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head back. You okay? Now? You feel it? Yeah. You're good. You're right. Yeah. I take it only two of us had, uh a lot of people are online. It's just a faithful few minutes is still has gone. But, uh, yeah, I did this. Get the link. I mean, could do. I mean, where did this shit earlier on the court Trainees page. Okay, Uh, for a few people on five minutes to have for them to, uh, pop in and see. Yeah. Christ. Yeah. Or if you want to go ahead and then you will make your record and just leave it on. Like for people to watch it later. Then you prop up. Mm. I mean, I don't really mind. Okay. Well, um, so we don't keep you waiting. Oh, we could have feel. Well, um, so we don't keep you waiting. Now, just wait for a few moments to see what else talks online. Just a few minutes with trying to get in was quite hard. Just post up about 705. Yeah. Mhm. Okay. Mhm. Mhm. Mhm. Mhm. Mhm. Oh, you're you're teaching. I think you're teaching God. Um retreated on the original men all treated platform, I think Feel like we teach everyone, um, teaching and then passing from time to check it is to actually happening. Um, yeah, OK, all sort of keep you waiting because, um, cracking and teach today. Well, thank you very much for Ashley. Finally making your teaching, and it's heading to deliver it. Folks, just go ahead and start. And then, uh, massive would join or hope everyone cut back some point and they can always watch it back later. Yeah. Okay, great. Let me just set up my notes so that I can see it. Hey, stir. My name is Carafate. IATA. I'm one of the psychiatric or trainees in North Yorkshire, and today we're going to be talking about hallucinations, particularly the neurological and psychiatric theory is behind it. Um, there's a caveat that we don't exactly know why each person experiences hallucinations, but these are our best theory so far. So to start with, we're going to be looking at useful definitions. Um, we're going to be talking about the different experiences of people who typically have hallucinations from an organic cause versus people who have hallucinations from functional causes. Then we're going to move on to what happens to brain imaging if we scanned people whilst they're having hallucinations, and we're going to be looking at the neurotransmitters that are thought to be implicated in hallucinations and then we're going to be talking about some theory is that people have put towards why people have hallucinations, So some useful definitions, firstly, to start off simply sensation. Now. Sensation is just the information that's received by sensory receptors, whether it be skin or the olfactory nerves, and then that transmit data in the form of neural impulses to the brain. Now that impulse is interpreting the sensation, but there's nothing. There's no meaning attached to it, really. But then we'll move on to perception where the brain finds meaning in what is sensed. And this actually relies on what you've experienced before. Um, your memory's your current emotional state, Um, whether you're motivated at the time and other psychological factors like that. So then the next one on the list is an illusion, which is an incorrect perception of a stimulus. But the important thing to differentiate between that and hallucination is that there is a stimulus. So, for example, if you are walking through a forest and you hear twigs crackling behind you. Now you hear the sensation of the sound of the twigs. Now your perception is that your brain and attaches meaning to that, um, from your emotional state. Oh, it's it's you're in the woods, you're a little bit dark, you're a little bit scared and you attach the meaning of, Oh, there's someone behind me that's that's an illusion. Every single twig looks like a I don't know, uh, the shape of a person in the background. So that's just an incorrect perception of an existing stimulus. Whereas if we skip a pseudo hallucinations there on the slide and go down to hallucination, hallucination is perception in the absence of a stimulus. So if I say look over to my left and see a dog that does not exist, that's a hallucination rather than an illusion, and then coming back to pseudo hallucinations just to confuse things further. This is mostly important in the context of auditory and visual hallucinations, and that occurs in the inner, subjective space. So a hallucination is when, say, I hear somebody talking to me with the absence of the stimulus of somebody's actually talking to me. Whereas the sweet hallucination is if I am hearing voices in my head saying things that I don't think is coming from me. So this is, uh, an example of an illusion. We term this ambiguous figure. So if you focus on the black aspects of the image you can see to face is looking at each other. Whereas if you then look at the white part of the image, you can see some sort of a cup of chalice. Um, it's to varying interpretations of the same stimulus. And then we have another example of an illusion is quite famous when you may have actually seen it. Um, and as you can see in those two images, you should find that you