Deficient maturation of aspects of attention and executive functions in early onset schizophrenia

The few existing long-term, neuropsychological follow-up studies of early onset schizophrenia (EOS) patients have reported relative stability in some cognitive functions but abnormal developmental trajectories in verbal memory, set shifting, aspects of attention, and speed of information processing throughout late adolescence into early adulthood. The current 5-year follow-up study compared the development of specific cognitive functions in EOS patients (N = 17) from the time of first-episode to chronic phase with that of healthy controls (N = 38) and secondarily to patients with other early onset, non-organic, non-affective psychoses (EOP) (N = 11). Speed of processing of executive functions, set shifting, and attention improved significantly in the healthy controls and reflected continuous functional maturation during late adolescence and early adulthood. The developmental progression of attention and set shifting but not speed of processing of executive functions was significantly subnormal in EOS patients. Other specific cognitive functions that had attained functional maturity in the healthy controls before or around the time of the baseline assessment showed normal development in EOS patients during the follow-up period, indicating stable cognitive deficits. These results suggest post-onset developmental deficits in two out of the three aspects of attention and executive functions that have protracted maturational trajectories and that overlap the age of onset of EOS. No significant difference in the development of any specific cognitive function was found between the EOS and EOP group

Neurocognitive functions and social functioning in young females with recent-onset anorexia nervosa and recovered individuals

BACKGROUND: Young individuals with anorexia nervosa (AN) or recovered from AN display impairments of social function. To date, however, it is not clear whether they differ from controls with respect to neurocognitive performance and whether those functions contribute to the compromised social function observed in individuals with AN. METHODS: We included 43 young females with first-episode AN, 28 individuals recovered from adolescent-onset AN, and 41 control individuals (14–22 yr), all without comorbid autism spectrum disorder. We compared the performance of participants across groups in seven neurocognitive functions relevant to social functioning: set-shifting, local processing, processing speed, working memory, sustained attention, verbal memory, and verbal abstraction. Further, we tested the association between neurocognitive function and social function, measured by Autism Diagnostic Observation Schedule (ADOS), with an ordinal logistic regression model. RESULTS: First, participants did not differ on any neurocognitive function across groups. Second, only the neurocognitive function “verbal memory” was significantly associated with social function. Higher performance in verbal memory was associated with lower odds of impaired social function. Diagnostic group remained a significant factor, but the absence of an interaction between group and neurocognitive performance indicated that the association between verbal memory and social function was independent of group membership. CONCLUSION: Young individuals with AN and those recovered from AN did not differ from controls with respect to neurocognitive performance. Verbal memory was associated with social function in all groups

Widespread higher fractional anisotropy associates to better cognitive functions in individuals at ultra-high risk for psychosis

In schizophrenia patients, cognitive functions appear linked to widespread alterations in cerebral white matter microstructure. Here we examine patterns of associations between regional white matter and cognitive functions in individuals at ultra-high risk for psychosis. One hundred and sixteen individuals at ultra-high risk for psychosis and 49 matched healthy controls underwent 3 T magnetic resonance diffusion-weighted imaging and cognitive assessments. Group differences on fractional anisotropy were tested using tract-based spatial statistics. Group differences in cognitive functions, voxel-wise as well as regional fractional anisotropy were tested using univariate general linear modeling. Multivariate partial least squares correlation analyses tested for associations between patterns of regional fractional anisotropy and cognitive functions. Univariate analyses revealed significant impairments on cognitive functions and lower fractional anisotropy in superior longitudinal fasciculus and cingulate gyrus in individuals at ultra-high risk for psychosis. Partial least squares correlation analysis revealed different associations between patterns of regional fractional anisotropy and cognitive functions in individuals at ultra-high risk for psychosis compared to healthy controls. Widespread higher fractional anisotropy was associated with better cognitive functioning for individuals at ultra-high risk for psychosis, but not for the healthy controls. Furthermore, patterns of cognitive functions were associated with an interaction-effect on regional fractional anisotropy in fornix, medial lemniscus, uncinate fasciculus, and superior cerebellar peduncle. Aberrant associations between patterns of cognitive functions to white matter may be explained by dysmyelination

Testing a decades’ old assumption : Are individuals with lower sensory gating indeed more easily distracted?

The sensory gating deficits in schizophrenia have been theorized to associate with increased distractibility. We explore the potential associations between sensory and sensorimotor gating and subjective and objective indices of distraction in healthy subjects. Forty healthy males were assessed with the P50 suppression and pre-pulse inhibition of the startle reflex (PPI) paradigms. Additionally, a neurocognitive test battery was administered in a cross-over design: with/without auditory distraction. Significant effects of distraction were found in response inhibition, and verbal working memory and attention. Parameters from the PPI and P50 suppression paradigms were significantly associated with the distractor effects on strategy formation, cognitive inhibition and flexibility, visual short-term memory, and the level of subjective distraction. Subjectively reported distraction was significantly associated with verbal working memory and attention as well as executive and supervisory processes. Sensory and sensorimotor gating efficiency do not reflect the effect of distraction across executive and attention functions i.e. we did not observe a generalized distractor effect. Gating only related to the effect of distraction on strategy formation, cognitive inhibition and flexibility, as well as visual short term memory. Future studies should investigate if gating deficits affect the distractibility of the same specific cognitive functions in patients with schizophrenia

Testing a decades’ old assumption : Are individuals with lower sensory gating indeed more easily distracted?

The sensory gating deficits in schizophrenia have been theorized to associate with increased distractibility. We explore the potential associations between sensory and sensorimotor gating and subjective and objective indices of distraction in healthy subjects. Forty healthy males were assessed with the P50 suppression and pre-pulse inhibition of the startle reflex (PPI) paradigms. Additionally, a neurocognitive test battery was administered in a cross-over design: with/without auditory distraction. Significant effects of distraction were found in response inhibition, and verbal working memory and attention. Parameters from the PPI and P50 suppression paradigms were significantly associated with the distractor effects on strategy formation, cognitive inhibition and flexibility, visual short-term memory, and the level of subjective distraction. Subjectively reported distraction was significantly associated with verbal working memory and attention as well as executive and supervisory processes. Sensory and sensorimotor gating efficiency do not reflect the effect of distraction across executive and attention functions i.e. we did not observe a generalized distractor effect. Gating only related to the effect of distraction on strategy formation, cognitive inhibition and flexibility, as well as visual short term memory. Future studies should investigate if gating deficits affect the distractibility of the same specific cognitive functions in patients with schizophrenia