Sequence learning in infancy: The independent contributions of conditional probability and pair frequency information

The ability to perceive sequences is fundamental to cognition. Previous studies have shown that infants can learn visual sequences as early as 2 months of age and it has been suggested that this ability is mediated by sensitivity to conditional probability information. Typically, conditional probability information has covaried with frequency information in these studies, raising the possibility that each type of information may have contributed independently to sequence learning. The current study explicitly investigated the independent contribution of each type of information. We habituated 2.5-, 4.5-, and 8.5-month-old infants to a sequence of looming visual shapes whose ordering was defined independently by specific conditional probability relations among pair elements and by the frequency of occurrence of such pairs. During test trials, we tested infants' sensitivity to each type of information and found that both types of information independently influenced sequence learning by 4.5 months of age

The Role of Auditory-Visual Synchrony in Capture of Attention and Induction of Attentional State in Infancy

This study was designed to examine the types of events that are most effective in capturing infant attention and whether these attention-getting events also effectively elicit an attentional state and facilitate perception and learning. Despite the frequent use of attention-getters (AGs) - presenting an attention-grabbing event between trials to redirect attention and reduce data loss due to fussiness - relatively little is known about the influence of AGs on attentional state. A recent investigation revealed that the presentation of AGs not only captures attention, but also produces heart rate decelerations during habituation and faster dishabituation in a subsequent task, indicating changes in the state of sustained attention and enhanced stimulus processing (Domsch, Thomas, & Lohaus, 2010). Attention-getters are often multimodal, dynamic, and temporally synchronous; such highly redundant properties generally guide selective attention and are thought to coordinate multisensory information in early development. In the current study, 4-month-old infants were randomly assigned to one of three attention-getter AG conditions: synchronous AG, asynchronous AG, and no AG. Following the AG, infants completed a discrimination task with a partial-lag design, which allowed for the assessment of infants' ability to discriminate between familiar and novel stimuli while controlling for spontaneous recovery. Analyses indicated that the AG condition captured and induced an attentional state, regardless of the presence of temporal synchrony. Although the synchronous and asynchronous AG conditions produced similar patterns of attention in the AG session, during familiarization infants in the asynchronous AG condition showed a pattern of increasing HR across the task and had higher overall HR compared to the synchronous AG and no AG conditions. Implications of the effect of attention-getters and temporal synchrony on infant performance are discussed

Concurrent neurological and behavioral assessment of number line estimation performance in children and adults

Children who struggle to learn math are often identified by their poor performance on common math learning activities, such as number line estimations. While such behavioral assessments are useful in the classroom, naturalistic neuroimaging of children engaged in real-world math learning activities has the potential to identify concurrent behavioral and neurological correlates to poor math performance. Such correlates may help pinpoint effective teaching strategies for atypical learners, and may highlight instructional methods that elicit typical neurological response patterns to such activities. For example, multisensory stimulation that contains information about number enhances infants\u27 and preschool children\u27s behavioral performance on many numerical tasks and has been shown to elicit neural activation in areas related to number processing and decision-making. Thus, when applied to math teaching tools, multisensory stimulation may provide a platform through which both behavioral and neural math-related processes may be enhanced. Common approaches to neuroimaging of math processing lack ecological validity and are often not analogous to real-world learning activities. However, because of its liberal tolerance of movement, near-infrared spectroscopy (NIRS) provides an ideal platform for such studies. Here, NIRS is used to provide the first concurrent examination of neurological and behavioral data from number line estimation performance within children and adults. Moreover, in an effort to observe the behavioral and neurological benefits to number line estimations that may arise from multisensory stimulation, differential feedback (i.e., visual, auditory, or audiovisual) about estimation performance is provided throughout a portion of the task. Results suggest behavioral and neural performance is enhanced by feedback. Moreover, significant effects of age suggest young children show greater neurological response to feedback, and increase in task difficulty resulted in decreased behavioral performance and increased neurological activation associated with mathematical processing. Thus, typical math learners effectively recruit areas of the brain known to process number when math activities become increasingly difficult. Data inform understanding typical behavioral and neural responses to real-world math learning tasks, and may prove useful in triangulating signatures of atypical math learning. Moreover, results demonstrate the utility of NIRS as a platform to provide simultaneous neurological and behavioral data during naturalistic math learning activities

Perception of audiovisual rhythm and its invariance in 4- to 10-month-old infants

