Useful information:

Useful information: • The readings are from 2 text books: 1) Carlson “Physiology of Behavior” latest (10th) edition (2009) and 2) Andreassi “Psychophysiology” 5th edition (2007). • Other readings and most class notes are on my web site:

To get to web site…. • Google J Peter Rosenfeld • On list that GOOGLE brings up , you’ll see Rosenfeld Lab Home Page Find out about current research in the Rosenfeldlab.Get information on groups.psych.northwestern.edu/rosenfeld/home.html *Click it. You’ll see:

Note the buttons • Clicking “publications” or “classes” gets you where you need to be for this course.

If you took 312-1….. • Then clicking “classes” then “312-2” and “Publications” gets you to all non-text assigned readings. That’s all you need to know. • Otherwise, you may want to click”classes”, then “312-1” and go to bottom of page for powerpoint presentations, and review the one called, “2. EEG,ERPs, & relation to single neuronal activity.” and check out the first 29 slides.

If, from “Classes,” you go to the 312-2 site… ….You’ll see the texts, the syllabus, lists of papers, chapters and powerpoint presentations (including this very presentation!) which go with this course. Let’s do for real…

Topic 1: Continuation of Neural Coding from 312-1 • You may recall that we previously subdivided this topic into 3 subtopics: • 1) Sensory coding, 2) Motor coding, 3) Coding of Psychological Events. • We saw that the brain represents sensory events in terms of neuronal firing patterns. Remember the following?

Or what about this?

These are neural representations of somatic sensory sensations… • Of course you read in 312-1 about neuronal representation of visual and auditory events. These are sensory codes. There are also codes for motor events, that is, firing patterns in the motor cortex and elsewhere that correlate with muscle action leading to body movements. These are motor codes.

Now for the almost unmanageably complex and largely unknown neural representations of “pure” psychological events…. • ….such as cognitions associated with emotions(love, hate, sexual arousal, perceptions), memories (real and false), learning (classical-automatic and instrumental), deceptions (altruistic and self-serving), and so on… This giant topic started out with the title, “Neural Coding of Behavior” in the 1950s.

We now refer to this effort also as “Neural Correlates of Behavior.” • Note that word, “Behavior…” (rather than “cognition” which is a much broader and more sensible term). That’s because the 1950s was the heyday at most universities of the Psychological Movement known as “Behaviorism” that dominated academic Psychology.

In case you forgot, here is the Wikipedia definition: • Behaviorism (or behaviourism), also called the learning perspective (where any physical action is a behavior), is a philosophy of psychology based on the proposition that all things that organisms do—including acting, thinking and feeling—can and should be regarded as behaviors.[1] The behaviorist school of thought maintains that behaviors as such can be described scientifically without recourse either to internal physiological events or to hypothetical constructs such as the mind.[2] Behaviorism comprises the position that all theories should have observationalcorrelates but that there are no philosophical differences between publicly observable processes (such as actions) and privately observable processes (such as thinking and feeling).[3]

Now this was crazy, and has been largely replaced by Cognitive Psychology… • But a convenient thing about behaviorism was its simplification of psychological things to observable behavior (omitting invisible thoughts and such). So if you wanted to study the neural substrates of learning, all you had to do was study the “neural correlates of observable behavior,” which is where that term came from.

So the typical experiment in Neural Correlates of Behavior went like this: • OK, you are interested in learning, so pick a standard learning protocol (paradigm): Training animals like cats to run down a maze to get food. 1. Get them hungry via food deprivation. 2. Put them at the ‘start’ end with the food many feet away at the ‘goal’. 3. Define ‘learning’ as the state obtained when they can run through the maze at top speed 5 times in a row with no wrong turns.

How do you study the neural coding of this process? • What neural events do you study? That was easy to answer: There was no method back in the 50s to record action potentials from single neurons in freely moving animals. (It is still not so easy to do.) So you have to study population neural activity such as EEG (spontaneous brain waves) recorded from “chronically implanted” animals.

From Carlson

OK, so back in 50’s we could record EEG from freely moving animals… • But a bigger question is: “From where do you record the EEG?” Well this is a learning experiment so just put the electrodes in the learning center(s). Where’s that?

There’s the problem: In the 50’s • We didn’t know what or where the learning center(s) is (are) and how they connect or how they interact. If we knew that we wouldn't need to do these experiments. So how did the neural correlators in the 50s proceed? They used reason. They reasoned that learning must involve association (ala John Stuart Mill and the British Associationists)..

So clearly, one needed record from places where associations are formed. • Such as association cortices…2-3 in each side?

The special thing about association areas are that in those places… • Different sensory pathways come together and “talk to each other” (synapse on the same neurons), so that one can form an association between say the tone CS and the smell of food as in Pavlovian conditioning—or between bar press and food in Skinnerian conditioning. Any other such places? (Class?)

Yes, reticular formation, so we should put a few electrodes up and down the r.f. too, maybe 4 or 6? (So far, 16 sites) • But learning also involves motivation and reinforcement, so we probably need 2 more on each side of hypothalamus. (total now 20.) • Animals have to see & hear stimuli and smell food, so in those sensory systems, figure to add 12 more to cover thalamus and cortex, bilaterally. We might be now up to 40! Why the exclamation point?

