Zsuzsa Kaldy

Identification of objects in 9-month-old infants: integrating ‘what’ and ‘where’ information

Following Leslie, Xu, Tremoulet and Scholl (1998), we distinguish between individuation (the establishment of an object representation) and identification (the use of information stored in the object representation to decide which previously individuated object is being encountered). Although there has been much work on how infants individuate objects, there is relatively little on the question of when and how property information is used to identify objects. Experiment 1 shows that 9-month-old infants use shape, but apparently not color, information in identifying objects that are each moved behind spatially separated screens. Infants could not simply have associated a shape with a location or a screen without regard to objecthood, because on alternate trials the objects switched locations/screens. Infants therefore had to bind shape information to the object representation while tracking the objects’ changing location. In Experiment 2, we tested if infants represented both objects rather than ‘sampled’ only one of them. Using the same alternation procedure, infants again succeeded in using shape (but not color) information when only one of the screens was removed ‐ the screen that occluded the first-hidden object (requiring the longer time in memory). Finally, we relate our behavioral findings both to a cognitive model and to recent neuroscientific studies, concluding that ventral ‘what’ and dorsal ‘where’ pathways may be functionally integrated by 9 months.

Visual Context Integration is Not Fully Developed in 4-Year-Old Children

Long-range horizontal interactions supporting contour integration were found to be weaker in children than in adults (Kovács et al, 1999 Proceedings of the National Academy of Sciences of the USA 96 12204–12209). In the present study, integration on a larger scale, between a target and its context was investigated. Contextual modulation of the percept of a local target can be directly measured in the case of geometric illusions. We compared the magnitude of a size contrast illusion (Ebbinghaus illusion or Titchener circles) in children and adults. 4-year-old children and adults performed 2AFC size comparisons between two target disks in the classical Ebbinghaus illusion display and in two other modified versions. We found that the magnitude of the illusion effect was significantly smaller in children than in adults. Our interpretation is that context integration is not fully developed in 4-year-old children. Closer-to-veridical-size estimations by children demonstrate that the perception of the local target is less affected by stimulus context in their case. We suggest that immature cortical connectivity is behind the reduced contextual sensitivity in children.

The neural mechanisms of object working memory: what is where in the infant brain?

The question of how representational capacities develop in humans has been engaging cognitive psychologists for decades. Looking time studies have explored when infants start to show signs of perceiving and remembering the properties of specific objects at specific locations. Here we integrate these findings into the neuroscientific framework of human visual working memory. We suggest that the development of a system involving the temporal cortex, thalamic and hippocampal structures and possibly the dorsolateral prefrontal cortex (later in development) can account for these behavioral results. Our explanation differs from most of the current approaches in developmental science as we put less emphasis on the contribution of lateral prefrontal areas. We discuss shortcomings of the theories that propose a functional subdivision of these areas and their difficulty in accounting for results from monkey lesion and infant studies. We believe that this shift in focus is desirable both in light of what recent results on medial temporal lobe processing reveal about object working memory, and given how well these results fit the behavioral developmental data.

Quantifying attentional effects on the fidelity and biases of visual working memory in young children

Attentional control enables us to direct our limited resources to accomplish goals. The ability to flexibly allocate resources helps to prioritize information and inhibit irrelevant/distracting information. We examined developmental changes in visual working memory (VWM) fidelity in 4- to 7-year-old children and the effects that a distracting non-target object can exert in biasing their memory representations. First, we showed that VWM fidelity improves from early childhood to adulthood. Second, we found evidence of working memory load on recall variability in children and adults. Next, using cues to manipulate attention, we found that older children are able to construct a more durable memory representation for an object presented following a non-target using a pre-cue (that biases encoding before presentation) compared with a retro-cue (that signals which item to recall after presentation). In addition, younger children had greater difficulties maintaining an item in memory when an intervening item was presented. Lastly, we found that memory representations are biased toward a non-target when it is presented following the target and away from a non-target when it precedes the target. These bias effects were more pronounced in children compared with adults. Together, these results demonstrate changes in attention over development that influence VWM memory fidelity.

Toddlers with Autism Spectrum Disorder Can Use Language to Update Their Expectations About the World

This study examined if two-year-olds with ASD can update mental representations on the basis of verbal input. In an eye-tracking study, toddlers with ASD and typically-developing nonverbal age-matched controls were exposed to visual or verbal information about a change in a recently encoded scene, followed by an outcome that was either congruent or incongruent with that information. Findings revealed that both groups looked longer at incongruent outcomes, regardless of information modality, and despite the fact that toddlers with ASD had significantly lower measured verbal abilities than TD toddlers. This demonstrates that, although there is heterogeneity on the individual level, young toddlers with ASD can succeed in updating their mental representations on the basis of verbal input in a low-demand task.

Goal prediction in 2-year-old children with and without autism spectrum disorder: An eye-tracking study: Goal prediction in autism

This study examined the predictive reasoning abilities of typically developing (TD) infants and 2‐year‐old children with autism spectrum disorder (ASD) in an eye‐tracking paradigm. Participants watched a video of a goal‐directed action in which a human actor reached for and grasped one of two objects. At test, the objects switched locations. Across these events, we measured: visual anticipation of the action outcome with kinematic cues (i.e., a completed reaching behavior); goal prediction of the action outcome without kinematic cues (i.e., an incomplete reach); and latencies to generate predictions across these two tasks. Results revealed similarities in action anticipation across groups when trajectory information regarding the intended goal was present; however, when predicting the goal without kinematic cues, developmental and diagnostic differences became evident. Younger TD children generated goal‐based visual predictions, whereas older TD children were not systematic in their visual predictions. In contrast to both TD groups, children with ASD generated location‐based predictions, suggesting that their visual predictions may reflect visuomotor perseveration. Together, these results suggest differences in early predictive reasoning abilities. Autism Res 2018, 11: 870–882.

