What I'd like to do now in this section, is to talk about major models of the way in which cognitive deficits in schizophrenia may contribute or help establish the clinical syndrome of the disorder. As we've already alluded to in the previous section, probably one of the most important sort of global theoretical models of cognitive function in people with schizophrenia can be attributed to Christopher Frith. Christopher Frith has described a model in a book called The Cognitive Neuropsychology of Schizophrenia. And in this book, he's argued that there are three main factors that can be used to explain many of the very agitated and heterogeneous symptoms that we see in the disorder. The three core deficits in people with schizophrenia are: deficits or a disorder of willed action; a disorder of correctly attributing degeneration of one's own thoughts; and a deficit in the ability of intuiting the thoughts of others around one. So there's a deficit in the monitoring of one's own thoughts and then a deficit in the monitoring of other people's thoughts. So these three factors: willed action; being able to tag and monitor one's own thoughts; and being able to interpret appropriately other people's thoughts, are what lead to all the different symptoms we've talked about in schizophrenia. By this view, the disorder of willed action that is the inability to generate behavior leads to the negative symptoms of the disorder, right? Alogia, social withdrawal, decreases in any type of motivated behavior. And it also explains some of the per-separative behavior in people with schizophrenia. So sort of a subtlety of this model, is that these deficits have willed action, while they interrupt sort of goal-directed behavior these highly routinized approaches to behavior, where a stimulus elicits a behavior remain intact. So the idea here is would be that, a person with schizophrenia perhaps have shown a fork would use that fork and bring that forth to their mouth as a routinized behavior of eating. So they would do this over and over again and be unable to override this sort of routinized stimulus response model. The inability to tag one's thoughts as one's own lead to experiences of thought insertion which we've talked about before the idea that someone has placed a thought in one's head that someone thoughts are controlled by an outside force, right? They might also be involved in the emergence of hallucinations, right? You think of thought. You're unable to tag it as your own you're unable to self-monitor and then that thought that you have becomes a voice from the outside, from God or Jesus. And then lastly, the inability to make appropriate attributions about other people's behavior might lead to paranoid delusions, right? That is to say, if you can't monitor other people's behavior that might suggest or you might make inaccurate and negative interpretations of other people's behavior. So that's the Frith model, a global model of deficits in people with schizophrenia. Deanna Barch and Jonathan Cohen have offered a second important model of the psychological difficulties in people with schizophrenia. According to this model, disruptions in cognition can be generally understood in terms of being a disruption in context, overall context. The idea here is that, when we are doing a task, we have to maintain an instructional set, right? We have to maintain what is it that we need to do. What are the responses that we need to offer. So we need to maintain an instructional set. We need to remember experiences that have just happened. And we need to use this or these goals to guide our future behavior. And Barch and Cohen have argued that this represents a deficit in understanding the context that is what is the, a series of instructions that are guiding our behavior in a specific situation. Deana Barch has modified this model, a little bit this context model and argued that in addition to keeping instructional set in mind, one must also have intact verbal memory, the ability to remember or I should say episodic memory, and intact working memory, the ability to hold items in mind over time. The Barch model of a cognitive dysfunction in schizophrenia can be understood probably best in terms of two major sets of processes. One set of processes that is goal-directed cognitive function, which involves typically a fair amount of effort on our part of guiding our behavior. It involves tuning our sensory systems and tuning our response output systems to the appropriate situation in which we're in. And then arguing, if there's a second cognitive system, which is a reactive system that reacts automatically to stimuli in the environment. Tuning our sensory systems and our behavioral outputs to specific events that occur in the environment. So to give this theory, some context to make this theory a little bit clearer, the best way to think about it would be the idea of going to the supermarket, having a list of things that you need to buy. Let's say you need to buy fish, you need to buy rice etcetera. You've got a goal here, right? So the goal, this goal-driven cognitive activity is go into the supermarket to buy these different items. You are using your working memory, right? By keeping these items in short-term store, right? You're thinking, okay, got to get the fish, got to get the rice, got to get the fish, got to get the rice. That's working memory. The goal of course is to complete or finish off your shopping list. And then you're tuning your sensory systems to look for these items that you need to get. So you're perhaps smelling in the grocery store, smell fish and move towards the fish counter. You're looking for a yellow box of rice, you're looking through multiple containers, trying to target your visual system towards looking for that. So this is your goal-directed cognitive activities that require memory, right? You have to remember the items that you have to get. And they require working memory and you have to keep active in your mind these items that you're looking for. This would be the sort of higher-level cognitive system that Deanna Barch and others have argued is disrupted in people with schizophrenia. That sort of goal-directed, context-dependent series of cognitive activities. That system then