The Semantic Memory of Physicians - and More...

 

I have the somewhat grandiose plan to model psychiatric diagnosis based on the cognition of a physician rather than focusing on the externals.  By the externals I mean classification systems and critiques of classification systems.  At a later date – I might try to comment on how this approach compares with AI.  For now, I will try to keep it focused on human diagnosticians.  I have an interest in this is because I have made and witnessed incredible diagnoses and treatments by physicians and psychiatrists who I have been affiliated with. I don’t think there has been much of a focus on the process.  A secondary consideration is that cognitive neuroscience is a neglected subject in psychiatry and I hope to make the point that should change. I would go as far as suggesting that cognitive neuroscience should be taught to all psychiatrists more urgently than focusing on another DSM.    

Since the early 1970s, memory functions are divided along various lines clinically and functionally. The first division is long term memory and working memory (also called short term memory).  On the long-term side there is a further division to declarative and procedural memory.  Declarative memory is divided into episodic and semantic memory.  Episodic memory is the ability to recall discrete events.  Semantic memory can have a number of graded definitions.  A minimalist definition is factual knowledge independent of the source (7). A definition more informed by recent research in cognitive psychology: “General (encyclopedic) knowledge as well as schematic representations of events distilled from lifelong experiences, retrieved independently from their original spatial or temporal context” (9).  The authors in that case give examples of knowing who wrote the book “1984” and what generally happens at a birthday party.  That naturally raises the question how does all of this freestanding knowledge occur in the first place?  And also – does that imply a connection to episodic memory? In other words, does semantic memory occur when the context surrounding episodic memory is forgotten?

In the case of physicians there is a very long list of formative experiences across the course of one’s career.  The ability to recall them often assists in making diagnoses and provides an advantage over a physician who has not experienced that event.  Semantic memory is about concepts, words, and their relationship independent of a specific event or experience.  It typically consists of a collection of general facts and word meanings.  For example, it would include facts that apples can be red, green, or yellow and what a mechanic does.

Anyone familiar with cognitive screening examinations has probably asked questions focused on semantic memory.  Naming, word similarities, verbal fluency by word generation, general knowledge questions, are all examples. 

The semantic memory of a physician will contain many unique concepts and they will vary based on experience and exposure to clinical scenarios.  The general categories can be described as the following:

1:  Meaningful prior experiences – even though episodic memory stores specific events at specific intervals, semantic memory contains the specific meaning.  In the case of psychiatry an example would be seeing the effects of CMV encephalitis in a major university transplant unit and a decade later seeing similar behavior and consulting on a case in a general community hospital for similar findings.  That similarity triggers non-analytic hypothesis generation.

2:  Prototypes - the patterns noted in the above example can be averaged over a group of patients and those averages can be consolidated into prototypes.  In the above case a psychiatrist may have seen many cases of encephalitis and many cases of meningitis resulting in encephalitis and meningitis prototypes.  Similar prototypes may exist for all major neurological, medical, and psychiatric condition that they have encountered.  Note that the prototype differs from diagnostic criteria (the typical focus) because it is recall of all of the relevant and in many cases unique clinical features that were experienced.

3:  Specific patient memories (exemplars) – all physicians recall specific patients.  These memories are important for non-analytical reasoning like pattern matching.

4:  Knowledge Encapsulation – medicine like most professions is based on a system of graduated learning.  Basic science transitions rapidly into clinical medicine and then into clinical practice and lifelong learning.  At each stage prior knowledge is reorganized in a more efficient way.  In this case – general biomedical knowledge from basic science is organized under higher level concepts. 

An example in one of the references is a person with an infection who is experiencing progressive physiological problems.  At the medical student/basic science level the analysis might proceed from the basic science level and pathophysiology first.  At the clinician level the relevant pathophysiology is organized as sepsis and that provides a more immediate pathway for intervention.  The encapsulation encompasses and efficiently organizes the lower-level information.  At the same time experts must retain a significant amount of that earlier information.  

5:  Illness Scripts – are mental representations of diseases containing three different dimensions.  The first is enabling conditions like risk factors, demographics, predisposition, and context.  The second is fault or underlying pathophysiology.  The third is consequences including signs, symptoms, lab findings, and course or natural history.  Experts have a significant collection of these features.   

