Hermann Bulf - Academia.edu (original) (raw)

Papers by Hermann Bulf

Research paper thumbnail of Small on the left, large on the right: numbers orient visual attention onto space in preverbal infants

Developmental science, Jan 12, 2015

Numbers are represented as ordered magnitudes along a spatially oriented number line. While cultu... more Numbers are represented as ordered magnitudes along a spatially oriented number line. While culture and formal education modulate the direction of this number-space mapping, it is a matter of debate whether its emergence is entirely driven by cultural experience. By registering 8-9-month-old infants' eye movements, this study shows that numerical cues are critical in orienting infants' visual attention towards a peripheral region of space that is congruent with the number's relative position on a left-to-right oriented representational continuum. This finding provides the first direct evidence that, in humans, the association between numbers and oriented spatial codes occurs before the acquisition of symbols or exposure to formal education, suggesting that the number line is not merely a product of human invention.

Research paper thumbnail of Small on the left, large on the right: numbers orient visual attention onto space in preverbal infants

Developmental Science, 2015

Numbers are represented as ordered magnitudes along a spatially oriented number line. While cultu... more Numbers are represented as ordered magnitudes along a spatially oriented number line. While culture and formal education modulate the direction of this number-space mapping, it is a matter of debate whether its emergence is entirely driven by cultural experience. By registering 8-9-month-old infants' eye movements, this study shows that numerical cues are critical in orienting infants' visual attention towards a peripheral region of space that is congruent with the number's relative position on a left-to-right oriented representational continuum. This finding provides the first direct evidence that, in humans, the association between numbers and oriented spatial codes occurs before the acquisition of symbols or exposure to formal education, suggesting that the number line is not merely a product of human invention.

Research paper thumbnail of Are Numbers, Size and Brightness Equally Efficient in Orienting Visual Attention? Evidence from an Eye-Tracking Study

PLoS ONE, 2014

A number of studies have shown strong relations between numbers and oriented spatial codes. For e... more A number of studies have shown strong relations between numbers and oriented spatial codes. For example, perceiving numbers causes spatial shifts of attention depending upon numbers' magnitude, in a way suggestive of a spatially oriented, mental representation of numbers. Here, we investigated whether this phenomenon extends to non-symbolic numbers, as well as to the processing of the continuous dimensions of size and brightness, exploring whether different quantitative dimensions are equally mapped onto space. After a numerical (symbolic Arabic digits or non-symbolic arrays of dots; Experiment 1) or a non-numerical cue (shapes of different size or brightness level; Experiment 2) was presented, participants' saccadic response to a target that could appear either on the left or the right side of the screen was registered using an automated eye-tracker system. Experiment 1 showed that, both in the case of Arabic digits and dot arrays, right targets were detected faster when preceded by large numbers, and left targets were detected faster when preceded by small numbers. Participants in Experiment 2 were faster at detecting right targets when cued by large-sized shapes and left targets when cued by small-sized shapes, whereas brightness cues did not modulate the detection of peripheral targets. These findings indicate that looking at a symbolic or a non-symbolic number induces attentional shifts to a peripheral region of space that is congruent with the numbers' relative position on a mental number line, and that a similar shift in visual attention is induced by looking at shapes of different size. More specifically, results suggest that, while the dimensions of number and size spontaneously map onto an oriented space, the dimension of brightness seems to be independent at a certain level of magnitude elaboration from the dimensions of spatial extent and number, indicating that not all continuous dimensions are equally mapped onto space.

Research paper thumbnail of I neonati riconoscono i movimenti biologici

Research paper thumbnail of LA SInTonIzzAzIonE PErCETTIVA VErSo I VoLTI dI AduLTo nEL PrIMo Anno dI VITA

ABSTRACT Within the first year of life, the face processing system tunes into the species, race a... more ABSTRACT Within the first year of life, the face processing system tunes into the species, race and gender of faces with which the most experience has been accumulated. However, up to date, no studies have investigated if and how the face processing abilities vary as a function of face age during early infancy. The aim of the current study is to evaluate whether, as for species and race biases, the asymmetry in the amount of experience and the high predisposition to interact with the caregiver, determine a perceptual bias to adult faces. The ability to distinguish and recognize adult and newborn faces has been examined in 4- and 9-month-old infants. Results show that 4-month-olds discriminate both adult and newborn faces, while 9-month-olds can distinguish adult but not newborn faces. These results suggest the existence of a perceptual attunement to adult faces between the ages of 4 and 9 months.

