Research Study Presentation on Color Constancy

Julianna Maisano

10 December 2015
Ana Radonjić: Research Study Presentation on Color Constancy
On Thursday, December 10, 2015 Dr. Ana Radonjić, a Research Associate at the University of Pennsylvania discussed her research on the mechanisms underlying color and lightness constancy using naturalistic stimuli and tasks. It is known that color enables us to judge certain properties of an object. When we look at an object, color from that object is reflected and is projected towards the eye. The surface color of the object reflects some colors, and absorbs all of the rest, hence why we we are only able to perceive the colors that are reflected. Dr. Radonjić spoke of her work on how color guides selection in real-life tasks, as we often choose objects based on their color across a change in illumination (Radonjić, 2015).
There are two different types of photoreceptors located within the retina of the eye, rods which enable us to distinguish between light and dark, and cones which allow us to see color. When the perceived stimulus enters the visual field, the photoreceptors within the eye transduce the sensed stimulus into an electrical signal. The electric signal is directed from the optic nerve to the brain, where a more detailed version of the presented stimulus is perceived. The surface reflectants determine the objects color, however, reflected light is ambiguous in nature.
According to Dr. Radonjić, color is a proxy for achieving a goal. When we are faced with a task of choosing between a fresh piece of salmon and a spoiled piece of salmon, despite being able to smell the difference, we are able to visualize it as well. Color plays in a vital role in our everyday life tasks whether we know it or not. To validate this claim Dr. Radonjić asked subjects to recreate the arrangement of blocks shown in the room on the left, as closely as possible, by replacing the four black blocks shown in the middle room with the blocks chosen from the room on the far right (Figure 1). Subjects were asked to perform this task under a change in illumination. Dr. Radonjić found that similar to real-world tasks, subjects more often than not use the color of the blocks to recreate the arrangement, even though it is never explicitly referred to the subjects prior to performing the task. Dr. Radonjić’s findings suggest that as humans we use color constancy when performing naturalistic tasks (Radonjić et al., 2015).
Overall, I thought that Dr. Radonjić did a fantastic job presenting her research and proved herself to be well versed in the mechanisms of the visual system and how color is perceived. From her talk I learned how reliant upon color and consistent illumination we are as humans. Our visual system is dependent upon perception, however, our cognitive style differences and varying ratios of photoreceptors enable us all to see color differently.
Figure 1: Arrangement of Dr. Radonjić’s block copying task used to analyze color constancy in during naturalistic tasks .

References

Figure 1. (2015). Retrieved from http://www.sas.upenn.edu/~radonjic/research.html

Radonjić, A. (2015, December 10). Color Selection and Color Constancy. Lecture presented at
Research Presentation for the Faculty Position in Social Cultural in Life Sciences Center Room 134, Hartford, CT.

Radonjic, A., Cottaris, N., & Brainard, D. (2015). Color constancy in a
naturalistic, goal-directed task. Journal of Vision, 15, 3-3.

Perception of Space

Tommy Hum-Hyder
Prof. Raskin
Neuroscience Across the Curriculum
November 23, 2015

Perception of Space

On November 23, 2015, Carly Leonard, PhD, a post-doctoral researcher at the University of California at Davis’s Center of Mind and Brain, spoke of the perception of space. She spoke of the historical and subjective perception of the external world, the biological mechanisms of perception, and some abstract principles that evolve from discussions of perception. She began with a brief discussion of the idea of extromission, which was a popular philosophical idea that was endorsed by Plato, Aristotle, and Euclid, among others, which believed that the eyes emitted a “visual fire” and that this light interacted with another body of light to produce the perception of space. Modern physiology tells us that this intuition is incorrect. Rods and cones within the fovea work to transduce photons of light to the optic nerve, which leads to the opening and closing of ion channels to allow for the brain activity to occur within the occipital lobe, extrastriate cortex, etc. However, with this knowledge of basic physiology, over 40% of individuals believe that at least some light is emitted from the eyes in order to visually perceive stimuli. Dr. Leonard used this idea to describe the various times when our perception fails us, and we do not see things that we may suspect that we see. In the “Door” study, researchers found that 50% of people did not notice when the person they were giving directions to was swapped out for another individual as a door passed them by. Leonard then spoke of how her research would run, with her using event related potentials from visuospatial attention with EEG.Her research would essentially prime individuals for a visual stimulus to appear on either the right side or the left side, with the patient having the understanding that the primer would be accurate. However, as trials continue, Leonard would vary the likelihood of the stimulus appearing on the primed side. At which point, the time it takes for the individual to push a key would be recorded to determine how quickly an individual can perceive a stimulus.

