Really?

Psychophysics and perception research is widely considered to be part of psychology, and has strong, falsifiable theories about how sensory stimuli are encoded and processed. Using purely behavioural methods, psychophysicists figured out that there were three color-sensitive "sensors" and pinned down their properties. I'm not sure it suddenly becomes biology because someone later found the cellular substrate, nor did it become chemistry when someone figured out the structure of opsin.

Likewise, I'd argue that a lot of the learning stuff (e.g., reinforcement learning) also describes the mind's operation in testable and falsifiable ways.

Let me give you an example, from visual perception.

The "Feature Integration Theory" suggests that low-level image features are processed in parallel: you extract information about the color, orientation, and movement in parallel across the entire visual field. However, these representations are separate, and a second, serial process is needed to combine information across the two areas.

This makes a specific, testable predictions. Suppose you're searching for a red triangle. If this shape is embedded in a sea of green triangles, your reaction time shouldn't vary as a function of the green triangles. The same thing should happen if the red triangle is surrounded by red circles--reaction times should be relatively constant regardless of the number of red circles. However, if you need to find a red triangle embedded in a mix of red circles and green triangles, you should a) be slower and b) your reaction time should be a function of the total number of shapes.

I'd argue that this theory is empirical (run the experiment, record reaction times) and about as falsifiable as it gets (it's easy to test the difference in RT. vs. item # slopes).

I'd also argue that this is a computational theory describing how visual search works, without worrying about the underlying implementation of that process. Clearly, it would be interesting to know that too, but it's certainly not necessary. David Marr proposed that cognitive processes could be studied on three levels: computational (what's the problem), algorithmic (what's a way to solve the problem), and implementation (what do the neurons do to run that algorithm), and each level was largely independent of the ones below.

You seem to be missing the point that, no matter how many hypotheses we make about the inner workings of the brain, we cannot turn them into science without either confirming or refuting them by direct examination of the brain itself. As long as we're hypothesizing about mechanisms that remain beyond direct observation, it's speculation. One cannot falsify a speculation.

Psychology doesn't study the brain, it studies the mind.

> I'd argue that this theory is empirical ...

The observation is empirical but the theory isn't. It cannot become science without validation by way of empirical evidence.

https://youtu.be/LIxvQMhttq4?t=32

> I'd also argue that this is a computational theory describing how visual search works, without worrying about the underlying implementation of that process.

Yes -- and because we cannot directly observe the processes we're hypothesizing about, we cannot make them a matter of empirical evidence, therefore we have no basis for falsification.

https://www.britannica.com/topic/criterion-of-falsifiability

Quote: "Criterion of falsifiability, in the philosophy of science, a standard of evaluation of putatively scientific theories, according to which a theory is genuinely scientific only if it is possible in principle to establish that it is false."

> Clearly, it would be interesting to know that too, but it's certainly not necessary.

Only necessary for science, otherwise not important.

On the contrary, the point I'm trying to make is that you can study the processing done by whatever's in your skull (mind, brain, GPU, nanobots, whatever) while being totally agnostic about the underlying hardware. You can develop theories about this, test them, falsify them, and revise them.

Returning to the feature integration theory, it says that during singleton search (red vs. green), reaction times should be constant regardless of the number of items, while reaction time should be a linear function of the number of items when the search involves combining information from multiple feature channels.

You can test this with a junky laptop or even some drawings and a stopwatch. In fact, if you really want, I'll send you a script so you can test it yourself. You can falsify this: just fit lines to the (item count, RT) data and see if the slopes match the predictions. People have, in fact, done this, and have shown that this explanation of visual search isn't quite complete--weird things happen when the target is very rare, for example.

Can you explain exactly what some neuroscience data would add here? Look, I'm not some hardcore dualist. I work in a systems neuroscience group and completely agree that brain-based theories are more interesting than phenomenological ones, which is why I put up with the hours, pay, etc. However, this doesn't make those psychological theories any less valid, nor does it make psychology less of a science.

Anyway, there are lots of other processes that are not directly observable. Gravity, for example, wasn't directly observed until last year. Evolution can't be observed directly either.