Research paper thumbnail of Discriminazione tra un movimento possibile e impossibile della mano alla nascita: integrazione tra rappresentazione motoria e visiva

Research paper thumbnail of Perceptual narrowing toward adult faces occurs within the first year of life

Research paper thumbnail of Tanti volti, una sequenza: l'apprendimento di una regola astratta a 7 mesi di vita

Research paper thumbnail of L'informazione numerica orienta l'attenzione visiva nello spazio: uno studio sui movimenti oculari nell'adulto

Research paper thumbnail of Newborns differentiate between possible and impossible movements

Research paper thumbnail of Discriminazione tra un movimento possibile e impossibile della mano alla nascita

Research paper thumbnail of La sintonizzazione percettiva verso i volti di adulto nel primo anno di

ABSTRACT Within the first year of life, the face processing system tunes into the species, race a... more ABSTRACT Within the first year of life, the face processing system tunes into the species, race and gender of faces with which the most experience has been accumulated. However, up to date, no studies have investigated if and how the face processing abilities vary as a function of face age during early infancy. The aim of the current study is to evaluate whether, as for species and race biases, the asymmetry in the amount of experience and the high predisposition to interact with the caregiver, determine a perceptual bias to adult faces. The ability to distinguish and recognize adult and newborn faces has been examined in 4- and 9-month-old infants. Results show that 4-month-olds discriminate both adult and newborn faces, while 9-month-olds can distinguish adult but not newborn faces. These results suggest the existence of a perceptual attunement to adult faces between the ages of 4 and 9 months.

Research paper thumbnail of Ordinare le grandezze sposta l'attenzione nello spazio rappresentazionale nella prima infanzia: evidenze dall'Operational Momentum

Research paper thumbnail of Newborn babies prefer biological-motion displays

Research paper thumbnail of Discrimination of Biomechanically Possible and Impossible Hand Movements at Birth

Child Development, 2014

The development of human body perception has long been investigated, but little is known about it... more The development of human body perception has long been investigated, but little is known about its early origins. This study focused on how a body part highly relevant to the human species, namely the hand, is perceived a few days after birth. Using a preferential-looking paradigm, 24-to 48-hr-old newborns watched biomechanically possible and impossible dynamic hand gestures (Experiment 1, N = 15) and static hand postures (Experiment 2, N = 15). In Experiment 1, newborns looked longer at the impossible, compared to the possible, hand movement, whereas in Experiment 2 no visual preference emerged. These findings suggest that early in life the representation of the human body may be shaped by sensory-motor experience.

Research paper thumbnail of Paternal Autistic Traits are Predictive of Infants Visual Attention

Journal of Autism and Developmental Disorders, 2013

Since subthreshold autistic social impairments aggregate in family members, and since attentional... more Since subthreshold autistic social impairments aggregate in family members, and since attentional dysfunctions appear to be one of the earliest cognitive markers of children with autism, we investigated in the general population the relationship between infants' attentional functioning and the autistic traits measured in their parents. Orienting and alerting attention systems were measured in 8-month-old infants using a spatial cueing paradigm. Results showed that only paternal autistic traits were linked to their children's: (1) attentional disengagement; (2) rapid attentional orienting and (3) alerting. Our findings suggest that an early dysfunction of orienting and alerting systems might alter the developmental trajectory of future ability in social cognition and communication.

