| 1. |
- von Hofsten, Olov, et al.
(författare)
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Simulating newborn face perception
- 2014
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Ingår i: Journal of Vision. - : Association for Research in Vision and Ophthalmology (ARVO). - 1534-7362. ; 14:13, s. 16-
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Tidskriftsartikel (refereegranskat)abstract
- A frequently asked question concerns what a newborn infant can actually see. The contrast sensitivity function of newborn infants is well known, but its implications for the ability of newborns to perceive faces of adults remain unclear. We filtered gray scale animations of facial expressions in terms of both spatial frequency and contrast to correspond to the properties of newborn infants' acuity and showed them to adult participants. We reasoned that if adults were unable to identify the depicted facial expressions, then it would also seem unlikely that newborn infants could identify the same expressions. We found that for the simulated acuity the different expressions could be rather well identified at a distance of 30 cm, but when the distance was increased to 120 cm their discriminability was much degraded. This shows that although the perception of faces and facial expressions can function at the low visual resolution of the newborn infant, it is insufficient for distinguishing faces and facial expressions at moderate distances.
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| 2. |
- Achard, B., et al.
(författare)
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Development of the infant's ability to retrieve food through a slit
- 2002
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Ingår i: Infant and Child Development. - : Wiley. - 1522-7227 .- 1522-7219. ; 11:1, s. 43-56
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Tidskriftsartikel (refereegranskat)abstract
- The main purpose of the present study is to explore infants' ability to comprehend task manipulation, and whether they can feed themselves with a spoon when food has to be retrieved through a slit in a lid placed over a plate. To access the food, the infant has to align the bowl of the spoon with the slit. The orientation of the slit is manipulated, and certain orientations require more elaborate modifications of the feeding action than others. The infants are observed at monthly intervals, from 12 to 17 months of age. The presence of the lid affects the behaviour of the infants at all ages. Some behaviours become more immature. The infants grasp the spoon with more primitive grasp configurations, they grasp the spoon less consistently at the top of the handle, and they orient the spoon less consistently, with its bowl facing upwards. These differences decrease with age. The infants also make attempts to adjust to the constraints of the task, mainly by inclining the spoon more vertically, and rotating the hand in such a way as to align the spoon with the orientation of the slit. These adjustments improve with age.
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| 3. |
- Andersson, Patrik, et al.
(författare)
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Readability of vertically vibrating aircraft displays
- 1999
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Ingår i: Displays (Guildford). - 0141-9382 .- 1872-7387. ; 20:1, s. 23-30
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Tidskriftsartikel (refereegranskat)abstract
- Vibrations pose a problem to the visual system. The vibrations in aircraft are mainly vertical and cause reading errors when the pilots read the instruments. In three experiments, reading capability was tested during vertical vibration of modern military aircraft, using symbols presented on a computer monitor. The results showed that complexity of symbols have a significant effect on the performance. The orientations of symbols were also of importance for their readability. Indexes made up of horizontally oriented lines were found to be especially difficult to read during vertical vibration. Orienting them 45° up or down improved readability in a significant way. The size of the symbols was found to be of importance especially when they were horizontally oriented.
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| 4. |
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| 5. |
- Bakker, Marta, et al.
(författare)
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Development of social perception : A conversation study of 6-, 12-and 36-month-old children
- 2011
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Ingår i: Infant Behavior and Development. - : Elsevier BV. - 0163-6383 .- 1879-0453. ; 34:2, s. 363-370
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Tidskriftsartikel (refereegranskat)abstract
- A conversation is made up of visual and auditory signals in a complex flow of events. What is the relative importance of these components for young children's ability to maintain attention on a conversation? In the present set of experiments the visual and auditory signals were disentangled in four filmed events. The visual events were either accompanied by the speech sounds of the conversation or by matched motor sounds and the auditory events by either the natural visual turn taking of the conversation or a matched turn taking of toy trucks. A cornea-reflection technique was used to record the gaze-pattern of subjects while they were looking at the films. Three age groups of typically developing children were studied; 6-month-olds, 1-year-olds and 3-year-olds. The results show that the children are more attracted by the social component of the conversation independent of the kind of sound used. Older children find spoken language more interesting than motor sound. Children look longer at the speaking agent when humans maintain the conversation. The study revealed that children are more attracted to the mouth than to the eyes area. The ability to make more predictive gaze shifts develops gradually over age.
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| 6. |
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| 7. |
- Bernspång, Birgitta, 1951-
(författare)
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Consequences of stroke : aspects of impairments, disabilities and life satisfaction : with special emphasis on perception and on occupational therapy
- 1987
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Perceptual and motor functions and self-care ability after stroke were assessed within two weeks (n:109; mean age 69±10) and 4-6 years (n:75;70±9) after admission to a non-intensive care stroke unit. Sixty-two of the long-term stroke survivors reported on their life satisfaction (7 items) as experienced (in retrospect) before the stroke and at the time of the investigation. Perceptual functions and actual levels of life satisfaction were registered in 60 clinically healthy subjects aged about 60 or about 80 years.Both early on and late after stroke the 16 items of perceptual function were clearly grouped into two factors, which neatly fitted an ecological perceptual concept. One factor characterized low-order and the other higher-order perception. Impairments of low-order perception occurred for about 10% of the patients, whether investigated early or late after stroke. No one among the reference populations had such impairments. Higher-order perceptual impairments prevailed in 60% early on and in 57% late after stroke and were often more pronounced than those occurring in the reference populations, among whom 35% of the 60 year olds and significantly more - 77% - of the 80 year olds had such impairments. Hence, perceptual impairments are common after stroke, but slight age-dependent reductions should be considered when higher-order perceptual function is assessed and treated after stroke.Together with motor function, which was impaired in 52% of the early and 36% of the late stroke samples, higher-order perceptual function and to a limited extent low-order perception could predict the level of self-care ability in 70% and 62% of the early and late samples, respectively.Whereas levels of global and of domain specific variables of life satisfaction were similar in the two reference populations, the stroke had lead to a reduction in life satisfaction for 61% of the long-term survivors. Reductions were particularly pronounced for global life satisfaction and for satisfaction with leisure and sexuality. Although significantly associated with motor impairment and self-care disability, these reductions could not be attributed only to impairments and disability.The findings are discussed with particular reference to assessment and treatment in occupational therapy.
