Interaction of attention and acoustic factors in dichotic listening for fused words.

Two dichotic listening experiments examined the degree to which the right-ear advantage (REA) for linguistic stimuli is altered by a "top-down" variable (i.e., directed attention) in conjunction with selected "bottom-up" (acoustic) variables. Halwes fused dichotic words were administered to 99 right-handed adults with instructions to attend to the left or right ear, or to divide attention equally. Stimuli in Experiment 1 were presented without noise or mixed with noise that was high-pass or low-pass filtered, or unfiltered. The stimuli themselves in Experiment 2 were high-pass or low-pass filtered, or unfiltered. The initial consonants of each dichotic pair were categorized according to voice onset time (VOT) and place of articulation (PoA). White noise extinguished both the REA and selective attention, and filtered noise nullified selective attention without extinguishing the REA. Frequency filtering of the words themselves did not alter performance. VOT effects were inconsistent across experiments but PoA analyses indicated that paired velar consonants (/k/ and /g/) yield a left-ear advantage and paradoxical selective-attention results. The findings show that ear asymmetry and the effectiveness of directed attention can be altered by bottom-up variables.

Comparison of domain-specific cognitive function after carotid endarterectomy and stenting.

BACKGROUND: Observational data indicate that carotid artery stenting (CAS) is associated with higher incidence of subclinical cerebral microemboli than carotid endarterectomy (CEA). We hypothesized that CEA would be associated with superior performance on detailed domain-specific cognitive testing compared with CAS. METHODS: Patients with >80% asymptomatic carotid artery stenosis were randomized to CEA or CAS with side of stenosis balanced across condition. A robust battery of tests was used to assess the cognitive domains of attention, memory, mood, visual-spatial skills, motor ability, processing speed, and executive functioning ≤10 days preoperatively and postoperatively at 6 weeks and 6 months. Tests were administered using standardized conditions and were scored by individuals blinded to treatment allocation. RESULTS: Baseline cognitive performance was similar between CAS (n = 29) and CEA (n = 31) groups (P > .05). Relative to baseline, verbal and visual memory and attention functions substantially improved in the CAS and CEA groups at 6 months (multiple cognitive tests achieved statistical significance). Compared with CEA, cognitive processing speed (Stroop Color test: 9.0 vs 7.3, P = .04; and Stroop Word test: 9.0 vs 7.4, P = .05) was superior in the CAS group at 6 weeks. Executive functioning (phonemic verbal fluency: 10.6 vs 8.4, P = .043) and motor function (Grooved Pegboard of nondominant extremity: 45.7 vs 38.9, P = .022) were also superior in the CAS group at 6 months. Tests of attention, memory, and visual-spatial skills were similar between CAS and CEA patients at 6 weeks and 6 months. CONCLUSIONS: Carotid revascularization improves memory and attention within the first 6 postoperative months. Compared with CEA, CAS produces improvements in cognitive processing speed, executive functioning, and motor function.

Combat exposure, PTSD symptoms, and cognition following blast-related traumatic brain injury in OEF/OIF/OND service members and Veterans.

Traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD) are frequently documented among the Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn (OEF/OIF/OND) veterans. This study will investigate both combat exposure and PTSD as factors that may influence objective cognitive outcomes following blast-related mild TBI (mTBI). Participants included 54 OEF/OIF/OND veterans who had been exposed to blast and reported symptoms consistent with mTBI and 43 combat-deployed control participants who had no history of blast exposure or TBI. Raw scores from the Controlled Oral Word Association Test, Trail Making Test, Color-Word Interference Test, and Verbal Selective Reminding Test were used to measure cognitive functioning. All participants demonstrated adequate effort on the Word Memory Test. Demographics, injury characteristics, overall intellectual functioning, and total scores from the PTSD Checklist-Civilian Version (PCL-C) and Combat Exposure Scale (CES) were used as the predictors for each cognitive measure. History of mTBI was significantly associated with higher PCL-C and CES scores. Multivariable linear regression, however, showed no significant differences in cognitive performance between groups. The absence of effect of mTBI, PTSD, and combat exposure on cognitive functioning noted in this study may be partially explained by the inclusion of only those participants who passed performance validity testing.

Clinician versus Veteran ratings on the Mayo-Portland Participation Index in veterans with a history of mild traumatic brain injury.

BACKGROUND: The Department of Veterans Affairs is encouraging administration of the Mayo-Portland Adaptability Inventory-4 Participation Index (M2PI) to identify long-term psychosocial outcomes of Operation Enduring Freedom (OEF), Operation Iraqi Freedom (OIF), and Operation New Dawn (OND) Veterans with a history of traumatic brain injury (TBI). OBJECTIVE: To evaluate clinician and Veteran interrater reliability and how response validity influences M2PI item ratings. PARTICIPANTS: A total of 122 OEF/OIF/OND Veterans who reported a history consistent with mild TBI during deployment and were referred for neuropsychological evaluation following Comprehensive TBI Evaluation. DESIGN: Interrater reliability study. MAIN MEASURES: M2PI; Minnesota Multiphasic Personality Inventory-2 Symptom Validity Scale (FBS). RESULTS: Veterans reported greater perceived restrictions than clinicians across all M2PI items and total score. Interrater correlations ranged from rs = 0.27 (residence) to rs = 0.58 (money management) across items, with a total score correlation of rs = 0.60. When response bias was indicated, both Veterans and clinicians reported greater participation restrictions than those reported by Veterans without evidenced response bias. CONCLUSION: Low interrater correlation is consistent with previous findings. As ratings of clinicians and Veterans should not be interpreted as equivalent, documenting the rater's identity is important for interpretation. Using objective indicators of functional outcome may assist clinician raters, particularly when self-report may be biased.

Validation and diagnostic utility of the dementia rating scale in a mixed dementia population.

The Dementia Severity Rating Scale (DSRS), a previously validated caregiver-based measure assessing dementia severity, was recently revised to improve clarity. Our study aims included: (1) identifying the DSRS factor structure, (2) examining the relation between neuropsychological measures, the Mini-Mental State Examination, and clinical diagnoses with the DSRS, and (3) determining the clinical utility of the DSRS in a mixed clinical sample. A total of 270 veterans were referred to a cognitive disorders clinic at a VA medical center and completed neuropsychological, affective, and cognitive screening measures. Caregivers completed the DSRS. Principal components analysis identified a 2-factor solution. After controlling for age and education, memory and language were related to the Cognitive factor, whereas attention, processing speed, visuospatial processing, and executive functioning were related to both Cognitive and Self-Care factors. Neither factors correlated with depression. The total DSRS score was able to differentiate patients by the Mini-Mental State Examination scores and diagnoses of mild cognitive impairment and dementia (mixed vascular Alzheimer, vascular dementia, and Alzheimer disease). A cut-score >15 was optimal for detecting dementia in a mixed clinical sample (sensitivity=0.41, specificity=0.79), with a posttest probability of 74%. This study suggests that the DSRS improves detection of dementia and requires minimal effort to implement.