This study investigated the perception of complex audiovisual rhythmic patterns in 4-, 6-, 8-, and 10-month-old human infants. In Experiment 1, we first habituated infants to an event in which an object could be seen and heard bouncing in a rhythmic fashion. We then tested them to determine if they would detect a relative temporal pattern change produced by rearranging the intrapattern intervals. Regardless of age, infants successfully detected the pattern change. In Experiment 2, we asked whether infants also can extract rhythmic pattern invariance amid tempo variations. Thus, we first habituated infants to a particular rhythmic pattern but this time varying in its tempo of presentation across trials. We then administered one test trial in which a novel rhythm was presented at a familiar tempo and another test trial in which a familiar rhythm was presented at a novel tempo. Infants detected both types of changes indicating that they perceived the invariant rhythm and that they did so despite the fact that they also detected the varying tempo. Overall, the findings demonstrate that infants between 4 and 10 months of age can perceive and discriminate complex audiovisual temporal patterns on the basis of relative temporal differences and that they also can learn the invariant nature of such patterns

Precis of neuroconstructivism: how the brain constructs cognition

Neuroconstructivism: How the Brain Constructs Cognition proposes a unifying framework for the study of cognitive development that brings together (1) constructivism (which views development as the progressive elaboration of increasingly complex structures), (2) cognitive neuroscience (which aims to understand the neural mechanisms underlying behavior), and (3) computational modeling (which proposes formal and explicit specifications of information processing). The guiding principle of our approach is context dependence, within and (in contrast to Marr [1982]) between levels of organization. We propose that three mechanisms guide the emergence of representations: competition, cooperation, and chronotopy; which themselves allow for two central processes: proactivity and progressive specialization. We suggest that the main outcome of development is partial representations, distributed across distinct functional circuits. This framework is derived by examining development at the level of single neurons, brain systems, and whole organisms. We use the terms encellment, embrainment, and embodiment to describe the higher-level contextual influences that act at each of these levels of organization. To illustrate these mechanisms in operation we provide case studies in early visual perception, infant habituation, phonological development, and object representations in infancy. Three further case studies are concerned with interactions between levels of explanation: social development, atypical development and within that, developmental dyslexia. We conclude that cognitive development arises from a dynamic, contextual change in embodied neural structures leading to partial representations across multiple brain regions and timescales, in response to proactively specified physical and social environment

Experiments on the dynamics of attention: Perception of visual rhythm and the time course of inhibition of return in the visual field

How attention is controlled is one of the challenging topics in cognitive neuroscience and psychology. For spatially represented targets in the visual field it has been shown that some features of visual stimuli like different colors instantaneously ‘pop-out’, while others require a serial search which is conceived of as an effortful task. It is an open question whether dynamic feature of a stimulus are processed instantaneously without high attentional demand or serially with high demand. This question was studied in experiments on rhythm perception with periodically moving stimuli, and a visual search paradigm was employed. The search display consisted of vertically moving dots with regular rhythms; one dot however moved with a different period, and this dot with a longer or shorter period had to be detected as fast as possible. To make the period of the movement a critical target, amplitudes and phases of the distractors were randomized. It was observed that the perception of a visual rhythm defined only by the period does not lead to a pop-out effect. Apparently, the conjunction of period, equal phase and equal amplitude of movements are necessary for an effortless processing of visual rhythms. Interestingly, a faster rhythm compared to the distractors was detected with shorter reaction times. In additional experiments, it was for instance shown that auditory information supports the extraction of rhythmic visual targets indicating an intermodal mechanism. In another experimental set-up it was tested whether the attentional machinery is controlled by a common temporal mechanism. Experiments on ‘inhibition of return’ (IOR) have indicated that attentional control in the peri-foveal region of the visual field underlies a different neuronal mechanism compared to the periphery of the visual field. This eccentricity effect of IOR raises the question, whether attentional control for the visual periphery is characterized by a longer time constant as the peripheral inhibitory control is much stronger. Experimental evidence indicates, however, that the two attentional systems share the same time window of approximately three seconds. These observations support the notion of a functional subdivision of the visual field which is overcome, however, by a common temporal control mechanism.Wie Aufmerksamkeit kontrolliert wird, ist eine der besonderen Herausforderungen in den kognitiven Neurowissenschaften und der Psychologie. Für räumlich repräsentierte Reize konnte gezeigt werden, dass bestimmte Aspekte visueller Reize wie verschiedene Farben sofort hervorstechen („pop-out“), während für andere Reize serielle Such-Strategien notwendig sind, die also mentalen Aufwand erfordern. Es ist eine offene Frage, ob dynamische Merkmale von Reizen ohne besonderen Aufwand verarbeitet werden, oder ob serielle Prozesse erforderlich sind, um sie zu erkennen. Diese Frage wurde in Experimenten über Rhythmus-Wahrnehmung mit periodisch sich bewegenden Reizen untersucht, und ein visuelles Such-Paradigma wurde angewandt. Es wurden auf einem Display vertikal sich bewegende Punkte gezeigt, wobei einer der Punkte sich mit einer anderen Periode, schneller oder langsamer, bewegte, und diese Punkte mussten so schnell wie möglich erkannt werden. Um nur die Periode als kritische Variable zu untersuchen, wurde die Phase und die Amplitude der anderen Reizpunkte randomisiert. Es wurde festgestellt, dass die unterschiedliche Periode allein nicht zu einem „pop-out“-Effekt führt. Damit ein abweichender, sich bewegender dynamischer Reiz erkannt wird, müssen offenbar Periode, Phase und Amplitude übereinstimmen. Reize mit einer kürzeren Periode als die Hintergrundreize wurden deutlich schneller erkannt. In weiteren Experimenten konnte beispielsweise gezeigt werden, dass akustische Information die Extraktion rhythmisch sich bewegender visueller Reize deutlich verbessert, was auf intermodale Effekte hinweist. In einer weiteren Studie wurde untersucht, ob die neuronale Aufmerksamkeits-Maschinerie gemeinsamen zeitlichen Prinzipien gehorcht. Versuche zum Phänomen des „Inhibition of Return“ (IOR, Hemmung der Aufmerksamkeits-Wiederkehr) haben ergeben, dass die Mechanismen der Aufmerksamkeits-Steuerung im perifovealen Bereich anderen Gesetzen gehorchen als in der Peripherie des Gesichtsfeldes. Dieser „Ekzentrizitäts-Effekt“ wirft die Frage auf, ob die zeitlichen Prozesse der Aufmerksamkeits-Kontrolle in der Peripherie durch längere Zeitkonstanten gekennzeichnet sind, da die inhibitorische Kontrolle dort ausgeprägter ist. Es zeigt sich allerdings, dass die beiden Aufmerksamkeits-Systeme das gleiche Zeitfenster von etwa drei Sekunden nutzen. Diese Beobachtungen stützen das Konzept der funktionellen Inhomogenität des Gesichtsfeldes, die aber durch einen gemeinsamen zeitlichen Mechanismus in eine kognitive Einheit gebracht wird

