2005 Program Abstracts


Gonadal differentiation and baseline behavior in tiger salamanders raised in wastewater

Amy Fabritius, Victoria Henderson, Jenifer Soto, David Derkacs, Angela Schwendiman, Priyanka Shah, Catherine R. Propper.

 Numerous natural and synthetic compounds have the ability to disrupt the natural functioning of endocrine systems in all animals.  Even in very low doses often present in water, these endocrine disrupting compounds (EDCs) can mimic or inhibit numerous hormones, often interfering with normal physiology, especially during development.  We looked at behavior and sex ratio in a wild population of tiger salamander (Ambystoma tigrinum) larvae collected from treated water at the wastewater facility in Sedona, AZ to determine baseline behavioral activity and sex ratios.  Animals were tested for general activity and response to an artificial predation event.  Following behavioral testing, all animals were euthanized, weighed, SVL measured, and the body cavity was opened.  The gonads were exposed and photographed, then removed with the kidney for histological examination.  There were no significant trends in the behavior due to high variability among individuals.  The sex ratio with this sample was not skewed.  This suggests that the water in which these animals were raised does not have strong antiestrogen or androgen-like compounds.


In Search of the ‘Hypnosis Bandwidth’

Michael C. Greene, Larry Stevens, Chris Pearson, Joyce Wu.

 Alpha (8-12Hz) and Theta (4-8Hz) EEG brainwave frequencies have been found in highest magnitudes during states of deep relaxation, serenity, and creative visual imagery¹.  Most research in this arena has yielded rather general results across conventional wavebands, e.g., Alpha or Theta changes in frontal and occipital regions².  However, narrow waveband (e.g., 2 Hz) data has not yet been examined extensively, due in part to the complex nature of such analyses. Precise EEG bandwidth data during states of relaxation and meditation are important for our understanding of the electrocortical changes that occur during such altered states of consciousness, and the technology now exists to make such studies feasible.  Consequently, the present investigation was conducted to discover which specific frequencies are affected during hypnosis and where these changes take place within the brain.

 Poster also presented at:

 48th Annual Scientific Meeting and Workshops of the American Society of Clinical Hypnosis (ASCH) to be held in Orlando, Florida March 24-28, 2006

 37th Annual Meeting of the Association for Applied Psychophysiology and Biofeedback (AAPB) to be held in Portland, Oregon April 6-9, 2006.


Does premaxillary protrusion enhance suction production in smallmouth bass (Micropterus dolomieu)?

Tim Miller, Rebecca Romasco, Alice Gibb.

 Teleosts are the most successful group of aquatic vertebrates and most of these fishes use suction feeding to capture prey.  Upper jaw protrusion (premaxillary protrusion) may contribute to effective suction feeding by increasing the volume of the buccal cavity and decreasing the mouth diameter, thus increasing the overall pressure change inside the head and increasing the velocity of water as it moves into the mouth.  We use smallmouth bass (Micropterus dolomieu) as a model system because they have been shown to be effective suction feeders that exhibit premaxillary protrusion.  We predicted that surgically attaching the premaxilla to the maxilla would result in a decrease in the ability of the smallmouth bass to generate suction and a decrease in prey capture success.  In this experiment, a pressure transducer is inserted into the buccal cavity of smallmouth bass to record pressure changes during feeding.  After several feeding events, the fish receives a surgery where the premaxilla is sutured to the maxilla to prevent premaxillary protrusion.  After another round of feeding events, the fish receives a “sham” surgery consisting of wrapping suture around the premaxilla without attaching it to the maxilla.  During all feeding events, simultaneous video recordings are obtained using a digital-imaging system.  If smallmouth bass produce less suction and have reduced prey capture success with an artificially attached premaxilla, this will support the general hypothesis that premaxillary protrusion enhances suction feeding performance.


Hypnotic Analgesia and the Physiological Processing of Painful Stimuli in High and Low Hypnotizable Individuals

Chris Pearson, S. Lavin, L. Stevens, J. Wu, & M. Greene.