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| 8. |
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| 9. |
- Brodd, Katarina Strand, et al.
(författare)
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Development of smooth pursuit eye movements in very preterm infants : 1. General aspects
- 2011
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Ingår i: Acta Paediatrica. - : Wiley. - 0803-5253 .- 1651-2227. ; 100:7, s. 983-991
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To investigate early oculo-motor development in a population-based cohort of very preterm infants.Methods: Early oculo-motor development was prospectively studied by measuring smooth pursuit eye movements at 2 and 4 months corrected age in a population of very preterm infants born in Uppsala County 2004–2007. Eighty-one preterm infants were studied, and 32 healthy term infants constituted the control group.Results: The study group consisted of infants with a mean gestational age of28 + 5 weeks. At 2 and 4 months corrected age, infants born very preterm showed lower gain (p < 0.001) and proportion of smooth pursuit eyemovements (p < 0.001) compared to the control group. The boys showed higher gain of smooth pursuit eye movements at both 2 and 4 months corrected age, compared to girls.Conclusions: Oculo-motor development measured by smooth pursuit eye movements is delayed in very preterm infants at 2 and 4 months corrected age. This might be a risk factor or early indicator of later perceptual and behavioural impairment.
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| 10. |
- Bäckström, Anna, et al.
(författare)
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Action planning in relation to movement performance in 6-year-old children with autism spectrum disorder
- 2019
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Konferensbidrag (refereegranskat)abstract
- Introduction: Recent research proposes problems with action planning as part of atypical motor functioning in children with autism spectrum disorder (ASD), although findings are inconsistent. This study investigated relations between action planning and movement performance in 6-year-old children with and without ASD.Patients and methods: 3D kinematic recordings of preferred arm/hand performance on a sequential peg rotation task with varying complexity of goal insertion (four endpoints and either visual or occluded goal display at onset) were conducted in 6 children with ASD (MAge = 6.4) and 6 typically developing (TD) controls (MAge = 6.5).Results: Analyses revealed significant (p < .05) group and task-endpoint differences for movement segmentation (number of movement units, MUs) and 3D movement distance. Children with ASD generally displayed more MUs and longer distances than controls and all children showed increased MUs and movement distance on more complex task-endpoints. TD controls showed significantly shorter movement initiation latency (MIL) durations than ASD in the visual condition and evidently longer MILs in the occluded than visual condition. In contrast, no difference between goal display conditions was shown for the ASD group.Conclusion: Children with ASD generally had longer movement distances and more segmented movements than controls, suggesting less efficient movement performance. Movement performance was not evidently affected by goal display condition in either group. However, the lack of MIL differences between goal display conditions within the ASD group indicates reduced pre-planning, possibly affecting movement execution efficiency.
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| 11. |
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| 12. |
- Bäckström, Anna, et al.
(författare)
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Atypical motor planning in an interpersonal context in 9-year-old children with autism spectrum disorder (ASD)
- 2023
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Ingår i: 35th EACD Annual meeting European Academy of Childhood Disability. - : European Academy of Childhood Disability. ; , s. 254-254
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Konferensbidrag (refereegranskat)abstract
- Introduction: Motor planning deviances may negatively affect interpersonal motor interactions in ASD, although detailed studies are sparse. This study examined motor planning kinematics in an interpersonal and non-interpersonal context in 9-year-old children with ASD and neurotypical peers.Patients and methods: Twelve children with ASD and 17 controls performed two different sequential manual tasks (preferred hand): grasping and placing a peg on a wooden disc (non-interpersonal) or in the hand of an examiner (interpersonal). Three-dimensional kinematic recordings of arm/hand movements were performed. Group and task differences were explored for total movement duration (MD), and for peak velocity (PV) and placement of peak velocity (PPV) during reach-to-grasp and transport-to-place movements, respectively.Results: Task differences were found in terms of longer MD and higher transport-to-place-PV in the disc- compared to hand-task. An interaction effect was evident for reach-to-grasp-PPV, where the control-group, but not ASD, had earlier reach-to-grasp-PPV and longer relative deceleration in the hand-task compared to the disc-task.Conclusion: Results show that the interpersonal context influenced initial reach-to-grasp motor planning in the control-group, but not the ASD-group. Later in the sequential movement (transport-to-place), the interpersonal context seemed to influence motor planning independent of group. Taken together, this indicates support towards a more careful peg-placing in the interpersonal hand-task in the control-group but much less clearly so in the ASD-group.Relevance for users and families: Atypical motor planning may influence motor interaction with peers. Investigations of motor planning and movement organization in ASD could thus inform interventions also targeting interpersonal exchange.
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| 13. |
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| 14. |
- Bäckström, Anna, et al.