think the bottom line, um, the line in the middle lifted two arrows look longer than the top one, but actually, if you measure them, they're the same length. We try to explain this using several theories again, we're not really sure where this illusion works, But if we take a step back and talk about guest salt therapy, that is the, um, the concept where you perceive an objective unchanging despite changes in sensory information. So you get much sleep. Look at the phone. You know that this is the same image, despite the fact that I'm turning it in a different way and your brain perceives the sensation that this object looks different. Um, same goes with and see in different lighting. Same goes as size, constancy as objects move towards you and further away them as location constancy when you perceive yourself as moving between the objects that you're receiving. So when looking at some of the explanations, one of the explanation is size constancy. So we try to interpret the middle image using this size constant application. So the top image, um, we feel it's shorter because the overall image seems smaller. Um, compared to the bottom image. There's also the depth cue explanation. So, um, it's thought that our brains perceive the depths of the middle line based on depth cue. So the top line looks like the edge of the building sloping away if if we're kind of turn the image on its side, whereas the bottom image looks like the corner of a room with the two hour roofs pointing outwards, so we perceive the top images being further away and therefore shorter. And then there's also the conflicting cues explanation. Um, which again our brains perceive the length of the middle line based on the actual length versus the over length of the figure. So that's a little rundown of some optical visual illusions now, going towards organic versus functional hallucinations and starting with organic hallucinations. When people have hallucinations from an organic course, they tend to be visual hallucinations, or they tend to be what we call elementary auditory hallucinations. So elementary is just course know noises such as a pure tone. For example, um, and the common courses of organic hallucinations are things like occipital lobe tumor's epilepsy, um, some dementia as and some metabolic disturbances. So some examples of an organic hallucination is Charles been a syndrome? Now that's a hallucination that is in the presence of visual disturbances, so people with quite common immaculate generations sometimes find that they start having visual hallucinations. Um, but these hallucinations have to be in the absence of another psychiatric disorder. It's thought to be quite underdiagnosed, Um, but it's probably because the diagnosed the diagnostic requirements are quite vague. Um, in that it's just visual disturbances in the presence in the absence of psychiatric disorders causing visual hallucinations. Um, now, the second example is delirium tremens, and that occurs in severe alcohol withdrawal. And this syndrome presents with confusion with autonomic hyperactivity and with cardiovascular collapse. But quite often in delirium tremens, you you get very vivid hallucinations, sometimes with affect hallucinations. And, um, that's an affect. Hallucination is when stimuli is incongruent with the emotional response to it. So, for example, um, hallucinating, I don't know someone being killed and having a positive emotion, respect, but and moving on to functional hallucinations, Um, they tend to commonly be auditory. No, it's not hard and fast rules. Sometimes you do find that, um, there are acceptance, and quite commonly, hallucinations are found in conditions such as it's a free NIA and mood disorders. So in schizophrenia, very classically, you get auditory hallucinations, their third person, so they're not speaking directly to you. And there may be one of multiple voices, and sometimes you get things like commentary, hallucinations, where you would do something and then you'd hear a voice in your head or out in this space outside your in her experience, for example, saying Oh, she's getting up from the sofa. She's going to the sink, etcetera, Um, or as hallucinations. Experience in effective disorders like depression and mania tend to be second person, and they tend to be mood congruent. So in depression, you get voices saying you are useless. You are worthless, etcetera, and in mania, you may hear voices congratulating you, singling you out, thinking you're special. Um, but it tends to be second person speaking directly to you, and it's worth remembering that hallucinations can be a normal variant. One of the other things that's worth remembering with that sometimes will go to sleep or wake up from sleep. They can experience quite commonly experienced hallucinations. And let's move on to some imaging. Uh, if, uh, put them through an MRI, you really get what you paint in these four areas. The superior capital gyros means the vortex. Okay, um, I'm going to do it. The area in the brain that wants to, uh, uh, understanding in the super temporal gyrus. It's also the area that's responsible for order