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Maturation of pattern vision in infants during the first 6 months
Abstract
Infants were tested by using their natural tendency to fixate a striped stimulus more than a gray one. Reliability was demonstrated by testing infants twice with 2 independent Os. Approximately the same acuity was found as from measurement of optokinetic nystagmus to a moving striped field. No difference in acuity was found with patterns subtending the same visual angles when presented at distances of 5, 10, or 20 in. The minimum separable visual angle was 40 min. under 1 mo., and reduced to 5 min. by 6 mo. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
... 4. Teller and colleagues: forced-choice enters preferential looking 4.1 Differences from Fantz's methods Teller et al. (1974) and Teller (1979) were aware of the "preferential looking" method of Fantz et al. (1962). In fact, they partly adopted the Fantz et al. (1962) methods. ...
... 4. Teller and colleagues: forced-choice enters preferential looking 4.1 Differences from Fantz's methods Teller et al. (1974) and Teller (1979) were aware of the "preferential looking" method of Fantz et al. (1962). In fact, they partly adopted the Fantz et al. (1962) methods. Teller (1979) provides the best explanation of their laboratory's techniques, as follows. ...
... They present a grating (striped pattern) on one side (left or right) of a center-point. Here, however, they diverge from Fantz et al. (1962) by having nothing but a luminance-matched gray background as the other "stimulus object," rather than having a distinct gray object on a common, darker background (Fantz et al., 1962). To explain: "The infant is shown a homogeneous visual display, in which a single visual stimulus is embedded, in a variable position" (Teller, 1979, p. 143). ...
Purpose
This study aims to examine the observer’s role in “infant psychophysics”. Infant psychophysics was developed because the diagnosis of perceptual deficits should be done as early in a patient’s life as possible, to provide efficacious treatment and thereby reduce potential long-term costs. Infants, however, cannot report their perceptions. Hence, the intensity of a stimulus at which the infant can detect it, the “threshold”, must be inferred from the infant’s behavior, as judged by observers (watchers). But whose abilities are actually being inferred? The answer affects all behavior-based conclusions about infants’ perceptions, including the well-proselytized notion that auditory stimulus-detection thresholds improve rapidly during infancy.
Design/methodology/approach
In total, 55 years of infant psychophysics is scrutinized, starting with seminal studies in infant vision, followed by the studies that they inspired in infant hearing.
Findings
The inferred stimulus-detection thresholds are those of the infant-plus-watcher and, more broadly, the entire laboratory. The thresholds are therefore tenuous, because infants’ actions may differ with stimulus intensity; expressiveness may differ between infants; different watchers may judge infants differently; etc. Particularly, the watcher’s ability to “read” the infant may improve with the infant’s age, confounding any interpretation of perceptual maturation. Further, the infant’s gaze duration, an assumed cue to stimulus detection, may lengthen or shorten nonlinearly with infant age.
Research limitations/implications
Infant psychophysics investigators have neglected the role of the observer, resulting in an accumulation of data that requires substantial re-interpretation. Altogether, infant psychophysics has proven far too resilient for its own good.
Originality/value
Infant psychophysics is examined for the first time through second-order cybernetics. The approach reveals serious unresolved issues.
... Perhaps the most basic index of the ability to respond to pattern is visual acuity (Fantz & Ordy, 1959;Fantz, Ordy, & Udelf, 1962). There are two major types of visual acuity studied in iufauts detection and minimal separation_. ...
... Consequently, they conclude that OKN measures of visual acuity, especially in the neonate, overestimate visual acuity because OKN measures the capacities of the functioning subcortex rather than those of the nonfunctioning visual cortex (Bronson, 1974;Linksz, 1973;Fantz, Ordy & Udelf, 1962). ...
... The PL technique is presumed to be a cortically-controlled response, with mean fixation length indicating central foveal activity and number of fixations indicating peripheral retinal activity and subcortical activity (Fantz,·Ordy & Udelf, 1962; also see Cohen, 1969Cohen, , 1972. The major difficulty with PL techniques is that, although the presence of a differential response may be regarded as indicative of the infant's ability to differentiate two stimuli, the absence of differential responsivity cannot be used to infer that the infant lacks the ability to differentiate two stimuli. ...
... Específicamente, en el área del razonamiento y la solución de problemas se han generado explicaciones alternativas, que recuperan los análisis desde una perspectiva menos computacional y más abierta, en la que están involucrados muchos más procesos, en contextos que no necesariamente son de laboratorio. Dunbar (1999) ha señalado que la futura investigación en solución de problemas y el razonamiento, deberá desprenderse de los paradigmas clásicos que marcó la Psicología del procesamiento de la información durante décadas, y empezar a indagar esos procesos superiores en el marco de contextos más complejos y más realistas. ...
... El panorama actual, hace suponer un necesario replanteamiento de la manera como los psicólogos cognitivos definimos el razonamiento, y en particular la cognición temprana. Klahr (2000) ha planteado que el problema necesita un debate más amplio que incorpore los nuevos elementos que usualmente permanecen al margen de las discusiones recientes: modelos descriptivos integrados, pensamiento científico en situaciones más naturalistas, modelos ecológicos de análisis, más acordes con el razonamiento de las personas (Dunbar, 1999), y con experimentos más centrados en recuperar la experimentación autodirigida por el sujeto en contextos familiares, lo que hace más fácil hacer un seguimiento del razonamiento científico en contextos naturales y escolares. Creemos que además de esos aspectos, habría que insistir mucho más en el papel determinante que cumplen las situaciones de resolución de problemas, y el uso de herramientas cognitivas que son parte del repertorio de los seres humanos. ...