(författare)
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Motor imagery ability in 7-year-old children with autism spectrum disorder
- 2020
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Introduction: Knowledge about motor imagery (MI) ability in autism spectrum disorder (ASD) is limited and inconclusive in young children with ASD. The aim of the current study was to investigate MI ability in 7-year-old children with ASD.Patients and methods: Thirteen children with ASD and 13 typically developing (TD) children performed a computerized hand laterality judgement task (HLJ) and a non-corporeal visual imagery (VI) control task. All participants passing a criterion test performed the tasks with images at 4 different rotational increments to vary the MI biomechanical demands (HLJ task) or VI angle rotational demands (VI task). Response times (RT) and accuracy were extracted.Results: Four children with ASD did not pass the HLJ criterion test and one failed the VI criterion test. The ASD-group had evidently more incorrect responses than TD on both tasks. Analyses of RT showed a biomechanical effect in the MI task and an angle increment effect in the VI task in both groups. Children with ASD had longer RT than TD children on VI but not MI tasks. Conclusion: Findings suggest that both the ASD and control children used MI to solve the HLJ task. However, failures to pass the HLJ criterion test and the increased error rate in the ASD group indicate that MI ability is weaker in young children with autism than TD controls. Notably, a large individual variability in employment of MI within the ASD group was found, ranging from functional, fractional but existing, to absent MI ability.
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| 15. |
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| 16. |
- Bäckström, Anna, et al.
(författare)
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Motor planning and movement execution during goal-directed sequential manual movements in 6-year-old children with autism spectrum disorder : A kinematic analysis
- 2021
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Ingår i: Research in Developmental Disabilities. - : Elsevier. - 0891-4222 .- 1873-3379. ; 115
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Tidskriftsartikel (refereegranskat)abstract
- Background: Atypical motor functioning is prevalent in children with autism spectrum disorder (ASD). Knowledge of the underlying kinematic properties of these problems is sparse.Aims: To investigate characteristics of manual motor planning and performance difficulties/diversity in children with ASD by detailed kinematic measurements. Further, associations between movement parameters and cognitive functions were explored.Methods and procedures: Six-year-old children with ASD (N = 12) and typically developing (TD) peers (N = 12) performed a sequential manual task comprising grasping and fitting a semi-circular peg into a goal-slot. The goal-slot orientation was manipulated to impose different motor planning constraints. Movements were recorded by an optoelectronic system.Outcomes and results: The ASD-group displayed less efficient motor planning than the TD-group, evident in the reach-to-grasp and transport kinematics and less proactive adjustments of the peg to the goal-slot orientations. The intra-individual variation of movement kinematics was higher in the ASD-group compared to the TD-group. Further, in the ASD-group, movement performance associated negatively with cognitive functions.Conclusions and implications: Planning and execution of sequential manual movements proved challenging for children with ASD, likely contributing to problems in everyday actions. Detailed kinematic investigations contribute to the generation of specific knowledge about the nature of atypical motor performance/diversity in ASD. This is of potential clinical relevance.
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| 17. |
- Bäckström, Anna, et al.
(författare)
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Visuomotor integration in action planning in 7-year-old children with autism spectrum disorder
- 2022
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Ingår i: Specia issue: Abstracts of the 34th annual meeting of the European Academy of Childhood Disability (EACD) Barcelona, Spain 18-21 May 2022. - : Mac Keith Press. ; , s. 65-65
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Konferensbidrag (refereegranskat)abstract
- Introduction: Difficulties with action planning and visuomotor integration may contribute to atypical motorfunctioning in children with autism spectrum disorder (ASD), although detailed studies of sensorimotorintegration in action planning are sparse. This ongoing study investigates visuomotor integration in actionplanning in 7-year-old children with and without ASD.Patients and methods: A sub-sample of 6 children with ASD and 6 typically developing (TD) controls wereincluded. Recordings of gaze synchronized with 3D kinematic registration were made during performance of amanual sequential peg rotation task with variations in goal insertion complexity. Group differences and relations between movement duration and number of gaze shifts over the sequential movement phases(latency, reach-to-grasp, grasp, and transport-to-fit) were explored.Results: No significant group differences were found for either movement duration or number of gaze shifts.When controlling for the between-participants variance, total number of gaze shifts and number of gaze shiftsin reach-to-grasp were related to movement duration in the initial phases of the movement in the TD-group but not in the ASD-group.Conclusion: The results indicate that, whilst performance measures were similar between groups, the overallpattern of visuomotor integration was related to feed-forward movement processes in the sequentialmovement in the TD-group but not in the ASD-group. This finding adds support to previous suggestions thatvisuomotor integration underpinning action planning may operate differently in ASD. Synchronizedexamination of gaze and detailed movement registration appears as a promising methodology for detailed investigation of visuomotor integration in action planning.
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| 18. |
- Cannon, Erin N., et al.
(författare)
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Action production influences 12-month-old infants' attention to others' actions
- 2012
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Ingår i: Developmental Science. - : Wiley. - 1363-755X .- 1467-7687. ; 15:1, s. 35-42
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Tidskriftsartikel (refereegranskat)abstract
- Recent work implicates a link between action control systems and action understanding. In this study, we investigated the role of the motor system in the development of visual anticipation of others actions. Twelve-month-olds engaged in behavioral and observation tasks. Containment activity, infants spontaneous engagement in producing containment actions; and gaze latency, how quickly they shifted gaze to the goal object of anothers containment actions, were measured. Findings revealed a positive relationship: infants who received the behavior task first evidenced a strong correlation between their own actions and their subsequent gaze latency of anothers actions. Learning over the course of trials was not evident. These findings demonstrate a direct influence of the motor system on online visual attention to others actions early in development.