Research paper thumbnail of Age-related face processing bias in infancy: Evidence of perceptual narrowing for adult faces

Developmental Psychobiology, 2014

Recent data demonstrate a perceptual processing advantage for adult faces in both adults and youn... more Recent data demonstrate a perceptual processing advantage for adult faces in both adults and young children, suggesting that face representation is shaped by visual experience accumulated with different face-age groups. As for species and race, this age bias may emerge during the first year of life as part of the general process of perceptual narrowing, given the extensive amount of social and perceptual experience accumulated with caregivers and/or other adult individuals. Using infant-controlled habituation and visual-paired comparison at test, two experiments were carried out to examine 3- and 9-month-olds' ability to discriminate within adult and infant faces. Results showed that, when they are provided with adequate time to visually compare the stimuli during test trials (Experiment 2), 3-month-olds exhibit above-chance discrimination of adult and infant faces. Instead, 9-month-olds discriminate adult faces but not infant faces (Experiments 1 and 2). Results provide the first evidence of age-related face processing biases in infancy, and show that by 9 months face representations tune to adult human faces.

Research paper thumbnail of Visual statistical learning in the newborn infant

Cognition, 2011

Statistical learning -implicit learning of statistical regularities within sensory input -is a wa... more Statistical learning -implicit learning of statistical regularities within sensory input -is a way of acquiring structure within continuous sensory environments. Statistics computation, initially shown to be involved in word segmentation, has been demonstrated to be a general mechanism that operates across domains, across time and space, and across species. Recently, statistical leaning has been reported to be present even at birth when newborns were tested with a speech stream. The aim of the present study was to extend this finding, by investigating whether newborns' ability to extract statistics operates in multiple modalities, as found for older infants and adults. Using the habituation procedure, two experiments were carried out in which visual sequences were presented. Results demonstrate that statistical learning is a general mechanism that extracts statistics across domain since the onset of sensory experience. Intriguingly, present data reveal that newborn learner's limited cognitive resources constrain the functioning of statistical learning, narrowing the range of what can be learned.

Research paper thumbnail of Newborns’ face recognition is based on spatial frequencies below 0.5 cycles per degree

Cognition, 2008

A critical question in Cognitive Science concerns how knowledge of speciWc domains emerges during... more A critical question in Cognitive Science concerns how knowledge of speciWc domains emerges during development. Here we examined how limitations of the visual system during the Wrst days of life may shape subsequent development of face processing abilities. By manipulating the bands of spatial frequencies of face images, we investigated what is the nature of the visual information that newborn infants rely on to perform face recognition. Newborns were able to extract from a face the visual information lying from 0 to 1 cpd (Experiment 1), but only a narrower 0-0.5 cpd spatial frequency range was successful to accomplish face recognition (Experiment 2). These results provide the Wrst empirical support of a low spatial frequency advantage in individual face recognition at birth and suggest that early in life low-level, non-speciWc perceptual constraints aVect the development of the face processing system.

Research paper thumbnail of Face Orientation and Motion Differently Affect the Deployment of Visual Attention in Newborns and 4-Month-Old Infants

PLOS ONE, 2015

Orienting visual attention allows us to properly select relevant visual information from a noisy ... more Orienting visual attention allows us to properly select relevant visual information from a noisy environment. Despite extensive investigation of the orienting of visual attention in infancy, it is unknown whether and how stimulus characteristics modulate the deployment of attention from birth to 4 months of age, a period in which the efficiency in orienting of attention improves dramatically. The aim of the present study was to compare 4-month-old infants' and newborns' ability to orient attention from central to peripheral stimuli that have the same or different attributes. In Experiment 1, all the stimuli were dynamic and the only attribute of the central and peripheral stimuli to be manipulated was face orientation. In Experiment 2, both face orientation and motion of the central and peripheral stimuli were contrasted. The number of valid trials and saccadic latency were measured at both ages. Our results demonstrated that the deployment of attention is mainly influenced by motion at birth, while it is also influenced by face orientation at 4-month of age. These findings provide insight into the development of the orienting visual attention in the first few months of life and suggest that maturation may be not the only factor that determines the developmental change in orienting visual attention from birth to 4 months.