processing, um, and something called the cocktail party effect. So that's when, if you are or listening to a lot of different conversations. Um, you have the ability to focus on one conversation that's relevant to you, maybe want to the middle temporal virus. Um, it's they're responsible for audio visual emotional recognition. Um, it's also important word meaning whilst reading and techs is responsible for executive functions such as planning decisions, short term memory, personality and everything's social behavior and controlling aspects of speech and language. Whereas this Arabella cortex responsible for motor adjustments. So you can see these four areas have functions in language functions in auditory perception and processing, Um, and other weird things like motor adjustments, which may be, um, imported in speech moving on to function region if you put them through an F emperor, whilst people are having hallucinations get increased flow in breakfast area, which is important in speech production, um, in the anterior cingulate cortex, which is important in attention reward anticipation, decision making, ethics, impulse control, performance monitoring and emotion, and also the left temporal cortex. We spoke about the temporal GI right earlier in the previous slide, and that's, um, involved in the auditory reception and processing. They're going back to the anterior singular cortex. One of the things that's important later is we're going to look at the effect of attention on hallucinations. And then if you then put people through a pet scan, you tend to get activation in the supplementary motor area. Where you, um, which responsible for planning complex movements? Um, the anterior cingulum, the medial superior front area, which can movement related and also quality functions, related decision making and the cerebellum, which we've spoken about so in summary, Quite a lot of changes in brain imaging occur with people who are having hallucinations and actually some of the areas that implicated in things like or do on auditory processes and speech. So now, looking at neuro transmitters, we believe that these at the moment are implicated in hallucinations. Now you can get dopamine, and you may be aware that if you have too much dopamine, i e. In schizophrenia, you can get hallucinations, but also, if you have two little dopamine i e. In Parkinson's disease, you can also get hallucinations, so there's obviously relationship between dopamine and hallucinations moving on in acetylcholine. Um, if you have hallucinations, it's We have found that people have reduced a seat I'll call in reduced acetylcholine levels and also found to have abnormal nicotinic masculinity receptor expression. Now glutamate is an interesting one. We think it's related to hallucinations because ketamine and masculine are hallucinogenic and ketamine is an NMDA receptor antagonist. So they theorized that reduced glutamate, um, NMDA receptors is implicated in having hallucination moving on to serotonin. We believe that it's implicated in hallucinations because it's a side effect of medications such as selective serotonin receptor inhibitors. And also, if you increase serotonin agonist activities such as if you take ecstasy or again Miska lean, you can sometimes have hallucinogenic effect, and the last neurotransmitter that we're talking about is GABA A and reduced GABA. A binding is linked to hallucinations, but as you can see, there's no clay path from the theory of why, um, these things are proposed to be linked to hallucinations to actually the production of hallucinations themselves. Now we have some cognitive theories, the first of which is, um, actually, these are some of the factors that can contribute to, um, the production of hallucinations. So if you fail to recognize that some of your thoughts come from yourself, sometimes that is perceived as a hallucination or sued a hallucination if you have a reduced sense of control over the events that are happening sometimes that is linked to people having hallucinations. Um, the perceptual quality of the things that you see can contribute to hallucinations, as are your emotional states at the time. And you've also got, um, self monitoring and source monitoring so again that that links into the idea of kind of recognizing that your thoughts are your own, etcetera, etcetera. Now there's a proposed theory called the Signal Detection Theory, where, um, the thought is the information recognition pretty much always takes place under some uncertainty. Um, an obvious example is, if we go back to the visual, um, illusions that were shown earlier. Um, there's a little bit of uncertainty into what into the meaning that's actually now information processing itself, then relies on pattern recognition, um, and your own experiences and your own biases. And it's proposed that people who hallucinate don't actually have a perceptual problem. So there's no issues in how the sensations go from the sensory organs to the brain. But the meaning that they attached to those sensory inputs cause the experience of hallucinations. And sometimes, actually, there's a There's a desire to reduce