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| 19. |
- Chen, Yu-ping, et al.
(författare)
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Movement Planning Reflects Skill Level and Age Changes in Toddlers
- 2010
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Ingår i: Child Development. - : Wiley. - 0009-3920 .- 1467-8624. ; 81:6, s. 1846-1858
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Tidskriftsartikel (refereegranskat)abstract
- Kinematic measures of children's reaching were found to reflect stable differences in skill level for planning for future actions. Thirty-five toddlers (18-21 months) were engaged in building block towers (precise task) and in placing blocks into an open container (imprecise task). Sixteen children were retested on the same tasks a year later. Longer deceleration as the hand approached the block for pickup was found in the tower task compared with the imprecise task, indicating planning for the second movement. More skillful toddlers who could build high towers had a longer deceleration phase when placing blocks on the tower than toddlers who built low towers. Kinematic differences between the groups remained a year later when all children could build high towers.
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| 20. |
- Cunha, Andrea Baraldi, et al.
(författare)
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Maturational and situational determinants of reaching at its onset
- 2015
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Ingår i: Infant Behavior and Development. - : Elsevier BV. - 0163-6383 .- 1879-0453. ; 41, s. 64-72
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Tidskriftsartikel (refereegranskat)abstract
- At 3 months of age, reaching behavior was measured in a group of 10 girls and 10 boys born at term. The assessments were carried out on the average 2 days after reaching onset. Reaching kinematics was measured in both supine and reclined positions. Girls reached more than boys, had straighter reaching trajectories and movements of shorter durations as well as fewer movement units. The reclined position gave rise to straighter trajectories in both girls and boys. Several anthropometric parameters were measured. Girls had less length and volume of the forearm than boys but similar upper arm volumes. There was a weak relation between kinematic and anthropometric variables.
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| 21. |
- deWit, Tessa, et al.
(författare)
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Young children with Autism Spectrum Disorder look differently at positive versus negative emotional faces
- 2008
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Ingår i: Research in Autism Spectrum Disorders. - : Elsevier BV. - 1750-9467. ; 2:4, s. 651-659
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Tidskriftsartikel (refereegranskat)abstract
- One of the core issues in Autism Spectrum Disorder (ASD) is problematic social interaction, which for an important part is reflected by poor processing of emotional information. Typically, adults show specific viewing patterns while scanning positive and negative emotional expressions in faces. In this study, we investigated whether the same pattern is present in a group of 3- to 6-year-old children with ASD and a 5-year-old control group. We found that although the group with ASD looked less at feature areas of the face (eye, mouth, nose) than the control group, both the children with ASD and the normally developing children displayed differential scanning patterns for faces displaying positive and negative emotions. Specifically, we found increased scanning of the eye region when looking at faces displaying negative emotions. This study shows that, although young children with ASD exhibit abnormal face scanning patterns, they do exhibit differential viewing strategies while scanning positive and negative facial expressions.
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| 22. |
- Domellöf, Erik, et al.
(författare)
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Kinematic characteristics of second‐order motor planning and performance in 6‐ and 10‐year‐old children and adults : Effects of age and task constraints
- 2020
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Ingår i: Developmental Psychobiology. - : John Wiley & Sons. - 0012-1630 .- 1098-2302 .- 0012-1649 .- 1939-0599. ; 62:2, s. 250-265
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Tidskriftsartikel (refereegranskat)abstract
- This study explored age‐related differences in motor planning as expressed in arm‐hand kinematics during a sequential peg moving task with varying demands on goal insertion complexity (second‐order planning). The peg was a vertical cylinder with either a circular or semicircular base. The task was to transport the peg between two positions and rotate it various amounts horizontally before fitting into its final position. The amount of rotation required was either 0°, 90°, 180°, or −90°. The reaching for the peg, the displacement of it, and the way the rotation was accomplished was analyzed. Assessments of end state comfort, goal interpretation errors, and type of grip used were also included. Participants were two groups of typically developing children, one younger (Mage = 6.7 years) and one older (Mage = 10.3 years), and one adult group (Mage = 34.9 years). The children, particularly 6‐year‐olds, displayed less efficient prehensile movement organization than adults. Related to less efficient motor planning, 6‐year‐olds, mainly, had shorter reach‐to‐grasp onset latencies, higher velocities, and shorter time to peak velocities, and longer grasp durations than adults. Importantly, the adults rotated the peg during transport. In contrast, the children made corrective rotations after the hand had arrived at the goal.
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| 23. |
- Domellöf, Erik, et al.
(författare)
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Sequential upper-limb action planning in children with autism spectrum disorder : a kinematic pilot study
- 2018
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Ingår i: Developmental Medicine & Child Neurology. - : Mac Keith Press. - 0012-1622 .- 1469-8749. ; 60:S2, s. 34-34
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Recent research on sensory-motor skill in children with autism spectrum disorder (ASD) suggest that problems with planning sequential actions may explain difficulties with motor execution in this population. The present pilot study investigated upper-limb movement kinematics during a goal-directed manual task requiring sequential action planning in children with and without ASD at 6-7 years.Patients and method: 3D kinematic recordings of performance with the preferred arm/hand during a sequential peg moving task with varying complexity of goal insertion (five endpoint conditions, open/revealed goal presentation) were carried out in 3 children with ASD (2 girls, mean age 6.3 years) and 3 typically developing children (3 girls, mean age 7 years). End state comfort and trial errors were also assessed.Results: Preliminary analyses of whole movement spatiotemporal segmentation (movement units, MUs) at trial level revealed significant main effects for group and endpoint condition. Overall, children with ASD consistently performed less proficiently (more MUs) than controls for all conditions across hand/arm and head. Independent of group, all children displayed increased MUs for the more complex endpoints. Children with ASD also showed evidently poorer planning behavior (less end state comfort and increased trial errors) than controls.Conclusion: Findings suggest difficulties with sequential movement planning in children with ASD in terms of suboptimal movement organization together with reduced end state comfort and inaccurate goal interpretations. In contrast to controls, children with ASD did not seem to have planned the onward action prior to action execution, contributing to the observed less proficient movement kinematics.