One of the questions in this area is what kind of illness script do physicians have?  Should they all be from their particular specialty or should these scripts encompass the totality of their training?  Some authors suggest that the pathophysiological mechanisms from basic science needs to be retained for true expertise – so my conclusion is that the illness scripts from the entirety of a physicians training probably remain relevant.

This is important in psychiatry because the general pathophysiology important in today’s environment was probably not taught is any detail in medical school and most conditions that are not secondary to medical conditions or the effects of drugs do not easily lend themselves to physiological explanations.  I would suggest that medical stability, generalized seizures and seizure variants, increased intracranial pressure, meningitis, encephalitis, cerebral localization, cerebellar dysfunction, peripheral neuropathies, coma, confusion/stupor/delirium, intoxication, and cranial nerve deficits are some of the illness scripts that every psychiatrist must have.

6:  Semantic Qualifiers - every physician has a lexicon of semantic qualifiers acquired in both medical school and post graduate training. They include anatomic descriptions (areas, more specific locations), pathological descriptions, disease course descriptions, and many others. Framing clinical scenarios with these qualifiers is often all that is needed to acquire associations to the disease of interest.

7:   Base rates and Context – experts by way of their clinical practice have an intuitive grasp of the base rates of various clinical conditions and how they typically present in their practice.  These rates of presentations and findings are integrated with the other features of semantic memory (disease scripts, patterns, etc) for more analysis and hypothesis generation.

These features of semantic memory are of course models of brain function for the most part determined by experimental models in cognitive psychology. Examples include testing for specific functions and seeing how those modelled functions vary among trainees and experts at various stages of development. 

Apart from the descriptive approaches used in many studies on physicians at various levels of training are there any more general models that could apply?  Cognitive neuroscience and cognitive psychology offer a more complete model of memory and knowledge structures as well as the underlying biology.  The lead figure for this post is a case in point and has the potential to consolidate many of the descriptions under a more comprehensive model based on experimental validation.

At levels B and C in the diagram we see a perceptual episode being processed from the left to the right in the diagram.  The activated or instantiated schema is a template for extracting relevant features and repressing irrelevant features.  In the diagram circles represent general concepts and squares are action scripts. Gist in the case of the model is a representation of a single episode where much of the detailed information is removed.  The overall sequence at level B depicts how a schema serves to form semantic type memory (gists) and at the same time can be altered or accommodated by new information.

Level A in the diagram illustrates what is known about the localization of these processes largely from human fMRI and preclinical studies.  Memory schemas are stored in various sites including the retrosplenial cortex (RSPL), middle and superior temporal gyrus (MTG/STG), anterior temporal lobe (ATL), and temporoparietal junction (TPJ).  These sites are bound per the diagram to the ventromedial prefrontal cortex (vmPFC).    Solid lines are context sensitive associative pathways biased by the vmPFC. Broken lines in the diagram represent context irrelevant associations that are not activated or inhibited.

How might all of this model work for psychiatry?  In general physicians are seeing a lot of patients in their training and practice.  In the course of that work - schemas are developed for diagnoses, signs, symptoms, and situations.  Here is a comparison of two scenarios that all psychiatrists are trained to recognize acute encephalitis and bipolar disorder, manic with psychotic features. 

	Encephalitis	Bipolar disorder, manic with psychosis
Schema	Acute illness, acute altered mental status, fever, seizures, focal neurological deficits, CSF/MRI abnormalities	Acute illness, euphoria/irritability/anger, hyperactivity, functional impairment, psychosis, temporal pattern, exclusion features
Subschema	Predisposing factors, pathophysiology patterns, temporal pattern	Euphoric expansive Irritable dysphoric Spontaneous v. precipitated
Gist	Acute confusion + fever + temporal lobe MRI changes = treat as HSV until proven otherwise" "Young woman + new psychosis + movement disorder = think anti-NMDAR, look for teratoma" "Summer encephalitis + flaccid paralysis = arboviral, likely West Nile" “Immunocompromised man with acute agitation = think CMV encephalitis	Episodic psychosis +/- mood changes (diagnosis gist) Mood stabilizer + antipsychotic (treatment gist) Severe postpartum psychosis = think bipolar disorder, manic with psychotic features Catatonia – think bipolar disorder, manic/depressed/mixed with psychotic features.