... Ideas on healthy infant development have changed throughout humanity's history (Fogel, 2010). Empirical research on infants has become widespread in the last 60 years after it has been shown that newborns perceive and respond to sensory perceptions very early on (Frantz et al., 1962). With this new understanding came the insight that the first few months of life are crucial for learning and establishing the infant-parent relationship (Nugent et al., 2008). ...
Human development is a complex interplay of different factors. This thesis focuses on two of these factors: sleep and gut bacteria. Sleep takes up more than half of each day in infancy and childhood, and gut bacteria make up around half of all cells in our body. Both undergo large transitions in infancy and childhood. Sleep has been suggested to be a marker of brain maturation. Gut bacteria have been suggested to be health markers. Studies in rodents and adults have found the first evidence that sleep and gut bacteria are linked. However, no studies have examined this link in infancy - a phase with rapid developmental changes.
This thesis fulfills two aims, which are addressed in 6 research articles. The first aim is to get more precise and standardized estimates of infant sleep behavior by improving the methodology of infant actigraphy sleep research. The second is to characterize sleep across development, focusing on the link between sleep and gut bacteria.
The first aim was addressed in three articles. Article 1 systematically reviewed the existing literature that uses actigraphy to measure sleep in infants and children. We rated the methodological reporting, highlighting which information is currently underreported. Additionally, we made recommendations for future studies. Article 2 compared the estimates from two commonly used algorithms (Sadeh and Oakley/Respironics) that score sleep-wake patterns from movement. We found major differences between the sleep estimates but proposed a standardized pipeline to reduce these differences. In Article 3, we applied a principal component approach to a large array of sleep variables to find underlying sleep composites. We found 5 sleep composites, which accurately reflect sleep maturation in the first year of life: Sleep Day (measuring daytime sleep duration and regularity), Sleep Night (measuring nighttime sleep duration), Sleep Timing (measuring nighttime sleep timing), Sleep Activity (measuring awakenings and activity during the night) and Sleep Variability (measuring variability of night sleep timing and duration across measurement days).
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For the second aim, we looked at sleep development across infancy, childhood, and adolescence. Articles 3 and 4 used a large cohort of 162 infants, measured at 3, 6, and 12 months of age with behavioral follow-up at 24 months. In Article 3, we characterized infant sleep in the first year of life. We confirmed the high variability between infants but also show a high variability within infants across the first year of life. We found stable sex differences in Sleep Activity already in infancy. Furthermore, we found that Sleep Day is associated with behavioral development. In Article 4, we investigated which role gut bacteria play in these associations. We showed that alpha diversity was associated with Sleep Day, especially in early development. Additionally, Sleep Activity was associated with bacterial maturity and enterotype. Furthermore, we found exciting associations between both sleep and gut bacteria and development; most notably, we extended the finding of Sleep Day as a maturational marker by showing that daytime sleep at 12 months negatively predicts gross motor development at 24 months. Additionally, we found a positive association between alpha diversity and early behavioral development. Overall, we showed complex and dynamic associations between sleep, gut bacteria, and behavioral development.
Articles 5 and 6 examined the spatio-temporal properties of sleep slow waves. In Article 5, we investigated a dataset of 29 children and adolescents between 2 and 17 years of age. We examined how sleep slow waves travel across the cortex, how this traveling behavior changes across the night, and if the traveling behavior is different across development. We found one aspect that had age-dependent changes across the night: slow wave propagation distance. It only decreases across the night in children younger than 5 years old. In Article 6, we reviewed the relationship of intracellular slow oscillations and scalp slow waves. Additionally, we showed that the origin of sleep slow waves is less likely to be located in frontal areas in children than in adolescents. We proposed that slow waves not only mirror brain maturation but might also be driving this maturation.
This thesis shows the remarkable development of sleep from infancy to adolescence. It also provides the first evidence of a sleep-gut link in infancy and reveals interesting associations between sleep and gut bacteria and behavioral development. I propose methodological recommendations and future research directions to increase our knowledge of infant development.
... Finally, it is also possible that there were individual differences in visual acuity in the infants we observed. In general, an infant's visual acuity is well-developed by about 6 months of age (see, e.g., References [38][39][40][41]), as well as the ability to visually scan the environment and track moving objects and people. Although it seems unlikely that poor acuity would have had a prominent influence on our results, otherwise we would not have obtained interpretable findings, measuring and equating visual acuity across conditions would strengthen the designs of future studies. ...
Early social-linguistic experience influences infants’ attention to faces but little is known about how infants attend to the faces of speakers engaging in conversation. Here, we examine how monolingual and bilingual infants attended to speakers during a conversation, and we tested for the possibility that infants’ visual attention may be modulated by familiarity with the language being spoken. We recorded eye movements in monolingual and bilingual 15-to-24-month-olds as they watched video clips of speakers using infant-directed speech while conversing in a familiar or unfamiliar language, with each other and to the infant. Overall, findings suggest that bilingual infants visually shift attention to a speaker prior to speech onset more when an unfamiliar, rather than a familiar, language is being spoken. However, this same effect was not found for monolingual infants. Thus, infants’ familiarity with the language being spoken, and perhaps their language experiences, may modulate infants’ visual attention to speakers.
