Applied neuropsychology. Adult
-
Appl Neuropsychol Adult · Jan 2012
Loss of semantic associative categories in patients with Alzheimer's disease.
Deterioration of semantic memory is one of the primary neuropsychological deficits caused by Alzheimer's disease (AD). In this study, we hypothesize that the breakdown of semantic memory in the mild-to-moderate stage of AD is due to the disruption of the semantic network that links the concepts. Furthermore, the loss of these links is not homogeneous through the semantic association categories (i.e., Superordinate, Contiguity, Part/Whole, Attribute, Function). ⋯ Both controls and patients with AD underwent extensive neuropsychological evaluation and three experimental tasks: (1) Naming Task, (2) Semantic Association Task, and (3) Semantic Knowledge Task. Results showed that: (1) The AD group was significantly different from the normal controls group in all the experimental tasks; (2) the Semantic Association Task was significantly worse than the other tasks; (3) for the AD group, the scores of the Function and Part/Whole association categories were higher than in the other categories; and (4) living stimuli were more impaired than nonliving. These data confirm prior research showing the semantic association is differently impaired in AD patients.
-
Appl Neuropsychol Adult · Jan 2012
Base rates of postconcussion syndrome by method of symptom report.
This study compared the base rate of postconcussion syndrome (PCS) symptoms using three different assessment methods in a nonclinical sample. Seventy-three university students with no history of brain injury or neurological disease reported symptoms experienced during the previous 2 weeks in response to an open-ended question, a structured interview (simulated), and the British Columbia Postconcussion Symptom Inventory (BC-PSI). Statistically significant differences (all p < .001, d = 1.80-3.93, large effect sizes) were found between the number of symptoms reported on all assessment methods, such that participants reported the most PCS symptoms on the BC-PSI (M = 9.45, SD = 2.52), followed by the structured interview (M = 5.58, SD = 2.02), and the open-ended question (M = 1.86, SD = 1.00). ⋯ Findings suggest that method of assessment influences PCS base rates, such that symptom elicitation decreases relative to the reduction in prompting associated with each assessment method. Therefore, different diagnostic conclusions may be drawn depending on method of assessment used. Clinicians need to consider how their chosen assessment method may be influencing the symptoms reported by their patients.