 

I came up with the following graphic (click to enlarge) based on the descriptive categories and the cognitive neuroscience model of Gilboa and Marlatte (12).  From left to right – the  “heterogenous construct supported by clinical utility” characterization is probably the most charitable one from philosophers.  Others like “this disorder does not exist” or “this disorder is not real” are two additional examples.  The central semantic memory category includes investigations and models of diagnostic reasoning conducted largely on medical students and physicians.  The cognitive neuroscience model contains schema and I have attempted to show how the concepts and actions map from the semantic memory to the schema model.  In both the semantic memory and cognitive neuroscience model, although the focus is memory the conceptualizations are really knowledge structures emphasizing a dynamic role for the schema in incorporating features of reality – in this case patient encounters. The cognitive neuroscience and semantic memory models also map on to brain anatomy – with a more comprehensive map for the cognitive neuroscience model as illustrated in the figure at the top.

What have I learned about this so far:

1:  The pattern matching of yesterday is more complicated today – I taught a course in diagnosis and diagnostic reasoning for 15 years into the early part of this century.  Pattern matching and pattern completion was a big part of that course.  The patterns were fairly simple and involved visual diagnoses (diabetic retinopathy, rashes) comparing physicians at various levels of training.  The most dynamic aspect was the implication that experts were better at matching incomplete patterns than novices.  Today’s conceptualizations of knowledge structures and schemas contain concepts, actions, and dynamically alter what is retained in memory and what is not. 

2:  There are clear implications for psychiatric diagnosis -   the DSM classification and all of the criteria do not capture the reality of medical and psychiatric diagnoses.  There is a qualifier in the manual that it is not a substitute for experience but that is never defined.  That reason becomes a lot clearer looking these cognitive models.  Classification systems attempt to operationalize the diagnostic reasoning of a physician by averaging a verbal description of those events.  I don’t think that is possible and I will cite a couple of examples.

Example 1:  A psychotherapist refers a 27-year-old woman to a psychiatrist because of concerns that she has histrionic personality disorder.  She has not been able to make progress in therapy.  The psychiatrist seeing the patient knows within minutes that she is manic.

Example 2:  An intern is presenting the history of a 68-year-old man to his psychiatric attending.  The patient is extremely depressed to the point that he believes that he is cursed based on a trivial event that occurred in his childhood. Within the first 5 minutes the attending realizes that the patient is delusional and communicates that to the intern. The intern acknowledges that this is true and wonders how he failed to make that diagnosis.

Both cases highlight that knowledge of a classification system is not enough.  The psychotherapist and the intern both know the DSM and use it regularly. They have both had didactics in classification of mental disorders.  The only difference is that the psychiatrist in both cases has experienced cases of the disorder and had knowledge structures and schema to make the diagnosis.  Written descriptions of schema and knowledge structures are an incomplete approach to diagnostic reasoning. 

3: Classifications artificially separate actions from concepts – any reading of the DSM gives the impression that “this is the universe of psychiatric disorders – in order to function as a psychiatrist, pick one and then come up with a treatment plan.”  This is problematic at two levels.  First, if the cognitive neuroscience model of memories and knowledge structures is correct – a classification system is operating at a sublevel that averages features.  It is blind to the overall gist that despite this averaging no two people are alike.  Second, it removes action features that are necessary to function as a physician.  That would include top level schemas like “This patient is medically unstable and requires medical or surgical care first” or “This is a life-threatening problem that requires a safe and closely monitored environment." Some will argue that is not the goal of classification.  I would argue that many consider classification to be a diagnosis and in order for it to function that way – it needs to include action items in addition to a general rule out of causative intoxication states and medical problems. The DSM as it exists is classification without diagnosis.

4:  Cognitive neuroscience models highlight the fact that the separation between diagnosis and treatment is artificial.  All physicians are taught to do exhaustive evaluations of medical problems.  That is the initial step in a career.  It is also critical to learn when that exhaustive process needs to be immediately interrupted to focus on a more acute problem. I can still recall seeing a 7-year-old boy who have been hit by a car while playing in the street. He was alert but had significant abdominal pain.  The car bumper struck him just below his left rib cage.  It took me less than 5 minutes to determine that he had an acute abdomen and call the trauma surgeons. That non-linear process happens frequently in acute care psychiatry and in outpatient psychiatry with patients in crisis who need verbal interventions to assist in the diagnostic and treatment process.  