Perception

Andrew Hatch
Prof. Raskin
Neuroscience Across the Curriculum
29 November 2015
Lecturer in Perception
What I took away was I am even more oblivious that I previous thought myself to be. More seriously, I was eager to attend these lectures because I find the subject matter really fascinating and I plan to take perception next term. She started off her lecture about visual perception by discussing extromission, which is an idea about how vision works, asserting that light emitted from the eye and light emitted from the sun combine and enable us to see objects. Supported by the ancient Greek philosophers, it was accepted for centuries as scientific fact and a recent study concluded that 40% of people still believe that light comes out of the eye.
Next, she discussed change blindness and transduction, principles I was already familiar with from past classes. On a side note, I did really well with the first change blindness scenario but struggled with the second one even after being told what was changing (there is that classic Andrew obliviousness.)

The Brain, Society, and Disease Transmission

The Brain, Society, and Disease Transmission
Dr. Patricia Lopes
Khaoula Ben Haj Frej

A Dr. Patricia Lopes’ “The Brain, Society, and Disease Transmission” lecture focused on neuroimmonumodulation and more importantly, the social acceptability of being ill. According to the speaker, disease exerts neural and hormonal changes, changes behavior, and that disease-induced changes in behavior are context-dependent. In fact, the “presence of mates, caring for offspring, competing for territories or maintaining social status” can impact how organisms behave in times of illness (Lopes, 2014). This research, though conducted on animals, can provide insight with human significance.
The speaker’s model animal for one study was the finch. Male finches tend to mate to exhaustion when introduced to a new female. In the study, a sick male, injected with LBS, under normal conditions would lie on the floor, acting completely abnormally, with a drastic drop in behavior. However, when introduced to a new female, the sick male completely transformed, moving around the cage and expressing courtship behavior, such as hopping and singing. A novel male had absolutely no effect, so it was the potential of mating which had the effect. These results back-up the claim that “sickness behaviors could be considered a motivational state” (Lopes, 2014). After all, the study animals act differently based on their surroundings and particular factors, whether in captivity or in their natural environment. Other studies involved postpartum parental care, early-age separation from parents, and male territorialism; in all cases, animals, regardless of model, showed different behaviors when ill (or when a partner was ill) in these situations and outside them (Lopes, 2014). Illness impacts behavior, but social “expectations,” if one may call them that for animals, can reverse or alter that impact.
Next, in her lecture, Dr. Lopes discussed how she also looked at the physiology, searching for changes in markers of inflammation in the brain. At this point, the researcher also chose to get more data form the birds, measuring their activity remotely and continuously, by providing them with a small “backpack” that acts somewhat like a smartphone, capable of measuring changes in acceleration. Low levels of acceleration are considered resting, slightly higher was hopping, and high levels were denoted flying. What was found was that birds that spent more time resting when sick had a higher level of immune-defenses but had diminished chances of mating. Those that did not voluntarily partake in sickness behavior pretended to be healthy and had higher chances of mating but also more of a risk of morbidity. As aforementioned, many animals seem to choose this latter option, often males in the presence of females, or others with young in need of care. This study showed the cost/profit balance considered among ill animals (Lopes, 2014).
When selecting a mate, animals produce signals for communication, which send certain signals denoting compatibility and other characteristics. The speaker explained that she decide to look for changes in these signals, this time in mice. Male mice produce ultrasonic vocalizations in the presence of females (or their urine, since it contains darcin, an attractive protein for mating). In this experiment, one male had an induced sickness (through a LPS injection) and another was healthy and they were placed on either side of a female, separated by a wall. Observations were made, then the windows between the animals were opened and they were observed. It was found that the sick male was not able to provide the attractive vocalizations and had lowered darcin levels. Furthermore, the female, after exploring their options, discriminated between the males, and spent more time at the window of the healthy male than the sick one. In this study, the female was able of realizing the cost and profit of mating with either male (Lopes, 2014), and thus chose the most profitable mate.
Why do these studies matter? According to the speaker, more than 50% of diseases come from wildlife and humans have a high amount of interaction with animals, as wildlife and food. Therefore, understanding animal diseases can affect one’s understanding of human illness. For example, disease has been shown to impact mouse social behavior, where a LPS-injected animal becomes removed from the animals within its social group, despite having interacted with them before becoming ill. It was found that this self-imposed isolation allowed for a better fate for the rest of the animals, resulting in less spread of the disease and thus fewer mortalities, than calculated for if interaction levels been higher.

