Daphne Maurer

McMaster University | McMaster · Department of Psychology, Neuroscience & Behaviour

How does experience shape the development of visual brain regions? We demonstrate that a transient period of visual deprivation early in life in humans leads to permanent alteration in the function of the early visual cortex (EVC), while leaving the categorical coding of downstream ventral occipito-temporal cortex (VOTC) mostly unaffected. We used...

All people (and some other animals) have aesthetic responses to sensory stimulation, responses of emotional pleasure or displeasure. These emotions vary from one person and culture to another, yet they share a common mechanism. To survive, an adaptive animal (as opposed to a tropic animal) needs to become comfortable with normality and to have slig...

Objective To assess the effectiveness of a kindergarten vision screening program by randomly assigning schools to receive or not receive vision screening, then following up 1.5 years later. Methods Fifty high-needs elementary schools were randomly assigned to participate or not in a vision screening program for children in senior kindergarten (SK;...

The fission and fusion illusions provide measures of multisensory integration. The sound-induced tap fission illusion occurs when a tap is paired with two distractor sounds, resulting in the perception of two taps; the sound-induced tap fusion illusion occurs when two taps are paired with a single sound, resulting in the perception of a single tap....

Importance Screening for amblyopia in primary care visits is recommended for young children, yet screening rates are poor. Although the prevalence of amblyopia is low (3%-5%) among young children, universal screening in schools and mandatory optometric examinations may improve vision care, but the cost-effectiveness of these vision testing strategi...

Through development, multisensory systems reach a balance between stability and flexibility: the systems integrate optimally cross-modal signals from the same events, while remaining adaptive to environmental changes. Is continuous intersensory recalibration required to shape optimal integration mechanisms, or does multisensory integration develop...

For four decades, investigations of the biological basis of critical periods in the developing mammalian visual cortex were dominated by study of the consequences of altered early visual experience in cats and nonhuman primates. The neural deficits thus revealed also provided insight into the origin and neural basis of human amblyopia that in turn...

Patients treated for bilateral congenital cataracts provide a unique model to test the role of early visual input in shaping the development of the human cortex. Previous studies showed that brief early visual deprivation triggers long-lasting changes in the human visual cortex. However, it remains unknown if such changes interact with the developm...

Objective To synthesize and appraise economic evaluations of vision screening to detect vision impairment in children.Methods Literature searches were conducted on seven electronic databases, grey literature, and websites of agencies conducting health technology assessments. Studies were included if they (1) were full, comparative economic evaluati...

Objective: To test the association of material deprivation and the utilization of vision care services for young children. Study design: We conducted a population-based, repeated measures cohort study using linked health and administrative datasets. All children born in Ontario in 2010 eligible for provincial health insurance were followed from...

A backgrounder on the science of memory and trauma for non-specialists.

Background: Visual problems can negatively affect visual development and learning but often go undetected. We assessed the feasibility of scaling up a school-based screening program to identify and treat kindergarten children with visual problems. Methods: We conducted a prospective cohort study offering vision screening to junior (JK) and senio...

Significance The perceptual validity of synesthesia has been established by behavioral and neuroimaging evidence; however, its developmental origins remain unclear. Here we tested the hypothesis that synesthesia arises when there is less experience-dependent pruning during development. We did so by comparing adults with and without synesthesia on a...

People are chemical machines yet we (and some other animals) develop a sense of beauty. Why and how did this evolve? How is beauty formed? The Maurers answer these questions as scientists with deep knowledge of the arts. They interweave experimental sciences with the histories of art, architecture, music, dance, speech, literature, and food. Alt...

Objectives To assess the diagnostic accuracy of five vision screening tools used in a school setting using sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Design We compared the results of the five best evidence-based screening tools available in 2014 to the results of a comprehensive eye exam with cy...

We charted the developmental trajectory of the perception of audiotactile simultaneity by testing three groups of children (aged 7, 9, and 11 years) and one group of adults. A white noise burst and a tap to the index finger were presented at 1 of 13 stimulus onset asynchronies (SOAs), and the participants were asked to report whether the two stimul...

Vision impairment has a significant impact on quality of life. Seventy percent of existing vision impairment in Canada is estimated to be correctable with prescription glasses. The sizeable proportion of correctable vision impairment appears related to the barriers to access to vision care in Canada. The objective of this scoping review is to deter...

A simultaneity judgment (SJ) task was used to measure the developmental trajectory of visuotactile simultaneity perception in children (aged 7, 9, 11, and 13 years) and adults. Participants were presented with a visual flash in the center of a computer monitor and a tap on their right index finger (located 20° below the flash) with 13 possible stim...