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| 24. |
- Ekberg, Therese L., et al.
(författare)
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Dynamic reaching in infants during binocular and monocular viewing
- 2013
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Ingår i: Experimental Brain Research. - : Springer Science and Business Media LLC. - 0014-4819 .- 1432-1106. ; 229:1, s. 1-12
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Tidskriftsartikel (refereegranskat)abstract
- This study examined reaching in 6-, 8-, and 10-month-olds during binocular and monocular viewing in a dynamic reaching situation. Infants were rotated toward a flat vertical board and reached for objects at one of seven positions along a horizontal line at shoulder height. Hand selection, time to contact the object, and reaching accuracy were examined in both viewing conditions. Hand selection was strongly dependent on object location, not on infants' age or whether one eye was covered. Monocular viewing and age did, however, affect time to object contact and contact errors: Infants showed longer contact times when one eye was covered, and 6-month-olds made more contact errors in the monocular condition. For right-hand selection, contact times were longer when the covered right eye was leading during the chair rotation. For left-hand selection, there were no differences in contact time due to whether the covered eye was leading during rotation.
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| 25. |
- Elsner, Claudia, 1986-
(författare)
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An Embodied Account of Action Prediction
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Being able to generate predictions about what is going to happen next while observing other people’s actions plays a crucial role in our daily lives. Different theoretical explanations for the underlying processes of humans’ action prediction abilities have been suggested. Whereas an embodied account posits that predictive gaze relies on embodied simulations in the observer’s motor system, other accounts do not assume a causal role of the motor system for action prediction.The general aim of this thesis was to augment current knowledge about the functional mechanisms behind humans’ action prediction abilities. In particular, the present thesis outlines and tests an embodied account of action prediction. The second aim of this thesis was to extend prior action prediction studies by exploring infants’ online gaze during observation of social interactions.The thesis reports 3 eye-tracking studies that were designed to measure adults’ and infants’ predictive eye movements during observation of different manual and social actions. The first two studies used point-light displays of manual reaching actions as stimuli to isolate human motion information. Additionally, Study II used transcranial magnetic stimulation (TMS) to directly modify motor cortex activity.Study I showed that kinematic information from biological motion can be used to anticipate the goal of other people’s point-light actions and that the presence of biological motion is sufficient for anticipation to occur.Study II demonstrated that TMS-induced temporary lesions in the primary motor cortex selectively affected observers’ gaze latencies.Study III examined 12-month-olds’ online gaze during observation of a give-and-take interaction between two individuals. The third study showed that already at one year of age infants shift their gaze from a passing hand to a receiving hand faster when the receiving hand forms a give-me gesture compared to an inverted hand shape.The reported results from this thesis make two major contributions. First, Studies I and II provide evidence for an embodied account of action prediction by demonstrating a direct connection between anticipatory eye movements and motor cortex activity. These findings support the interpretation that predictive eye movements are driven by a recruitment of the observer’s own motor system. Second, Study III implicates that properties of social action goals influence infants’ online gaze during action observation. It further suggests that at one year of age infants begin to show sensitivity to social goals within the context of give-and-take interactions while observing from a third-party perspective.
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| 26. |
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| 27. |
- Eriksson, Lars, 1963-, et al.
(författare)
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Effects of visual flow display of flight maneuvers on perceived spatial orientation
- 2005
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Ingår i: Human Factors. - 0018-7208 .- 1547-8181. ; 47:2, s. 378-393
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Tidskriftsartikel (refereegranskat)abstract
- Postural responses were utilized as measures of the effectiveness of a wide-angle visual flow display in determining perceived spatial orientation (SO). The general experimental setup included a 150 degrees x 34 degrees wide-field display showing flight over computer-generated ground with horizon. Simulated roll maneuvers on this display induced postural sway in the observer that was registered by a head-tracker system. Two experiments with 16 participants in each investigated the effects of visual flow, display exclusions in the central visual field, and display extensions into the visual periphery. Clear vestibular and proprioceptive suppression effects were demonstrated on postural sway with the inclusion of visual flow of forward ego motion in roll maneuvers. Compared with the full view, up to 20 degrees x 20 degrees central field omission either did not reduce the effect or reduced the effect but, frequently, only moderately. Limiting the display area to 45 degrees in the horizontal dimension reduced display effectiveness significantly, whereas a 105 degrees area did not, compared with the full view. Utilizing postural responses as indications of visual display resonance with our SO mechanism, actual or potential applications of this research include the design of an interface integrating flight-adapted visual flow to counteract or reduce pilot spatial disorientation.