5:  Psychotherapy – there are recent perspectives on how cognitive psychology applies to the psychotherapeutic process at both the psychological and biological levels using these models.  Basically, maladaptive schemas are confronted and modified during the therapy.  There is some empirical evidence that this may happen particularly in the area of positive and negative self-schemas.  Much of this literature draws on existing cognitive behavioral therapy.  That leads to a question of what is the difference between a therapy focused on a cognition or an isolated memory compared with a schema focused therapy?

At the highest level of analysis memory focused therapies generally involve isolated autobiographical memories and schema focused therapies are about knowledge structures abstracted across multiple events that involve emotion, cognition, and behavior.  In theory the schema focused therapies may be useful in cases where the memory focused therapy is not effective, but a competing consideration is that schemas can be entrenched and difficult to change.  The memory focused therapy could be considered a bottom-up type of approach and the schema focused a top-down approach. 

6:  Criticisms – Criticizing the DSM as a diagnostic system is a cottage industry in the US and the UK.  As we approach a new version of the DSM expect most media sites to start months and even years of criticism. Practically everybody does it rarely discussing their motivations, understanding, and the limitations of their proposed system if they have one.  If diagnostic reasoning is a complex process consistent with the cognitive neuroscience models and requires direct experience, criticism of the manual rings hollow.  It is equivalent to reading about things that might exist and proclaiming you are an expert.  Psychiatrists with criticisms are also limited if they have insufficient experience in the areas they are criticizing.  Psychiatrists with the broadest experience will produce the best criticism. If you are criticizing a list of diagnostic criteria in a classification system in isolation – that is exactly what you are doing.  It is trivial compared with an actual diagnosis by a trained and experienced psychiatrist.        

This brief focus on the cognitive neuroscience of diagnosis should highlight that psychiatric education and practice is seriously lagging in this knowledge base.  If we are taking the “diagnosis” in DSM seriously it has to be modified to include this important brain science.  All of the current competing models face the same criticism.  A diagnosis by a physician is much more than typed criteria attempting to capture a dynamic process.  Secondly, psychiatry needs modern approaches to the mind. Approaches that correlate with neurobiology and have a clear empirical basis. Much of the DSM claims a sketchy atheoretical basis that should no longer be acceptable when powerful explanatory theories may exist.  Philosophy is no substitute.  Finally, we must find a way to implement these across all of our training programs and practitioners.  We should be devoting as many resources to integrating cognitive neuroscience into psychiatry as we do modifying the DSM.

And that should be the first step.  What does a DSM looked like with cognitive neuroscience baked in?  The answer goes a lot farther than “dimensions”.      

   

George Dawson, MD, DFAPA

 

 

References:

 

1:  Norman G, Young M, Brooks L. Non-analytical models of clinical reasoning: the role of experience. Med Educ. 2007 Dec;41(12):1140-5. doi: 10.1111/j.1365-2923.2007.02914.x. Epub 2007 Nov 13. PMID: 18004990.

2:  Brush JE Jr, Sherbino J, Norman GR. Diagnostic reasoning in cardiovascular medicine. BMJ. 2022 Jan 5;376:e064389. doi: 10.1136/bmj-2021-064389. PMID: 34987062.

3:  Custers EJ. Thirty years of illness scripts: Theoretical origins and practical applications. Med Teach. 2015 May;37(5):457-62. doi: 10.3109/0142159X.2014.956052. Epub 2014 Sep 2. PMID: 25180878.

4:  Koufidis C, Manninen K, Nieminen J, Wohlin M, Silén C. Unravelling the polyphony in clinical reasoning research in medical education. J Eval Clin Pract. 2021 Apr;27(2):438-450. doi: 10.1111/jep.13432. Epub 2020 Jun 22. PMID: 32573080.

 5:  Binder JR, Desai RH, Graves WW, Conant LL. Where is the semantic system? A critical review and meta-analysis of 120 functional neuroimaging studies. Cereb Cortex. 2009 Dec;19(12):2767-96. doi: 10.1093/cercor/bhp055. Epub 2009 Mar 27. PMID: 19329570; PMCID: PMC2774390.