... The present study, in which both gazes presented the same contrast distribution in the face template and contrast symmetry, demonstrates that the anatomic explanation of eyes and its contrast/directions 26 is not the sole possible explanation. These results also suggest that visual abilities of newborns may have been underestimated, as suggested by some authors 42 : Visual acuity and distance perception have not been revisited since Fantz 43 and Teller 44 earlier studies. For example, further studies have shown, through forced choice preferential looking, that newborns can see up to 1 m, thus far more than the 18-25 cms suggested by Fantz' studies 42 . ...
Previous studies evidenced that already from birth, newborns can perceive differences between a direct versus an averted gaze in faces both presented in static and interactive situations. It has been hypothesized that this early sensitivity would rely on modifications of the location of the iris (i.e. the darker part of the eye) in the sclera (i.e. the white part), or that it would be an outcome of newborns’ preference for configurations of faces with the eye region being more contrasted. One question still remains: What happens when the position of the iris is not modified in the sclera, but the look is ‘faraway’, that is when the gaze is toward the newborns’ face but above his or her own eyes? In the present study, we tested the influence of a direct versus a faraway gaze (i.e., two gazes that only differed slightly in the position of the iris on the vertical axis and not on the horizontal axis) on newborns’ face recognition. The procedure was identical to that used in previous studies: using a familiarization-test procedure, we familiarized two groups of newborns (N = 32) with videos of different talking faces that were presented with either a direct or a faraway gaze. Newborns were then tested with photographs of the face seen previously and of a new one. Results evidenced that newborns looked longer at the familiar face, but only in the direct gaze condition. These results suggest that, already from birth, infants can perceive slight differences of gazes when someone is addressing to them.
... During the studies, the newborns sat on the experimenter's lap and watched the stimuli presented on a monitor (24″) in front of them. Newborns' eye level was aligned to the centre of the screen and the distance between their face and the monitor was about 35 cm, to maximize their visual acuity 50,51 . Black cardboard and black curtains covered the area around the monitor to prevent external stimuli from engaging the newborns' attention. ...
Peripersonal space immediately surrounds the body and can be represented in the brain as a multisensory and sensorimotor interface mediating physical and social interactions between body and environment. Very little consideration has been given to the ontogeny of peripersonal spatial representations in early postnatal life, despite the crucial roles of peripersonal space and its adaptive relevance as the space where infants’ earliest interactions take place. Here, we investigated whether peripersonal space could be considered a delimited portion of space with defined boundaries soon after birth. Our findings showed for the first time that newborns’ saccadic reaction times to a tactile stimulus simultaneous to sounds with different intensities changed based on the sound intensity. In particular, they were significantly faster when the sound was lounder than a critical intensity, in a pattern that closely resembled that showed by adults. Therefore, provided that sound intensity on its own can cue newborns’ sound distance perception, we speculate that this critical distance could be considered the boundary of newborns’ rudimentary peripersonal space. Altogether, our findings suggest that soon after birth peripersonal space may be already considered as a bounded portion of space, perhaps instrumental to drive newborns’ attention towards events and people within it.
... On the one hand, there is substantial evidence that infants' performance in these studies depends heavily on the characteristics of the learning environment. For example, early work demonstrated that infants under six months of age prefer to look at patterned than at homogenous grey stimuli (Fantz, Ordy, & Udelf, 1962), and in a seminal series of categorization experiments with three-month-old infants, Quinn and colleagues demonstrated that the category representations infants form are directly related to the visual variability of the familiarization stimuli they see (Quinn, Eimas, & Rosenkrantz, 1993; see also Younger, 1985). More recently, four-month-old infants were shown to learn animal categories when familiarized with paired animal images, but not when presented with the same images individually (Oakes, Kovack-Lesh, & Horst, 2009; see also Kovack-Lesh & Oakes, 2007). ...
Infants are curious learners who drive their own cognitive development by imposing structure on their learning environment as they explore. Understanding the mechanisms by which infants structure their own learning is therefore critical to our understanding of development. Here we propose an explicit mechanism for intrinsically motivated information selection that maximizes learning. We first present a neurocomputational model of infant visual category learning, capturing existing empirical data on the role of environmental complexity on learning. Next we “set the model free”, allowing it to select its own stimuli based on a formalization of curiosity and three alternative selection mechanisms. We demonstrate that maximal learning emerges when the model is able to maximize stimulus novelty relative to its internal states, depending on the interaction across learning between the structure of the environment and the plasticity in the learner itself. We discuss the implications of this new curiosity mechanism for both existing computational models of reinforcement learning and for our understanding of this fundamental mechanism in early development.
... The newborns sat on the experimenter's lap and watched the stimuli presented on a monitor (24″) in front of them. The distance between the newborns' face and the monitor was about 30 cm, distance at which visual acuity at birth is better (Fantz, Ordy, & Udelf, 1962;Slater, 2002). Black cardboard and black curtains covered the area around the monitor to prevent external stimuli from engaging the newborns' attention. ...
The ability to discriminate the trajectories of moving objects is highly adaptive and fundamental for physical and social interactions. Therefore, we could reasonably expect sensitivity to different trajectories already at birth, as a precursor of later communicative and defensive abilities. To investigate this possibility, we measured newborns' looking behavior to evaluate their ability to discriminate between visual stimuli depicting motion along different trajectories happening within the space surrounding their body. Differently from previous studies, we did not take into account defensive reactions, which may not be elicited by impending collision as newborns might not categorize approaching stimuli as possible dangers. In two experiments, we showed that newborns display a spontaneous visual preference for trajectories directed toward their body. We found this visual preference when visual stimuli depicted motion in opposite directions (approaching vs. receding) as well as when they both moved toward the peripersonal space and differed only in their specific target (i.e., the body vs. the space around it). These findings suggest that at birth human infants seem to be already equipped with visual mechanisms predisposing them to perceive their presence in the environment and to adaptively focus their attention on the peripersonal space and their bodily self.