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| 28. |
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| 29. |
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| 30. |
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| 31. |
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| 32. |
- Eriksson, Lars, 1963-
(författare)
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Visual Flow Display for Pilot Spatial Orientation
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Pilot spatial disorientation (SD) is a significant cause of incidents and fatal accidents in aviation. The pilot is susceptible to SD especially in low visibility when the visual system is deprived of information from outside the cockpit. This thesis presents the notion of visual flow displays as enhancement of symbology on flight displays primarily in low visibility for improved support of the pilot’s spatial orientation (SO) and control actions. In Studies I and II, synthetic visual flow of forward ego-motion was presented on displays and postural responses were used as measures of display effectiveness in determining SO. The visual flow significantly affected SO, and although the increased stimulation of the visual periphery from a width of 45° to about 105° increased the effects there was no further effect at a width of about 150° (Studies I and II). Studies I and II also showed that omitting 20°- or 30°-wide central fields of view from the visual flow either reduced or not reduced the effects. Further, although inconclusive, Study II may indicate that horizon symbology in central visual field may enhance the effects of peripheral visual flow. The appropriate integration of peripheral visual flow with the head-up display symbology of the Gripen aircraft was presented. Acceleration in a human centrifuge was used in Study III to investigate the effects of synthetic visual flow on the primarily vestibular-dependent somatogravic illusion of pitch-up. Two experiments revealed a reduced illusion with the visual flow. The results of Experiment 2 showed the visual flow scene not only reduced the illusion compared with a darkness condition but also compared with the visual scene without visual flow. Thus, similar to the main findings of Studies I and II, synthetic visual flow can significantly affect SO and supports the visually dependent SO system in an essential manner.
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| 33. |
- Fagard, Jacqueline, et al.
(författare)
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Reaching and grasping a moving object in 6-, 8-, and 10-month-old infants : Laterality and performance
- 2009
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Ingår i: Infant Behavior and Development. - : Elsevier BV. - 0163-6383 .- 1879-0453. ; 32:2, s. 137-146
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Tidskriftsartikel (refereegranskat)abstract
- The goal of this study was to investigate some of the visuo-motor factors underlying an infant's developing ability to grasp a laterally-moving object. In particular, hand preference, midline crossing, and visual-field asymmetry were investigated by comparing performance as a function of the object's direction of motion. We presented 6-, 8-, and 10-month-old infants with a graspable object, moving in a circular trajectory in the horizontal plane. Six-month-old infants reached for the object with the ipsilateral hand and grasped it with the contralateral hand. Eight-month-old infants showed a strong right-hand bias for both reaching and grasping. Ten-month-old infants showed a greater diversity of strategy use including bimanual and successful ipsilateral grasping following ipsilateral reaching in both directions of motion. Thus, motor constraints due to spatial compatibility, hand preference and bimanual coordination (but not midline crossing) must be taken into account to understand age differences in grasping a moving object.
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| 34. |
- Falck-Ytter, Terje, et al.
(författare)
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Face scanning distinguishes social from communication impairments in autism
- 2010
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Ingår i: Developmental Science. - : Wiley. - 1363-755X .- 1467-7687. ; 13:6, s. 864-875
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Tidskriftsartikel (refereegranskat)abstract
- How closely related are the social and communicative impairments in Autism Spectrum Disorder (ASD)? Recent findings in typically developing children suggest that both types of impairment are highly heritable but have only moderate behavioural and genetic overlap. So far, their respective roles in social perception are poorly understood. Here we show that when looking at other people’s faces, children with ASD who are better at socio-emotional behaviours than non-verbal communication look more at the eyes, while those with the opposite profile look more at the mouth (Study 1). For the mouth area, a similar pattern was observed for inverted faces, suggesting that information from this area is perceived on a featural basis. In Study 2, we found that when shown a person performing manual actions, ‘eye-lookers’ from Study 1 tended to look most at the face of the actor, while ‘mouthlookers’ from Study 1 tended to look at the action itself (hand ⁄ objects). This result was found in both ASD and typical development. In Study 3, the main finding in Study 1 was replicated in a new sample. Taken together, we interpret these results as supporting the view that the neural systems underlying socio-emotional versus non-verbal communication skills are separable, a finding that has important theoretical and clinical implications. The results also suggest that a similar differentiation of looking behaviour may operate in normal development.
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| 35. |
- Falck-Ytter, Terje, et al.
(författare)
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Gaze performance in children with autism spectrum disorder when observing communicative actions.
- 2012
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Ingår i: Journal of Autism and Developmental Disorders. - : Springer Science and Business Media LLC. - 0162-3257 .- 1573-3432. ; 42:10, s. 2236-2245
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Tidskriftsartikel (refereegranskat)abstract
- The main purpose of this eye tracking study was to map the correlates of gaze performance in a brief test of spontaneous gaze and point-gesture following in young children with autistic disorder (AD), Pervasive developmental disorder-not otherwise specified (PDD-NOS), or typical development (TD). Gaze measures included the children's spontaneous tendency to look at the correct (attended) toy, and the latency of their correct responses. In addition to group differences (AD vs. TD), we found that in AD, accuracy of performance was specifically related to adaptive communication skills. The study also indicated that the latency of correct gaze shifts is related to verbal intelligence. These results have direct implications for our understanding of (responsive) joint attention impairments in AD.
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| 36. |
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| 37. |
- Falck-Ytter, Terje, et al.