6:  Duff MC, Covington NV, Hilverman C, Cohen NJ. Semantic Memory and the Hippocampus: Revisiting, Reaffirming, and Extending the Reach of Their Critical Relationship. Front Hum Neurosci. 2020 Jan 24;13:471. doi: 10.3389/fnhum.2019.00471. PMID: 32038203; PMCID: PMC6993580.

7:  Insaustu R, Amaral DG. Hippocampal Formation. In: Mai JK, Paxinos G (eds) The Human Nervous System, 3^rd ed.  Elsevier, London, 2012: p. 933.

8:  Mazoué A, Gaultier A, Rocher L, Deruet AL, Vercelletto M, Boutoleau-Bretonnière C. Does a rabbit have feathers or fur? Development of a 42-item semantic memory test (SMT-42). J Clin Exp Neuropsychol. 2022 Sep;44(7):514-531. doi: 10.1080/13803395.2022.2133088. PMID: 36269845.

9:  Renoult L, Irish M, Moscovitch M, Rugg MD. From Knowing to Remembering: The Semantic-Episodic Distinction. Trends Cogn Sci. 2019 Dec;23(12):1041-1057. doi: 10.1016/j.tics.2019.09.008. Epub 2019 Oct 28. PMID: 31672430.

10:  Brown TI, Rissman J, Chow TE, Uncapher MR, Wagner AD. Differential Medial Temporal Lobe and Parietal Cortical Contributions to Real-world Autobiographical Episodic and Autobiographical Semantic Memory. Sci Rep. 2018 Apr 18;8(1):6190. doi: 10.1038/s41598-018-24549-y. PMID: 29670138; PMCID: PMC5906442.

11:  Teghil A, Bonavita A, Procida F, Giove F, Boccia M. Temporal Organization of Episodic and Experience-near Semantic Autobiographical Memories: Neural Correlates and Context-dependent Connectivity. J Cogn Neurosci. 2022 Nov 1;34(12):2256-2274. doi: 10.1162/jocn_a_01906. PMID: 36007071.

12:  Gilboa A, Marlatte H. Neurobiology of Schemas and Schema-Mediated Memory. Trends Cogn Sci. 2017 Aug;21(8):618-631. doi: 10.1016/j.tics.2017.04.013. Epub 2017 May 24. PMID: 28551107.

13:  Reyna VF, Edelson S, Hayes B, Garavito D. Supporting Health and Medical Decision Making: Findings and Insights from Fuzzy-Trace Theory. Med Decis Making. 2022 Aug;42(6):741-754. doi: 10.1177/0272989X221105473. Epub 2022 Jun 23. PMID: 35735225; PMCID: PMC9283268.

14:  Wilhelms EA, Fraenkel L, Reyna VF. Effects of Probabilities, Adverse Outcomes, and Status Quo on Perceived Riskiness of Medications: Testing Explanatory Hypotheses Concerning Gist, Worry, and Numeracy. Appl Cogn Psychol. 2018 Nov-Dec;32(6):714-726. doi: 10.1002/acp.3448. Epub 2018 Sep 1. PMID: 30686857; PMCID: PMC6345391.

15:  Hawke LD, Provencher MD, Parikh SV. Schema therapy for bipolar disorder: a conceptual model and future directions. J Affect Disord. 2013 May 15;148(1):118-22. doi: 10.1016/j.jad.2012.10.034. Epub 2012 Dec 4. PMID: 23218898.

16:  Lane RD, Ryan L, Nadel L, Greenberg L. Memory reconsolidation, emotional arousal, and the process of change in psychotherapy: New insights from brain science. Behav Brain Sci. 2015;38:e1. doi: 10.1017/S0140525X14000041. Epub 2014 May 15. PMID: 24827452.

Graphics Credit:

1:  The lead graphic as noted is from Cell Press and reference #12.  It is reproduced here with permission from Elsevier and this is their acknowledgement:

Reprinted from Trends in Cognitive Sciences, August 21(8), Gilboa A, Marlatte H. Neurobiology of Schemas and Schema-Mediated Memory, p. 618., Copyright 2017, with permission from Elsevier.  License 6278000229455, May 29, 2026 

2:  Second graphic was made by me using Microsoft Visio.