Dr. Patricia Lopes

Andrew Hatch
Prof. Raskin
Neuroscience Across the Curriculum
19 November 2015
Dr. Patricia Lopes Research Presentation
Instantly I found myself stuck by the fact micro organism interact— I probably know that they did, but Dr. Lopes electron microscope images made it all the more real. The topic of social interaction while suffering from illness was fascinating and something I believe Trinity students would enjoy researching. Her research into the role disease has in our social environment, initially conducted in mice, had variables easily convertible to human subjects.
I found Dr. Lopes’ introduction of sick behaviors and subsequent conversation to have significant parallels in the “human world”; most noticeable was slowing of movement and resting behavior. Curiously, she spoke about how these behaviors are integral to the survival of the individual and remain conserved across species. These behaviors, while not essential (in most cases) in the human species, are highly encouraged and also appear to be “hard-wired.”
Perhaps of the greatest interest for me was Dr. Lopes’ research of mating behavior of “sick” zebra fish. In her experiment, Dr. Lopes was able to extract the lipopolysaccharide membrane of a pathogen and inject it into lab animals, producing an inflammatory response without actually making the animal sick: the test subjects showed the classic sick behaviors, despite being perfectly healthy. Across all subjects, male or female, a general drop in activity was noticed.
While alone, males remained near sessile but when a female was introduced they started to get very active and moved around the cage and a majority of the males engaged in courtship behavior, including a call and dance. An increase in activity was true for most animals tested but not all and may correlate to a level of sickness—possible further research?

Luis Martinez

Jonah Meltzer
COLL118-01
Neuro Across the Curriculum
Luis Martinez

Luis Martinez, an assistant professor, with a lab at the University of Minnesota,  visited to  talk about the research that he has conducted thus far. Martinez’s research has largely revolved around the notion of drug abuse in animal models.
In the research that Martinez presented on his visit to Trinity he looked at the whether metabotropic glutamate receptor 5 (mGluR5) is required for the effects of estradiol on locomotor responses to cocaine to take place. The study used ovariectomized rats, which were given injections of cocaine daily. The rats were then tested for locomotor effects on the first and fifth days that they received injections. Two days prior to the locomotor activity tests the rats were also treated with an mGluR5 antagonist and estradiol. The mGluR5 antagonist, MPEP, served to block estradiol’s effect on locomotor sensitization in the rats.
The findings of the study served to establish the role that mGluR5 plays in estradiol’s facilitation of cocaine induced locomotor sensitization. The novel finding shows how estradiol can increase the effect of cocaine induced locomotor sensitization in females. Furthermore, because new data has shown that women exhibit heightened responsiveness to the stimulating and addictive properties of stimulants such as cocaine, the results of this study provide a potential therapeutic target for treating the addictive properties of stimulants in women through the use of the steroid hormone estradiol.
The one drawback that merits further research is the self-administration aspect of the estradiol and mGluR5 treatment for stimulant addiction in women. While the treatment showed promise in its effects on mediating the behavioral sensitization, which is highly correlated to addiction, the rats in this study were not given the choice of whether or not to take the cocaine or treatment to begin with. Therefore, the treatment may have a different effect on females who fall into the population of self-administering drug users. Regardless, this research offered promising results as to a possible treatment for mediating the sex differences of the heightened responsiveness to the stimulating and addictive properties of stimulants.

Social Impetus: Hormones & the Social Brain !

