Unraveling the relations between post-traumatic stress symptoms, neurocognitive functioning, and limbic white matter in pediatric brain tumor patients.

Background: Pediatric brain tumor patients are at risk of developing neurocognitive impairments and associated white matter alterations. In other populations, post-traumatic stress symptoms (PTSS) impact cognition and white matter. This study aims to investigate the effect of PTSS on neurocognitive functioning and limbic white matter in pediatric brain tumor patients. Methods: Sixty-six patients (6-16 years) completed neuropsychological assessment and brain MRI (1-year post-diagnosis) and parents completed PTSS proxy questionnaires (CRIES-13; 1-3 months and 1-year post-diagnosis). Mean Z-scores and percentage impaired (>1SD) for attention, processing speed, executive functioning, and memory were compared to normscores (t-tests, chi-square tests). Multi-shell diffusion MRI data were analyzed for white matter tractography (fractional anisotropy/axial diffusivity). Effects of PTSS on neurocognition and white matter were explored with linear regression models (FDR correction for multiple testing), including age at diagnosis, treatment intensity, and tumor location as covariates. Neurocognition and limbic white matter associations were explored with correlations. Results: Attention (M = -0.49, 33% impaired; P < .05) and processing speed (M = -0.57, 34% impaired; P < .05) were significantly lower than healthy peers. PTSS was associated with poorer processing speed (ß = -0.64, P < .01). Treatment intensity, age at diagnosis, and tumor location, but not PTSS, were associated with limbic white matter metrics. Neurocognition and white matter metrics were not associated. Conclusions: Higher PTSS was associated with poorer processing speed, highlighting the need for monitoring, and timely referrals to optimize psychological well-being and neurocognitive functioning. Future research should focus on longitudinal follow-up and explore the impact of PTSS interventions on neurocognitive performance.

Pediatric traumatic brain injury affects multisensory integration.

OBJECTIVE: To investigate the impact of pediatric traumatic brain injury (TBI) on multisensory integration in relation to general neurocognitive functioning. METHOD: Children with a hospital admission for TBI aged between 6 and 13 years (n = 94) were compared with children with trauma control (TC) injuries (n = 39), while differentiating between mild TBI without risk factors for complicated TBI (mildRF-; n = 19), mild TBI with ≥1 risk factor (mildRF+; n = 45), and moderate/severe TBI (n = 30). We measured set-shifting performance based on visual information (visual shift condition) and set-shifting performance based on audiovisual information, requiring multisensory integration (audiovisual shift condition). Effects of TBI on set-shifting performance were traced back to task strategy (i.e., boundary separation), processing efficiency (i.e., drift rate), or extradecisional processes (i.e., nondecision time) using diffusion model analysis. General neurocognitive functioning was measured using estimated full-scale IQ (FSIQ). RESULTS: The TBI group showed selectively reduced performance in the audiovisual shift condition (p = .009, Cohen's d = -0.51). Follow-up analyses in the audiovisual shift condition revealed reduced performance in the mildRF+ TBI group and moderate/severe TBI group (ps ≤ .025, ds ≤ -0.61). These effects were traced back to lower drift rate (ps ≤ .048, ds ≤ -0.44), reflecting reduced multisensory integration efficiency. Notably, accuracy and drift rate in the audiovisual shift condition partially mediated the relation between TBI and FSIQ. CONCLUSION: Children with mildRF+ or moderate/severe TBI are at risk for reduced multisensory integration efficiency, possibly contributing to decreased general neurocognitive functioning. (PsycINFO Database Record

Impaired Visual Integration in Children with Traumatic Brain Injury: An Observational Study.