Research paper thumbnail of Small on the left, large on the right: numbers orient visual attention onto space in preverbal infants

Developmental science, Jan 12, 2015

Numbers are represented as ordered magnitudes along a spatially oriented number line. While cultu... more Numbers are represented as ordered magnitudes along a spatially oriented number line. While culture and formal education modulate the direction of this number-space mapping, it is a matter of debate whether its emergence is entirely driven by cultural experience. By registering 8-9-month-old infants' eye movements, this study shows that numerical cues are critical in orienting infants' visual attention towards a peripheral region of space that is congruent with the number's relative position on a left-to-right oriented representational continuum. This finding provides the first direct evidence that, in humans, the association between numbers and oriented spatial codes occurs before the acquisition of symbols or exposure to formal education, suggesting that the number line is not merely a product of human invention.

Research paper thumbnail of Small on the left, large on the right: numbers orient visual attention onto space in preverbal infants

Developmental Science, 2015

Numbers are represented as ordered magnitudes along a spatially oriented number line. While cultu... more Numbers are represented as ordered magnitudes along a spatially oriented number line. While culture and formal education modulate the direction of this number-space mapping, it is a matter of debate whether its emergence is entirely driven by cultural experience. By registering 8-9-month-old infants' eye movements, this study shows that numerical cues are critical in orienting infants' visual attention towards a peripheral region of space that is congruent with the number's relative position on a left-to-right oriented representational continuum. This finding provides the first direct evidence that, in humans, the association between numbers and oriented spatial codes occurs before the acquisition of symbols or exposure to formal education, suggesting that the number line is not merely a product of human invention.

Research paper thumbnail of Are Numbers, Size and Brightness Equally Efficient in Orienting Visual Attention? Evidence from an Eye-Tracking Study

PLoS ONE, 2014

A number of studies have shown strong relations between numbers and oriented spatial codes. For e... more A number of studies have shown strong relations between numbers and oriented spatial codes. For example, perceiving numbers causes spatial shifts of attention depending upon numbers' magnitude, in a way suggestive of a spatially oriented, mental representation of numbers. Here, we investigated whether this phenomenon extends to non-symbolic numbers, as well as to the processing of the continuous dimensions of size and brightness, exploring whether different quantitative dimensions are equally mapped onto space. After a numerical (symbolic Arabic digits or non-symbolic arrays of dots; Experiment 1) or a non-numerical cue (shapes of different size or brightness level; Experiment 2) was presented, participants' saccadic response to a target that could appear either on the left or the right side of the screen was registered using an automated eye-tracker system. Experiment 1 showed that, both in the case of Arabic digits and dot arrays, right targets were detected faster when preceded by large numbers, and left targets were detected faster when preceded by small numbers. Participants in Experiment 2 were faster at detecting right targets when cued by large-sized shapes and left targets when cued by small-sized shapes, whereas brightness cues did not modulate the detection of peripheral targets. These findings indicate that looking at a symbolic or a non-symbolic number induces attentional shifts to a peripheral region of space that is congruent with the numbers' relative position on a mental number line, and that a similar shift in visual attention is induced by looking at shapes of different size. More specifically, results suggest that, while the dimensions of number and size spontaneously map onto an oriented space, the dimension of brightness seems to be independent at a certain level of magnitude elaboration from the dimensions of spatial extent and number, indicating that not all continuous dimensions are equally mapped onto space.

Research paper thumbnail of I neonati riconoscono i movimenti biologici

Research paper thumbnail of LA SInTonIzzAzIonE PErCETTIVA VErSo I VoLTI dI AduLTo nEL PrIMo Anno dI VITA

ABSTRACT Within the first year of life, the face processing system tunes into the species, race a... more ABSTRACT Within the first year of life, the face processing system tunes into the species, race and gender of faces with which the most experience has been accumulated. However, up to date, no studies have investigated if and how the face processing abilities vary as a function of face age during early infancy. The aim of the current study is to evaluate whether, as for species and race biases, the asymmetry in the amount of experience and the high predisposition to interact with the caregiver, determine a perceptual bias to adult faces. The ability to distinguish and recognize adult and newborn faces has been examined in 4- and 9-month-old infants. Results show that 4-month-olds discriminate both adult and newborn faces, while 9-month-olds can distinguish adult but not newborn faces. These results suggest the existence of a perceptual attunement to adult faces between the ages of 4 and 9 months.