Amblyopia is a developmental disorder that affects the spatial vision of one or both eyes in the absence of an obvious organic cause; it is associated with a history of abnormal visual experience during childhood. Subtypes have been defined based on the purported etiology, namely, strabismus (misaligned eyes) and/or anisometropia (unequal refractiv...

Adults need to discriminate between stimuli and recognize those previously seen. For faces, feature changes (e.g., different eyes) and spacing changes (e.g., distances between eyes) are important cues. In two experiments, we assessed the influence of these on discrimination and recognition of houses, a commonly used control in face studies. In both...

Vision is very immature at birth and takes many years to become adult-like. The immaturities begin in the retina and extend to the primary visual cortex and throughout the dorsal and ventral extrastriate pathways. However, the rates of development differ for different key brain areas and the visual capabilities they allow. Here, we illustrate key f...

The current study investigated the impact of birth weight on the ability to recognize facial expressions in adulthood among the longest known prospectively followed cohort of extremely low birth weight survivors (ELBW; <1,000 g). We measured perceptual threshold to detect subtle facial expressions and confusion among different emotion categories in...

We examined audiovisual and visuotactile integration in the central and peripheral visual field using visual fission and fusion illusions induced by sounds or taps. The fission illusion occurs when a single flash is perceived as two flashes if paired with two beeps or taps; the fusion illusion, by contrast, occurs when two flashes are perceived as...

Studies of children treated for dense cataracts afford an opportunity to examine the role of visual experience in driving visual perceptual development. Collectively, the data indicate that there are multiple periods during which deprivation can damage visual development, but their timing and duration cannot be predicted from the normal development...

Temporal simultaneity provides an essential cue for integrating multisensory signals into a unified perception. Early visual deprivation, in both animals and humans, leads to abnormal neural responses to audiovisual signals in subcortical and cortical areas [1-5]. Behavioral deficits in integrating complex audiovisual stimuli in humans are also obs...

Is a short and transient period of visual deprivation early in life sufficient to induce lifelong changes in how we attend to, and integrate, simple visual and auditory information [1, 2]? This question is of crucial importance given the recent demonstration in both animals and humans that a period of blindness early in life permanently affects the...

Hebb's (1949) book The Organisation of Behaviour presented a novel hypothesis about how the baby learns to see. This article summarizes the results of my research program that evaluated Hebb's hypothesis: first, by studying infants' eye movements and initial perceptual abilities and second, by studying the effect of visual deprivation (e.g., congen...

Simultaneity is one of the basic rules of multisensory integration and the basis for learning associations between visual and auditory (or tactile) stimuli. Here, we compared the audiovisual and visuotactile simultaneity windows in normal development and in patients who had been deprived of patterned vision during the first 0.3-28.3 months of life...

What role does early visual experience play in the development of the visual cortex? Animal models have demonstrated that transient visual deprivation early in life permanently alters the response properties of neurons in the visual cortex (Wiesel & Hubel, 1965). In humans, studies with blind adults suggest a critical role of early visual experienc...

Adults who missed early visual input because of congenital cataracts later have deficits in many aspects of face processing. Here we investigated whether they make normal judgments of facial attractiveness. In particular, we studied whether their perceptions are affected normally by a face’s proximity to the population mean, as is true of typically...

The current experiment measured symbolic SNARC (Spatial-Numeric Association of Response Codes) and distance effects in school-aged children and investigated the relation between these measures and visuospatial skills and mathematics ability. In the experiment, 6-, 7-, and 8-year-olds performed a magnitude-relevant SNARC task, in which they indicate...

We measured the typical developmental trajectory of the window of audiovisual simultaneity by testing four age groups of children (5, 7, 9, and 11years) and adults. We presented a visual flash and an auditory noise burst at various stimulus onset asynchronies (SOAs) and asked participants to report whether the two stimuli were presented at the same...

Faces are adaptively coded relative to visual norms that are updated by experience, and this adaptive coding is linked to face recognition ability. Here we investigated whether adaptive coding of faces is disrupted in individuals (adolescents and adults) who experience face recognition difficulties following visual deprivation from congenital catar...

We tested the effect of early monocular and binocular deprivation of normal visual input on the development of contour interpolation. Patients deprived from birth by dense central cataracts in one or both eyes, and age-matched controls, discriminated between fat and thin shapes formed by either illusory or luminance-defined contours. Thresholds ind...

Significant controversies have arisen over the developmental trajectory for the perception of global motion. Studies diverge on the age at which it becomes adult-like, with estimates ranging from as young as 3 years to as old as 16. In this article, we review these apparently conflicting results and suggest a potentially unifying hypothesis that ma...

The study of sensory deprivation is a striking model to reveal the role experience plays in sculpting the functional architecture of the brain. Here we used functional Magnetic Resonance Imaging to characterize brain responses to auditory stimuli in 11 adults who had been deprived of all patterned vision at birth by dense congenital cataracts in bo...