be contrasted with the more ballistic system that responds to attention grabbing stimuli in the environment. And the best example of this would be you're looking for your items on your shopping list, you're looking for the yellow box of rice, smelling for the fish, looking where the fish counter is, and then you run into a friend. And all of a sudden, the friend draws all your cognitive skills, right? All of these working memory skills are being used to keep those items in your mind. The verbal memory skills will be involved in remembering what was on the list. They get disrupted, right? And now, all your cognitive systems, your sensory systems, your response systems are tuned now to this immediate environment, which is your friend who's asking you about how you're doing. You engage in these interactions. Maintenance of your goal is temporarily disrupted, right? Your memory for the items that you've been putting in working memory is disrupted and this new set of cognitive processes takes over. Barch's argument has been that that goal-directed system that was guiding you in getting items, as you were walking through the supermarket is in fact disrupted by this stimulus-driven set of cognitive processes. And for someone with schizophrenia, that goal-directed system is so impaired that the person with schizophrenia will be unable to return back to the list of shopping items and to be able to purchase those from the supermarkets. That's the idea of there being sort of two sets of cognitive systems, one cognitive system that's goal-driven, another one that's driven by sensory stimuli in the environment, attention-grabbing sensory stimuli in the environment. Okay. The fourth model that I would like to talk about, the fourth sort of a general cognitive model of schizophrenia that I would like to talk about is a model that looks at schizophrenia as a disruption of the subjective experience of self. This is a approach that's been described by Paul and John Lysaker. And in this model, schizophrenia is believed to be a disruption in self-experience. Now, how do we define self-experience? According to this model, our self-emerges in our environment, in our interactions with people in our environment. There's no sort of independent or authorial or all powerful I. But rather for all of us, healthy people and people with the psychiatric disorder, our sense of self emerges from our interactions with people in our environment. According to the Lysakers, we develop what are called self-positions, self-positions would include the idea that one might be a husband or wife. One might also be a truck driver or a teacher, right? They might have a role in their work-life and they might also be a friend. They might have friends and play the role of a friend. The idea is that, in healthy people, people make these shifts in self-positions very easily. One goes very quickly from being a husband or a wife to then going and being a teacher, right? And that's a different sort of sense of self. And then being in the role of a friend, helping out other people or maintaining relationships with other people. And that these self-positions, which are quite different are behaviors you can imagine in these settings are very, very different. But our ability to shift our behavioral set from one setting to another in healthy people is intact, right? We shift these self-positions all the time. According to this model, people with schizophrenia have a disruption in shifting these self-positions. These self-positions can be disrupted in a variety of different ways. One way that a self-position can be disrupted is that one gets stuck in one specific self-position and is unable to shift to others. An example of this would be a person who believes that they are admired or are looked up to and that's sort of their sense of self that they have and they are unable to shift that sense, sense of self in any other social setting. So, at all times, they feel like they are admired or even envied. And because of this static, unable to sort of shift self-position, they end up developing delusions that people are out to get them because they are so deeply admired or because people are so envious of them. So that would be an example of one disruption. Another disruption might be that person with schizophrenia can't even develop one self-position, right? They can't even develop a self-position as a friend or as a partner or as a worker. They just have no self-position that they're able to develop in relationship to other people. As a function of this inability to develop any type of self-position, they develop an extreme social withdrawal and isolation, right? Because they're unable to sort of have any sense of self at all. What's interesting about the Lysaker model is it puts first person experience at the center of models of processing in people with schizophrenia. So, work by the Lysakers has typically involved actually listening to narratives, having clients talk about their experiences, and trying to get a sense of how integrated their sense of self is. Are they able to describe self-positions, different self-positions when they describe what's going on in terms of their sort of narrative thought processes? And the idea here is that through psychotherapy or other psycho-social interventions, the people with schizophrenia may in fact develop more consistent self-positions and self-positions that may shift from one environment to another and that will be a sign that the person is getting healthier or better. What's important about this model is it places the subjective experience of the person with schizophrenia at the center. So, it's a first-person approach to understanding schizophrenia. This semester, as we've talked about these various studies, in all cases, we've been using a third-person view, right? The idea is that we are looking at the person with schizophrenia, assessing their performance on some task, right? And then sort of measuring that in sort of a third-person relationship. Again, the Lysaker model of a subjective experience is the idea that the experience subjective self is actually disrupted. And for that reason, first-person accounts of psychological disruption of people with schizophrenia are very important to the study.
