuli. Methods: The stimuli were Lu...

In order to investigate differences in the effects of spatial attention between the left visual field (LVF) and the right visual field (RVF), we employed a full/poor attention paradigm using stimuli presented in the LVF vs. RVF. In addition, to investigate differences in the effects of spatial attention between the dorsal and ventral processing str...

Purpose: To determine whether contrast sensitivity in preterm (PT) infants matches that of fullterm (FT) infants when the two groups are of the same postnatal age (PNA), suggesting that sensitivity is governed primarily by visual experience, or the same postconceptional age (PCA), suggesting that sensitivity is governed by “biological maturation”....

Iconicity is a property that pervades the lexicon of many sign languages, including American Sign Language (ASL). Iconic signs exhibit a motivated, nonarbitrary mapping between the form of the sign and its meaning. We investigated whether iconicity enhances semantic priming effects for ASL and whether iconic signs are recognized more quickly than n...

In order to investigate potential effects of visual experience vs. preprogrammed mechanisms on visual development, we have investigated how well variation in contrast sensitivity (CS) across a large group of typical infants (n = 182) can be accounted for by a variety of factors that differ in the extent to which they are tied to visual experience....

Study of healthy preterm infants affords an opportunity to investigate the contributions of visual experience vs. preprogrammed mechanisms on visual development. By comparing the developmental trajectories of contrast sensitivity (CS) in preterm vs. fullterm infants, we can determine if development is primarily tied to postterm age, in which visual...

Purpose: Previous VEP studies have investigated the development of chromatic (Chr) and luminance (Lum) contrast sensitivity. Here, we used a psychophysical technique to longitudinally track the development of Chr and Lum sensitivity between 2–7 months. In addition, we tested pre-term infants to determine whether Chr and Lum sensitivity are differen...

“Purpose: To determine the extent to which contrast sensitivity (CS) development is governed by genetic mechanisms vs. environment, we compared CS between pairs of twin infants and pairs of unrelated infants. If genetics have a strong influence on CS, correlations for Monozygotic (Mz) twin pairs should be greater than those for Dizygotic (Dz) twin...

In order to investigate the contributions of visual experience vs. preprogrammed mechanisms on visual development, the current study compared contrast sensitivity in preterm vs. fullterm infants. If development is tied to time since conception, preterm infants should match the developmental trajectories of fullterm infants when plotted in postterm...

The perceptual loop theory of self-monitoring posits that auditory speech output is parsed by the comprehension system. For sign language, however, visual input from one's own signing is distinct from visual input received from another's signing. Two experiments investigated the role of visual feedback in the production of American Sign Language (A...

To investigate effects of visual experience versus preprogrammed mechanisms on visual development, we used multiple regression analysis to determine the extent to which a variety of variables (that differ in the extent to which they are tied to visual experience) predict luminance and chromatic (red/green) contrast sensitivity (CS), which are media...

To investigate nasal-temporal asymmetries in the detection of horizontal motion and in cortical motion visual evoked potential (mVEP) responses in normal infants and children and in patients with infantile esotropia. Monocular motion-detection thresholds were obtained separately for nasalward- and temporalward-moving random-dot patterns in a forced...

Several lines of evidence suggest that the image statistics of the environment shape visual abilities. To date, the image statistics of natural scenes and faces have been well characterized using Fourier analysis. We employed Fourier analysis to characterize images of signs in American Sign Language (ASL). These images are highly relevant to signer...

The purpose of this study was to investigate asymmetries in detection of horizontal motion in normal infants and children and in patients with infantile esotropia. Motion detection thresholds (% motion signal) were measured in 75 normal infants and in 36 eyes of 27 infants with infantile esotropia (ET), using a forced-choice preferential looking pa...

To define the prevalence and time course of significant changes in angle of deviation during the first months after the diagnosis of infantile esotropia and to determine whether long-term alignment and sensory outcomes differ when surgical alignment is performed on infants with stable vs unstable angles of deviation. Prospective cohort study. setti...

Between 6 and 12 mo of age, blood levels of the (n-3) long-chain PUFA, docosahexaenoic acid (DHA), in breast-fed infants typically decrease due to diminished maternal DHA stores and the introduction of DHA-poor solid foods displacing human milk as the primary source of nutrition. Thus, we utilized a randomized, clinical trial format to evaluate the...

Careful measurements of the dynamics of speech production have provided important insights into phonetic properties of spoken languages. By contrast, analytic quantification of the visual properties of signed languages remains largely unexplored. The purpose of this study was to characterize the spatial and temporal visual properties of American Si...

Visual abilities in deaf individuals may be altered as a result of auditory deprivation and/or because the deaf rely heavily on a sign language (American Sign Language, or ASL). In this study, we asked whether attentional abilities of deaf subjects are altered. Using a direction of motion discrimination task in the periphery, we investigated three...

Recently, we reported a strong right visual field/left hemisphere advantage for motion processing in deaf signers and a slight reverse asymmetry in hearing nonsigners (Bosworth & Dobkins, 1999). This visual field asymmetry in deaf signers may be due to auditory deprivation or to experience with a visual-manual language, American Sign Language (ASL)...

In order to investigate the effects of divided attention and selective spatial attention on motion processing, we obtained direction-of-motion thresholds using a stochastic motion display under various attentional manipulations and stimulus durations (100-600 ms). To investigate divided attention, we compared motion thresholds obtained when a singl...

Careful measurements of the dynamics of speech production have provided important insights into phonetic properties of spoken languages. By contrast, analytic quantification of the visual properties of signed languages remains largely unexplored. The purpose of this study was to characterize the spatial and temporal visual properties of American Si...

Evidence from neurophysiological studies in animals as well as humans has demonstrated robust changes in neural organization and function following early-onset sensory deprivation. Unfortunately, the perceptual consequences of these changes remain largely unexplored. The study of deaf individuals who have been auditorily deprived since birth and wh...

Purpose While anecdotal evidence suggests lhat the deaf "see" better than the hearing, few psychophysical experiments have bsen conducted to address this claim. Because native deaf signers rely on a visual language (i.e., American Sign Language, ASL), in which hand motion conveys linguistic ir formation, we reasoned that deaf signers may exhibit su...