the uncertainty in which information recognize it takes place or who have hallucinations have problems deciphering which sensory inputs are real. Okay, um, when you want to reduce the uncertainties proposed, taken a lot more information. So, um, signals that are ambiguous symptoms that make signals that might be irrelevant. So reduct in your auditory threshold in which that's picked up by the brain and a meeting and you make which could in turn, reduce the threshold in which signals are, um, detected. Now executive and him inhibitory controls are implicated because it's reduced. Uh, it's linked with the reduced sense of control. Um, there's another theory that it says that there's a called the spontaneous activation model where, actually, there's increased spontaneous activity in the auditory and associated memory areas. So actually, it's nothing to do with what people are trying to perceive. But actually, some occult activity that originates in the brain causes these hallucinations. Um, now, we briefly mentioned attention when I was talking about, um, the areas of the brain that are implicated in imaging, and actually they're in people who have hallucinations. There's a heightened awareness of the ambiguous sensor sensor inputs that some people, some people who don't have hallucinations, tend to at all. And with that, there's an intrusion of material that's irrelevant from long term memory, so that meaning that attached to the hallucinations is altered. No, there is a last theory that I will talk about where there's a series of steps in which it the end results are hallucinatory experiences. So someone posited the early traumatic insults results in an aberrant function activation of the auditory network. And that, um, causes problems down the line in which auditory signals are picked up. Aberrantly, um added with some emotional modulation in whatever emotional states that people are in some personal experience, is that people have had and, um, delusional ideas and reduced insight in people who who may be suffering from a psychotic or a mood disorder that can all add up to a hallucinatory experience. So in summary, we spoke about the differences between sensation and perception, and then the three similar sounding things that are allusion, pseudo hallucinations and hallucinations. We briefly touched on organic and functional hallucinations. We looked at what brain imaging looked like in people who have hallucinations. We looked at some neurotransmitters that are thought to be implicated. And then we looked at some cognitive theory is to do with hallucinations, and that is all from me. Okay. Okay. Can you hear me? Yeah. Okay. Thank you. Thank you very much. That was quite, um, detailed. Um, it's, um it's probably going to be for interest only for most people. Unless you go into psychiatry and do the royal college exams. But much recommended everyone can. Psychiatry. Mhm. Fantastic stuff. Um, So what we're gonna do on that is basically, we'll see if anyone has any costumes. Uh, focus. Property I/O. Um, but yeah, that was that was really good. Um, in terms of, like, imaging, what would you say would be like the gold standard or what we should if we want to order less inning or it's not in because you would prepare people for if an apartment. But if, um, let's see if an essential working in, like, what would be your first line of goats and imaging? You want quantification that you think, um, or represent with features of hallucination. So, in terms of hallucinations, if say, you don't have any clues from the previous psychiatrist. Flashman. Um, physical health history. It's probably the most important to look up for organic courses. First, um, they rule out anything that's potentially reversible. So it depending on the presentation, that might give you close to which ones you want to rule out, Um, in terms of previous a Andy experience, um, our seniors tend to look for CT heads to rule out anything glaring or, um, very, very obvious. But quite often it will turn out normal and certainly in functional, um, functional hallucinations. It'll be normal in terms of, um, when you have a patient where you're very much sure that it's functional hallucinations and there are no organic causes that your concern about the neuro imaging that I was talking about is mostly for research purposes and to an individual patient. Um, getting imaging wouldn't particularly change the management management plan. At this stage, we would empirically treat with, um things like, um, therapy and antipsychotics. So in terms of imaging in in A and E, it's mostly useful for ruling organic causes. All right, fantastic. All right. Thank you very much. Um, I don't think we're going to have any more questions for tonight. um So the recording will be able able probably by tomorrow, I think. And then they could always watch it back. And you could always watch that share that you want. Um, thank you very much for giving this lovely tension. I do really appreciate it. Honestly. All right. Let me not keep you much further. Um, in Georgia, rest of the evening. And again, Thank you very much. All right, you, too.