Chloe White

Professor Martinez Lecture
11.15.2015 !
Social Impetus: Hormones & the Social Brain !
Luis Martinez, a Biological Psychology professor at the University of Minnesota (Yay!
Minnesota Pride!), came to Trinity to give a lecture titled “Social Impetus: Hormones & the
Social Brain.” Since he may potentially be a professor at Trinity in upcoming years, Mr.
Martinez gave this lecture in order to explain how he teaches class at the University of
Minnesota, and how he would teach a class here on this subject. When planning a course,
Professor Martinez has two course objectives: the first is to have the students develop a strong
understanding of the subject matter, and the second is to strengthen their critical thinking skills.
By fulfilling these two objectives, Professor Martinez aims to explain to his students the
relationship between hormones, the brain areas they act upon and their role in human social
behavior.
In order to fulfill the first course objective, Professor Martinez initially explained the very
basics of hormones to us. His definition of hormones was “compounds produced and released by
glands which travel throughout the whole body and the brain.” By doing this, hormones
influence many of the most important aspects of our daily lives, such as behaviors and cognitive
processes, as well as more long-term aspects such as reproduction. Specifically, Professor
Martinez finds a lot of interest in oxytocin, such as oxytocin in new romantic couples and other
similar studies. Other ways he helps students develop a strong understanding of the subject
material is to provide historical context and discuss recent and empirical research. In the case of
oxytocin, he would discuss the discovery of oxytocin and how oxytocin can be manipulated in
the brain. Empirical research here would include links between oxytocin and autism, which is
recent research that a lot of students would probably find interest in.
In order to fulfill the second course objective (to strengthen critical thinking skills),
Professor Martinez stated he would have students critically assess scientific literature. He would
do this by having students create small groups and discuss the literature together in class, and
then write some sort of assessing report to be handed in either at the end of class, or for
homework. The emphasis here would be on student-led discussions, which would be based off of
the primary research and review articles given to them.

Wayne Hawley

Jonah Meltzer
COLL118-01
Neuro Across the Curriculum
Wayne Hawley

Wayne Hawley made his way to Trinity to speak on the research that he has conducted thus far in his career. His interests, in regards to neuroendocrinology, revolve around the use of estradiol and G-1 as a treatment to enhance spatial recognition in ovariectomized rats.
Amidst a number of corny sex jokes related to his research, Hawley gave an insightful presentation that mixed his interests in neuroscience with a background in the psychology of psychosocial-sexual behaviors. The talk focused on the idea of spatial novelty, the idea that rats seek the opportunity to find novel areas in which they can nest, mate, and explore. The rats used in his experiment had been ovariectomized, meaning they were female rats that’d had their ovaries removed via a simple surgery. This rat type is often used when designing treatments and cures for diseases such as osteoporosis. The removal of the ovaries most notably results in the loss of production of estrogen.
The rats were given injections of estradiol 24 hours and 48 hours before they were placed in the Y-maze task. The rats were also split into two test groups, one group received 1ug of estradiol, while the second group received a 25ug injection of G-1. The results showed that after exploring the first arm of the maze in their first trial both test groups showed an improvement in their preference for the novel environment. Furthermore, the second test group, which which received 25ug of G-1, showed a greater preference for the novel environment.
The study also found that rats that had performance compromises, such as cholinergic function, that were treated in the same does as the experimental rats showed improvements in acetylcholine levels in the hippocampus when completing spatial memory tasks. This finding has implications in areas of neurodegenerative research such as Alzheimer’s disease, which is characterized by a lack of cholinergic function.

“Gonadal Hormone Signaling and Sexual Behaviors”

Julianna Maisano

17 November 2015
Dr. Wayne Hawley: “Gonadal Hormone Signaling and Sexual Behaviors”
On Tuesday, November 10, 2015 Dr. Wayne Hawley from Franklin & Marshall University presented his current research study entitled, “Gonadal Hormone Signaling and Sexual Behaviors”. To begin, Dr. Hawley noted that reproduction facilitates pair bonding and stimulates the reward pathway within the brain and centrally released oxytocin mediates mating-induced anxiolysis (anxiety) in male rats. Dr. Hawley’s research centers on analyzing gonad hormone signaling and corresponding sexual behaviors in male and female rats.
While it is known that males possess high levels of testosterone, females also produce small amounts of testosterone as well. Both forms of testosterone activate androgen receptors, however only estradiol activates estrogen in females. If a single dose of testosterone is administered shortly after birth to female rats, their anal-gential space size decreases. Subsequently, female rats also exemplify male rat aesthetics when treated with testosterone after birth. Furthermore, cognition also plays a vital role in the process of reproduction. The effect cognition and gonadal hormones on the hippocampus specifically, enable memory tests to be conducted on rats to analyze activity. When one removes the testes in a male rate, the modulation of neurons in the hippocampus, a major center for the consolation of information and memories, is effected (Hawley, 2015).
Dr. Hawley explained that sex has five distinct stages: attraction, motivation, receptivity, copulation, and post-copulation. In his recent research study, Dr. Hawley has discovered that the activation of g-protein coupled receptor 30 is important in developing spatial cognition in female rats. Estrogen levels naturally elevate during the facilitation of long-term spatial recognition in females and the activation of g-protein coupled receptor 30 aids in a female rat’s long-term spatial recognition memory. Subsequently, testosterone facilitates long-term spatial recognition memory in male rats. Dr. Hawley’s research on gonadal hormone signaling during reproduction, allows for the role of hormone receptors and related neuromodulators during sexual modulation to be analyzed to determine if they impact memory for sexual experience, stress, and sexual behaviors (Hawley, 2015).
In his most recent study, Dr. Hawley allowed male rates to freely explore three open chambers for 20 minutes. He hypothesized that males should spend their time in the chamber that is closest to the sexually receptive female. After the 20 minutes has passed, the female is taken out of chamber and is allowed to freely roam, in which the two most likely have sexual encounters. The task is repeated once again, however this time the males spent the majority of their time in the chamber looking for the female in her last know whereabouts for the first ten minutes and search for her in other places for the last the last ten minutes. Dr. Hawley’s new study allows for the role of gonadal hormone signaling and sexual behaviors in male and female rats the be analyzed (Hawley, 2015).
Overall, I thought that Dr. Hawley did a great job presenting his research and proved himself to be extremely knowledge in the reproductive behaviors of rats. From his lecture I learned that despite being gonad hormones, testosterone and estrogen play integral roles in our long-term spatial recognition memory. reliant upon color and consistent illumination we are as humans. Our reproductive is very complex and involves many more structures other than the most important ones to be properly regulated and exercised.
References
Hawley, W. (2015, November 10). Gonadal Hormone Signaling and Sexual Behaviors. Lecture
presented in Life Sciences Center Room 134, Hartford, CT.