Well 40 wires coming from the animal’s recording socket is a lot. • Rats like this with just 6 wires are not big enough, one must use a cat or dog. In 50’s these head preamps were unavailable. One had to use wires embedded with mercury powder. Very Heavy. A cat with 40 of them would “run” down the maze with head tilted over. But that’s what they did! (Not terribly natural.)

Besides the question of how many electrodes and where to put them.. • ..was the question of what neural events to analyze from the ongoing EEG. • What would a page of ongoing EEG look like, taken from a live subject like a cat?

Here’s page of 14 site’s worth in about 30 sec… This actually is unusually pretty

This is more realistic---but I digress

In the old days, there were no FFTs etc.. • Just amplitude and frequency. • So the old neural correlators of the 1950s would plot amplitude and frequency for each of the 40 brain sites during, say, pre-learning, early learning, mid-learning, asymptote learning, and extinction. The results read like this: “In early learning, the visual cortex amplitude is high but the frequency is low, but the …..etc” It was like the stock market:

“In January, Boeing was up but… Microsoft was low, but Apple was up, but GE was middling while Exxon and ATT were recovering…etc, etc…. In Spring, however, Boeing and Exxon crashed, while Microsoft and GE reached new historic highs….etc etc…”

If every lab got the same results, no matter how complex, well OK. • But in 1961, there were 2 well-known review papers that summarized the neural correlates literature: One: High nervous functions: brain functions and learning ER John - Annual Review of Physiology, • The other: Electrophysiological contributions to the neural basis of learning F Morrell - Physiological Reviews, 1961

These papers both summarized over a thousand studies…. • They both should have ended the neural correlates literature, because both essentially noted the same thing, namely, that no labs replicated themselves, let alone others!!! • The literature did taper off, producing 2 reactions, and 2 new literatures:

The reactions: • 1) The Operant Controlled Neural Event approach: Operant Conditioning of ERP components. • 2) The Cognitive Psychophysiology literature: The less radical and longer lasting carefully controlled scientific study of ERP indicators of psychological events. • (We’ll start with the first reaction now)

The “OCNE” approach began with a paper* outlining this first reaction. The paper involved 3 things: • 1. A systematic critique of the neural correlates literature. • 2. The rather ambitious program outlined in reaction (Note title): 3. An empirical description and demonstration of the method. *The paper was by Fox & Rudell (1968) Science, and is on 312-2 web page, article 9

1. The critique: • A) F&R cited the replicability issues as noted by John and Morrell in the ‘61 reviews. • B) problem of choosing electrode sites and neural parameters for study. • C) Correlation approach: let animals do their own thing and see what neural events from what sites correlate. That’s not controlled science. • D) Time base issues: Learning takes days vs. EEG, ERPs, action potentials that are measured in milliseconds. One cannot make laws connecting things measured in such different units. (The “reduction problem”—see Bergmann, “The Philosophy of Science.” 1966

The OCNE approach was supposed to solve all these problems… • We’ll see if it did (and how) later, after we consider OCNE’s empirical approach, which went something like this: “The old neural correlators wanted to see systematic & reliable brain wave changes by training behavior and looking for brain wave correlates. Why bother? If you want see a brain wave change, TRAIN IT DIRECTLY.”

That is, specify a brain wave variable from some brain site, and operantly condition it like a bar press, by rewarding its occurence. • The following figure, from the F&R ‘68 paper, shows 2 sets of superimposed photicerps (visual eps) elicited by a light flash, recorded from chronically installed electrodes in a freely moving Cat’s visual area 19 (tertiary visual cortex). (Why there? It’s convenient on top.)

The cats had been operated on and electrodes as well as a milk tube …had been installed. They were recovered and each one was run in a chamber (former hollowed out ‘fridge) as the strobe lights flashed every 3 seconds, evoking the eps. The 2 sets of waves shown next are during baseline (A) and training (B) within one day:

The area between the lines had been pre-selected as the critical area, i.e., • F&R had decided that the cat was to lower the amplitude of the EP amplitude between the lines. (They saw that in the naïve cat, this was a variable amplitude.) Every time the cat did so, a computer (6’x3’x3’) detected this and caused a relay to close, delivering ~ 1cc milk through the tube implanted that ended in the roof of the hungry cat’s mouth.

So F & R decided to treat a deviant ERP amplitude like a bar press and give the cat a reward for making them. • These EP amplitudes varied within a bell curve, and F&R rewarded deviant samples in the blue tail at left. They chose rare but occasionally occurring samples with a finite probability (.16) of occurrence.

Of course the cats were able to do it, increasing negativity:

Of course the naysayers said, “well, it’s simply the effect of milk on the EP…” • i.e., the non-contingent or non-associative effect of reinforcement. It isn’t learning. • There was evidence. Others had shown that food or shock affects ERPs. I did myself with Routtenberg. But then how do you explain the following?

Now the cats are making thecriterion segment go UP. they are increasing positivity

The naysayers can’t have it both ways…. • If the unconditional/non-associative effect of milk is making wave go up then the down effects are learning • If the unconditional/non-associative effect of milk is making wave go down then the up effects are learning

Useful information: