Modulatory role of serotonin in neural information processing: implications for human psychopathology.

Investigation of the role of 5-hydroxytryptophan (5-HT), which functions as a modulator in the central nervous system, across behavioral contexts suggests that a general principle of transmitter function may be derived that is independent of specific behaviors and specific neural loci. A functional principle of 5-HT action in neural information processing in the central nervous system is proposed. Extremes deviations in 5-HT activity result in biases in information processing that may have direct effects on behavior. Such biases may predispose to pathological conditions such as violent suicide and aggression.     

Regular and irregular inflection in the acquisition of German noun plurals.

In this paper we study the acquisition of German noun plurals in relation to the question of how children represent regular and irregular inflection. Pinker and Prince (1992) have demonstrated several dissociations between regular and irregular inflection in the English past tense system. However, in English, the default status of -ed is confounded with its high frequency; therefore inflectional systems other than English past tense formation must be examined. The noun plural system in German is particularly interesting, because most nouns have irregular plurals in German and the regular (default) plural is less frequent than several of the irregular plurals. Thus it is unclear how a language learner determines whether German even has a regular plural, and if so what form it takes. Based on longitudinal data from impaired and unimpaired monolingual German-speaking children, we find a striking, statistically significant correlation: plural affixes that are used in overregularizations, namely -n or -s, are left out within compounds. This correlation shows that even impaired children are sensitive to the distinction between regular and irregular morphology. We propose a linguistic analysis of the correlation in terms of Kiparsky's (1982, 1985) level-ordering model plus an additional ordering condition on affixes: default (regular) affixes cannot serve as input to compounding processes.     

From concepts to lexical items.

In this paper we address the question how in language production conceptual structures are mapped onto lexical items. First we describe the lexical system in a fairly abstract way. Such a system consists of, among other things, a fixed set of basic lexical entries characterized by four groups of information: phonetic form, grammatical features, argument structure, and semantic form. A crucial assumption of the paper is that the meaning in a lexical entry has a complex internal structure composed of more primitive elements (decomposition). Some aspects of argument structure and semantic form and their interaction are discussed with respect to the issue of synonymy. We propose two different mappings involved in lexical access. One maps conceptual structures to semantic forms, and the other maps semantic forms to conceptual structures. Both mappings are context dependent and are many-to-many mappings. We present an elaboration of Levelt's (1989) model in which these processes interact with the grammatical encoder and the mental lexicon. Then we address the consequences of decomposition for processing models, especially the nature of the input of lexical access and the time course. Processing models that use the activation metaphor may have difficulties accounting for certain phenomena where a certain lemma triggers not one, but two or more word forms that have to be produced with other word forms in between.     

Predictors of short-term treatment outcome in bulimia nervosa inpatients.

Recent studies, mostly performed on bulimic outpatients, did not find consistent predictors of treatment outcome in bulimia nervosa. This is the first study to investigate anamnestic and clinical factors predictive of the short-term outcome of hospital treatment in 31 female bulimia nervosa patients with a mean age of 22.9 yr. Treatment outcome was assessed by several self-rating instruments measuring different features of the specific and unspecific psychopathology of bulimia nervosa. The most relevant predictors of the outcome of the 8-week hospital treatment were duration of previous inpatient treatments for bulimia, the intensity of anorexic tendency and the pretreatment level of depression. The majority of predictors tested did not show a strong relationship to treatment outcome. The findings are discussed in relation to results of other studies as well as to possible implications for treatment and research.     

Cue-exposure vs self-control in the treatment of binge eating: a pilot study.

From a recent theory on the learned nature of craving responses and binge eating, it follows that craving will extinguish when the CS-US bond is broken by prolonged exposure to the cues predicting excessive food intake with response prevention. The present authors treated six obese bulimics with cue exposure and response prevention. Six other patients learned to avoid or escape the binge-related cues with the aid of self control techniques. Although both treatments appeared to be effective in reducing the binge frequency, a most remarkable finding of the present study is that all patients treated by cue exposure were abstinent, directly after treatment and during the 1 yr follow-up. In contrast to the 100% binge-free subjects treated by cue exposure, self control techniques and relapse prevention led to abstinence in merely 33% of the subjects.     

Reaction time to threat stimuli in panic disorder and social phobia

Two studies assessed response time among clinically anxious subjects and normal controls when presented with threat, positive and neutral stimuli under perceptual (lexical decision) and semantic (category decision) task conditions. In Study 1, panic disorder subjects' (n = 14) performance was compared to that of matched normal controls (n = 14) while in Study 2 social phobic subjects (n = 24) were compared to matched normal controls (n = 24). Relative to matched normal controls, panic disorder subjects but not social phobics tended to show greater slowing in performance on the more cognitively complex (category) task. A second finding, consistent across both studies was that, compared to the normal control groups, both panic and social phobic groups showed significantly slowed responses to threat words in both the perceptual and semantic tasks. Such findings are directly counter to the predictions of a mood congruence hypothesis. This apparent contradiction is resolved by a review of the literature which indicates that mood-related facilitation effects are obtained only in tasks which tap awareness of threat information rather than speed of response. It is suggested that while anxiety may produce enhanced awareness of threat, it may inhibit responsiveness to it. The results of these studies are seen as consistent with ethological theories of inhibited motoric responses under certain threat conditions. Furthermore, the findings suggest that caution is indicated in interpreting slowed reaction time to threat stimuli in tasks such as the Stroop color naming task as purely the result of attentional processes.     

Emergenesis. Genetic traits that may not run in families.

Traits that are influenced by a configuration--rather than by a simple sum--of polymorphic genes may not be seen to be genetic unless one studies monozygotic twins (who share all their genes and thus all gene configurations) because such "emergenic" traits will tend not to run in families. Personal idiosyncrasies that have been found to be surprisingly concordant among MZ twins separated in infancy and reared apart may be emergenic traits. More speculatively, important human traits like leadership, genius in its many manifestations, being an effective therapist or parent, as well as certain psychopathological syndromes may also be emergenic. These ideas reemphasize the importance of the role played in human affairs by genetic variation.     

Scientific rewards and conflicts of ethical choices in human subjects research.

The primary responsibility of the American Psychological Association's (APA) Committee on Standards in Research (CSR) is to advise the APA on issues and standards related to the protection of human participants in psychological research. A related goal is to enhance the use of good ethical practices by APA members. The purpose of this article is to foster the view of research ethics not as an affront to the integrity of sound research, but as opportunities for scientific rewards, including increased understanding of the meaning of data, enhanced recruitment, and the inclusion of more representative samples. Three ethical practices are discussed as examples of this general premise: respect for confidentiality, use of debriefing, and assurance that participants are noncoerced volunteers. The Committee's intent is to promote consideration of these issues, not to promulgate specific guidelines or procedures.