... The authors are right that neonatal vision is much worse than child or adult vision. However, to convince the reader to disregard the cross-modal number studies with neonates, the authors would need to provide actual evidence that typical newborn visual acuity is below the threshold needed to see the stimuli used in these particular studies (e.g., estimates from Fantz et al. [1962] and Kellman & Arterberry [2007] suggest otherwise). ...
Leibovich et al. opened up an important discussion on the nature and origins of numerosity perception. The authors rightly point out that non-numerical features of stimuli influence this ability. Despite these biases, there is evidence that from birth, humans perceive and represent numerosities, and not just non-numerical quantitative features such as item size, density, and convex hull.
... The authors are right that neonatal vision is much worse than child or adult vision. However, to convince the reader to disregard the cross-modal number studies with neonates, the authors would need to provide actual evidence that typical newborn visual acuity is below the threshold needed to see the stimuli used in these particular studies (e.g., estimates from Fantz et al. [1962] and Kellman & Arterberry [2007] suggest otherwise). ...
Leibovich et al. challenge the prevailing view that non-symbolic number sense (e.g., sensing number the same way one might sense color) is innate, that detection of numerosity is distinct from detection of continuous magnitude. In the present commentary, the authors' viewpoint is discussed in light of the integrative theory of numerical development along with implications for understanding mathematics disabilities.
... The authors are right that neonatal vision is much worse than child or adult vision. However, to convince the reader to disregard the cross-modal number studies with neonates, the authors would need to provide actual evidence that typical newborn visual acuity is below the threshold needed to see the stimuli used in these particular studies (e.g., estimates from Fantz et al. [1962] and Kellman & Arterberry [2007] suggest otherwise). ...
The conclusions reached by Leibovich et al. urge the field to regroup and consider new ways of conceptualizing quantitative development. We suggest three potential directions for new research that follow from the authors' extensive review, as well as building on the common ground we can take from decades of research in this area.
... The authors are right that neonatal vision is much worse than child or adult vision. However, to convince the reader to disregard the cross-modal number studies with neonates, the authors would need to provide actual evidence that typical newborn visual acuity is below the threshold needed to see the stimuli used in these particular studies (e.g., estimates from Fantz et al. [1962] and Kellman & Arterberry [2007] suggest otherwise). ...
Leibovich et al. propose that non-symbolic numerosity abilities develop from the processing of more basic, continuous magnitudes such as size, area, and density. Here I review similar arguments arising in the visual perception field and further propose that the evolvement of discrete representations from continuous stimulus properties may be a fundamental characteristic of cognitive development.
... The authors are right that neonatal vision is much worse than child or adult vision. However, to convince the reader to disregard the cross-modal number studies with neonates, the authors would need to provide actual evidence that typical newborn visual acuity is below the threshold needed to see the stimuli used in these particular studies (e.g., estimates from Fantz et al. [1962] and Kellman & Arterberry [2007] suggest otherwise). ...
The authors rightly point to the theoretical importance of interactions of space and number through the life span, yet propose a theory with several weaknesses. In addition to proclaiming itself unfalsifiable, its stage-like format and emphasis on the role of selective attention are at odds with what is known about the development of spatial-numerical associations in infancy.
... The authors are right that neonatal vision is much worse than child or adult vision. However, to convince the reader to disregard the cross-modal number studies with neonates, the authors would need to provide actual evidence that typical newborn visual acuity is below the threshold needed to see the stimuli used in these particular studies (e.g., estimates from Fantz et al. [1962] and Kellman & Arterberry [2007] suggest otherwise). ...
In response to the commentaries, we have refined our
suggested model and discussed ways in which the model could be
further expanded. In this context, we have elaborated on the role
of specific continuous magnitudes. We have also found it important
to devote a section to evidence considered the “smoking gun” of the
approximate number system theory, including cross-modal studies,
animal studies, and so forth. Lastly, we suggested some ways in
which the scientific community can promote more transparent
and collaborative research by using an open science approach,
sharing both raw data and stimuli. We thank the contributors
for their enlightening comments and look forward to future
developments in the field.
... Experiment 2 replicated Experiment 1 using a longitudinal design to gather more detailed information about how infant CFF thresholds develop between three and six months of age. Because of the positive relation between CFF and age that has been found in previous infant CFF literature and the fact that other aspects of visual development improve with age in infancy (e.g., acuity; Fantz, Ordy, & Udelf, 1962;Teller, Morse, Borton, & Regal, 1974), it was hypothesized that CFF would be positively correlated with infant age in both experiments. ...