Research paper thumbnail of Discriminazione tra un movimento possibile e impossibile della mano alla nascita: integrazione tra rappresentazione motoria e visiva

Research paper thumbnail of Perceptual narrowing toward adult faces occurs within the first year of life

Research paper thumbnail of Tanti volti, una sequenza: l'apprendimento di una regola astratta a 7 mesi di vita

Research paper thumbnail of L'informazione numerica orienta l'attenzione visiva nello spazio: uno studio sui movimenti oculari nell'adulto

Research paper thumbnail of Newborns differentiate between possible and impossible movements

Research paper thumbnail of Discriminazione tra un movimento possibile e impossibile della mano alla nascita

Research paper thumbnail of La sintonizzazione percettiva verso i volti di adulto nel primo anno di

ABSTRACT Within the first year of life, the face processing system tunes into the species, race a... more ABSTRACT Within the first year of life, the face processing system tunes into the species, race and gender of faces with which the most experience has been accumulated. However, up to date, no studies have investigated if and how the face processing abilities vary as a function of face age during early infancy. The aim of the current study is to evaluate whether, as for species and race biases, the asymmetry in the amount of experience and the high predisposition to interact with the caregiver, determine a perceptual bias to adult faces. The ability to distinguish and recognize adult and newborn faces has been examined in 4- and 9-month-old infants. Results show that 4-month-olds discriminate both adult and newborn faces, while 9-month-olds can distinguish adult but not newborn faces. These results suggest the existence of a perceptual attunement to adult faces between the ages of 4 and 9 months.

Research paper thumbnail of Ordinare le grandezze sposta l'attenzione nello spazio rappresentazionale nella prima infanzia: evidenze dall'Operational Momentum

Research paper thumbnail of Newborn babies prefer biological-motion displays

Research paper thumbnail of Discrimination of Biomechanically Possible and Impossible Hand Movements at Birth

Child Development, 2014

The development of human body perception has long been investigated, but little is known about it... more The development of human body perception has long been investigated, but little is known about its early origins. This study focused on how a body part highly relevant to the human species, namely the hand, is perceived a few days after birth. Using a preferential-looking paradigm, 24-to 48-hr-old newborns watched biomechanically possible and impossible dynamic hand gestures (Experiment 1, N = 15) and static hand postures (Experiment 2, N = 15). In Experiment 1, newborns looked longer at the impossible, compared to the possible, hand movement, whereas in Experiment 2 no visual preference emerged. These findings suggest that early in life the representation of the human body may be shaped by sensory-motor experience.

Research paper thumbnail of Paternal Autistic Traits are Predictive of Infants Visual Attention

Journal of Autism and Developmental Disorders, 2013

Since subthreshold autistic social impairments aggregate in family members, and since attentional... more Since subthreshold autistic social impairments aggregate in family members, and since attentional dysfunctions appear to be one of the earliest cognitive markers of children with autism, we investigated in the general population the relationship between infants' attentional functioning and the autistic traits measured in their parents. Orienting and alerting attention systems were measured in 8-month-old infants using a spatial cueing paradigm. Results showed that only paternal autistic traits were linked to their children's: (1) attentional disengagement; (2) rapid attentional orienting and (3) alerting. Our findings suggest that an early dysfunction of orienting and alerting systems might alter the developmental trajectory of future ability in social cognition and communication.