(författare)
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Human infants orient to biological motion rather than audiovisual synchrony
- 2011
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Ingår i: Neuropsychologia. - : Elsevier BV. - 0028-3932 .- 1873-3514. ; 49:7, s. 2131-2135
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Tidskriftsartikel (refereegranskat)abstract
- Both orienting to audiovisual synchrony and to biological motion are adaptive responses. The ability to integrate correlated information from multiple senses reduces processing load and underlies the perception of a multimodal and unified world. Perceiving biological motion facilitates filial attachment and detection of predators/prey. In the literature, these mechanisms are discussed in isolation. In this eye-tracking study, we tested their relative strengths in young human infants. We showed five-month-old infants point-light animation pairs of human motion, accompanied by a soundtrack. We found that audiovisual synchrony was a strong determinant of attention when it was embedded in biological motion (two upright animations). However, when biological motion was shown together with distorted biological motion (upright animation and inverted animation, respectively), infants looked at the upright animation and disregarded audiovisual synchrony. Thus, infants oriented to biological motion rather than multimodally unified physical events. These findings have important implications for understanding the developmental trajectory of brain specialization in early human infancy.
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| 38. |
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| 39. |
- Falck-Ytter, Terje, et al.
(författare)
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Visualization and Analysis of Eye Movement Data from Children with Typical and Atypical Development
- 2013
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Ingår i: Journal of autism and developmental disorders. - : Springer Science and Business Media LLC. - 0162-3257 .- 1573-3432. ; 43:10, s. 2249-2258
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Tidskriftsartikel (refereegranskat)abstract
- Looking at other children's interactions provides rich learning opportunities for a small child. How children with autism look at other children is largely unknown. Using eye tracking, we studied gaze performance in children with autism and neurotypical comparison children while they were watching videos of semi-naturalistic social interactions between young children. Using a novel, bottom-up approach we identified event-related measures that distinguished between groups with high accuracy. The observed effects remained in a subset of the total sample matched on IQ, and were replicated across several different stimuli. The described method facilitates the detection of meaningful patterns in complex eye tracking data. Also, the approach significantly improves visualization, which will help investigators understand, illustrate, and generate new hypotheses.
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| 40. |
- Forssman, Linda, et al.
(författare)
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Eighteen-month-olds' ability to make gaze predictions following distraction or a long delay
- 2014
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Ingår i: Infant Behavior and Development. - : Elsevier BV. - 0163-6383 .- 1879-0453. ; 37:2, s. 225-234
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Tidskriftsartikel (refereegranskat)abstract
- The abilities to flexibly allocate attention, select between conflicting stimuli, and make anticipatory gaze movements are important for young children's exploration and learning about their environment. These abilities constitute voluntary control of attention and show marked improvements in the second year of a child's life. Here we investigate the effects of visual distraction and delay on 18-month-olds' ability to predict the location of an occluded target in an experiment that requires switching of attention, and compare their performance to that of adults. Our results demonstrate that by 18 months of age children can readily overcome a previously learned response, even under a condition that involves visual distraction, but have difficulties with correctly updating their prediction when presented with a longer time delay. Further, the experiment shows that, overall, the 18-month-olds' allocation of visual attention is similar to that of adults, the primary difference being that adults demonstrate a superior ability to maintain attention on task and update their predictions over a longer time period. (C) 2014 Elsevier Inc. All rights reserved.
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| 41. |
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| 42. |
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| 43. |
- Fredriksson Kaul, Ylva
(författare)
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From Eye to Mind : Early Visuomotor Performance and Developmental Trajectories in Children Born Preterm
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Children born very preterm, at less than 32 weeks of gestation, have an increased risk of developing problems with attention, cognition, perception and motor function. Despite this, the developmental trajectories leading from preterm birth to later impairments are not fully understood.This thesis focused on investigating the development of the visuomotor system in infants born very preterm, in relation to neurodevelopment at 2.5-3 years (including cognitive, language and motor functions) and 6.5 years (including cognitive functions and attention). Two early visuomotor functions were investigated: at 4 months of corrected age we looked at their visual tracking of moving objects and at 8 months of corrected age we examined how they reached for moving objects. Visual tracking performance is the ability to follow, sustain attention on and predict the future positions of a moving object. When infants reach for moving objects, these requirements are enhanced by movements of the arm and hand.This was a prospective, population-based cohort study of children born very preterm in 2004-2007, who were longitudinally assessed from the neonatal period until 6.5 years of age. The results showed that the two most important early visual tracking parameters were gaze gain, which is effectively combining eye and head movements to follow the trajectory of the object, and timing of gaze to the motion of the object. Gaze gain correlated with neurodevelopment at 2.5-3 years and with cognition and attention at 6.5 years. Early reaching was also related to outcomes at 2.5-3 years, but the pattern differed for children born before and after 28 weeks of gestation. Parameters of prediction and movement planning were the most important factors for the children of the lowest gestational age, but strategies and success had greater associations with later function in those who were less premature.The results confirmed that children born very preterm in the first decade of the 2000’s still faced increased risks of developmental delays. Early visual tracking performance, and reaching for moving objects, were shown to be important visuomotor functions in the developmental process of children born very preterm. The studies in this thesis illustrate how early basic functions were related to different neurodevelopmental areas at a later stage and offer important new insights into developmental trajectories of children at risk of developmental impairments. These findings suggest that attention and predictive elements of adjusting one´s movements to motion, may be key mechanisms and possible targets in future intervention studies.
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| 44. |
- Fredriksson Kaul, Ylva, et al.
