Biomedical subjects

R D Vanderploeg

Publications and source records attributed to R D Vanderploeg.

23 records · Page 2Linked to original sources

PubMed1987

Judgments of emotion in words and faces: ERP correlates.

Visual event-related potentials (ERPs) to two types of stimuli (faces and words) were analyzed to determine the effects of the perceived emotional connotations of the stimuli (positive, neutral, or negative) in 10 right-handed normal functioning adult males. Principal component analysis (PCA) of the ERPs reveals 5 factors accounting for over 90% of the ERP waveform variance for both faces and words. In the facial data, two ERP components varied in amplitude according to the perceived emotional connotation of the stimulus. For the P3 component, neutrally rated stimuli produced significantly larger amplitudes than stimuli rated as positive or negative. This effect was lateralized to the left hemisphere. A later positive component, the slow wave (448-616 ms), manifested complementary effects, i.e. faces perceived as positive and negative produced larger amplitudes than those perceived as neutral over the right hemisphere. The verbal stimuli did not result in significant main effects for perceived emotional connotation, but produced subtle connotation-related differences in slow wave topography. Hemispheric asymmetries, unrelated to affective connotation, were evident in the verbal data, manifesting different patterns of lateralization depending on the ERP component. The results suggest that differential processing of emotional connotation affects ERP waveforms and that the effects can be understood in terms of ERP components known to be associated with more general aspects of cognitive processing.

Adult↗

PubMed1987

A reevaluation of the use of the MMPI in the assessment of combat-related posttraumatic stress disorder.

This study attempts to validate previously developed, empirically based Minnesota Multiphasic Personality Inventory (MMPI) decision rules (Keane, Malloy, & Fairbank, 1984) to aid in the diagnosis of combat-related posttraumatic stress disorder (PTSD). Four groups of 21 subjects each were identified: PTSD, psychotic, depressed, and chronic pain. A decision rule based on the standard clinical scales resulted in a correct classification rate (PTSD vs. non-PTSD) of 81% across the four-group sample. An empirically derived MMPI PTSD scale resulted in a correct classification rate of 77%. However, 43% of the PTSD subjects were incorrectly classified as non-PTSD by these rules. Independent, blind sorting of the 84 MMPI profiles by two doctoral-level clinical psychologists resulted in "hit rates" similar to the MMPI decision rules. The present results suggest that the previously derived, empirically based MMPI decision rules for PTSD do scarcely better than chance on correct classification of individuals with PTSD. We suggest that the differential diagnosis of PTSD is difficult because of the wide variety of symptoms in common with other diagnostic groups, and hence the variability of PTSD subjects on psychometric measures. We also suggest that the MMPI decision rules of Keane et al. (1984) may have utility in identifying subgroup(s) of combat-related PTSDs.

Chronic Disease↗

PubMed1987

Relationship between systolic and diastolic blood pressure and cognitive functioning in hypertensive subjects: an extension of previous findings.

The relationship between blood pressure and neuropsychological functioning in a group of 15 male hypertensives (mean age = 51.2 years) was studied. Thirteen of the 15 subjects showed cognitive deficits on a battery of neuropsychological tests. More significant negative correlations were found among test scores and systolic pressure than diastolic pressure. Stepwise multiple regression analyses confirmed significant relationships between both systolic and diastolic blood pressure and neuropsychological status. Following biofeedback training, subjects in whom blood pressure decreased the most showed the greatest improvement in Category Test performance. Findings suggest that level of systolic pressure is a sensitive predictor of hypertensives' intellectual and cognitive status, that it may be better than diastolic level, and that decreasing blood pressure is predictive of reversal of at least some of the cognitive impairments associated with hypertension.

Journal Article↗

PubMed1986

Treatment of posttraumatic stress disorder with relaxation and biofeedback training.

This study investigated the use of biofeedback and relaxation training on six patients with posttraumatic stress disorder (PTSD) referred routinely for biofeedback treatment in a VA medical center. Subjects received between 8 and 14 sessions of training overall, as well as concurrent individual and group therapy. Measures used to assess treatment outcome include pre- and posttreatment MMPI, State-Trait Anxiety Inventory, Beck Depression Inventory, and Multidimensional Health Locus of Control scores, as well as electromyographic and subjective measures of tension within each session. Additionally, an overall posttreatment clinical rating of change and 1- to 2-year follow-up data were obtained for each subject. Slight to marked improvements were demonstrated for each subject, as evidenced by improvements on the State Anxiety Inventory Scale and the Beck Depression Inventory, a decrease in overall MMPI scores, and lowered EMG and subjective tension ratings for all participants. Possible alternative explanations for improvement (situational demand characteristics, regression toward the mean, lack of independent subject evaluation) are described, along with other study limitations. This preliminary investigation suggests that the use of relaxation training and biofeedback may be a particularly useful component within a comprehensive treatment program for this disorder.

Adult↗

PubMed1986

Left-handedness and variant patterns of cerebral organization: a case study.

A left-middle-cerebral artery infarct in a 51-year-old, nonfamilial left-handed man failed to produce aphasia, but did result in imparied visuospatial functioning, construction dyspraxia, mild limb dyspraxia, and temporal/sequential skill dysfunction. The patient also had severe right-sided sensory and body neglect, right-sided hemiparesis, and mildly dysarthric speech. These neuropsychological findings strongly suggest a reversed pattern of cerebral organization. Posterior anatomical size asymmetries were also reversed, in that the right occipitalparietal area was somewhat larger than the left. However, this patient's limb dyspraxia followed no known pattern of cerebral organization. His dyspraxia suggests that control of complex motor skills in nonfamilial left-handers may remain a left-hemisphere or bilaterally represented function, even when other cognitive abilities are reversed.

Journal Article↗