Neuroscience and the Humanities

Carsten Lohan
On Tuesday December 1st, the Trinity Institute for Interdisciplinary Studies hosted a well attended lecture titled: Neuroscience and the Humanities. Three speakers each spoke on the notion of memory, and sought to clarify what current scientific knowledge of the brain could tell us about the study of the past. The first speaker, a Trinity professor of Psychology, Elizabeth Casserly, briefed the audience on the more concrete aspects of memory, and how it acts as a function of the brain. She discussed the notion of a concept network as it pertained to the linguistic label of the word ‘cat.’ While that label of ‘cat’ could trigger a concept network of other words or ideas related to a cat, professor Casserly could not remember the name of her grandparents cat, just that it was black in color, and agreeable. As she said this, I had recalled an instance from a week or so earlier where I attempted to draw a floorplan for home I lived in until I was six. Comparing my floorplan with those of other units in the building (from online for sale listings), I had done a very good job of representing the rooms and hallways of my childhood apartment. However, I could not remember the floor it was on for the life of me. This irked me to great avail, and it emphasised what Ms. Casserly had been saying when she mentioned the difference of how memory was encoded in the brain under normal circumstances, and how it was encoded as a ‘flashbulb’ memory. My own autobiographical ‘flashbulb’ memories made me certain of the placement of the dining room table, as I had severely cut myself on it one day as a young child running through the house.
The next speaker, Aaron Seider, a classics professor at Holy Cross gave an interesting viewpoint of memory from the classical greek and roman perspectives. Perhaps the most interesting facet of information I took away from Mr. Seider was his mention of the Roman lawyers and how they had to often remember important details of their cases without notes. They used the method of Loci, where one creates a memory palace and places objects in that space. Sure, I had heard of this practice before (even by name,) but I did not know those of ancient times practiced it. One thing that Seider did not particularly mention was the heavy dependence of oral history in these times, and it’s flawed interpretations (or reinterpretations) of the past.
Yet, I was delighted when Professor Evelien spoke next, with his frequent quotations from German philosopher, Walter Benjamin. Evelien quoted an important line from Benjamin, “Memory is not an instrument for surveying the past but it’s theater. It is the medium of past experience, just as the earth is the medium in which dead cities lie buried. He who seeks to approach his own buried past must conduct himself like a man digging.” While I fully embrace Benjamin’s notion, I simply can not trust memory as the foundation of history. To do so would be dishonest to the past. Memory, as science can tell us, is unreliable. This is a notion I struggle with as a History major. To trust someone’s recollection as fact can prove dangerous. This is why I often place less emphasis on autobiographies of historical figures written later in their life. What would our understanding of American slavery be if we solely relied on the oral testimonials given by former slaves during the 1930’s as part of the WPA Slave Narrative Project? Most of those interviewed were in their 80’s or 90’s at the time, and were only children when emancipated. Thus, it is the task of the historian not to leverage memory as fact, but rather to interpret it through the lens of the past.