Supplementary 1:  Nobel Laureate and Psychiatrist Eric Kandel noted the importance of cognitive neuroscience years ago and this was a quote from his book:  The Age of Insight.

 

Layered Psychiatry

 

I had this idea about how to present the complexity of the psychiatric diagnostic and treatment process.  After putting up a couple of diagrams for comment, I went ahead with a PowerPoint. For about 15 years I taught a course in how not to mistake a medical diagnosis for a psychiatric diagnosis.  My audience at the time was 3rd and 4th year medical students.  The lecture included a discussion of the research at the time in pattern matching and pattern completion, heuristics and common biases, Bayesian considerations, and inductive reasoning. It was generally well received but really cannot be appreciated until you are a senior clinician.  Over the time since I taught that course there also seems to be a distinct bias toward considering DSM criteria to be the basis for psychiatric diagnosis and decision making – and that is clearly a mistake.

The very first time I really became aware of the importance of pattern matching occurred when I was a fourth-year medical student.  I was on an Infectious Disease rotation and my job was to get the consults for the day, go out and see the patients we would be rounding on, do my basic compulsive medical student work up and present the findings and my ideas about the case to the attending physicians. ID docs are very bright people and like most impressive rotations I contemplated becoming an ID specialist for a while.  My patient that day had spontaneous bacterial peritonitis and the question for us was: “Do you agree with the diagnosis and current antibiotic treatment?”  I met with the patient, took a complete history, did a physical exam, reviewed the hospital course and labs, and had time for a little research. At the time I was carrying a copy of Phantom Notes for Medicine – basically an outline of the major medicine text of the day. I looked up the differential diagnosis.  I was also carrying a copy of Sanford’s guide to antibacterial therapy – the 1982 version and looked up the recommended antibiotics for peritonitis.  I was all set for rounds at that point.

Both of our ID attendings were very serious physicians. There was not a lot of banter or joking.  I anticipated presenting all of the dry facts and either getting a brief agreement, some questioning until I could no longer answer, or a long discussion of the diagnosis and treatment.  In this case the attending came into the patient’s room. He was 15 feet away from the patient and he said: “What am I seeing from right here that is a potential problem?”  Our team consisting of the ID fellow, two Internal Medicine residents, and myself – stopped in our tracks.  Nobody had an answer.  Weren’t we here for peritonitis?  How can you diagnose that from across the room?

“What is wrong with the patient’s shin?” Dr. R stated looking as serious as usual.  Sure enough there was a light pink confluent rash covering about 10 square inches of the patient’s left shin area. Dr. R happened to be an expert in streptococcal infections. He rattled off the type of strep he expected and suggested that we get a culture and send it to his lab for confirmation. I completed my presentation.  The primary diagnosis and treatment by the medicine team did not change, but now there was a new diagnosis and treatment that depended on Dr. R’s ability to recognize the pattern of this rash and make a rapid diagnosis – even though he was not expecting it.  But beyond that – we all saw the rash (although we had to be prompted to see it). Dr. R not only saw it, he processed it as a unique rash, and then a rash most likely caused by a specific kind of streptococcal bacteria. And over the next several days he was proven correct by the culture result.

Pattern matching and pattern completion are critical skills acquired by clinicians over the course of their training and careers that allows for not only more rapid diagnosis and treatment but also more accuracy in classifying ambiguous cases. Some of the examples I used in my course included ophthalmologists compared with primary care physicians diagnosing diabetic retinopathy and dermatologists compared with primary care physicians across a series of rashes.  In both cases the specialists had a higher degree of accuracy and were better at diagnosing ambiguous cases.

Cognitive neuroscience encompasses a broad range of perceptual studies starting with the early studies of visual processing by Hubel and Wiesel to more recent studies that look at the encoding that occurs in perceptual systems and what level of processing occurs at the level of primary sensory and association cortices, what the higher-level cortical structures may be, and whether or not top down processing influences perception. According to Superior Pattern Processing (SPP) theory (3), both perceived and mentally constructed patterns are processed by encoding and integration and at that point can be used for decision making or transferring approximations to other individuals.  In my example, Dr. R not only sees the pattern of the rash, but it is integrated into a feature set that has a time, visuospatial, social, and emotional context that makes it more likely that he will make a correct diagnosis. Experimental data suggests that he is not seeing the rash like any other person in the room – largely as a function of top-down control of his perceptual process.  The actual transfer of this pattern to his junior colleagues is limited because they see the rash as being a universal truth – that is they just “missed it” and therefore need to memorize what this rash looks like and not let it happen again.  They are also unaware of the processes involved in pattern matching or processing or they might have asked him about it.  For example, a logical question would have been: “What features of this rash do you notice that are suggestive of strep or a specific kind of strep?”