Processing speed, which can be measured behaviorally in various sensory domains, has been shown to be a strong marker of central nervous system health and functioning in adults. Visual temporal processing speed (measured via critical flicker fusion [CFF] thresholds) represents the speed at which the visual system can detect changes. Previous studies of infant CFF development have been limited and inconsistent. The present study sought to characterize the development of CFF thresholds in the first year of life using a larger sample than previous studies and a repeated measures design (in Experiment 2) to control for individual differences. Experiment 1 (n = 44 infants and n = 24 adults) used a cross-sectional design aimed at examining age-related changes that exist in CFF thresholds across infants during the first year of life. Adult data were collected to give context to infant CFF thresholds obtained under our specific stimulus conditions. Experiment 2 (n = 28) used a repeated-measures design to characterize the developmental trajectory of infant CFF thresholds between three and six months of age, based on the results of Experiment 1. Our results reveal a general increase in CFF from three to four and one-half months of age, with a high degree of variability within each age group. Infant CFF thresholds at 4.5 months of age were not significantly different from the adult average, though a regression analysis of the data from Experiment 2 predicted that infants would reach the adult average closer to 6 months of age. Developmental and clinical implications of these data are discussed.
... Null findings are problematic, as they acknowledge, especially in light of earlier literature. Fantz et al. (1962) reported that infants could resolve 40 min. of visual arc with 1/8-in. stripes at 10 in. ...
When employing between-infant designs young infants’ looking style is related to their
development: Short looking (SL) infants are cognitively accelerated over their long looking
(LL) peers. In fact, looking style is a within-infant variable, and depends on infant i’s look
distribution over trials. For the paired array setting, a model is provided which specifies
the probability, πi ∈ [0, 1], that i is SL. The model is employed in a face preference
study; 74 Caucasian infants were longitudinally assessed at 3, 6, and 9 months. Each
i viewed same race (Caucasian) vs. other race (African) faces. Infants become SL with
development, but there are huge individual differences in rate of change over age. Three
month LL infants, π ˆi < 1/2, preferred other race faces. SL infants, π ˆi > 1/2, preferring
same race faces at 3, and other race faces at 6 and 9 months. Looking style changes
precede and may control changes in face preference. Ignoring looking style can be
misleading: Without considering looking style, 3 month infants show no face preference
... Procedimentos comportamentais que permitem inferir capacidades sensoriais ou perceptuais em bebês e crianças baseiam-se, na sua maior parte, (Fantz, 1956(Fantz, , 1958(Fantz, , 1960(Fantz, , 1961(Fantz, , 1963(Fantz, , 1964(Fantz, , 1965Fantz & Miranda, 1975;Fantz & Nevis, 1967;Fantz & Ordy, 1959;Fantz, Ordy, & Udelf, 1962). Essa descoberta forneceu a base metodológica para estudar percepção desde o início da vida e constituiu o ponto de partida para uma nova compreensão a respeito das habilidades e competências do recém-nascido. ...
Behavioral procedures that allow the estimation of sensory or perceptual abilities in infants and children are greatly based on the seminal discovery made in the 1950s by psychologist Robert Fantz that, given the choice, birth infants prefer to look at complex stimuli rather than to gaze at monotonous scenes. Based on the new discovery, the group of scientists led by Davida Teller, at the University of Washington, developed a methodology for psychophysical assessment of vision in babies that allowed a great advancement in the study of development and maturation of several basic visual functions, such as visual acuity, color vision, contrast sensitivity, stereoscopic vision, and vision of movement. The present review examines this literature showing how visual functions are assessed in babies and what has been learnt so far about the capacity to see color by the newborn.
... Forced preferential looking (FPL) relies on children preferentially fixating patterned over uniform stimuli. Detection can be quantified by scoring eye movements either by a judge 13 , or an automated analysis of eye position 14 . However, estimates of visual function from FPL are necessarily lower bounds on performance, since the procedure cannot distinguish failures of detection from inattention. ...
Although the contrast sensitivity function (CSF) is a particularly useful way of characterising functional vision, its measurement relies on observers making reliable perceptual reports. Such procedures can be challenging when testing children. Here we describe a system for measuring the CSF using an automated analysis of optokinetic nystagmus (OKN); an involuntary oscillatory eye movement made in response to drifting stimuli, here spatial-frequency (SF) band-pass noise. Quantifying the strength of OKN in the stimulus direction allows us to estimate contrast sensitivity across a range of SFs. We compared the CSFs of 30 observers with normal vision measured using both OKN and perceptual report. The approaches yield near-identical CSFs (mean R = 0.95) that capture subtle intra-observer variations in visual acuity and contrast sensitivity (both R = 0.84, p < 0.0001). Trial-by-trial analysis reveals high correlation between OKN and perceptual report, a signature of a common neural mechanism for determining stimulus direction. We also observe conditions where OKN and report are significantly decorrelated as a result of a minority of observers experiencing direction-reversals that are not reflected by OKN. We conclude that there are a wide range of stimulus conditions for which OKN can provide a valid alternative means of measuring of the CSF.
... Forced preferential looking (FPL) relies on children preferentially fixating patterned over uniform stimuli. Detection can be quantified by scoring eye movements either by a judge 13 , or an automated analysis of eye position 14 . However, estimates of visual function from FPL are necessarily lower bounds on performance, since the procedure cannot distinguish failures of detection from inattention. ...
Although the contrast sensitivity function (CSF) is a particularly useful way of characterising functional vision, its psychophysical measurement relies on observers being able to make reliable perceptual reports. This can be challenging e.g. when testing children. Here we describe a system for measuring the CSF without observer-report using an automated analysis of optokinetic nystagmus (OKN), an oscillatory eye movement made in response to moving stimuli (here, spatial-frequency - SF - band-pass noise). We show that predicting perceived direction using the proportion of eye movements that are consistent with OKN in the stimulus direction allows us to make an unbiased estimate of contrast sensitivity across SF. We next compare CSFs of 25 observers derived using either OKN or perceptual report. Both approaches yield near-identical CSFs that capture subtle inter-observer variations in acuity (R=0.80, p< 0.0001) and contrast sensitivity (R=0.80, p< 0.0001) amongst observers with ostensibly normal vision. A trial-by-trial analysis reveals that, even when observers' perceptual report is at chance, there is a very high correlation between our OKN-derived measure and observers' perceptual report. This indicates that OKN and self-report are likely tapping into a common neural mechanism providing further support for the proposal that OKN is a valid alternative to the current gold standard measures of CSF based on perceptual report. We discuss how our approach can be paired with an efficient psychophysical method to derive rapid automated measures of the CSF and other measures of functional vision.
