Neural network processing and brain chemistry

Cholinergic Neuromodulation Changes Phase Response Curve Shape and Type in Cortical Pyrimidal Neurons (Stiefel, Gutkin, and Sejnowski)

One of the most important and fundamental findings of neuroscience is that neuron behavior is essentially digital: all-or-nothing, on or off, active or resting. The neuron either fires an action potential or not; there's no such thing as a partial action potential. This digital behavior, along with differential elicitation of activity in regions of the brain given exposure to various stimuli, leads to the prevailing hypothesis that the brain is a modular biological computer that processes information through networks of massively-interconnected neurons. A major challenge, then, in describing the link between brain tissue behavior and the needs of the animal in the "real world" is that many stimuli are analog, differing in small degrees sometimes across a wide range of values: sound volume, light brightness, pressure on skin, etc. To represent (and process and react to) analog phenomena, neurons alter their firing rate - often, a strong stimulus elicits a rapid firing of action potentials over a given period of time, whereas a weaker stimulus elicits a slower firing of action potentials. It's also important for the brain to be able to alter these "spike trains" as new stimuli come in, and as they are further processed - the pattern in which these spike trains are altered by new stimuli is called the "phase response curve". The above article demonstrates that certain neurons in the cortex change their phase response curve based on exposure to a very prevalent neurotransmitter, acetylcholine. Demonstrating this sensitivity implicates that neurotransmitters may be involved in more than just the elicitation of an individual action potential; they may, in fact, influence the behavior of entire neural networks, and therefore exert influence over large-scale cognitive function. This is an incredible finding with significant implications on our models for brain states, mind states, and the relationship between the two.

Standards, teachers, and educational concentration gradients

I've been thinking a lot lately about the role of standards in education. In my opinion, my school is experiencing some growing pains with regard to our standards-based approach to the curriculum and grading system. Some of these pains, I think, are related to the complexity of the standards-based approach as well as the incremental fine-tuning that's happened over the years since the standards philosophy was first implemented. I've found myself stepping back a bit and trying to get a sense for the "big picture": what was the intent of the standards movement, how has it been implemented, and what has changed - if anything - as a result? Perhaps some reflection on these questions will help us to find the next step, and offer some guidance to other schools that might be in the process of adopting the standards-based framework.

The overall intent of the standards movement was to reform the educational system such that it would produce better-learned students. The audacity of the goal was commendable, but the many-pronged nature of systemic reform created confusion among constituents in the system itself. Perhaps most importantly - and astonishingly - the stake-holders with the most direct influence on student learning - teachers - received little guidance, training, or support. In essence, teachers were criticized for lackluster production due to didactic pedagogy, yet the policy makers were themselves didactic in their approach to teacher professional development (if and when it even occurred). Unfortunately, this trend seems to be true at my school - subject area standards were articulated and expectations about student learning were raised. However, even though faculty were involved in articulating the standards and setting the expectations, I learned in a faculty meeting this year that not one professional day since that time has been spent on actually helping teachers to improve their practice. We've spent a lot of time making incremental changes to the standards-based policies, but little to none on training for implementing them.

So, what has changed? It might be true that we no longer graduate students who have not met expectations on our standards - but it could also be true that our stated expectations might be different from those actually imposed on students (vis-a-vis late work, make-up work, re-testing with smaller sets of questions, isolating rather than integrating subject area standards, etc.). At that same faculty discussion when we discussed a lack of time spent on developing better pedagogical methods, we also discussed that most of our assignments and teaching methods have not changed since applying the standards-based framework. On a positive note, the standards framework has resulted in a more detailed articulation and consistent implementation of the curriculum. Furthermore, the framework has also resulted in ensuring that the students must, at some point in time, demonstrate some greater-than-zero knowledge of all of the standards.

I think that these are significant results for a complex policy implemented almost exclusively from the top-down. Given that this is a systemic reform movement, and with the goal of improving, I think the next step is to build capacity from the bottom-up. For us, it's critical to start spending some time working with teachers to evaluate and improve pedagogical methods. For schools just starting this process, I'd recommend implementing the standards framework from the top-down and bottom-up right from the beginning. If you must choose due to limited time & resources, I would recommend starting from the bottom-up. Systemic reform is bound to fail if the process isn't integral, and being didactic from the top-down sends a message that is loud, clear: do as I say, not as I do. Building consensus between administration and faculty is critical for the top-down part of the reform, and building capacity among students and faculty is critical for the bottom-up part of the reform. The keystones in the systemic reform are obvious: teachers.

In my role in my school, I need to be involved in both the top-down and bottom-up aspects of the process. I've had plenty of involvement in the top-down part, but in this reflective process I've realized that I need to be more involved in the bottom-up part, too. In my most recent post, I proposed the idea that a source of power for educational systems to effect change in society stems from the concentration gradient of studies and effort that we create across the school/classroom door. Part of the consensus building process should acknowledge the perpetual uphill battle that teachers face, and build the shared vision that the uphill journey is worth the effort. Part of the capacity building process should ensure, as much as possible, that teachers have the energy to put in the effort, and that they are trained to become more and more efficient uphill climbers. Although a clear implication of this model for educational systems is that the there will never be a perfect reform that will "fix schools", and that any reform that is implemented will always be a work in progress, it brings into clear focus the critical role of the teacher in creating the power of the educational system.

Standards-based grading and the role of effort

I've only recently discovered the blog What It's Like on the Inside (check it out, it's great reading for anyone interested in standards-based education). A December 6 post about standards-based grading and effort prompted me to leave my first comment - it helped that I happened to have the time and energy at the moment, too! In writing this comment, I really liked the idea that hit me at the end about the "concentration gradient" of studies and effort between schools and society as a source of power for educational systems to effect societal change (much akin to the findings that electrochemical gradients are a source of energy for cells). I figured I'd publish my thoughts here so that I am more likely to build on them in the future.

So, here's my comment on "There is No Spoon". Thanks, "Science Goddess", for some very thought-provoking posts!

"I work at a school with a standards-based approach, grading and curriculum. I'm only in my second year on the job here, but "late work" and "make up work" are issues that really displease quite a number of our faculty. While I support, to some degree, the separation of effort and outcome, I do think that a complete divide between the two is extremist reductionism and a mistake; so much of the success that we've observed in others and experienced personally as adults comes not only from skill (and sometimes not at all), but almost always from hard work. It's frustrating to deal with teenagers who don't value effort, particularly when so much effort is required for good teaching.

I also think it's important to acknowledge that discipline - in this case, a lower grade - can (possibly) be a learning experience. You're right to point out that high school students aren't college students, but it's also right to point out that effort does matter and that a lack of effort does deserve negative consequences. We only allow students to meet expectations at the lowest level on their late / make-up work -- reserving the higher grades for students who do their work on time and with good quality. We're also making time this year to discuss our policies on effort - what we call "academic initiative" standards - to figure out what we can improve, with the goal of getting more students to meet with more success in their classes (on-time and the first time). We're tossing around ideas of linking effort to eligibility for honor roll, co-curricular participation, and academic support structures ... and maybe even making it a part of the summary grade calculation (yes, we grade each standard individually).

But the simple truth - as Roger points out above - is that we need more effort from more of our students to get the outcomes we desire of and for our students. It is, and should be, an uphill battle - the "concentration" of studies and effort in a school setting should be greater within that community than we find in the general public. Establishing such a "gradient" is the critical source of power that enables educational systems to disrupt the equilibrium state of these variables in society. So the question that I wonder about a lot is: how can I support my faculty in their never-ending uphill journey?