The question of what represents a pattern is critical to the idea of pattern recognition and processing.  There is a natural tendency to associate the term with visual or auditory stimuli, but without too much imagining patterns can clearly exist in any sensory modality and often involves the integration of multiple sensory inputs.  Cortical organization generally reflects primary sensory input to the cortex with adjacent sensory association areas and further information flow to heteromodal areas in the frontal and temporal cortex where additional integration occurs. Patterns can be sensed, encoded, recognized encoded and processed across theses systems.  The resulting integration yields a very complex array of patterns that are not intuitive.  For example, Mattson suggests that pattern processing in the human brain forms the basis of human intellect including problem solving, language and abstract thought and that it includes fabricated patterns.  Those fabricated patterns allow vicarious problems solving without having to conduct real world experiments.  The recent cognitive neuroscience of pattern processing is a significant advance compared with the old diagnostic paradigms I taught 20 years ago.  Those old experiments were basically a comparison of a non-expert to an expert diagnostician focused on a relatively basic clinical problem like a pathology slide, x-ray, ECG, or physical finding and the results were not a surprise – the experts typically prevailed in both accuracy and speed.  The sheer amount of information in a clinical encounter looks at what is essentially an infinite array of patterns, including patterns that are generally not even mentioned as being clinically relevant.

In considering what kind of patterns that need to be recognized and processed by a psychiatrist – the patterns that exist in clinical practice are a starting point.  These patterns and the associated phenomenology have been grossly oversimplified by an overemphasis on nosology. I talk with far too many people who see psychiatric diagnoses as phrases on a page in the DSM. I cringe when I hear: “The patient does or does not meet criteria for (DSM diagnosis x)”.  Kendler was correct when he referred to the DSM approach as an indexing system.  It gets people into the same ballpark, but it is not be very useful for predicting response to treatment or that specific person’s response to being ill.  It is also based on a fraction of the information collected in a psychiatric evaluation. When I consider the feature sets that psychiatrists are considering in evaluations it may look something the graphic below.  Of course, these features sets are simplified for the purpose of making a useful graphic. They will vary with the individual, their experience, social context, and culture. They will also be blended across space and have their own individual levels of integration and patterning.  Let me provide a couple of examples to illustrate these points.

Consider the above diagram as representing the possible features that must be recognized in order to assess a patient presenting to a psychiatrist and formulating and optimal diagnostic and treatment plan. My overriding concern in the first few minutes of the evaluation is whether this person really has a psychiatric disorder or a misdiagnosed medical problem and as a corollary - are they medically stable? That sounds like a basic consideration but prioritizing it is not listed anywhere in the DSM or any medical text that I know about. It does involve rapid recognition of patterns of acute medical illness particularly the most likely patterns to be misdiagnosed as psychiatric disorders and what I am seeing in real time.  It also involves pattern recognition of the thousands of psychiatric presentations that I have see that were really medical disorders.  Real life examples have included an almost immediate recognition that the patient had a stroke (many cases), seizures (many cases), meningitis, encephalitis, cerebral edema, serotonin syndrome, and neuroleptic malignant syndrome.  These rapid diagnoses were all predicated on experience-based pattern recognition rather than written criteria and these diagnoses had nothing to do with the DSM at the time.

A more cross-cutting feature in the diagram would be transference issues and defenses that can arise as soon as the initial evaluation or be indirectly evident by the patients historical description of their relationships with important people in their life.  These patterns will involve several layers in the above diagram and most importantly may suggest a psychotherapeutic intervention that can be implemented as early as the original assessment.  A similar process occurs if the patient is describing features of a major medication responsive illness.  In that situation, features from multiple layers result in a pattern that may be recognizable to the psychiatrist in terms of specific medical treatments or the urgency of those treatments.