BACKGROUND: Axonal injury after traumatic brain injury (TBI) may cause impaired sensory integration. We aim to determine the effects of childhood TBI on visual integration in relation to general neurocognitive functioning. METHODS: We compared children aged 6-13 diagnosed with TBI (n = 103; M = 1.7 years post-injury) to children with traumatic control (TC) injury (n = 44). Three TBI severity groups were distinguished: mild TBI without risk factors for complicated TBI (mildRF- TBI, n = 22), mild TBI with ≥1 risk factor (mildRF+ TBI, n = 46) or moderate/severe TBI (n = 35). An experimental paradigm measured speed and accuracy of goal-directed behavior depending on: (1) visual identification; (2) visual localization; or (3) both, measuring visual integration. Group-differences on reaction time (RT) or accuracy were tracked down to task strategy, visual processing efficiency and extra-decisional processes (e.g. response execution) using diffusion model analysis. General neurocognitive functioning was measured by a Wechsler Intelligence Scale short form. RESULTS: The TBI group had poorer accuracy of visual identification and visual integration than the TC group (Ps ≤ .03; ds ≤ -0.40). Analyses differentiating TBI severity revealed that visual identification accuracy was impaired in the moderate/severe TBI group (P = .05, d = -0.50) and that visual integration accuracy was impaired in the mildRF+ TBI group and moderate/severe TBI group (Ps < .02, ds ≤ -0.56). Diffusion model analyses tracked impaired visual integration accuracy down to lower visual integration efficiency in the mildRF+ TBI group and moderate/severe TBI group (Ps < .001, ds ≤ -0.73). Importantly, intelligence impairments observed in the TBI group (P = .009, d = -0.48) were statistically explained by visual integration efficiency (P = .002). CONCLUSIONS: Children with mildRF+ TBI or moderate/severe TBI have impaired visual integration efficiency, which may contribute to poorer general neurocognitive functioning.

Pediatric Traumatic Brain Injury and Attention Deficit.

BACKGROUND: We investigated the impact of pediatric traumatic brain injury (TBI) on attention, a prerequisite for behavioral and neurocognitive functioning. METHODS: Children aged 6 to 13 years who were diagnosed with TBI (n = 113; mean 1.7 years postinjury) were compared with children with a trauma control injury (not involving the head) (n = 53). TBI severity was defined as mild TBI with or without risk factors for complicated TBI (mild(RF+) TBI, n = 52; mild(RF-) TBI, n = 24) or moderate/severe TBI (n = 37). Behavioral functioning was assessed by using parent and teacher questionnaires, and the Attention Network Test assessed alerting, orienting, and executive attention. Ex-Gaussian modeling determined the contribution of extremely slow responses (lapses of attention) to mean reaction time (MRT). RESULTS: The TBI group showed higher parent and teacher ratings of attention and internalizing problems, higher parent ratings of externalizing problems, and lower intelligence than the control group (P < .05, d ≥ 0.34). No effect of TBI on alerting, orienting, and executive attention was observed (P ≥ .55). MRT was slower in the TBI group (P = .008, d = 0.45), traced back to increased lapses of attention (P = .002, d = 0.52). The mild(RF-) TBI group was unaffected, whereas the mild(RF+) TBI and moderate/severe TBI groups showed elevated parent ratings of behavior problems, lower intelligence, and increased lapses of attention (P ≤ .03, d ≥ 0.48). Lapses of attention fully explained the negative relation between intelligence and parent-rated attention problems in the TBI group (P = .02). CONCLUSIONS: Lapses of attention represent a core attention deficit in children with mild(RF+) TBI (even in the absence of intracranial pathology) or moderate/severe TBI, and relate to daily life problems after pediatric TBI.

Prosodic cues for morphological complexity: the case of Dutch plural nouns.

It has recently been shown that listeners use systematic differences in vowel length and intonation to resolve ambiguities between onset-matched simple words (Davis, Marslen-Wilson, & Gaskell, 2002; Salverda, Dahan, & McQueen, 2003). The present study shows that listeners also use prosodic information in the speech signal to optimize morphological processing. The precise acoustic realization of the stem provides crucial information to the listener about the morphological context in which the stem appears and attenuates the competition between stored inflectional variants. We argue that listeners are able to make use of prosodic information, even though the speech signal is highly variable within and between speakers, by virtue of the relative invariance of the duration of the onset. This provides listeners with a baseline against which the durational cues in a vowel and a coda can be evaluated. Furthermore, our experiments provide evidence for item-specific prosodic effects.

Processing reduced word forms: the suffix restoration effect.

Listeners cannot recognize highly reduced word forms in isolation, but they can do so when these forms are presented in context (Ernestus, Baayen, & Schreuder, 2002). This suggests that not all possible surface forms of words have equal status in the mental lexicon. The present study shows that the reduced forms are linked to the canonical representations in the mental lexicon, and that these latter representations induce reconstruction processes. Listeners restore suffixes that are partly or completely missing in reduced word forms. A series of phoneme-monitoring experiments reveals the nature of this restoration: the basis for suffix restoration is mainly phonological in nature, but orthography has an influence as well.