Development of visual sustained selective attention and response inhibition in deaf children.

Studies of deaf and hard-of-hearing (henceforth, deaf) children tend to make comparisons with typically hearing children for the purpose of either identifying deficits to be remediated or understanding the impact of auditory deprivation on visual or domain general processing. Here, we eschew these clinical and theoretical aims, seeking instead to understand factors that explain variability in cognitive function within deaf children. A total of 108 bilingual deaf children ages 7-13 years who use both English and American Sign Language (ASL) participated in a longitudinal study of executive function (EF) development. We report longitudinal data from a visual continuous performance task that measured sustained selective attention and response inhibition. Results show that the impact of deafness on these processes is negligible, but that language skills have a positive relationship with both: better English abilities were associated with better selective sustained attention, and better ASL abilities with better response inhibition. The relationship between sustained selective attention and English abilities may reflect the cognitive demands of spoken language acquisition for deaf children, whereas better ASL abilities may promote an "inner voice," associated with improved response inhibition. The current study cannot conclusively demonstrate causality or directionality of effects. However, these data highlight the importance of studies that focus on atypical individuals, for whom the relationships between language and cognition may be different from those observed in typically developing populations.

Visual Sequence Repetition Learning is Not Impaired in Signing DHH Children.

The auditory scaffolding hypothesis states that early experience with sound underpins the development of domain-general sequence processing abilities, supported by studies observing impaired sequence processing in deaf or hard-of-hearing (DHH) children. To test this hypothesis, we administered a sequence processing task to 77 DHH children who use American Sign Language (ASL) and 23 hearing monolingual children aged 7-12 years and found no performance difference between them after controlling for age and nonverbal intelligence. Additionally, neither spoken language comprehension scores nor hearing loss levels predicted sequence processing scores in the DHH group, whereas ASL comprehension scores did. Our results do not indicate sequence processing deficits in DHH children and do not support the auditory scaffolding hypothesis; instead, these findings suggest that factors related to experience with and/or proficiency in an accessible language during development may be more important determinants of sequence processing abilities.

Profiling coping strategies in male and female rats: Potential neurobehavioral markers of increased resilience to depressive symptoms.

Coping strategies have been associated with differential stress responsivity, perhaps providing a valuable neurobiological marker for susceptibility to the emergence of depressogenic symptoms or vulnerability to other anxiety-related disorders. Rats profiled with a flexible coping phenotype, for example, exhibit increased neurobiological markers of emotional regulation compared to active and passive copers (Bardi et al., 2012; Lambert et al., 2014). In the current study, responses of male and female rats to prediction errors in a spatial foraging task (dry land maze; DLM) were examined after animals were exposed to chronic unpredictable stress (CUS). Brains were processed following the DLM training/assessment for fos-activation patterns and several measures of neuroplasticity in relevant areas. Behavioral responses observed during both the CUS and DLM phases of testing suggested that males and females employ different means of gathering information such as increased ambulatory exploration in males and rear responses in females. Fecal samples collected during baseline and following CUS swim exposure revealed higher corticosterone (CORT) in active copers, whereas flexible copers had higher dehydroepiandrosterone (DHEA) and DHEA/CORT ratios, both indications of enhanced emotional regulation. Focusing on the neural analysis, flexible copers exhibited fewer fos-immunoreactive cells in the basolateral amygdala and a trend toward lower activation in the insula while encountering the prediction error associated with the DLM probe trial. Coping profiles also differentially influenced markers of neuroplasticity; specifically, flexible copers exhibited higher levels nestin-immunoreactivity (ir). Further, less hippocampal glucocorticoid receptor-ir was observed in the flexible copers than the active and passive copers. In sum, flexible coping rats exhibited evidence of emotional resilience as indicated by several neurobiological measures; however, despite increased rates of depression and related symptoms reported in human females, sex effects weren't as pervasive as coping strategy profiles in the analysis of neurobiological markers employed in the current study.

Natural-enriched environments lead to enhanced environmental engagement and altered neurobiological resilience.

The mammalian brain has evolved in close synchrony with the natural environment; consequently, trends toward disengagement from natural environments in today's industrialized societies may compromise adaptive neural responses and lead to psychiatric illness. Investigations of rodents housed in enriched environments indicate enhanced neurobiological complexity; yet, the origin of these stimuli, natural vs. manufactured, has not been sufficiently explored. In the current study, groups of rats were exposed to one of three environments: (1) a standard environment with only food and water, (2) an artificial-enriched environment with manufactured stimuli and (3) a natural-enriched environment with natural stimuli. Results indicated that, during the dark phase, natural-enriched animals exhibited longer durations interacting with objects than the artificial-enriched group; further, the natural-enriched group engaged in more social behavior than the other two groups. Both enriched groups exhibited less anxiety in response to a novel object but the natural-enriched rats exhibited less anxiety-typical behavior in response to a predator odor than the other groups. Less fos activation in the amygdala was observed in both enriched groups following a water escape task whereas an increase in fos activation in the nucleus accumbens was observed in the natural-enriched animals. Thus, the current findings indicate the potential importance of exposure to complex environments, especially natural-like habitats, in the maintenance of emotional health, perhaps providing a buffer against the emergence of anxiogenic responses.