And finally - what might the graphical representations of these pattern matching processes be?  Here are a few examples.  In the case of psychotherapeutic examples, it will depend on the exposure to specific therapies in training and practice. Each therapy has a specific pattern or series of patterns that the therapy depends up as well as patterns more specific to the conduct of therapy.  These graphics contain critical books from my library shelves with those elements.  In the case of the diagnostic and treatment process - the school of therapy and potential application are important patterns to recognize in the initial assessment.

All of these books contain symbolic representations of clinical patterns in the form of vignettes designed to assist the student of psychotherapy in learning techniques. They also contain information about the patterns of intervention that are relevant for a specific therapy and in some cases the common factors required in all successful therapies. I have graphically represented what happens in pattern processing once a theme is noted in the clinical assessment of the patient.  Clinical teaching of this process is often problem identification followed by an algorithm of features that might predict a successful course of therapy or limitations in therapy based on the students knowledge level at the time. As is true for most pattern matching and processing, the more extensive a physician's previous pattern exposure - the more likely they are to match the optimal intervention to the problem. 

I will resist making this first post of the New Year too long and wrap it up at this point with a diagram that I think pulls it all together (see below).  Each layer of this diagram consists of patterns and all of the associated pattern processing that leads to psychiatric diagnosis, formulation and treatment.  A few of the key features include the fact that diagnosis and treatment are interchangeable processes.  There will be times even during the initial information gathering that a verbal treatment intervention needs to occur and the entire interview occurs in the context of empathy and what Ghaemi, et al (4) have described as an existential psychotherapy based encounter – even if the administrative focus is on pharmacology. A second feature is that the information exchange is necessarily large if the psychiatrist and the patient are capable of it. There has been no research that I am aware of on the optimal amount of information that is required, but there are many limitations.  The advent of the electronic health record for example has led to the universal use of templates that are very restrictive in terms of information, typically dichotomous responses. A third implicit feature is the concept of patterns, what they imply for diagnosis and decision making and how there is almost a complete lack of discussion about this process in an era where diagnoses seem to have collapsed to a brief list of bullet points.  Cognitive neuroscience is a critical area of research focused these processes that I first became aware of when reading Kandel’s book “The Age of Insight” (5).  It is an area that does not typically get a lot of attention from psychiatrists, but it is a logical extension of the work done by behavioral neurologists from 20 years ago.  If we really want to focus on how psychiatrists think about diagnosis and treatment – we need to study this field, especially as the experiments get more complex.

I will wrap up this post at this point with the hope that 2021 is a much better year and that mankind is able to put this pandemic virus behind us by the summer and approach future pandemics with more science and wisdom.

 

Happy New Year!

George Dawson, MD, DFAPA

 

References:

1:  Constantine-Paton M. Pioneers of cortical plasticity: six classic papers by Wiesel and Hubel. J Neurophysiol. 2008 Jun;99(6):2741-4. doi: 10.1152/jn.00061.2008. Epub 2008 Jan 23. PMID: 18216235.

2: Poirier CC, De Volder AG, Tranduy D, Scheiber C. Neural changes in the ventral and dorsal visual streams during pattern recognition learning. Neurobiol Learn Mem. 2006 Jan;85(1):36-43. doi: 10.1016/j.nlm.2005.08.006. Epub 2005 Sep 22. PMID: 16183306.

3:  Mattson MP. Superior pattern processing is the essence of the evolved human brain. Front Neurosci. 2014 Aug 22;8:265. doi: 10.3389/fnins.2014.00265. PMID: 25202234; PMCID: PMC4141622.

4:  Ghaemi SN, Glick ID, Ellison JM. A Commentary on Existential Psychopharmacologic Clinical Practice: Advocating a Humanistic Approach to the "Med Check". J Clin Psychiatry. 2018 Apr 24;79(4):18ac12177. doi: 10.4088/JCP.18ac12177. PMID: 29701934.

5:  Kandel ER.  The Age of Insight. Random House, New York, 2012.

Graphics:

All generated by me for a PowerPoint presentation by the same name.  The photo at the top are two pamphlets that I carried as a med student along with a copy of Phantom Notes.  I was carrying them when I was in the room with Dr. R as he made the diagnosis described above.  I would not trade my medical school experience for anything.