In my presidential address, I described the early trap I fell into of describing the super-baby capable of one after another adult perceptual ability, then how I discovered that two atypical populations of adults allowed me to study developmental mechanisms, namely, the role of early sensory input in sculpting the nervous system and the biological...

Animal and human studies have demonstrated that transient visual deprivation early in life, even for a very short period, permanently alters the response properties of neurons in the visual cortex and leads to corresponding behavioral visual deficits [1-7]. While it is acknowledged that early-onset and longstanding blindness leads the occipital cor...

We examined interpolation in 6- and 9-year-old children and in adults, in the two most common forms of fragmentation: subjective and partially occluded contours. Experiment 1 examined the effects on adults' interpolation of contour geometry, specifically, the effect of a scale-dependent factor (i.e., retinal size) and a scale-independent factor (i....

It is unclear whether reported deficits in face processing in individuals with autism spectrum disorders (ASD) can be explained by deficits in perceptual face coding mechanisms. In the current study, we examined whether adults with ASD showed evidence of norm-based opponent coding of facial identity, a perceptual process underlying the recognition...

We combined an external noise paradigm with an efficient procedure for obtaining contrast thresholds (Lesmes et al., 2006) in order to model developmental changes in the effect of noise on contrast discrimination during childhood. Specifically, we measured the contrast thresholds of 5-, 7-, 9-year-olds and adults (n = 20/age) in a two alternative f...

We measured developmental changes (7-, 9-, and 11-year-olds, and adults) in audiovisual integration utilizing the visual fission and fusion illusions induced by sounds. In the fission illusion, a single flash is perceived as two flashes when accompanied by two beeps. In the fusion illusion, two flashes are perceived as a single flash when accompani...

Synaesthesia is a neurological condition in which input to one sense causes an automatic and consistent extra percept, often in another sense (e.g., C sharp elicits a pale yellow). Synaesthesia is hypothesized to arise, at least in part, from less-than-normal neural pruning of the exuberant connections in sensory cortical areas during infancy (revi...

Humans use the direction of eye gaze and facial identity to make important social judgments. We carried out the first measurements of spatial frequency (SF) tuning for judgments of eye gaze, and compared SF tuning for judgments of facial identity and eye gaze. In Experiment 1, participants discriminated between leftward and rightward shifts of gaze...

Background / Purpose: Adults find average faces, that approximate the population mean, to be more attractive than most other faces ( Langlois & Roggman, 1990 ). We investigated the importance of early visual experience by taking advantage of a rare condition: adults who were born with bilateral cataracts that blocked all patterned visual input un...

Children take many years to become as skilled as adults in differentiating among faces and there is debate about the role of face experience in improving their skills. Here we tested whether the increase in exposure to the faces of children associated with entering school leads to improved face discrimination for this face category. To do so, we co...

Adults use the orientation of people’s heads as a cue to the focus of their attention. We examined developmental changes in mechanisms underlying sensitivity to head orientation during childhood. Eight-, 10-, 12-year-olds, and adults were adapted to a frontal face view or a 20°° left or right side view before judging the orientation of a face at or...

To examine individual differences in adults’ sensitivity to facial expressions, we used a novel method that has proved revealing in studies of developmental change. Using static faces morphed to show different intensities of facial expressions, we calculated two measures: (1) the threshold to detect that a low intensity facial expression is differe...

In this article, we begin with a summary of the evidence for perceptual narrowing for various aspects of language (e.g., vowel and consonant contrasts, tone languages, visual language, sign language) and of faces (e.g., own species, own race). We then consider possible reasons for the apparent differences in the timing of narrowing (e.g., apparentl...

Patients treated for bilateral congenital cataract are later impaired on several hallmarks of adults' expertise with upright faces but report no problem with remembering faces. Here, we provide the first formal data on their face memory. We compared 12 adults with a history of visual deprivation from bilateral congenital cataracts to 24 age-matched...

We investigated the effects of early visual deprivation on the underlying representation of the six basic emotions. Using multi-dimensional scaling (MDS), we compared the similarity judgments of adults who had missed early visual input because of bilateral congenital cataracts to control adults with normal vision. Participants made similarity judgm...

The expertise of adults in face perception is facilitated by their ability to rapidly detect that a stimulus is a face. In two experiments, we examined the role of early visual input in the development of face detection by testing patients who had been treated as infants for bilateral congenital cataract. Experiment 1 indicated that, at age 9 to 20...

Adults use gaze and voice signals as cues to the mental and emotional states of others. We examined the influence of voice cues on children's judgments of gaze. In Experiment 1, 6-year-olds, 8-year-olds, and adults viewed photographs of faces fixating the center of the camera lens and a series of positions to the left and right and judged whether g...

