Influence of Predator Stress on Empathy Helping Behavior in Rats

Previous research on nonhuman social behavior has indicated that rats (Rattus norvegicus) may have the ability to experience empathy and/or enact empathy-like helping behaviors towards conspecifics (i.e., others of the same species). My study further explores this possibility by testing the effects of an environmental stressor on empathy-like helping behavior.

Six pairs of rats, one free (i.e., the “helper”) and one held in a tube which could only be opened from the outside, were placed in an open-field that either did or did not contain the scent of a predator (cat). A second open-field which was dark and contained familiar rat-scented shavings was attached to offer a place of escape to safety for the helper. Over the course of 14 consecutive days, the helpers were observed to determine if they demonstrated empathy-like helping behavior, defined by efforts to free their trapped cagemate (e.g., unlocking the door, sniffing, touching, and rooting inside the tube).

Based on previous findings that rats are more likely to freeze and avoid the possible presence of a predator, I predict that the predator scent should inhibit the helper rats' inclinations towards helping behavior. If the drive to help their cagemates is strong enough, however, helpers may instead overcome the aversiveness of the stressor and display more helping behaviors towards their trapped cagemate than control helpers. A preliminary review of the video data showed that control rats displayed helping behaviors sooner than predator scent rats, but that the helping did not persist. Data analysis is on-going.

Eden Ehrmann & Prof. Erin Colbert White
Summer 2015


Entraining Brain Oscillations to Influence Facial Perception

Relatively little is known about the role of brain oscillations in relation to cognitive function. Oscillations of all frequencies have been associated with most any neural process. However, no conclusive data has been found to support if oscillations are simply emergent – a phenomenon that merely occurs – or if they play a causal role in cognitive functions. To make headway on this problem, we employed entrainment, a technique used to synchronize brain oscillations. Entrainment was achieved by presenting subjects with alternating images of a neutral face and a scrambled face at 4 Hz. Presenting images as such guaranteed that the faces were presented at 2 Hz. After a few seconds of entrainment, a target image of either a face expressing happiness or disgust, or another scramble, was shown in-phase (in time) or out-of-phase (out of time) of the entraining faces and was quickly followed by a masking image. Finally, subjects were asked to identify if the target image was a scramble or a face, and if the face was expressing happiness or disgust.

By monitoring neural activity with electroencephalography (EEG), which records electrical activity in the outer layers of the brain using scalp electrodes, we found that entrainment was successful. Oscillations in the occipital cortex were strongest around 4 Hz, and those in the parietal, central, and frontal cortices were strongest around 2 Hz. We also found that faces shown in-phase were easier to detect than those shown out-of-phase. Thus, our initial results suggest entrainment can influence facial perception. To further understand the influence entrainment can have on neural activity, we will analyze the collected data for differences between event-related potentials – an ERP associated with facial perception – for in-phase faces versus out-of-phase faces.

Rosie Irwin & Prof. David Andresen
Summer 2015


Predicting Attitude Toward Organization Change

This study examined specific components that influence employee attitude toward organizational change. Prior research tested the effects of organizational identity, cultural readiness to change, age, and tenure as variables that predict attitude toward organizational change. While perception of the change is discussed in past research as another potential variable, it has yet to be examined as a mediating variable between the various components and attitude toward organizational change. In this study, we predicted that the mediating variable, perception of organizational change, affects the relation between organizational identity, cultural readiness to change, age, and tenure, and attitude toward organizational change.

To substantiate our prediction, we compiled a survey comprised of items measuring the multiple constructs in the model. The survey addressed the change associated with the transition from Cascade to PeopleSoft servers at the University of Puget Sound. The survey was distributed by the Institutional Research Department to faculty and staff.

We hoped to gain knowledge about the components influencing attitude toward organizational change, for the purpose of more accurately predicting attitude. A better understanding of the effects of organizational change, coupled with more accurate predictions of attitude, could allow the university to take calculated measures during the implementation of future changes for the purpose of gaining a wider acceptance during transitions.

Analysis revealed that an employee’s perception of appropriateness had the most influence on their attitude towards organizational change. This suggests that an employer should emphasize the importance and necessity of a transition in order to maximize the employees’ positive attitude following the organizational change. Data analysis is on going.

Frank Antonio Manibusan & Prof. Sarah Moore
Summer 2015


EEG Investigation of Mirror-Neuron Activity Before and After Conscious Perception of Emotion in Faces

This summer I investigated how the mirror neuron system functions (as indexed by measuring mu-wave suppression with EEG) while unconsciously and consciously determining facial emotions. Mu-wave suppression, specifically the increase in suppression, has been used as an indicator of the Mirror Neuron System which is involved in action interpretation and social understanding. As social interaction occurs or is viewed by an individual, the greater the measured suppression is in the bands of electrical activity between 8 and 13 Hz in the motor cortex. This change in frequency of the mu-waves can then be measured using EEG. For this study participants viewed either a sad, angry, or scrambled face image over a period of 32 seconds while connected to an EEG. Each stimulus began covered with visual noise and lifted to 0% noise, revealing the facial emotion underneath. As the image was revealed participants were instructed to determine which emotion was being expressed at the earliest moment possible, and to indicate their decision by pressing the left (angry), right (sad), or both (scrambled control stimuli) arrow keys simultaneously. This allowed for the examination of the mu-wave suppression occurring throughout the process of becoming consciously aware of a facial emotion. The image was then covered again to 100% visual noise as a way to examine the conscious processing of facial emotions. The study was completed to test two hypotheses for the unconscious processing of facial emotions: that there will be a gradual increase in mu-wave suppression (or increased activity in the Mirror Neuron System) as the participant becomes aware of a facial emotion, or that there will be a significant increase in suppression at the exact moment the participant becomes conscious of the emotion. Due to the experimental design of the study, two additional hypotheses were able to be tested for the conscious processing of facial emotions. First, that there would be no change in mu-wave suppression once the participant is aware of the facial emotion as it is covered with visual noise again after being revealed. The second hypothesis tested is that there would be a gradual reduction in suppression as the image is covered back to 100% noise.

Katie Singsank & Prof. David Andresen
Summer 2015


Stimuli Dependence in Mirror Neuron Systems

My project was on how the location of mirror neuron activity could possibly change depending on the stimuli presented. Mirror neurons are typically activated not only when an individual engages in an action itself, but also when the individual observes another engaging in the same action. The location of mirror neuron activity has typically been attributed to the posterior frontal lobe and the inferior parietal lobe in the human brain, although these findings have not been conclusive across studies. In order to examine how the location of mirror neuron activity might change in response to differing stimuli, participants were presented with images of faces portraying fear and anger emotions and with images of bodies portraying fear and anger while connected to the EEG. I predicted that expressive faces would produce mirror neuron activation in the posterior area of the brain while expressive bodies would produce activation in more centralized areas of the brain.

Rachel Traut & Prof. David Andresen
Summer 2015