Vanja Kljajevic’s research while affiliated with University of Oslo and other places

About one-third of stroke survivors experience aphasia, i.e., language dysfunction caused by brain damage. Aphasia affects not only a person's ability to communicate, but it often leads to the inability to return to work, loss of close relationships, diminished quality of life, negative self-perception, and depression. Yet persons with aphasia are globally underserved due to limited access to resources, which limits their chance for recovery. Immersive virtual reality (VR) has the potential to solve this problem and deliver efficient, personalized treatments to millions of people worldwide who need access to rehabilitation services or more flexibility in treatment delivery. To reduce the global burden of stroke experts recommend taking bold, pragmatic actions across all four pillars of stroke quadrangle—surveillance, prevention, acute care, and rehabilitation. Embracing immersive VR-based rehabilitation of poststroke aphasia would be one step in that direction.

The argument for a female advantage in word list learning is often based on partial observations that focus on a single component of the task. Using a large sample (N = 4403) of individuals 13–97 years of age from the general population, we investigated whether this advantage is consistently reflected in learning, recall, and recognition and how other cognitive abilities differentially support word list learning. A robust female advantage was found in all subcomponents of the task. Semantic clustering mediated the effects of short-term and working memory on long-delayed recall and recognition, and serial clustering on short-delayed recall. These indirect effects were moderated by sex, with men benefiting more from reliance on each clustering strategy than women. Auditory attention span mediated the effect of pattern separation on true positives in word recognition, and this effect was stronger in men than in women. Men had better short-term and working memory scores, but lower auditory attention span and were more vulnerable to interference both in delayed recall and recognition. Thus, our data suggest that auditory attention span and interference control (inhibition), rather than short-term or working memory scores, semantic and/or serial clustering on their own, underlie better performance on word list learning in women.

Objectives The variability in patterns of acquisition of literacy and numeracy skills in young children with autism spectrum disorder (ASD) is currently not well understood. In the present study, we investigated these skills in cognitively able children with ASD ages 7–12 years. Methods Using independent samples t test, we compared autistic children’s scores on word reading, spelling, and numerical operations with those of typically developing children in the same age group. A paired-samples t test was used to assess whether reading, spelling, and numerical operations scores were comparable within the ASD group. Finally, we tested whether verbal IQ mediated the effect of diagnostic status on these scores. Results The main findings of the study are that autistic children had worse scores on numerical operations than the control group ( t (54.112) = − 3.326, p = .002, d = − .314), but the groups’ scores were similar in word reading and spelling. The autistic children had significantly better scores on word reading and spelling than on numerical operations. All scores of autistic children were positively associated with their verbal IQ scores. Verbal IQ mediated the effect of diagnostic status on all outcome variables. Conclusion These findings extend current understanding of patterns of acquisition of literacy and numeracy skills in young children with ASD, suggesting a critical role of verbal abilities in the acquisition of numerical skills.

In the present study, we investigated whether interpretation of proverbs differs across the lifespan and if so, whether it is associated with age-related fronto-temporal atrophy. Using a sample of 333 healthy individuals aged 18–89 years, we found a significant effect of age on proverb interpretation [H(2) = 12.001, p = 0.002]: old adults (OA) were better than young adults (YA) (p = 0.002), and so were middle-aged-adults (MA) (p = 0.005). OA and MA had significantly less grey matter (GM) than YA in frontal and temporal lobes bilaterally, and OA less than MA in the right temporal lobe. GM volumes in these regions did not moderate the effect of age on the proverbs scores. The whole-brain analysis of groups’ GM maps revealed that the proverbs scores were associated with more GM in YA relative to OA in the right middle temporal gyrus, which is consistent with evidence on the role of this area in processing of unfamiliar proverbs. Overall, our data suggest that interpretation of proverbs is well preserved in late adulthood, despite considerable age-related cortical atrophy.

This chapter explores perception and conceptualization of space in virtual reality. Some basic notions, such as frames of reference, spatial memory and cognitive map are reviewed and discussed with regard to findings from virtual reality studies. Completing spatial tasks in virtual environments may require more time and cognitive resources than comparable tasks in the physical world, which suggests the use of different strategies and may implicate different neural substrates. Although virtual proxemic patterns largely resemble the proxemic patterns observed in the physical world, they do not quite match them. Some important aspects of experiencing space set apart virtual environments and the physical world, and the main issue remains the extent to which spatial skills acquired in virtual environments are transferable to settings in the physical world.

Successful social interaction requires adherence to social norms, awareness of one’s own behavior and flexibility to adjust it as a social situation unfolds. It also requires the ability to track mental states of others. Since virtual environments afford endless possibilities for interventions in own self, the interplay between such possibilities and our cognitive milieu, biological and sociocultural inheritance may result in virtual selves that are much different from who we generally are, and that relate to others differently, as reflected in use of different relational models in the two types of environments. Furthermore, collaborative virtual environments require virtual togetherness and shared intentionality.

Virtual environments may afford bodies and actions that are not afforded by the physical world, which raises some issues related to virtual-to-real body mapping. In this chapter we discuss the concept of agency and action possibilities, the dual-stream model of visual processing, and the role of the dorsal stream and egocentric coordinates in vision for action. We also discuss the concepts such as hierarchies of the action system, action representation, and intentional action. Since avatars are not cognitive agents, participant’s intention to act, decision when to act, and whether to act or inhibit the action may be compromised by technology-related issues. Finally, we address the concept of joint action and effects of synchronization on dyads and groups, noting similarities and differences in action processing in virtual environments relative to the physical world.

The field of virtual reality research is relatively young and quickly evolving. Proposals on what virtual reality is and how the mind deals with it are continually being refined. In this chapter, we outline a view according to which virtual reality is a tool enabling a unique kind of extension: it extends not only the space in which participants can act, but also their sense of corporeality and more generally the sense of who they are. The illusory transformations in virtual reality may lead, at least temporarily, to changes in participants’ attitudes and behaviors, and sometimes such changes may continue in real life situations. Participants may or may not be aware of such changes. The power of virtual reality is in evoking such responses, despite limitations of current virtual reality technology.