Experiments on the dynamics of attention: Perception of visual rhythm and the time course of inhibition of return in the visual field

How attention is controlled is one of the challenging topics in cognitive neuroscience and psychology. For spatially represented targets in the visual field it has been shown that some features of visual stimuli like different colors instantaneously ‘pop-out’, while others require a serial search which is conceived of as an effortful task. It is an open question whether dynamic feature of a stimulus are processed instantaneously without high attentional demand or serially with high demand. This question was studied in experiments on rhythm perception with periodically moving stimuli, and a visual search paradigm was employed. The search display consisted of vertically moving dots with regular rhythms; one dot however moved with a different period, and this dot with a longer or shorter period had to be detected as fast as possible. To make the period of the movement a critical target, amplitudes and phases of the distractors were randomized. It was observed that the perception of a visual rhythm defined only by the period does not lead to a pop-out effect. Apparently, the conjunction of period, equal phase and equal amplitude of movements are necessary for an effortless processing of visual rhythms. Interestingly, a faster rhythm compared to the distractors was detected with shorter reaction times. In additional experiments, it was for instance shown that auditory information supports the extraction of rhythmic visual targets indicating an intermodal mechanism. In another experimental set-up it was tested whether the attentional machinery is controlled by a common temporal mechanism. Experiments on ‘inhibition of return’ (IOR) have indicated that attentional control in the peri-foveal region of the visual field underlies a different neuronal mechanism compared to the periphery of the visual field. This eccentricity effect of IOR raises the question, whether attentional control for the visual periphery is characterized by a longer time constant as the peripheral inhibitory control is much stronger. Experimental evidence indicates, however, that the two attentional systems share the same time window of approximately three seconds. These observations support the notion of a functional subdivision of the visual field which is overcome, however, by a common temporal control mechanism.Wie Aufmerksamkeit kontrolliert wird, ist eine der besonderen Herausforderungen in den kognitiven Neurowissenschaften und der Psychologie. Für räumlich repräsentierte Reize konnte gezeigt werden, dass bestimmte Aspekte visueller Reize wie verschiedene Farben sofort hervorstechen („pop-out“), während für andere Reize serielle Such-Strategien notwendig sind, die also mentalen Aufwand erfordern. Es ist eine offene Frage, ob dynamische Merkmale von Reizen ohne besonderen Aufwand verarbeitet werden, oder ob serielle Prozesse erforderlich sind, um sie zu erkennen. Diese Frage wurde in Experimenten über Rhythmus-Wahrnehmung mit periodisch sich bewegenden Reizen untersucht, und ein visuelles Such-Paradigma wurde angewandt. Es wurden auf einem Display vertikal sich bewegende Punkte gezeigt, wobei einer der Punkte sich mit einer anderen Periode, schneller oder langsamer, bewegte, und diese Punkte mussten so schnell wie möglich erkannt werden. Um nur die Periode als kritische Variable zu untersuchen, wurde die Phase und die Amplitude der anderen Reizpunkte randomisiert. Es wurde festgestellt, dass die unterschiedliche Periode allein nicht zu einem „pop-out“-Effekt führt. Damit ein abweichender, sich bewegender dynamischer Reiz erkannt wird, müssen offenbar Periode, Phase und Amplitude übereinstimmen. Reize mit einer kürzeren Periode als die Hintergrundreize wurden deutlich schneller erkannt. In weiteren Experimenten konnte beispielsweise gezeigt werden, dass akustische Information die Extraktion rhythmisch sich bewegender visueller Reize deutlich verbessert, was auf intermodale Effekte hinweist. In einer weiteren Studie wurde untersucht, ob die neuronale Aufmerksamkeits-Maschinerie gemeinsamen zeitlichen Prinzipien gehorcht. Versuche zum Phänomen des „Inhibition of Return“ (IOR, Hemmung der Aufmerksamkeits-Wiederkehr) haben ergeben, dass die Mechanismen der Aufmerksamkeits-Steuerung im perifovealen Bereich anderen Gesetzen gehorchen als in der Peripherie des Gesichtsfeldes. Dieser „Ekzentrizitäts-Effekt“ wirft die Frage auf, ob die zeitlichen Prozesse der Aufmerksamkeits-Kontrolle in der Peripherie durch längere Zeitkonstanten gekennzeichnet sind, da die inhibitorische Kontrolle dort ausgeprägter ist. Es zeigt sich allerdings, dass die beiden Aufmerksamkeits-Systeme das gleiche Zeitfenster von etwa drei Sekunden nutzen. Diese Beobachtungen stützen das Konzept der funktionellen Inhomogenität des Gesichtsfeldes, die aber durch einen gemeinsamen zeitlichen Mechanismus in eine kognitive Einheit gebracht wird