Editorial: The Cognitive Neuroscience of Visual Working Memory

Visual working memory (VWM) allows us to temporarily maintain and manipulate visual information in order to solve a task. The study of the brain mechanisms underlying this function began more than a half century ago, with Scoville and Milners (1957) seminal discoveries with amnesic patients. As of 2016, more than 4000 studies have examined the brain mechanisms underlying VWM. In this Research Topic, our goal was to bring together perspectives on the cognitive neuroscience of VWM from multiple fields that have traditionally been fairly disjointed: human neuroimaging, electrophysiological and animal lesion studies, both in adults and in development. The classic model of VWM posits that persistent delay activity in the prefrontal cortex is both sufficient and necessary to mediate visual working memory. Riley and Constantinidis contribute a thorough review of relevant primate studies, and provide compelling fresh evidence for it. They also survey a number of alternative models of VWM and conclude that each one can only mediate a limited range of memory-dependent behaviors. They also provide a detailed account of the tissue characteristics that make the prefrontal cortex (PFC) uniquely specialized to support this function. Further support for the classic model is provided by Boschin and Buckley, who enhance it by offering an account of the functions of the frontopolar cortex (FPC) from a series of pioneering lesion and behavioral studies in the non-human primate. Specifically, they suggest that the FPC supports the exploration and evaluation of relative values of novel alternatives, some of which may turn out to be distractors, while the dorsolateral PFC maintains, manipulates, and selects relevant information, rules and strategies for the task at hand. Mansouri et al. review the role of VWM in executive control functions with an emphasis on abstract features, and representations of errors and conflicts in order to make adaptive behavioral adjustments. They note that primate performance in a Wisconsin Card Sorting Task analog is disrupted after lesions of the dorsolateral PFC, orbitofrontal cortex, but also of anterior cingulate cortex. Tsutsui et al. offer an integration of findings on visuospatial WM from two animal models: primates and rodents. Both lesion and

Is there an independent planning system? Suggestions from a developmental perspective

Glover argues that separate representations underlie the planning and the control phase of actions, and he contrasts his model with Goodale and Milner’s perception/action model. Is this representation indeed an independent representation within a more general action system, or is it an epiphenomenon of the interaction between the perception/action systems of the Goodale–Milner model? We contrast the Glover and the Goodale–Milner models in Figure 1. According to our understanding, one of the main differences between them is the way they conceptualize the representation that the motor program is based on. In the Goodale–Milner model (Goodale & Milner 1992), it is the “action” representation of the dorsal stream (Repraction); while in Glover’s model, it is a representation underlying the planning phase (Reprplanning). The two models disagree about the potential effects of visual context on this representation. According to Glover’s model, context has a potentially large effect on Reprplanning, while in the Goodale–Milner theory it does not (or the effect can only be small). Glover also claims that Reprplanning determines certain parameters of the motor program, such as lifting force, posture choice, movement time and grip acceleration, and these parameters can be strongly influenced by illusion effects (see Glover, sect. 2.6.1. para. 4). Not all motor program parameters are under the control of Reprplanning; some – such as maximum grip aperture and pointing accuracy – are driven by Reprcontrol, and these are the parameters that context-induced illusions do not influence. We propose an experiment motivated by our recent developmental studies that could significantly contribute to this issue. We have studied four-year-old children’s and adults’ performance in a 2AFC version of the Ebbinghaus illusion (Titchener circles) task (Kaldy & Kovacs 2003; see also Kovacs 2000). Both children and adults were asked to decide which one of the target circles amidst the context circles appeared larger. The task was entirely perceptual, that is, no action was required toward the target circles. Our results have shown that the magnitude of the illusion effect was significantly smaller in children than in adults, and our interpretation is that visual context integration is not fully developed in fouryear-olds. In terms of the Goodale–Milner model, we found an age-dependent effect of the magnitude of the context-induced illusion on Reprperception. We proposed earlier that the ontogenetic development of the dorsal “action” system is faster than that of the ventral “perception” system in humans (Kovacs 2000). Based on the age-dependent illusion effect on Reprperception, and on the faster maturation of the “action” system, we suggest an experiment that could decide about the independent existence of the “planning” system in Glover’s model. As Glover suggests, there are particular parameters of movement that seem to be affected by illusions because they are determined by Reprplanning. Movement time as measured in the Ebbinghaus illusion is one of those parameters (van Donkelaar 1999). Taking into account the faster Commentary/Glover: Separate visual representations in the planning and control of action BEHAVIORAL AND BRAIN SCIENCES (2004) 27:1 41 Figure 1 (Kaldy & Kovacs). Comparison of the Glover and the Goodale–Milner models. This schematic diagram represents the temporal relations between the two separate visual representations according to the Glover versus the Goodale–Milner model. In our view, the most significant difference is in how the two models conceptualize the acting representation between the beginning of motor planning and action. maturation of planning related areas, the Glover model would predict that children should demonstrate adult-like illusion effects in terms of movement time well before they do in the perceptual version of the Ebbinghaus illusion task. However, the Goodale–Milner model, in the strict sense, does not allow for illusion effects arising from the “action” system; therefore, the origin of the illusion should be in Reprperception. In this case, young children should behave the same way as in the perceptual task: They should demonstrate much smaller illusions than adults. This test would be an interesting way to study the relationship between the two hypothetical concepts, Reprplanning and Reprperception, and the controversial period before the action starts. Action planning in humans and chimpanzees but not in monkeys