Parameter identification in multinomial processing tree models

Multinomial processing tree models form a popular class of statistical models for categorical data that have applications in various areas of psychological research. As in all statistical models, establishing which parameters are identified is necessary for model inference and selection on the basis of the likelihood function, and for the interpretation of the results. The required calculations to establish global identification can become intractable in complex models. We show how to establish local identification in multinomial processing tree models, based on formal methods independently proposed by Catchpole and Morgan (1997) and by Bekker, Merckens, and Wansbeek (1994). This approach is illustrated with multinomial processing tree models for the source-monitoring paradigm in memory research.     

The use of the analyst as an autistic shape

In this paper I describe through detailed clinical material the challenges posed by patients who employ entangled autistic defenses. I discuss the complicated nature of treating a patient who employed entangled autistic defenses and utilized my voice in an effort to preserve an undifferentiated state of dual unity. My patient's pursuit of dual unity took a very concrete form in her attempt to mitigate the terror of separateness. This concreteness was expressed via the patient's urgent request that I read letters she wrote to me between sessions. This type of autistic defense placed great strain on my ability to think analytically and I also became increasingly concrete in my response to the patient. Crucial to the analyst's regaining a space in which to think and a sense of separateness is the ability to contact the ground floor of her separate bodily experience. This is just the beginning step in the analyst separating herself from the powerful press to join the patient in a state of dual unity. Interpretation in action (Ogden, 1994) was an effective way to convey the importance of creating and tolerating internal space in myself and begin to create internal space in the patient. Previously such space had been closed down in order to manage primitive fears of annihilation. When a patient is absorbed in an entangling autistic retreat words do not reach the patient on a symbolic level but rather are experienced primarily as an assault on the need for dual unity with the analyst. The patient's need to be wrapped in a sensation based world of dual unity is preferable to a world of spoken words that carry the danger of delineating psychic separateness. In essence there is no self to speak words, only a whirl of an amorphous sensation self lacking definition. I believe with certain kinds of patients it may be necessary to first lose and then work to regain one's analytic mind, as I have powerfully described in the case of Linda. Linda's profound loss of connection to the ground floor of her experience could only begin to be addressed when I worked to extricate myself from ‘our magic carpet ride’ of dual unity, contacting the reality of my bodily experience, and begin to tolerate the terror I felt regarding my separateness from Linda. I also describe the confusing vacillation between entangled and encapsulated defenses in patients like Linda as previously identified by Cohen and Jay (1996). Ultimately, this kind of slow difficult analytic work began to help Linda develop a capacity to think and provided an alternative to the deadened world of her autistic protections.     

Knowing Versus Caring: The Role of Affect and Cognition in Political Perceptions

This paper examines the importance of political knowledge in shaping accurate perceptions of the political world—specifically, how levels of general political knowledge influence the accuracy of specific political judgments, how those judgments might also be shaped by "wishful thinking," and how political knowledge attenuates the impact of wishful thinking on political judgments. Predictions of who would win the U.S. presidential election in 1984, 1988, 1992, and 1996, as surveyed in the National Election Studies conducted in those years, were used as a measure of the accuracy of political perceptions. Analysis of these data reveals that both political knowledge and wishful thinking are important determinants of the accuracy of people's perceptions; in addition, the impact of wishful thinking on perceptions is attenuated by political knowledge.     

Optimistic biases in observational learning of value

Action-outcome contingencies can be learnt either by active trial-and-error, or vicariously, by observing the outcomes of actions performed by others. The extant literature is ambiguous as to which of these modes of learning is more effective, as controlled comparisons of operant and observational learning are rare. Here, we contrasted human operant and observational value learning, assessing implicit and explicit measures of learning from positive and negative reinforcement. Compared to direct operant learning, we show observational learning is associated with an optimistic over-valuation of low-value options, a pattern apparent both in participants’ choice preferences and their explicit post-hoc estimates of value. Learning of higher value options showed no such bias. We suggest that such a bias can be explained as a tendency for optimistic underestimation of the chance of experiencing negative events, an optimism repressed when information is gathered through direct operant learning.