Spatial representation and visual impairement - Developmental trends and new technological tools for assessment and rehabilitation

It is well known that perception is mediated by the five sensory modalities (sight, hearing, touch, smell and taste), which allows us to explore the world and build a coherent spatio-temporal representation of the surrounding environment. Typically, our brain collects and integrates coherent information from all the senses to build a reliable spatial representation of the world. In this sense, perception emerges from the individual activity of distinct sensory modalities, operating as separate modules, but rather from multisensory integration processes. The interaction occurs whenever inputs from the senses are coherent in time and space (Eimer, 2004). Therefore, spatial perception emerges from the contribution of unisensory and multisensory information, with a predominant role of visual information for space processing during the first years of life. Despite a growing body of research indicates that visual experience is essential to develop spatial abilities, to date very little is known about the mechanisms underpinning spatial development when the visual input is impoverished (low vision) or missing (blindness). The thesis's main aim is to increase knowledge about the impact of visual deprivation on spatial development and consolidation and to evaluate the effects of novel technological systems to quantitatively improve perceptual and cognitive spatial abilities in case of visual impairments. Chapter 1 summarizes the main research findings related to the role of vision and multisensory experience on spatial development. Overall, such findings indicate that visual experience facilitates the acquisition of allocentric spatial capabilities, namely perceiving space according to a perspective different from our body. Therefore, it might be stated that the sense of sight allows a more comprehensive representation of spatial information since it is based on environmental landmarks that are independent of body perspective. Chapter 2 presents original studies carried out by me as a Ph.D. student to investigate the developmental mechanisms underpinning spatial development and compare the spatial performance of individuals with affected and typical visual experience, respectively visually impaired and sighted. Overall, these studies suggest that vision facilitates the spatial representation of the environment by conveying the most reliable spatial reference, i.e., allocentric coordinates. However, when visual feedback is permanently or temporarily absent, as in the case of congenital blindness or blindfolded individuals, respectively, compensatory mechanisms might support the refinement of haptic and auditory spatial coding abilities. The studies presented in this chapter will validate novel experimental paradigms to assess the role of haptic and auditory experience on spatial representation based on external (i.e., allocentric) frames of reference. Chapter 3 describes the validation process of new technological systems based on unisensory and multisensory stimulation, designed to rehabilitate spatial capabilities in case of visual impairment. Overall, the technological validation of new devices will provide the opportunity to develop an interactive platform to rehabilitate spatial impairments following visual deprivation. Finally, Chapter 4 summarizes the findings reported in the previous Chapters, focusing the attention on the consequences of visual impairment on the developmental of unisensory and multisensory spatial experience in visually impaired children and adults compared to sighted peers. It also wants to highlight the potential role of novel experimental tools to validate the use to assess spatial competencies in response to unisensory and multisensory events and train residual sensory modalities under a multisensory rehabilitation