A longitudinal examination of stress generation in depressive and anxiety disorders

The current study compared two competing theories of the stress generation model of depression (stress causation vs. stress continuation) using interview-based measures of episodic life stress, as well as interpersonal and noninterpersonal chronic life stress. We also expanded on past research by examining anxiety disorders as well as depressive disorders. In addition, we examined the role of neuroticism and extraversion in these relationships. Participants were 627 adolescents enrolled in a two-site, longitudinal study of risk factors for depressive and anxiety disorders. Baseline and follow-up assessments were approximately one year apart. Results supported the stress causation theory for episodic stress generation for anxiety disorders, with neuroticism partially accounting for this relationship. The stress causation theory was also supported for depression, but only for more moderate to severe stressors; neuroticism partially accounted for this relationship as well. Finally, we found evidence for interpersonal and noninterpersonal chronic life stress continuation in both depressive and anxiety disorders. The present findings have implications regarding the specificity of the stress generation model to depressive disorders, as well as variables involved in the stress generation process.     

Perception and the Categories: A Conceptualist Reading of Kant's Critique of Pure Reason

Abstract: Philosophers interested in Kant's relevance to contemporary debates over the nature of mental content—notably Robert Hanna and Lucy Allais—have argued that Kant ought to be credited with being the original proponent of the existence of ‘nonconceptual content’. However, I think the ‘nonconceptualist’ interpretations that Hanna and Allais give do not show that Kant allowed for nonconceptual content as they construe it. I argue, on the basis of an analysis of certain sections of the A and B editions of the Transcendental Deduction, for a ‘conceptualist’ reading of Kant's Critique of Pure Reason. My contention is that since Kant's notion of empirical intuition makes essential reference to the categories, it must be true for him that no empirical intuition can be given in sensibility independently of the understanding and its categories.     

Role of the dorsal hippocampus in object memory load

The dorsal hippocampus is crucial for mammalian spatial memory, but its exact role in item memory is still hotly debated. Recent evidence in humans suggested that the hippocampus might be selectively involved in item short-term memory to deal with an increasing memory load. In this study, we sought to test this hypothesis. To this aim we developed a novel behavioral procedure to study object memory load in mice by progressively increasing the stimulus set size in the spontaneous object recognition task. Using this procedure, we demonstrated that naive mice have a memory span, which is the number of elements they can remember for a short-time interval, of about six objects. Then, we showed that excitotoxic selective lesions of the dorsal hippocampus did not impair novel object discrimination in the condition of low memory load. In contrast, the same lesion impaired novel object discrimination in the high memory load condition, and reduced the object memory span to four objects. These results have important heuristic and clinical implications because they open new perspective toward the understanding of the role of the hippocampus in item memory and in memory span deficits occurring in human pathologies, such as Alzheimer's disease and schizophrenia.     

Elective mutism in a first grader: The remediation of a complex behavioral problem

Teachers frequently deal with unusual and perplexing behavioral problems in their classes. This study demonstrates how spontaneous and prompted speech were produced in a six-year-old mute by a first-grade teacher and her aide. A reinforcement system for peer-prompted speech and spontaneous speech was employed in three separate school classes in a multiple-baseline fashion. The reinforcement system produced prompted and spontaneous speech in each situation. Postchecks in the second grade indicated the child was still speaking and conversing spontaneously with his peers. This study suggests a method that teachers can use in the classroom to deal with this severely handicapping condition.     

The attentional demands of mnemonic control processes

In order to assess the processing (i.e., attentional) demands of different control processes, subjects were required to perform a secondary choice reaction time task in addition to primary verbal tasks. The performance of the secondary task yielded a measure termedexpended processing capacity (EPC), which was used to infer the attentional demands of the primary tasks. Two factors, mediator type (experimenter-supplied vs. subject-generated) and intentionality (incidental vs. intentional), were varied in a paired-associate situation in an effort to affect the degree of elaboration processing. Only mediator type had an effect on recall accuracy and on EPC during both initial processing and recall. Subject-generated mediators resulted in higher recall and in higher EPC during initial processing, but in lower EPC during recall, than did experimenter-supplied mediators. Implications of these findings are discussed.