Does the d2 Test of Attention only assess sustained attention? Evidence of working memory processes involved

Abnormal temporal perception is a hallmark characteristic of schizophrenia associated with cognitive impairment, however the relationship between these functions is yet to be characterised within translational models. Using the maternal immune activation (MIA) rat model, this study investigated the contribution of sustained attention and working memory capacity to temporal perception impairments via operant paradigms. In addition, we also investigated the involvement of L-arginine metabolites in timing and cognition via high performance liquid chromatography and liquid chromatography/mass spectrometry. Principally, we identified that underestimation of interval durations (2-8 s) in MIA rats was related to attentional capacity. MIA rats were found to exhibit impaired working memory maintenance, however this was not related to temporal perception. In addition, we identified evidence of MIA impacting PFC L-arginine metabolites, L-citrulline and putrescine, which both correlated with working memory maintenance impairments. MIA also appeared to produce discrete differences in glutamate levels depending on whether inflammation was incited early or late in gestation (gestation day 10/18). Following late gestation MIA exposure, higher glutamate levels in PFC corresponded with poorer sustained attention capacity. These findings represent the first direct identification of a timing-attention relationship within rodents, and provide clues regarding the potential involvement of elevated dopamine in timing-cognition pathology in schizophrenia. Moreover, we present preliminary evidence that changes in L-arginine metabolism have functional consequences for cognition. These outcomes commend the MIA rat model as a tool for potential future investigations exploring the biological instantiation of timing deficits.

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Education did not interact with major depression on performance of memory tests in acute southern Brazilian in patients

Dementia & Neuropsychologia ◽

10.1590/s1980-57642008dn10100005 ◽

2007 ◽

Vol 1 (1) ◽

pp. 24-31 ◽

Cited By ~ 1

Author(s):

Analuiza Camozzato ◽

Marcelo Pio de Almeida Fleck ◽

Vera Delgado ◽

Marcia Lorena Fagundes Chaves

Keyword(s):

Working Memory ◽

Major Depression ◽

Sustained Attention ◽

Rating Scale ◽

Memory Performance ◽

Remote Memory ◽

Independent Effect ◽

Psychoactive Drugs ◽

Memory Tests ◽

Cognitive Memory

Abstract The relationship of cognitive function to depression in older adults has become a topic of extensive clinical interest and research. Objective: To analyze association between cognitive/memory performance, Major Depression, and education in 206 inpatients from the Psychiatry and Internal Medicine Departments. Methods: Patients were evaluated by the Mini Mental State Examination, a battery of memory tests, and the MontgomeryÅsberg Depression Rating Scale. Depression patients comprised 45 severe and 42 mild/moderate, according to the Montgomery-Asberg scale. The effect of psychoactive drugs was recorded (30% drug-free). Education was measured in years. Cognitive/memory tests assessed five domains: general mental functioning, attention, sustained attention/working memory, learning memory (verbal), and remote memory. An index for memory impairment was created (positivity: 50% of tests below cutoff). Results: The chief effect on worse performance was Major Depression for the domains (age and education adjusted) of attention, learning, remote memory, and general functioning. For the domain "sustained attention and working memory", only severely depressed patients differed from the medical controls (p=.008). Education showed an independent effect on test performances. No interaction between depression and educational status was observed. We also observed an independent effect of psychoactive drugs on some cognitive/ memory domains. Logistic Regression showed Major Depression as the main risk for cognitive impairment. Conclusions: These data demonstrated association of Major Depression with impaired cognitive performance independent of educational attainment or psychiatric medications.

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