A Behavioral Neuroscience Blog containing not-so-random snippets of information of interest to me and my students at Washington College (www.washcoll.edu)
Prior to the SfN conference I challenged readers to try and identify what it is that is represented in the SfN Conference Logo. Tomorrow I'll post the answer.So there is still time to submit your answer as a comment to this post. Here are some hints:
It is found in the cell membrane of some neurons.
It has a ligand binding site - a site where chemical messengers (e.g., neurotransmitters) can bind.
It was a great privilege to attend the 2012 SOMAS Luncheon at the annual SfN meeting yesterday. This is a great program that has supported undergraduate neuroscience instructors in the early stages of their careers and provided funding in support of the collaborative student-faculty research.
The 2012 SOMAS award winners and their students are:
Carlita Favero, Ph.D. Ursinus College
Elizabeth Glater, Ph.D. Harvey Mudd College
Josef G. Trapani, Ph.D. Amherst College
Charles Weaver, Ph.D. Saginaw Valley State University
Sophisticated and highly technical functional brain imaging techniques such as fMRI and PET have revolutionized the cognitive and behavioral neurosciences. These techniques offer a valuable non-invasive means for visualizing, localizing, and quantifying patterns of brain activity. But a recent essay in the journal Nature focuses on what might be the important functions of the baseline brain activity that occurs when subjects in these scanners are instructed to "clear your mind". In such instances brain activity diminishes by just a 1-5%. Some investigators believe that there is much to be learned from examining the resulting patterns in activity in the idling brain (mind). Here are some suggestions that are presented by the essays author, Kerri Smith:
idling brain activity may keep essential neural pathways interconnected.
the activity may be necessary to prime the brain for action
it might be performing essential "off-line" functions related to such processes as memory consolidation.
it may even be that this activity may be "meaningless" - e.g., fMRI actually measures patterns of regional blood flow, not neural activity itself.
However, according to Smith, there is general agreement among most investigators that these are mere guesses (hypotheses). What is more, it is not clear how to devise experiments to test these alternative hypotheses.
Here are some other facts that are shared in the essay:
patterns of intrinsic brain activity differ in distinctive ways between healthy controls and individuals with various brain disorders such as Alzheimer Disease and Autism.
distinctive patterns of intrinsic brain activity at any instant might predispose individuals to respond to ambiguous situations or stimuli.
To illustrate the latter point, Smith summarizes the result of a study (Hesselmann et al., 2008) that is somewhat similar to another I learned about in a recent presentation at the College by Bill Klemm of Texas A&M. Hesselmann et al. compared the intrinsic patterns of brain activity in subjects just before they were presented with some classic ambiguous visual stimuli. When presented with such stimuli subjects might perceive either the image of a face or some other image such as a vase or a reclining woman. According to Klemm what a particular individual is more likely to see initially is relatively constant from one trial to the next – the perception that an individual experiences first tend to be reliably consistent. Another way to say this is that is seems that their brain is prepared (possibly biased) toward perceptions of a particular nature. And in the study by Hesselmann et al. the intrinsic pattern of activity observed in those participants who initially perceive a face was characterized by enhanced activity with a region that is known to play a role in facial perception - the fusiform face area (FFA). The intrinsic activity of their brian just before the stimulus presentation apparently influenced their perceptions.
Are you prepared to step on your accelerator? What hypotheses might you have for the function of intrinsic brain activity? Do you anticipate that such intrinsic activity should resemble activity during mediation or sleep? Please share your hypotheses or ideas for how experiments might be performed to test some hypothesis presented above.
So what did Close have to share in his public presentation? Due to health issues that left Close unable to travel, he appeared via a satellite link from his studio in NYC. For the first half-hour he shared with us the events and circumstances in his life that shaped his art. Among these were, poverty his family experienced, the early death of his father, the influence of his grandmother who herself was housebound by agoraphobia, his great difficulty recognizing faces, his learning disabilities, the mid-career collapse of a spinal artery that left him unable to move below his chest and how it was that art had ultimately "saved his life". How had art done this? Because despite what appeared to be limitations, art allowed him to demonstrate that he still had something he could contribute. There has been something about the accomplishments that Close has attained that has transcended his physical abilities. To me what this may illustrate is just how much will remain to be explained by neuroscience even if we ultimately reach a complete understanding of the biological workings of the brain. While I am usually more comfortable in my own research working from the assumptions of a biological reductionist, the alternative explanations remain both a challenge and an inspiration for pursuing research in the behavioral and neural sciences. In my view, there remains no greater challenge in science than to pursue an understanding of brain function. Yet even should we obtain such an understanding, what might ultimately remain unfathomable will surely be inspiration for the efforts of future neuroscientists. To be a scientists is inevitably to recognize that each answer that is achieved results in an innumerable number of questions that you've likely to have never contemplated. As Close shared, the process of constructing each of his portraits was often more rewarding than the product. Another way of expressing this is that the journey is somehow more enlightening than reaching your destination. In my experience, this is almost always the case. To enhance his journey, at each new phase of Close's career he challenge himself to embark upon a new approach to portraiture - remove color, add it back, add elements ("incremental units") within either a horizontal, diagonal or radial grid. In each instance, the challenge that Close set for himself seemed to me to be much like the challenge before each chemists, physicist or neuroscientist. That challenge is to understand how such incremental units (e.g., each, element, subatomic particle or neuron), which in isolation may seem rather simple, can collectively contribute to something much greater. There is also something inspiring to me, and I hope to my students, about how the collective contributions of a single neuroscientist may ultimately result in achieving a much more comprehensive understanding of the brain and mind than would otherwise be attainable. Today the total number of registrants attending the SfN conference reached nearly 28,000. By the end of the conference that number will probably exceed 30,000. That is very encouraging. Lastly, there are a few things Close shared that piqued my curiosity. For example, he described his face-blindness as a difficulty recognizing three-dementional faces. It was much easier for him to work from two-dimensional photographs of his subjects than the subjects themselves. One of the great quandaries in neuroscience is the Binding Problem -- i.e., how is it that features (elements) that are represented in disparate regions or neural circuits are somehow combined to create a perceptual unity, e.g., a unique facial percept. I wonder if there have been any studies that might indicate that face-blindness might arise in some instances from a deficit in a circuit that is responsible for binding "flat" incremental facial features into a three-dimensional facial percept. Anyone out there know if their is any evidence of this in the neuroscience literature? Notably, most studies of prosopagnosia employ two-deimensional "flat" facial stimuli. Might this mean that the incidence of face-blindness is even more common than is estimated?
Prior to the SfN conference I challenged readers to try and identify what it is that is represented in the SfN Conference Logo. Tomorrow I'll post the answer.So there is still time to submit your answer as a comment to this post.
To illustrate the latter point, Smith summarizes the result of a study (Hesselmann et al., 2008) that is somewhat similar to another I learned about in a recent presentation at the College by Bill Klemm of Texas A&M. Hesselmann et al. compared the intrinsic patterns of brain activity in subjects just before they were presented with some classic ambiguous visual stimuli. When presented with such stimuli subjects might perceive either the image of a face or some other image such as a vase or a reclining woman. According to Klemm what a particular individual is more likely to see initially is relatively constant from one trial to the next – the perception that an individual experiences first tend to be reliably consistent. Another way to say this is that is seems that their brain is prepared (possibly biased) toward perceptions of a particular nature. And in the study by Hesselmann et al. the intrinsic pattern of activity observed in those participants who initially perceive a face was characterized by enhanced activity with a region that is known to play a role in facial perception - the fusiform face area (FFA). The intrinsic activity of their brian just before the stimulus presentation apparently influenced their perceptions.
