Biomedical subjects

N L Denburg

Publications and source records attributed to N L Denburg.

7 recordsLinked to original sources

PubMed2005

The ability to decide advantageously declines prematurely in some normal older persons.

The prefrontal region of the brain, including the ventromedial sector which supports reasoning and decision-making, may undergo disproportionate aging in some older persons, but the empirical evidence is decidedly mixed. To help resolve this, we tested 80 neurologically and psychiatrically healthy Younger (aged 26-55) and Older (aged 56-85) adults on a "Gambling Task", which provides a close analog to real-world decision-making by factoring in reward, punishment, and unpredictability, yielding a sensitive index of ventromedial prefrontal function. A subset of the Older group manifested a decision-making impairment on the Gambling Task, in spite of otherwise intact cognitive functioning. This finding raises the possibility of disproportionate aging of the ventromedial prefrontal cortex in these individuals. Our finding has important societal and public policy implications (e.g., choosing medical care, allocating personal wealth), and may also help explain why many older individuals are targeted by and susceptible to fraudulent advertising.

Adult↗

PubMed2001

The amygdala's role in long-term declarative memory for gist and detail.

In humans, the emotional nature of stimuli appears to have a complex influence on long-term declarative memory for those stimuli: Whereas emotion enhances memory for gist, it may suppress memory for detail. On the basis of prior studies, the authors hypothesized that the amygdala helps mediate the above 2 effects. Long-term memory for gist and for visual detail of aversive and neutral scenes was assessed in 20 subjects with unilateral amygdala damage and 1 rare subject with bilateral amygdala damage. Comparisons with 2 control groups (15 brain-damaged and 47 healthy) provided evidence that bilateral, but not unilateral, damage to the amygdala results in poorer memory for gist but superior memory for visual details. The pattern of findings provides preliminary support for the idea that the amygdala may help filter the encoding of relevant information from stimuli that signal threat or danger.

Adult↗

PubMed1999

Adult norms for the Rey-Osterrieth Complex Figure Test and for supplemental recognition and matching trials from the Extended Complex Figure Test.

The Rey-Osterrieth Complex Figure Test ("the Rey"; Osterrieth, 1944; Rey, 1941) has accumulated a considerable literature as a test of visual-spatial perception/construction and memory. The Extended Complex Figure Test (ECFT; Fastenau, 1996a, in press-a; Fastenau & Manning, 1992) supplements the Rey with Recognition and Matching trials that follow Copy, Immediate Recall, and Delayed Recall. The Rey and ECFT were administered to 211 healthy adults. Age ranged from 30 years to 85 years (M = 62.9, SD = 14.2), education ranged from 12 years to 25 years (M = 14.9, SD = 2.6), 55% were women, and over 95% were Caucasian. Age and education effects were evident on all trials (Multiple R ranged .23 to .50, p < .05), but education explained minimal variance (usually 2-3%) on copy and memory trials. Gender effects were negligible, if present. Age-appropriate norms are presented using Osterrieth's 36-point scoring, overlapping cells, and convenient tables for converting raw scores to scaled scores.

Adult↗

PubMed1998

Parallel short forms for the Boston Naming Test: psychometric properties and norms for older adults.

Four 15-item and two 30-item short forms for the Boston Naming Test were validated using 108 non-neurological community-dwelling adults, ages 57-85. All forms were administered to all participants (counterbalanced), with no effect of administration sequence on any score. An age effect emerged (Multiple R = .28, p< or =.01). No effects for education or gender were found, nor were there any interactions (p> or = .10). Descriptive data are stratified by age group. Reliability and validity for each form were demonstrated in several ways. These short forms should be very useful as screening instruments and/or as alternate forms for the BNT in test-retest clinical protocols, pre-post experimental designs, and longitudinal research.

Adult↗

PubMed1996

Age differences in retrieval: further support for the resource-reduction hypothesis.

Age differences in processing resources seem salient to age-related declines in secondary (or "recent") memory. Community-dwelling adults (N = 90, ages 30-80) completed 4 memory tests: Wechsler Memory Scale-Revised (WMS-R) Logical Memory (LM), Cowboy Story (CS), WMS-R Visual Reproductions (VR), and Extended Complex Figure Test (ECFT; Fastenau, in press). Two space-capacity measures (WMS-R Digit Span and Visual Memory Span) and 4 processing speed measures (cancellation and mental-tracking tasks) assessed processing resources. A statistical control procedure was used to isolate retrieval efficiency and measures contributions of age and processing resources to retrieval. A negative relationship between age and retrieval efficiency emerged on all measures (p < .05). The age effect was reduced 60% on LM and CS when processing resources were controlled, eliminated for VR, and unchanged on ECFT. It is possible that visual-spatial retrieval requires fewer processing resources than does verbal retrieval.

Adult↗

PubMed1996

Application of psychometric standards to scoring system evaluation: is "new" necessarily "improved"?

Psychometric guidelines are suggested that expand the evaluation of scoring systems beyond the most frequently (and often singly) considered criterion, that of interrater reliability. Principles of reliability and validity are elaborated and discussed with regard to scoring systems. Also addressed are assays for efficiency in applying a new system, the effects of rater proficiency on outcome scores, the comparison of costs and benefits of new scoring systems, and the comparison of a new scoring system to an existing system to demonstrate its advantage. As a timely example to illustrate these principles, a new scoring system is introduced for the Rey-Osterrieth Complex Figure Test and is compared to the most popular scoring system for this test (Lezak, 1983, p. 400). The proposed principles would be relevant to any scoring system that codes subjective behavioral data into objective values.

Adult↗

PubMedDate not supplied

Verbal and nonverbal emotional memory following unilateral amygdala damage.

The amygdala is involved in the normal facilitation of memory by emotion, but the separate contributions of the left and right amygdala to memory for verbal or nonverbal emotional material have not been investigated. Fourteen patients with damage to the medial temporal lobe including the amygdala (seven left, seven right), 18 brain-damaged, and 36 normal controls were exposed to emotional and neutral pictures accompanied by verbal narratives. Memory for both narratives and pictures was assessed with a free recall test 24 h later. Subjects with left amygdala damage failed to show the normally robust enhancement of memory for verbal and nonverbal emotional stimuli. The group with right amygdala damage showed the normal pattern of facilitation of memory by emotion for both verbal and nonverbal stimuli despite an overall reduction in memory performance. Furthermore, subjects with left amygdala damage were disproportionately impaired on memory for emotional narratives as compared with memory for emotional pictures. The latter finding offers partial support for a lateralized and material-specific pattern of the amygdala's contribution to emotional memory.

Amygdala↗