Research paper thumbnail of Age-related face processing bias in infancy: Evidence of perceptual narrowing for adult faces

Developmental Psychobiology, 2014

Recent data demonstrate a perceptual processing advantage for adult faces in both adults and youn... more Recent data demonstrate a perceptual processing advantage for adult faces in both adults and young children, suggesting that face representation is shaped by visual experience accumulated with different face-age groups. As for species and race, this age bias may emerge during the first year of life as part of the general process of perceptual narrowing, given the extensive amount of social and perceptual experience accumulated with caregivers and/or other adult individuals. Using infant-controlled habituation and visual-paired comparison at test, two experiments were carried out to examine 3- and 9-month-olds' ability to discriminate within adult and infant faces. Results showed that, when they are provided with adequate time to visually compare the stimuli during test trials (Experiment 2), 3-month-olds exhibit above-chance discrimination of adult and infant faces. Instead, 9-month-olds discriminate adult faces but not infant faces (Experiments 1 and 2). Results provide the first evidence of age-related face processing biases in infancy, and show that by 9 months face representations tune to adult human faces.

Research paper thumbnail of Visual statistical learning in the newborn infant

Cognition, 2011

Statistical learning -implicit learning of statistical regularities within sensory input -is a wa... more Statistical learning -implicit learning of statistical regularities within sensory input -is a way of acquiring structure within continuous sensory environments. Statistics computation, initially shown to be involved in word segmentation, has been demonstrated to be a general mechanism that operates across domains, across time and space, and across species. Recently, statistical leaning has been reported to be present even at birth when newborns were tested with a speech stream. The aim of the present study was to extend this finding, by investigating whether newborns' ability to extract statistics operates in multiple modalities, as found for older infants and adults. Using the habituation procedure, two experiments were carried out in which visual sequences were presented. Results demonstrate that statistical learning is a general mechanism that extracts statistics across domain since the onset of sensory experience. Intriguingly, present data reveal that newborn learner's limited cognitive resources constrain the functioning of statistical learning, narrowing the range of what can be learned.

Research paper thumbnail of Newborns’ face recognition is based on spatial frequencies below 0.5 cycles per degree

Cognition, 2008

A critical question in Cognitive Science concerns how knowledge of speciWc domains emerges during... more A critical question in Cognitive Science concerns how knowledge of speciWc domains emerges during development. Here we examined how limitations of the visual system during the Wrst days of life may shape subsequent development of face processing abilities. By manipulating the bands of spatial frequencies of face images, we investigated what is the nature of the visual information that newborn infants rely on to perform face recognition. Newborns were able to extract from a face the visual information lying from 0 to 1 cpd (Experiment 1), but only a narrower 0-0.5 cpd spatial frequency range was successful to accomplish face recognition (Experiment 2). These results provide the Wrst empirical support of a low spatial frequency advantage in individual face recognition at birth and suggest that early in life low-level, non-speciWc perceptual constraints aVect the development of the face processing system.

Research paper thumbnail of Face Orientation and Motion Differently Affect the Deployment of Visual Attention in Newborns and 4-Month-Old Infants

PLOS ONE, 2015

Orienting visual attention allows us to properly select relevant visual information from a noisy ... more Orienting visual attention allows us to properly select relevant visual information from a noisy environment. Despite extensive investigation of the orienting of visual attention in infancy, it is unknown whether and how stimulus characteristics modulate the deployment of attention from birth to 4 months of age, a period in which the efficiency in orienting of attention improves dramatically. The aim of the present study was to compare 4-month-old infants' and newborns' ability to orient attention from central to peripheral stimuli that have the same or different attributes. In Experiment 1, all the stimuli were dynamic and the only attribute of the central and peripheral stimuli to be manipulated was face orientation. In Experiment 2, both face orientation and motion of the central and peripheral stimuli were contrasted. The number of valid trials and saccadic latency were measured at both ages. Our results demonstrated that the deployment of attention is mainly influenced by motion at birth, while it is also influenced by face orientation at 4-month of age. These findings provide insight into the development of the orienting visual attention in the first few months of life and suggest that maturation may be not the only factor that determines the developmental change in orienting visual attention from birth to 4 months.