BrainBlog

BrainBlog

Thursday, March 30, 2017

New From Dr. Peggy Mason



A second edition of Dr. Peggy Mason's excellent textbook was published earlier this month. She can be found on Twitter at @neuroMOOC and her MOOC course remains available at Coursera.

Neuropsychology Abstract of the Day: When Self-Report Is Invalid...

From PubMed:

Bowler, R.M., Adams, S.W., Schwarzer, R, Gocheva, V.V., Roels, H.A., Kim, Y., Kircos, C.L., ... Lobdell, D.T. (2017). Validity of self-reported concentration and memory problems: Relationship with neuropsychological assessment and depression. Journal of Clinical and Experimental Neuropsychology, doi: 10.1080/13803395.2017.1301392. [Epub ahead of print]

BACKGROUND: This study investigated the validity of self-reported concentration and memory problems (CMP) in residents environmentally exposed to manganese (Mn). METHOD: Self-report of CMP from a health questionnaire (HQ) and the Symptom Checklist-90-Revised (SCL-90-R) was compared to neuropsychological assessment (Trails A&B; Digit Span; Digit Symbol; Similarities; Auditory Consonant Trigrams, ACT; NAB Memory; Rey-Osterrieth, Rey-O, Delayed). Participants included 146 residents from Ohio exposed to air-Mn, with a modeled average concentration of 0.55 µg m(-)(3) (range = 0.01-4.58).

RESULTS: Residents were primarily White (94.5%), aged 30-64 years (M = 51.24), with a minimum of 10 years of residence (range = 10-64). Ninety-four (65.3%) participants reported concentration problems, and 107 residents (73.3%) reported memory problems. More participants endorsed CMP on the SCL-90-R than on the HQ. The prevalence of self-reported CMP was higher for women than for men (88.4% vs. 68.3%). Point-biserial and Pearson's correlations between self-reported CMP and neuropsychological test scores were nonsignificant and weak for both the HQ (rpb = -.20 to rpb = .04) and the SCL-90-R (r = -.12 to r = .007). Greater levels of depression, anxiety, and female sex predicted having more self-reported CMP on both the HQ and the SCL-90-R. Air-Mn and blood-Mn were not associated with self-reported CMP. Residential distance from the Mn source accounted for a small proportion of variance (sr(2) = .04), although depression remained the largest predictor (sr(2) = .21).

CONCLUSION: These results indicate that self-report of CMP in Mn-exposed residents appear to be invalid when compared to neuropsychological test scores. The participants' misperception of having CMP is associated with less education and higher levels of depression. Neuropsychological assessment is recommended to attain valid results.

DOI: 10.1080/13803395.2017.1301392
PMID: 28353391

Wednesday, March 29, 2017

Neuropsychology Abstract of the Day: Semantic Aphasia

From PubMed:

Dragoy, O., Akinina, Y., & Dronkers, N. (2016). Toward a functional neuroanatomy of semantic aphasia: A history and ten new cases. Cortex. doi:10.1016/j.cortex.2016.09.012

Almost 70 years ago, Alexander Luria incorporated semantic aphasia among his aphasia classifications by demonstrating that deficits in linking the logical relationships of words in a sentence could co-occur with non-linguistic disorders of calculation, spatial gnosis and praxis deficits. In line with his comprehensive approach to the assessment of language and other cognitive functions, he argued that deficits in understanding semantically reversible sentences and prepositional phrases, for example, were in line with a single neuropsychological factor of impaired spatial analysis and synthesis, since understanding such grammatical relationships would also draw on their spatial relationships. Critically, Luria demonstrated the neural underpinnings of this syndrome with the critical implication of the cortex of the left temporal-parietal-occipital (TPO) junction. In this study, we report neuropsychological and lesion profiles of 10 new cases of semantic aphasia. Modern neuroimaging techniques provide support for the relevance of the left TPO area for semantic aphasia, but also extend Luria's neuroanatomical model by taking into account white matter pathways. Our findings suggest that tracts with parietal connectivity - the arcuate fasciculus (long and posterior segments), the inferior fronto-occipital fasciculus, the inferior longitudinal fasciculus, the superior longitudinal fasciculus II and III, and the corpus callosum - are implicated in the linguistic and non-linguistic deficits of patients with semantic aphasia.

Copyright © 2016 Elsevier Ltd. All rights reserved.

DOI: 10.1016/j.cortex.2016.09.012
PMID: 28277283