Meeting abstract presented at VSS 2016
... The authors are right that neonatal vision is much worse than child or adult vision. However, to convince the reader to disregard the cross-modal number studies with neonates, the authors would need to provide actual evidence that typical newborn visual acuity is below the threshold needed to see the stimuli used in these particular studies (e.g., estimates from Fantz et al. [1962] and Kellman & Arterberry [2007] suggest otherwise). ...
In this review, we are pitting two theories against each other: the more accepted theory-the 'number sense' theory-suggesting that a sense of number is innate and non-symbolic numerosity is being processed independently of continuous magnitudes (e.g., size, area, density); and the newly emerging theory suggesting that (1) both numerosities and continuous magnitudes are processed holistically when comparing numerosities, and (2) a sense of number might not be innate. In the first part of this review, we discuss the 'number sense' theory. Against this background, we demonstrate how the natural correlation between numerosities and continuous magnitudes makes it nearly impossible to study non-symbolic numerosity processing in isolation from continuous magnitudes, and therefore the results of behavioral and imaging studies with infants, adults and animals can be explained, at least in part, by relying on continuous magnitudes. In the second part, we explain the 'sense of magnitude' theory and review studies that directly demonstrate that continuous magnitudes are more automatic and basic than numerosities. Finally, we present outstanding questions. Our conclusion is that there is not enough convincing evidence to support the number sense theory anymore. Therefore, we encourage researchers not to assume that number sense is simply innate, but to put this hypothesis to the test, and to consider if such an assumption is even testable in light of the correlation of numerosity and continuous magnitudes.
... The most common measure of grating acuity during infancy is preferential looking (reviewed in Maurer & Lewis, 2001a, 2001b. This method takes advantage of infants' preference to look at something patterned over something plain (Fantz, Ordy, & Udelf, 1962). The infant is shown black-and-white stripes paired with a gray stimulus of the same mean luminance, and the size of the stripes is varied across trials. ...
Visual acuity measurement is an essential component of any eye exam. In adults and older children, letter-based acuity (i.e., recognition acuity) is commonly used to measure vision. However, in infants and toddlers, performing traditional visual acuity testing is nearly impossible. Instead, modified optotypes such as gratings and pictures are shown to observe the young child's visual behavior. Additionally, there are objective visual acuity methods that negate the need for observing visual behavior. For the practicing clinician, the choices are many and can be confusing. With new commercial products coming into the market every day, it is nearly impossible to comprehensively cover each one of them. Instead, in this chapter, commonly used and/or studied visual acuity tests are covered. For each test, the set-up, procedure, documentation, and scientific evidence supporting or negating its use are discussed.
The innate knowledge problem is a classical problem in philosophy, which has been known since the classical antiquity. Plato in his dialogues Meno and Phaedo formulated the doctrine of innate ideas and proposed an early version of the poverty of the stimulus argument, which is the most frequently used argument in innate knowledge debates. In the history of philosophy there was also an opposite view. This approach is often associated with J. Locke’s philosophy. Locke thought that all our knowledge about the world is a product of the universal learning mechanisms whose functioning is based on perception. The question about the presence of innate ideas in the human mind still remains relevant. New findings in cognitive science and neurosciences and also some recent arguments from philosophers contribute to the contemporary discussion between the spokesmen of the rival approaches to this problem. The paper presents the investigation of one of the approaches to solving the problem of innate concepts, which is called a “concept nativism.” It highlights the outstanding characteristics of the concept nativism: (a) domain specificity position, (b) belief that domain-specific mechanisms of learning are innate and (c) belief that at least some concepts are innate. The article also proposes an analysis of notions “innateness” and “idea” which is important for understanding nativists’ approach to innate ideas theory. And finally, it describes the most popular nativists’ arguments: (a) references to empirical studies using the preferential looking technique, (b) the poverty of the stimulus argument and (c) the argument from animals.
The purpose of the present study was to devise a method for assessing the visual function of people with severe cerebral palsy (CP). Participants in the study were 24 people with severe cerebral palsy who were residents of an institution for people with developmental disabilities. Their visual function was assessed on a 3-point ordinal scale using 9 different visual reaction tests. When the findings were classified with cluster analysis, the results reveals that the participants' visual function could be classified into 5 groups using 4 of the 9 tests. The groups were: (a) group 1: no visual reaction, (b) group 2: reaction to perceiving light, in which the stimulus was a light and the response measured was the pupillary light reflex, (c) group 3: avoidance reaction and gazing at or following a visual object with the eyes, in which the avoidance reaction recorded was the participant covering one eye, (d) group 4: an attentional shift toward the peripheral visual field, based on an orienting response, which made possible a behavioral visual-field screening test, and (e) group 5: reaction to grating acuity cards, measured by the participant's discrimination of the gratings on the cards. These 4 tests enabled classification of the participants' visual function without the need for a special technique or equipment or for assessment by an ophthalmic specialist. This suggests that classification using these 4 tests might be useful for evaluating the level of visual function in people with severe cerebral palsy and, from those results, for selecting an intervention.