 Twenty-two participants selected for high (N=11) and low (N=11) hypnotizability and previously screened with the Psychological Absorption Scale (PAS), Stanford Group Hypnotic Susceptibility Scale: Form C (SGHSS: C), and the Harvard Group Scale of Hypnotic Susceptibility: Form A (HGSHS: A), were exposed to a cold pressor pain test while EEGs were recorded during counterbalanced conditions of waking relaxation, distraction, and hypnosis.  Subjective Pain reports were taken at a 30- and 60-second interval of each immersion condition using a 0-10 visual analogue scale (VAS).  Results indicated significant decreases in pain scores for hypnosis and distraction and significant increases in high theta, low alpha, and high alpha during hypnotic analgesia compared to distraction for both hypnotizability groups combined, with most prominent effects for low hypnotizables. 


Gunnison Prairie Dog (Cynomys gunnisoni) Alarm Calls in Response to Novel Stimuli

Ken Sterling, Con Slobodchikoff.

Prompted by results from a previous study (Ackers & Slobodchikoff 1999), alarm calls from Gunnison’s prairie dogs (Cynomys gunnisoni) were recorded and analyzed to see if there was a significant difference between calls elicited by various novel stimuli both in respect to shape and differently sized shapes. Previous studies have indicated that prairie dog alarm calls differentiate between predator species (Slobodchikoff et. al. 1986) and even individual predators, as well as encoding such information as color, shape, sex and rate of approach (Slobodchikoff et. al.1991).  While plausible theories can be formulated to explain why this behavior may have evolved, deeper questions would be raised if prairie dogs are shown to differentiate between novel stimuli in their communication.


The biomechanical basis of intramandibular bending: a novel jaw joint facilitates substrate feeding in the Poeciliidae

Rebecca Romasco, Tim Miller, Alice Gibb.

To produce the near 180° gape necessary to maximize grazing behaviors, a novel intramandibular joint between the dentary and angular-articular bones of the lower jaw is needed. This joint has evolved independently in a number of teleost groups and illustrates a convergent adaptation that is often associated with increased plant matter in the diet. To explore the functional significance of intramandibular (IM) kinesis, several species of the family Poeciliidae are used. This group possesses a unique, cartilage based, version of the intramandibular joint. Some Poeciliid species have a flange on the dentary which appears to serve as the mechanism to produce IM kinesis; the anterior region of the jaw is pulled caudally and the jaw flexes about the cartilage. We use Poecilia (Molly), Xiphohorus (Swordtail), and Heterandria (Least “killifish”) to represent the lineages that possess this flange. We use Gambusia (Mosquito fish) to represent the taxa without the flange and Fundulus (Killifish) as an out-group species. Using these models we demonstrate that species within the subfamily Poeciliinae that possess a posterior directed flange on the medial surface of the dentary will produce intramandibular bending during prey capture to facilitate capturing food items from the substrate.

 Poster also presented at:

Society for Integrative and Comparative Biology Annual Meeting January 4-8, 2006 Buena Vista Palace Resort and Spa in the Walt Disney World Resort Orlando, FL


The Effects of Consuming Chocolate or Cacao Nibs on EEG Recordings

Joyce Wu, Larry Stevens, Michael Greene, Chris Pearson.   

 Fifteen participants were exposed to a resting baseline, to anticipatory stimuli for chocolate consumption, and to either .25 or .34 grams/kilogram body weight of ground cacao nibs or processed chocolate, respectively, in capsule form, followed by a 20-minute digestion period.  Nineteen-channel EEGs were recorded at each stimulation phase.  Analysis of the EEG data found a significant decrease in frontal High Theta (6-7.99 Hz) and Low Alpha (8-9.99 Hz) wave bands from baseline to digestion.  It is hypothesized that the decrease in Theta and Alpha activity is due to reduced relaxation and potentially to reduced creativity and imagination.  The present study also found greater significance when participants ingested processed chocolate than when they ingested roasted cacao nibs.  This effect may be due to the enhanced stimulatory effects of sugars in processed chocolate.  Implications for future research are discussed.

 Poster also presented at:

 48th Annual Scientific Meeting and Workshops of the American Society of Clinical Hypnosis (ASCH) to be held in Orlando, Florida March 24-28, 2006

 37th Annual Meeting of the Association for Applied Psychophysiology and Biofeedback (AAPB) to be held in Portland, Oregon April 6-9, 2006.