Biomedical subjects

Heath A Demaree

Publications and source records attributed to Heath A Demaree.

7 recordsLinked to original sources

PubMed2003

Healthy high-hostiles evidence low-alpha power (7.5-9.5Hz) changes during negative affective learning.

The present experiment was designed to better understand the impact of positive and negative emotional processing among low- and high-hostile individuals. Based on previous research which found increased sympathovagal balance among low-hostiles to the negative version of the Affective Auditory Verbal Learning Test (AAVL), it was hypothesized that low-hostiles would experience increased cortical arousal to this stimulus whereas their high-hostile counterparts would not. As expected, low-hostiles experienced significantly reduced low-alpha power (7.5-9.5Hz) relative to high-hostiles during the presentation of the negative AAVL. In a replication of prior research, significant primacy and recency effects were noted for the negative and positive word lists, respectively. Results are discussed in terms of cerebral activation theory and the potential impact of emotional processing among high-hostile individuals and their likelihood to develop coronary heart disease.

Adolescent↗

PubMed2003

The neuropsychology of depression: a literature review and preliminary model.

Neuropsychological research provides a useful framework to study emotional problems, such as depression, and their correlates. This paper reviews several prominent neuropsychological theories. Functional neuroanatomical systems of emotion and depression are reviewed, including those that describe cerebral asymmetries in emotional processing. Following the review, a model that is composed of three neuroanatomical divisions (left frontal, right frontal, and right posterior) and corresponding neuropsychological emotional sequelae within each quadrant is presented. It is proposed that dysfunction in any of these quadrants could lead to symptomatology consistent with a diagnosis of depression. The proposed model combines theories of arousal, lateralization, and functional cerebral space and lends itself to scientific methods of investigation. Accordingly, research, prevention, and treatment programs in accordance with the proposed model may promote an improved understanding of the neuropsychological mechanisms involved in depression.

Brain↗

PubMed2003

Differentiating simple versus complex processing speed: influence on new learning and memory performance.

The current study was designed to examine how the construct of human information processing speed is conceptualized and measured, while also examining the influence of information processing speed on higher cognitive processes (i.e., learning). A mixed medical sample of 92 subjects participated in this study. Subjects underwent a broad-based neuropsychological evaluation, including measures of verbal and visuospatial new learning, spatial and verbal working memory, simple reaction time, choice reaction time, and information processing speed. Principal components factor analysis with varimax rotation resulted in a three-factor solution, comprised of: (1) simple speed/reaction time, (2) complex information processing and new learning, and (3) working memory. Notably, this factor solution identified 2 distinct forms of processing speed--simple and complex information processing speeds. In contrast to the abundance of literature grouping these two constructs together under one term (i.e., processing speed), these results indicate simple and complex speed to be distinct constructs assessed with different neuropsychological instruments. While the expected relationship between complex information processing capacities and working memory abilities was evident in this study, information processing speed also showed a significant relationship with new learning ability. The implications of this intriguing relationship are discussed.

Adult↗

PubMed2003

Quantitative EEG diagnostic confirmation of expressive aprosodia.

Quantitative electroencephalography (QEEG) was used to confirm predictions emanating from the neuropsychological examination of an adolescent with expressive aprosodia. Previous research has indicated that expressive deficits in prosody can be caused by cerebral damage to the right hemisphere region homologous to Broca's area. The neuropsychological evaluation of this individual indicates probable right anterior cerebral dysfunction. Taken together, a priori hypotheses included a relative deficit in cerebral arousal of right-relative to left-frontotemporal regions. EEG results confirm the hypothesis and provide case study evidence for both: (a). right anterior mediation of prosodic expression as well as (b). support for the inclusion of QEEG as part of a clinical neuropsychological evaluation.

Adolescent↗

PubMed2003

Low alpha power (7.5-9.5 Hz) changes during positive and negative affective learning.

There is evidence that the positive and the negative word lists of the Affective Auditory Verbal Learning Test (AAVL) are useful with regard to mood induction. To date, however, changes in brain activation, as indicated by quantitative electroencephalographic recording, have not been examined. Thus, changes in low alpha power (7.5-9.5 Hz) were examined during and after completion of the positive or the negative learning list of the AAVL among 37 undergraduate men and women. Three primary findings from the study include the following: (1) Previously reported recall patterns were replicated; (2) participants who completed the negative list reported a significant decline in mood state at the end of the session; and (3) participants who completed the negative word list evidenced a significant reduction in low alpha power (in comparison with baseline) within the parietal regions. The findings noted above are seemingly counter to contemporary theories of mood regulation (i.e., asymmetrical changes in anterior activity, rather than changes in parietal regions). Although the AAVL may have limited utility as a tool for mood induction, it may serve as a functional tool for examination of the cerebral processes associated with affective verbal memory.

Adolescent↗

PubMed2002

Hostility as a moderator of physical reactivity and recovery to stress.

This experiment was designed to assess differences in physiological reactivity and recovery to stress among low- and high-hostile men. Specifically, 25 low- and 25 high-hostile undergraduates were identified using the Cook-Medley Hostility Scale (Cook & Medley, 1954). To ensure homogeneity, all subjects were right-handed and had a general right hemibody preference, as indicated by a score of +7 or higher on the Coren, Porac, and Duncan Laterality Test (Corer, Porac, & Duncan, 1979). All subjects underwent a traditional cold-pressor stressor test. Physiological measures--heart rate, systolic blood pressure, and diastolic blood pressure--were recorded before the stressor (Prestress), after the stressor (Poststress), and then again 9 min later (Recovery). Increased physiological arousal between pre- and poststress measurements was used as an indicator of reactivity. Subsequent decreases in physiological arousal were used as recover measures. Given the current models of negative emotion and hostility, it was expected that high-hostiles, relative to low-hostiles, would evidence increased physiological arousal and decreased recovery to stress. Interestingly, high-hostiles experienced significantly greater reactivity to stress in heart rate only, and no group differences were found with regard to recovery. Results are discussed in terms of previous research and current models of emotion.

Adult↗

PubMed2002

Asymmetry in hand grip strength and fatigue in low- and high-hostile men.

The present study examined the relationship between hostility level and cerebral hemispheric motor functioning of 70 left-cerebral dominant men. Using the Cook-Medley Hostility Scale, the subject group was divided into thirds: One-third (N = 23) were classified as low-hostile, one-third (N = 23) were classified as high-hostile, and the remainder (N = 24) were excluded from analysis. A hand dynamometer was used to assess hand grip strength, perseveration, and fatigue, as measures of hemispheric motor functioning. Results yielded a hand-by-hostility group interaction, which indicated that high-hostile men evidenced significantly less hand grip strength at the right hand and significantly greater hand grip strength at the left hand relative to low-hostile men. These results suggest that high-hostile men may experience relatively greater right-cerebral arousal relative to their low-hostile counterparts. In other results, both groups showed greater perseveration at the left hand than at the right hand. Both groups also showed significant fatigue across trials at both hands. Analysis also revealed a hand-by-trial interaction, indicating that the right hand fatigued more quickly than the left hand across trials. Resistance to fatigue at the left hand and overestimation or relative imprecision in motor movement at the left hand are discussed in terms of arousal theory. These results and others are cited as contributing inroads into distinguishing between the emotional problems of depression, anxiety, and hostility.

Adult↗