Purpose
This paper aims to extend the companion paper on “infant psychophysics”, which concentrated on the role of in-lab observers (watchers). Infants cannot report their own perceptions, so for five decades their detection thresholds for sensory stimuli were inferred from their stimulus-evoked behavior, judged by watchers. The inferred thresholds were revealed to inevitably be those of the watcher–infant duo, and, more broadly, the entire Laboratory. Such thresholds are unlikely to represent the finest stimuli that the infant can detect. What, then, do they represent?
Design/methodology/approach
Infants’ inferred stimulus-detection thresholds are hypothesized to be attentional thresholds, representing more-salient stimuli that overcome distraction.
Findings
Empirical psychometric functions, which show “detection” performance versus stimulus intensity, have shallower slopes for infants than for adults. This (and other evidence) substantiates the attentional hypothesis.
Research limitations/implications
An observer can only infer the mechanisms underlying an infant’s perceptions, not know them; infants’ minds are “Black Boxes”. Nonetheless, infants’ physiological responses have been used for decades to infer stimulus-detection thresholds. But those inferences ultimately depend upon observer-chosen statistical criteria of normality. Again, stimulus-detection thresholds are probably overestimated.
Practical implications
Owing to exaggerated stimulus-detection thresholds, infants may be misdiagnosed as “hearing impaired”, then needlessly fitted with electronic implants.
Originality/value
Infants’ stimulus-detection thresholds are re-interpreted as attentional thresholds. Also, a cybernetics concept, the “Black Box”, is extended to infants, reinforcing the conclusions of the companion paper that the infant-as-research-subject cannot be conceptually separated from the attending laboratory staff. Indeed, infant and staff altogether constitute a new, reflexive whole, one that has proven too resilient for anybody’s good.
In many experimental situations it is of interest to assess how a set of circumstances or a treatment affects a population of subjects. In such studies it is important that we take care to control as much as possible for any additional circumstances or characteristics other than those under investigation that might also affect the outcome of the measurements to be collected. For example, gender and age would be important factors to take into account when evaluating the effect of a medication to treat high blood pressure. Similarly, environmental living conditions would be an important factor to consider when comparing subjects with a respiratory disease. Two commonly used approaches to facilitate experimental control of possible confounding factors are provided by the experimental research designs known as matched pairs and paired replicates.
Visual acuity is one of the most studied visual functions during the fi rst years of life. Visual acuity reflects the ability to resolve fine details from an observed object. Grating stimuli has been used in infants, pre-verbal and non-verbal patients to evaluate visual acuity. Clinical methods to measure grating acuity currently available along with normal developmental data of this function are presented.
Leibovich et al. do not present enough empirical support to overturn decades of work supporting a number sense nor to convince the reader that a magnitude sense provides a better explanation of the literature. Here we highlight what we feel are the main points of weakness and the types of evidence that could be provided to be more convincing.
Assessment of visual function forms an important part of the neurological evaluation of the newborn infant. It provides information on the integrity of the visual pathway and also has been claimed to be a marker of higher cortical function and thus a reliable predictor of later intellectual performance (Hack et al 1977).
Twelve profoundly retarded nonverbal, nonambulatory children were repeatedly exposed to one of two visual stimuli-a 2 times 2 or a 12 times 12 black-and-white checkerboard target-until a set criterion of habituation was demonstrated, as measured by a decrement in visual fixation time. When the habituation criterion was reached, the children were shown alternative presentations of the same and a novel target. Results showed an increase in visual fixation to the novel target. A control condition was instituted also; so that when the habituation criterion was reached, the children were shown only presentations of the same target. Results showed no increase in visual fixation to the same targets. Together these results suggest that profoundly retarded children do show habituation and dishabituation to visual stimuli, and are actively storing and processing information about their perceptual world. The educational implications of the habituation paradigm for the special education teacher in the classroom are discussed.
The perception of flicker demands the resolution of two stimuli separated in time; by visual acuity is generally meant the power of the eye to resolve two stimuli separated in space, i.e. it is fundamentally related to the spatial relationships between receptor elements as opposed to the temporal characteristics of the response of a single element.
Nativists have long believed in the infant’s innate preference to look at patterned visual stimuli. Over the past decade, this behavioural response has been translated into Preferential Looking (P.L.) (Fantz 1962, Teller 1979, 1986), a new visual acuity test for children below the age of three.
The present chapter will provide a selective review of findings on the growth of visual pattern perception in infants ranging in age from birth to seven months. (More comprehensive reviews are readily available in Cohen and Salapatek, 1975 and Haith and Campos, 1977.) We will first present the basic measures or operational definitions of infant visual perception. One such measure is the infant’s tendency to devote more fixation to some stimuli than to others. Such naturally occurring visual preferences have been used to study a number of aspects of visual perception. Two preferences particularly useful in the study of infant perception are greater attention to patterned than to plain targets and a tendency to devote more attention to a novel than to a previously seen target. Illustrations will show how a general preference for patterning has been used to study the development of visual acuity. Preferences for novelty will be considered for the information they have yielded on more subtle types of pattern perception such as the development of the infant’s ability to differentiate among faces. Following a discussion of basic measures of infant visual perception, particular illustrations of the development of pattern perception from birth to seven months will be presented. The summary will begin with estimates of the infant’s ability to detect patterns and a compilation of the basic visual dimensions to which infants attend in discriminating among patterns. The review will then consider pattern perception from three to seven months.