> Can you explain exactly what some neuroscience data would add here?

Certainly -- it would move the issue from the metaphysical to the physical realm. That might make it science. There's no science of the metaphysical.

> Anyway, there are lots of other processes that are not directly observable.

Yes, but not scientific ones.

> Gravity, for example, wasn't directly observed until last year.

Orbital mechanics both predicts and observes gravity. Each successful spacecraft journey represents another successful prediction of the physical theory of gravity. Dark Energy shows that a physical gravitation theory can be potentially falsified, a property all self-respecting scientific theories must have.

Gravitational time dilation represents an empirical confirmation of Einstein's General Relativity, our present theory about gravity. To be accurate, the atomic clocks on board GPS satellites must take this time dilation into account (as well as that from Special Relativity).

Einstein rings represent another direct observation of gravity. I think you mean that gravitational waves weren't observed until last year. Predicted long ago, finally observed.

> Evolution can't be observed directly either.

There is copious, empirical evidence for evolution. Start with how and why antibiotics lose their effectiveness over time. Then move on to laboratory studies of the evolution of Drosophila Melanogaster (fruit fly), chosen for its short reproduction cycle. Examples abound, all empirical and falsifiable.

These are all examples of experimental confirmation of empirical theories, all potentially falsifiable by observing nature.

Great--thanks for the examples.

I'm still a little hung up on the metaphysical part though.

Suppose we ignore all the baggage around the "mind" and just consider an input/output relationship: a visual stimulus goes in and some response comes out. We can formulate a theory about the transfer function that maps between them, and then test it by applying different stimuli and comparing the observed response with the expected one.

A) Suppose the device is a machine. It initially looks like it responds by beeping when illuminated. However, we falsify this theory by finding different patterns of light and dark, some of which cause the machine to beep and others that don't, falsifying that theory. However, it suggests that some feature of the image may matter, so we test it to see if varying the color of the light matters (it doesn't), or if the relative spacings of light and dark do matter (it does). We try more features and eventually discover that it responds to every single one of the barcodes we try, but nothing else, and hypothesize that it's a barcode scanner.

B) Suppose we're recording from a single neuron in a rat or cat's brain while the animal views a screen. In early experiments, we discover that cells in this brain area--and this neuron specifically--responds to visual stimuli. We adjust the stimuli and note that it only responds to some of the stimuli, so we construct a quantitative model giving the expected distribution of responses as a function of stimulus features. This suggests more tests of the model--perhaps the model has very limited spatial support and thus claims that far apart stimuli have no effect. We present the animal (and thus, the neuron) with stimuli outside the supported region and, to our surprise, the responses change. We revise the model to include some suppressive interactions, and try again....

C) Suppose we're recording the behavioural responses of a human subject. We show the subject pictures of other humans, and ask them to report whether the individual shown is a man or woman. We hypothesise that certain features in the image guide this decision, so we modify the images to enhance or degrade those features and repeat the experiment. Some of these changes have no effect, others increase or decrease the speed and accuracy with which they respond. So, we modify the images more selectively, or only in certain locations, and repeat the experiment, revising our model as we go.

It seems like you would admit A and B as being "scientific", but think that C is flawed. Is this right?

> Suppose the device is a machine. It initially looks like it responds by beeping when illuminated. However, we falsify this theory by finding different patterns of light and dark, some of which cause the machine to beep and others that don't, falsifying that theory.

But that's not a theory, it's an observation, and it cannot be falsified, only contradicted. We observe the machine's outputs without any deep understanding of the reasons for the behavior or a grasp of why it's acting as it is. Therefore when we draw a conclusion about a repetitive pattern, and make an assertion about the pattern, we could easily be contradicted by another observer seeing a different pattern and drawing a different conclusion. Those are contradictions, not falsifications.

Say we're an alien, visiting earth, and we see cars moving along a road. By observation we conclude that the cars have to stay in line, no one can force their way through all the other cars. It's a "theory".

Then a fire truck appears and does exactly what we asserted could not happen -- it makes all the other cars move out of the way. But our "theory" is not falsified, it's contradicted. A falsification would require (a) a deep understanding of why cars behave the way they do, and (b) a theoretical falsification based on that deep understanding, not simply a new observation that contradicts an old one.

