Biomedical subjects

Joel Ellwanger

Publications and source records attributed to Joel Ellwanger.

4 recordsLinked to original sources

PubMed2006

Processing of own versus other names differentially affects startle reflex modification.

Previous research suggests that the startle eyeblink response may be differentially modified at very short latencies by words that attract more versus fewer attentional resources. These studies were conducted using threat and non-threat words as stimuli. The goal of the present study was to examine whether startle blink modification is similarly affected by differential attention when one's own name versus another name is used as a lead stimulus. Fifty-six undergraduates were presented repeatedly with their own name or another name displayed visually, followed (60, 120, 300, or 2000 ms later) by an acoustic startling noise burst. Startle magnitude was differentially modified by own versus other names, primarily at the 60 and 120 ms lead intervals. Other names demonstrated greater magnitude potentiation at the 60 ms interval and greater magnitude inhibition at the 120 ms lead interval compared with own names, suggesting the startle modification paradigm is sensitive to early attentional processes engaged during the reading of non-threat-related words.

Acoustic Stimulation↗

PubMed2006

Strategic and automatic threat processing in chronic musculoskeletal pain: a startle probe investigation.

Attentional bias research with chronic pain samples has yielded conflicting results. In the present investigation the startle paradigm was used to test the postulate that fear-based mechanisms play an important role in attentional biases for pain-related threat in chronic pain. Participants, including 31 individuals with chronic musculoskeletal pain and 20 healthy controls, completed a startle task designed to measure attention to different types of words (neutral vs sensory pain vs affective pain vs health catastrophe) presented at different levels of cognitive processing (strategic vs automatic). Measures of fear-based individual difference variables, including anxiety sensitivity and fear of pain, were also completed. Startle amplitudes and latencies to acoustic startle probes that followed word presentations were recorded. Data were analyzed with repeated measures ANOVAs and correlational analysis. Significant between-group differences were found indicating that, relative to chronic pain participants, healthy controls had higher startle amplitude index scores for health catastrophe words. There was also a trend among patients with chronic pain for greater startle amplitude index scores for strategic presentations of sensory pain words. In the automatic condition, all participants demonstrated a lower startle latency index for sensory words relative to both affect and health catastrophe words, suggesting participants had more difficulty disengaging from affect and health catastrophe words or were more avoidant of sensory words. Correlational analyses indicated that startle response indices for words related to health catastrophe became more pronounced for chronic pain patients as anxiety sensitivity and fear of pain increased. Implications and directions for future research are discussed.

Acoustic Stimulation↗

PubMed2005

Female schizophrenia patients have prepulse inhibition deficits.

BACKGROUND: Prepulse inhibition (PPI) of startle shows sexual dimorphism: women have lower levels of PPI than do men, and have menstrual cycle shifts in PPI. Many studies report PPI deficits in male schizophrenia patients; one recent report identified PPI deficits in male but not female patients. This study was designed to determine whether female schizophrenia patients have lower levels of PPI than normal females. METHODS: Twenty-five female schizophrenia patients, and 26 normal females were tested in a startle paradigm using 115 dB startle pulses and prepulses of 8 and 16 dB above a 70 dB background, with 30 and 120 msec prepulse intervals. RESULTS: Female patients had significantly less PPI compared with normal females, particularly when 16 dB prepulses were utilized. Patients also exhibited a nonsignificant trend towards lower levels of habituation compared to normal subjects. CONCLUSIONS: Under the present paradigmatic and subject acquisition conditions, female schizophrenia patients had PPI deficits compared to normal females.

Acoustic Stimulation↗

PubMed2003

The relationship of age to prepulse inhibition and habituation of the acoustic startle response.

Prepulse inhibition (PPI) of the startle response reflects an early stage of information processing that is abnormal in schizophrenia and certain other specific neuropsychiatric disorders that are distinguished by the inability to inhibit redundant or relatively irrelevant sensory, cognitive, or motor information. The goal of the present study was to characterize the effect of normal aging on PPI and habituation of the startle response and to examine the hypothesis that normal aging is characterized by a global decline in inhibitory function. Ninety-seven non-psychiatric controls (age range 18-88) were tested for startle eyeblink response using electromyogram (EMG) recording. Startle magnitude decreased and startle latency increased with aging. PPI demonstrated an inverted U-shaped function with age (greatest PPI at intermediate ages) while there was no significant effect of age on startle habituation. The results do not support the theory that aging is associated with a general decline in inhibitory function and contrast with previous studies that have compared only extreme age groups and have found no effects of age on PPI.

Acoustic Stimulation↗