(författare)
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Visual tracking at 4 months in preterm infants predicts 6.5-year cognition and attention
- 2022
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Ingår i: Pediatric Research. - : Springer Nature. - 0031-3998 .- 1530-0447. ; 92:4, s. 1082-1089
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Visual tracking of moving objects requires sustained attention and prediction of the object’s trajectory. We tested the hypothesis that measures of eye-head tracking of moving objects are associated to long-term neurodevelopment in very preterm infants.METHODS: Visual tracking performance was assessed at 4 month’s corrected age in 57 infants with gestational age <32 weeks. An object moved in front of the infant with sinusoidal or triangular (i.e. abrupt) turns of the direction. Gaze gain, smooth pursuit gain, and timing of gaze to object motion were analyzed. At 6.5 years the Wechsler Intelligence Scale for Children (WISC-IV), the Brown Attention Deficit Disorder (Brown ADD), and visual examination were performed. RESULTS: Gaze gain and smooth pursuit gain at 4 months were strongly related to all WISC-IV parameters at 6.5 years. Gaze gain for the triangular and sinusoidal motion patterns related similarly to the cognitive scores. For the sinusoidal motion pattern, timing related to most Brown ADD parameters. There were no statistically significant differences in associations dependent on motion pattern. Visual function did not influence the results. CONCLUSION: The ability to attend to and smoothly track a moving object in infancy is an early marker of cognition and attention at 6.5 years.
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| 45. |
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| 46. |
- Gottwald, Janna, Dr, 1983-
(författare)
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Infants in Control : Prospective Motor Control and Executive Functions in Action Development
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis assesses the link between action and cognition early in development. Thus the notion of an embodied cognition is investigated by tying together two levels of action control in the context of reaching in infancy: prospective motor control and executive functions.The ability to plan our actions is the inevitable foundation of reaching our goals. Thus actions can be stratified on different levels of control. There is the relatively low level of prospective motor control and the comparatively high level of cognitive control. Prospective motor control is concerned with goal-directed actions on the level of single movements and movement combinations of our body and ensures purposeful, coordinated movements, such as reaching for a cup of coffee. Cognitive control, in the context of this thesis more precisely referred to as executive functions, deals with goal-directed actions on the level of whole actions and action combinations and facilitates directedness towards mid- and long-term goals, such as finishing a doctoral thesis. Whereas prospective motor control and executive functions are well studied in adulthood, the early development of both is not sufficiently understood.This thesis comprises three empirical motion-tracking studies that shed light on prospective motor control and executive functions in infancy. Study I investigated the prospective motor control of current actions by having 14-month-olds lift objects of varying weights. In doing so, multi-cue integration was addressed by comparing the use of visual and non-visual information to non-visual information only. Study II examined the prospective motor control of future actions in action sequences by investigating reach-to-place actions in 14-month-olds. Thus the extent to which Fitts’ law can explain movement duration in infancy was addressed. Study III lifted prospective motor control to a higher that is cognitive level, by investigating it relative to executive functions in 18-months-olds.Main results were that 14-month-olds are able to prospectively control their manual actions based on object weight. In this action planning process, infants use different sources of information. Beyond this ability to prospectively control their current action, 14-month-olds also take future actions into account and plan their actions based on the difficulty of the subsequent action in action sequences. In 18-month-olds, prospective motor control in manual actions, such as reaching, is related to early executive functions, as demonstrated for behavioral prohibition and working memory. These findings are consistent with the idea that executive functions derive from prospective motor control. I suggest that executive functions could be grounded in the development of motor control. In other words, early executive functions should be seen as embodied.
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| 47. |
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| 48. |
- Gottwald, Janna M., et al.
(författare)
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Infants prospectively control reaching based on the difficulty of future actions : To what extent can infants' multiple step actions be explained by Fitts' law?
- 2017
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Ingår i: Developmental Psychology. - : American Psychological Association (APA). - 0012-1649 .- 1939-0599. ; 53:1, s. 4-12
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Tidskriftsartikel (refereegranskat)abstract
- Prospective motor control, a key element of action planning, is the ability to adjust one's actions with respect to task demands and action goals in an anticipatory manner. The current study investigates whether 14-month-olds can prospectively control their reaching actions based on the difficulty of the subsequent action. We used a reach-to-place task, with difficulty of the placing action varied by goal size and goal distance. To target prospective motor control, we determined the kinematics of the prior reaching movements using a motion-tracking system. Peak velocity of the first movement unit of the reach served as indicator for prospective motor control. Both difficulty aspects (goal size and goal distance) affected prior reaching, suggesting that both these aspects of the subsequent action have an impact on the prior action. The smaller the goal size and the longer the distance to the goal, the slower infants were in the beginning of their reach toward the object. Additionally, we modeled movement times of both reaching and placing actions using a formulation of Fitts' law (as in heading). The model was significant for placement and reaching movement times. These findings suggest that 14-month-olds can plan their future actions and prospectively control their related movements with respect to future task difficulties.
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| 49. |
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| 50. |
- Gredebäck, Gustaf, et al.
(författare)
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Action Type and Goal Type Modulate Goal-Directed Gaze Shifts in 14-Month-Old Infants
- 2009
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Ingår i: Developmental Psychology. - : American Psychological Association (APA). - 0012-1649 .- 1939-0599. ; 45:4, s. 1190-1194
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Tidskriftsartikel (refereegranskat)abstract
- Ten- and 14-month-old infants' gaze was recorded as the infants observed videos of different hand actions directed toward multiple goals. Infants observed an actor who (a) reached for objects and displaced them, (b) reached for objects and placed them inside containers, or (c) moved his fisted hand. Fourteen-month-olds, but not 10-month-olds, anticipated the goal of reaching actions but tracked all the other actions reactively. Fourteen-month-olds also produced more anticipatory gaze shifts during containment compared with displacement and differentiated between reaching actions dependent on whether the overall goal was to displace objects or place objects inside containers. These results demonstrate that action type and goal type modulate the latency of goal-directed gaze shifts in infants.
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