One of the issues repeatedly raised concerning developmental disabilities in the preschool child, and I think the most important one, is how the knowledge bases of different professional groups may be integrated, rather than existing independently or even competitively, to serve the handicapped young child. Each of us, schooled in our various disciplines, often sees a child quite differently and consequently we do not treat the child but treat the “problem.” For example, a mother tells us she is worried because her son shows little interest in his surroundings. As anticipated from her report, the 3-month-old is unable to track an object that moves slowly across the visual field, although he seems to fixate on stationary objects. How do different professionals interpret this observation?
All preferential looking procedures are based on the observation, originally noted by Berlyne (1958) and Fantz (1958), that young infants stare more at a pattern than at a blank field. Following up on this observation, Fantz developed a procedure, known as preferential looking (PL), that has allowed researchers to study the visual abilities of the young infant.
After nearly a century of theory and research, a strong consensus has emerged that recognizes the fundamental biological character of lateralization of cortical function in humans. What is less certain is when and how this specialization is expressed in early development.
The concept of continuity in human development has long been a provocative subject. The riddle of the Sphynx drew an ironic parallel between the inadequacy of infancy and the infirmity of old age. When Oedipus solved the riddle and freed the city of Thebes, the Sphynx killed herself in disgust, not having expected anyone to answer her question. It took the genius of Freud to discover that psychological causes operate from the distance of childhood in a particular way, through transformations of the psychosexual stages and especially the Oedipus complex. Many objected to this answer too, but it has come to represent the dominant view of psychodynamic theory.
Let us begin by examining the development of some very simple perceptual functions in normal children. Consider visual acuity as a first example. A number of studies using various methods (Fantz, Ordy, and Udelf, 1962; Gorman, Cogan, and Gillis, 1957; Dayton, Jones, Aiu, Rawson, Steele, and Rose, 1964) find the visual acuity of infants between zero and 1 month of age to be between 20/150 and 20/400 Snellen. It increases over the first several months of age and then rapidly through childhood, reaching maximum (20/20 to 20/15 Snellen) about the age of 10 years (Weymouth, 1963). Consider auditory acuity as a second example. Steinschneider, Lipton, and Richmond (1966) found neonates sensitive to sounds of 70 db or more. Bartoshuk (1964) found that the function relating responsivity and intensity of sound in neonates was similar to that of adults, and Eagles, Wishik, Doerfler, Melnick, and Levine (1963) found auditory acuity increasing slowly and gradually between 5 and 13 years with a slight decrease in sensitivity at 14. Even somewhat more complex perceptual functions such as those involved in size constancy seem to show gradual improvement with age. Typical of these studies is one by Zeigler and Leibowitz (1957). Children between 7 and 9 years of age showed less constancy than a group of adults in adjusting a rod 5 feet away to match the size of one varying from 10 to 100 feet away.
“If any sort of instinctive cognizance were inborn,” maintained Helmholtz in support of his Empirical Theory of Perception, “one would expect that it would have to be first of all in the recognition of the maternal breast and the knowledge of those movements by which [the newborn] could turn toward this visual image”. But such a cognizance is quite obviously missing. One sees that the child…turns away from the breast just as often as towards it, even though it can see it freely. Apparently, it is unable to interpret the visual image or the direction of its movements.
This book provides an overview by international authorities, spanning the disciplines of neuroscience, psychology, ophthalmology, optometry, and paediatrics, of normal and pathological infant visual development. It covers the development of retinal receptors; infant sensitivity to detail, colour, contrast, and movement; binocularity, eye movements, and refraction; and cognitive processing. Childrens' visual deficits, including amblyopia and cataract, are covered.
1. 1. EEGs of 277 normal, full-term babies, ages 22 min. to 125 hours, were recorded. Loud auditory stimuli were presented during sleep in 52 cases; single and repetitive light flashes in 65 cases. 2. 2. In general, previous descriptions of EEG patterns during wakefulness and sleep in newborns were confirmed. No relationship was observed in these data between EEG patterns and (a) type of maternal analgesia during labor, (b) type of maternal anesthesia during delivery, or (c) length of 2nd stage of labor. 3. 3. Loud auditory stimuli during sleep may elicit the following generalized responses with or without movement: (a) flattening of tracings, (b) K-type response (rare), or (c) K-type response followed by flattening of tracings. Spontaneous movement during sleep may also be followed by flattening of tracings. 4. 4. Single light flashes to the eyes often elicit evoked potentials in the occipital area. These responses tend to differ from those observed in adults in the following ways: 4.1. (a) they are of more variable wave-form, 4.2. (b) they are of more variable amplitude, 4.3. (c) they show greater "fatiguability", and 4.4. (d) they are of much longer latency (160-220 msec.). 5. 5. Trains of light flashes at 2 f/sec. or faster tend to elicit responses at the beginning (ON responses) and end (OFF responses) of stimulation. "Driving" effects were observed in only 2 cases, at 2.5-3.5 f/sec. 6. 6. The evoked response data are interpreted as reflecting the physiological immaturity of the newborn's nervous system, associated with its anatomical immaturity. The major factor accounting for the long latencies of evoked responses is felt to be slow conduction in the afferent fiber tracts, but retinal and synaptic events may also be contributory. The peculiarities of wave-form and amplitude are felt to be functions of the immature visual cortex.