In this article, the authors introduce a new theoretical framework for understanding intersensory development. Their approach is based upon insights gained from adults who experience synesthesia, in whom sensory stimuli induce extra cross-modal or intramodal percepts. Synesthesia appears to represent one way that typical developmental mechanisms ca...

In experiment 1, we examined developmental changes in the influence of symmetry on judgments of attractiveness by showing adults and children pairs of individual faces in which one face was transformed 75% toward perfect symmetry, while the other face was transformed by exaggerating its asymmetries by 75%. Adults and 9-year-olds, but not 5-year-old...

Background / Purpose: To provide the first measure of the effect of convexity on figure-ground judgments in children. Main conclusion: Under the present testing conditions, convex contours strongly bias figure-ground judgments by three years of age.

Children and adults consistently match some words (e.g., kiki) to jagged shapes and other words (e.g., bouba) to rounded shapes, providing evidence for non-arbitrary sound-shape mapping. In this study, we investigated the influence of vowels on sound-shape matching in toddlers, using four contrasting pairs of nonsense words differing in vowel sound...

Background / Purpose: Adults rate averaged faces approximating the population mean as more attractive than most individual faces. However, an average created from highly attractive faces is judged by adults to be more attractive than an average created from a wider selection of faces (1, 2). We created two “attractiveness dimensions”: one of 21 m...

We examined developmental changes in the influence of averageness on judgments of facial attractiveness by showing adults and children pairs of individual faces in which one face was transformed 50% toward its group average, whereas the other face was transformed 50% away from that average. In one comparison, adults and 5-year-olds rated the more a...

We investigated the efficacy of training adults to recognize full spectrum inverted faces presented with different viewpoints. To examine the role of different spatial frequencies in any learning, we also used high-pass filtered faces that preserved featural information and low-pass filtered faces that severely reduced that featural information. Al...

This volume synthesizes and integrates the broad literature in the subdisciplines of developmental psychology. The volume features an opening chapter by the volume editor outlining the organization of the field, as well as a concluding chapter in which the volume editor outlines future directions for developmental psychology. This volume synthesize...

We examined the influences of face inversion and facial expression on sensitivity to eye contact in high-functioning adults with and without an autism spectrum disorder (ASD). Participants judged the direction of gaze of angry, fearful, and neutral faces. In the typical group only, the range of directions of gaze leading to the perception of eye co...

Early visual deprivation impairs some, but not all, aspects of face perception. We investigated the possible developmental roots of later abnormalities by using a face detection task to test infants treated for bilateral congenital cataract within 1 hour of their first focused visual input. The seven patients were between 5 and 12 weeks old (n = 3)...

Binocular visual experience is necessary for normal visual development. When it is missing during a critical period early in lifebecause of an eye turn or a cataractmany aspects of later vision are compromised. Nevertheless, studies of animal models and human patients indicate that a variety of interventions are effective in improving vision after...

At birth, infants can see only large objects of high contrast located in the central visual field. Over the next half year, basic visual sensitivity improves dramatically. The infant begins to perceive the direction of moving objects and stereoscopic depth, and to integrate the features of objects and faces. Nevertheless, it takes until about 7 yea...

In two experiments, we investigated whether adults use holistic processing even for faces that are grossly distorted because their eyes have been moved asymmetrically to violate the common layout of a face (distorting its first-order relations). To this end we used a compelling demonstration that faces are processed as wholes, the composite-face ef...

The human visual system is not an ideal transmitter of information. A number of separate, quantifiable factors, such as internal noise (Barlow, 1956; Pelli, 1981), have been introduced to characterize what limits our visual sensitivity and how it changes as a result of attention (Lu & Dosher, 1998), training/learning (Li & Levi, 2004), or aging (Be...

Although rudimentary skills emerge during infancy (e.g., Morton & Johnson, 1991; Pascalis & de Schonen, 1995; Pascalis, de Haan, Nelson, & de Schonen, 1998), the recognition of facial identity improves into adolescence (Mondloch, Le Grand, & Maurer, 2002). Here we examined the influence of entering school on face recognition. We hypothesize that th...

Amblyopia is a condition involving reduced acuity caused by abnormal visual input during a critical period beginning shortly after birth. Amblyopia is typically considered to be irreversible during adulthood. Here we provide the first demonstration that video game training can improve at least some aspects of the vision of adults with bilateral dep...

Patients deprived of visual experience during infancy by dense bilateral congenital cataracts later show marked deficits in the perception of global motion (dorsal visual stream) and global form (ventral visual stream). We expected that they would also show marked deficits in sensitivity to biological motion, which is normally processed in the supe...