Carol Lin - SUPC PPT final

Editor's Notes

• #3: SZ is a severe neurodevelopmental disorder1 that causes impaired emotional and social abilities, among other debilitating symptoms such as hallucinations, delusions, paranoia, and deteriorating quality of life.2 The exact etiology is unknown to this day, but it afflicts approximately 1% of the world’s population today.3 On average, the age of SZ onset is 18 in men, and 25 in women4.
• #4: Adolescent-onset psychosis, or AOP, is one subtype of SZ that is defined as emergence of over psychosis prior to age 18. AOP is a particularly virulent and chronic form of schizophrenia associated with poorer prognosis, more profound difficulties in behaving, thinking and communicating, and greater deficits in cognition and functioning relative to adult-onset SZ.
• #5: One particular area of impairment for patients with psychosis is social cognition, which is the ability to understand another individual’s intentions, emotions, and perspectives. Theory of Mind is one aspect of social cognition that is defined as the ability to predict another person’s behavior by associating emotions such as desires and beliefs. However, while ToM deficits are widely documented among adult-onset SZ patients, little is known about such impairments in AOP, warranting further examination.
• #6: Therefore, the current study sought to examine ToM deficits in the AOP population as compared to typically developing adolescents. We hypothesized that individuals with AOP would demonstrate impaired ToM skills, as evidenced by poorer performance on a ToM Task.
• #7: Participants were selected from a larger, ongoing study at UCLA. Our final sample consisted of 22 patients and 35 controls, who were demographically matched on age, gender, current IQ, years of education, and ethnicity. Patients met criteria for a psychotic-spectrum disorder, while controls were free of any Axis I disorders and any psychosis among first-degree relatives. All participants were administered a battery of clinical and neuropsychological measures including a ToM Task.
• #8: This ToM task is called Animations. Participants viewed 8 silent video clips (34-45s in length) that illustrated interactions between triangles moving around stationary rectangles. The 8 clips comprised 2 conditions; 4 Theory of Mind scenarios, which were simulated human interactions, & 4 random scenarios, or triangles that aimlessly moved around the screen. Clips were presented in randomized order to each participant. After viewing each clip, the participants were asked to describe what happened without feedback from the examiner and without an imposed time limit.
• #9: Each clip was then scored on the dimensions of Intentionality, the degree to which the subject describes complex, intentional mental states and interactions as depicted by the animated triangles, & Appropriateness, which is the accuracy of the descriptive response. Variables were scored on a scale from 0-5 for Intentionality, higher Intentionality scores meaning that more emotionally expressive verbs were used to describe interactions between multiple entities. Simple action verbs (e.g., floating, running) received scores of 0, while those suggesting intentions and motives received score of 5 (e.g., seducing, coaxing) Appropriateness was scored on a scale from 0-3, with higher scores meaning more accurate descriptions of the events in the clips. Average Intentionality and Appropriateness scores were then calculated for each person from the 4 clips comprising the Dimension (e.g., the 4 ToM clips, and the 4 Random clips). Therefore, each individual was left with 4 scores (ToM_I, ToM_A, RD_I, and RD_A) Group differences in Intentionality and Appropriateness scores were evaluated using a repeated measure ANOVA, with dimensions of 2 (Group: AOP vs. controls) x 2 (Condition: ToM vs. Random) on SPSS v. 2.0
• #10: Significant group by condition interactions for Intentionality and Appropriateness were found such that the difference in scores on intentionality and appropriateness between patients and controls varied according to task condition (ToM or Random).
• #11: In this figure, the group differences in intentionality scores across Condition Type are clearly visible. To orient you, on the x-axis are the two conditions of clips (ToM or random), while the y axis displays the average intentionality score for each participant across the 8 clips (4 in each condition). We see that patients were less adept at appropriately identifying mental states and social interactions in the ToM condition, and ascertaining that none were present in the random condition.
• #12: This figure displays the average score for appropriateness (or description accuracy) alongside the two task conditions. Again, there are clear group differences in average Appropriateness Scores across Condition Type. Patients appear more likely than controls to focus on describing the factual events of a clip in the presence of emotion-laden content during the ToM condition, but struggle more when the events of a clip are less structured. Controls show the opposite effect, such that they are more accurate in factually describing an event in the absence of clear human-like interactions.
• #13: Overall, results revealed that as compared to typically developing adolescents, patients experience more deficits in identifying mental states and relationships (Intentionality) in social situations, and instead focus more on factual information (Appropriateness). They were also less likely to differentiate between ToM and Random conditions when attempting to describe interactions between figures (i.e., on intentionality domain) This is in line with prior research showing deficits in social perception among patients with SZ, including impaired ability to infer mental states and to recognize emotional content. Our results are also in line with the idea that typically developing individuals are perhaps more likely to focus on emotion-based content as opposed to neutral stimuli in a given situation, perhaps explaining why the accuracy of their factual descriptions increased when in the random condition.
• #14: Limitations to our study included using a relatively small sample size and a cross-sectional approach, not investigating the role of covariates on observed effects (such as age, age of illness onset, IQ, gender), and not examining the association between observed deficits and functional/functioning outcome. Therefore, these are areas to be addressed in future studies, along with assessing the underlying neural mechanisms of observed ToM deficits using neuroimaging techniques.
• #15: Special thanks to the participants, funding sources, and advisors/lab personnel that helped to make this project what it is today. I definitely could not have done it without their help and advice. Thank you!
• #16: Any Questions?