Performance of patients with epilepsy or psychogenic non-epileptic seizures on four measures of effort.

Exaggeration of cognitive symptoms or poor effort on cognitive testing has been addressed primarily in the traumatic brain injury literature. The present investigation aims to extend the evaluation of effort to the epilepsy monitoring setting, where base rates of failure on effort testing remain unknown for patients with intractable epilepsy (ES), psychogenic nonepileptic seizures (PNES), or both conditions (ES+PNES). In addition, this investigation explores how well four measures of effort (DMT, LMT, TOMM, PDRT) distinguish between these diagnostic groups.

Cluster analysis of normal personality traits in patients with psychogenic nonepileptic seizures.

The literature on patients with psychogenic nonepileptic seizures (PNES) suggests that they are a heterogeneous population. This study addresses this heterogeneity by describing subtypes of PNES based on a cluster analysis of normal personality traits in patients with PNES. In addition, the identified PNES subtypes are further described on dimensions of psychopathology as measured by the Minnesota Multiphasic Personality Inventory, Second Edition (MMPI-2), and cognition.

Detection of feigned head injury symptoms on the MMPI-2 in head injured patients and community controls.

MMPI-2 results from 39 moderately to severely head injured (HI) and 44 community volunteer (CV) participants given instructions to feign symptoms or answer honestly during an analog forensic neuropsychological examination were compared. No significant effects for HI or the interaction between the HI and instruction set (IS) factors were noted on either clinical or selected validity scales (F, Fb, Fp, Ds2, FBS). However, the main effect of IS was significant for both clinical and validity scales (median Cohen's d=1.

Head injury and the ability to feign neuropsychological deficits.

This study investigated the possibility that head-injured patients, by virtue of their exposure to medical and legal evaluations, are better able to feign deficits than controls. Both internal and external validity issues were addressed in a malingering simulation using 46 moderately to severely head injured and 46 matched control subjects who were administered a battery of neuropsychological and motivational tests under standard or malingering instructions. Results showed no significant interaction between malingering instructions and head injury status on commonly used motivational tests or neuropsychological tests, nor were the head injured malingerers better able to avoid detection using established cutting scores on motivational tests.

The effects of two motivational manipulations on the neuropsychological performance of mildly head-injured college students.

Recently, much research has focused on the development and utilization of various motivational assessment techniques designed to identify malingered neuropsychological test performance. Other findings have suggested a strong link between the motivation of the subject and the degree to which the neuropsychological test results validly represent the individual's true level of functioning. However, the majority of the empirical work in this area has focused on only one end of the motivational spectrum, decreased motivation.