Another example. For a while there was a mental illness called "Asperger Syndrome". It came into being in meetings of psychologists who talked about it, and who eventually voted it into the DSM.

Everybody liked this new mental illness, it became very popular. Some psychologists even claimed that a lot of famous people had it -- Isaac Newton, Thomas Jefferson, Albert Einstein and Bill Gates, to name just a few. This roster of famous "Aspies" made the mental illness even more popular, especially among young people.

Then things got out of control, and people were actually proactively demanding the diagnosis, for themselves and/or their children. The fact that they could collect Social Security disability payments might have been a factor.

Seeing the clamor about this disease and fearing the consequences of a public backlash, the psychologists held another vote and voted Asperger Syndrome out of the DSM (http://www.nytimes.com/2009/11/03/health/03asperger.html).

So, was Asperger Syndrome falsified? No, not at all. It wasn't falsified because it was never more than an observation -- it never had a theoretical basis. As a result, Asperger Syndrome is neither true nor is it false, and anyone can contradict anyone else while discussing it. By the way, the same thing was true about homosexuality about 30 years ago, with the same controversy and the same outcome -- it was a recognized, listed mental illness, then it wasn't.

This is not science. And it won't be until we understand the brain. Understanding the mind is not only not helping, it's an obstacle, because people have come to think of the mind as a cause of behavior, when it's clearly an effect of the workings of the brain, and science can't be based on effects -- it must be based on causes.

> The mind is not a physical thing

I was with you until here. I'd say you were getting religious if you tried to represent the mind as anything other than an emergent physical phenomenon.

> I'd say you were getting religious if you tried to represent the mind as anything other than an emergent physical phenomenon.

A similar argument could be made from the opposite perspective. The mind is not part of nature, of reality. It's an artificial philosophical construct, arising from observations of behavior, and on that basis extrapolating the existence of something for which there's no direct evidence. Not unlike God in that respect.

By definition, an emergent physical phenomenon would be something that ultimately emerged in physical form. The mind cannot do that. I think you're speaking of behavior, which does meet the definition.

I think you're putting a lot of weight on "study the mind" versus "study the brain." Not many psychologists are dualists.

They tend to say "mind" because they want to abstract over the actual hardware--they're interested in studying what happens in the skull, not how it is implemented. This doesn't make it any less scientific than a biologist who studies where birds fly while neglecting the aerodynamics of the birds' wings.

> They tend to say "mind" because they want to abstract over the actual hardware--they're interested in studying what happens in the skull, not how it is implemented.

Yes, but asking what isn't science by itself, which tries to say how a particular observation came about.

Also, psychologists don't really know what's happening inside our skulls. Studying the mind can't tell us what the brain is doing or how, any more than a computer display can tell us how a CPU works -- for the latter, we need access to the source, not its external manifestation.

* If I say, “The night sky is filled with tiny points of light,” I've offered a description. Another observer might contradict my description, for example by emerging from his cave on an overcast night and not seeing any points of light, but the contradicting observation can itself be contradicted on the next clear night, without any chance for resolution. So, apart from being shallow, inconclusive and trivial, it's not science.

* If I say, “Those points of light are distant thermonuclear furnaces like our sun,” I've offered an explanation, one that makes predictions about phenomena not yet observed and that's falsifiable by empirical test. On the basis of this explanation we might build a small-scale star (a fusion reactor) to see if our experiment shows any similarity to the spectra and behavior of stars. This deep explanation represents a theoretical claim that's linked to other areas of human knowledge, predicts phenomena not yet observed and is conclusively falsifiable by comparison with reality (our fusion reactor might fail to imitate the stars). It's science.

> This doesn't make it any less scientific ...

But it does -- one cannot falsify an observation, one can only contradict it.

> This doesn't make it any less scientific than a biologist who studies where birds fly ...

If the biologist only records where the birds flew, it's not science. If he crafts a testable, falsifiable theory about why the birds flew there, that might be science. Science is about crafting theories that go beyond simple observation, that explain them and suggest new phenomena not yet observed.