German inflection: single route or dual route?

The German plural system has recently become a focal point for conflicting theories of language, both linguistic and cognitive. Marcus et al. (1995) highlight the German plural as support for the dual-route account of inflectional morphology first proposed by Pinker and colleagues (Pinker & Prince, 1988). On the dual-route account, inflectional morphology is universally subserved by a symbolic rule route which deals with regular inflection and an associative memory component which deals with irregular inflection. This contrasts with single-route connectionist systems. We seek to counter supposed evidence for the dual-route account through large-scale simulations as well as through experimental data. We argue that, in its current form, the dual-route account is incapable of generating experimental data provided by Marcus et al. (1995) as support. Finally, we provide direct quantitative comparisons between single-route and dual-route models of German plural inflection and find single-route performance superior on these tests.     

The role of good form in young Infants' perception of partly occluded objects

Young infants have been reported to perceive the unity of a center-occluded object when the visible ends of the object undergo common motion, but not on the basis of stationary information (e.g., P. J. Kellman & E. S. Spelke, 1983). We investigated the possibility that 4-month-old infants will attend to and utilize the global configuration (i.e., the "good form") of a partly occluded, moving object to perceive its unity and coherence behind the occluder. In the first experiment, infants viewed a partly occluded circle or cross that translated laterally. Infants who habituated in the minimum number of trials ("fast habituators") showed a reliable posthabituation preference for a broken object over a complete object, indicating perception of unity in the habituation display. Slow habituators exhibited no posthabituation preference. In the second experiment, infants were presented with small ring and cross displays, and the infants looked longer at the broken object. There were no reliable differences in performance between fast and slow habituators. A control group demonstrated no reliable posthabituation preference. In three additional conditions, infants viewed either a partly occluded half ring or a display in which two rod parts were either relatable and nonaligned or nonrelatable. The results indicated that curvature per se provided information in support of completion, in addition to global configuration and motion. Implications for theories of infants' visual development are discussed.     

Emotional experience in everyday life across the adult life span

Age differences in emotional experience over the adult life span were explored, focusing on the frequency, intensity, complexity, and consistency of emotional experience in everyday life. One hundred eighty-four people, age 18 to 94 years, participated in an experience-sampling procedure in which emotions were recorded across a 1-week period. Age was unrelated to frequency of positive emotional experience. A curvilinear relationship best characterized negative emotional experience. Negative emotions declined in frequency until approximately age 60, at which point the decline ceased. Individual factor analyses computed for each participant revealed that age was associated with more differentiated emotional experience. In addition, periods of highly positive emotional experience were more likely to endure among older people and periods of highly negative emotional experience were less stable. Findings are interpreted within the theoretical framework of socioemotional selectivity theory.     

Changing internal constraints on action: the role of backward inhibition

Flexible control of action requires the ability to disengage from previous goals or task sets. The authors tested the hypothesis that disengagement during intentional shifts between task sets is accompanied by inhibition of the previous task set ("backward inhibition"). As an expression of backward inhibition the authors predicted increased response times when shifting to a task set that had to be abandoned recently and, thus, suffers residual inhibition. The critical backward inhibition effect on the level of abstractly defined perceptual task sets was obtained across 6 different experiments. In addition, it was shown that backward inhibition can be differentiated from negative priming (Experiment 2), that it is tied to top-down sequential control (Experiment 3), that it can account at least partially for "residual shift costs" in set-shifting experiments (Experiment 4), and that it occurs even in the context of preplanned sequences of task sets (Experiment 5).     

A cross-cultural study of suicide intent in parasuicide patients

As part of the WHO/EURO Multicentre Study on Parasuicide, the level of suicide intent among female and male parasuicide patients from various European regions was compared. From nine regions, a total of 1,212 parasuicide patients, 752 females and 460 males, were included in the study. Although some statistical significant differences in level of suicide intent between the regions and genders were found, the effect sizes of these relationships were so small that the differences have neither theoretical nor practical significance. As far as level of suicide intent is concerned, the WHO study has succeeded in recruiting a relatively homogeneous group of self-harming patients across borders of region, culture, and country.     

Recognition of heterospecific alarm vocalizations by bonnet macaques (Macaca radiata)

Recognition of heterospecific alarm vocalizations is an essential component of antipredator behavior in several prey species. The authors examined the role of learning in the discrimination of heterospecific vocalizations by wild bonnet macaques (Macaca radiata) in southern India The bonnet macaques' flight and scanning responses to playbacks of their own alarm vocalizations were compared with their responses to playbacks of vocalizations of Nilgiri langurs (Trachypithecus johnii), Hanuman langurs (Semnopithecus entellus), and sambar deer (Cervus unicolor). The study was conducted in 3 regions that differed in the frequency with which bonnet macaques encountered these species and included an urban setting. Call recognition was highest in adults and in regions where individuals were frequently exposed to the calling species; calls were not recognized by urban monkeys. Thus, age and experience are important factors in heterospecific call recognition by bonnet macaques.     

Emotional responses in patients with borderline as compared with avoidant personality disorder

The aim of this study was to assess psychophysiological affect correlates, in addition to the usual self-report in borderline personality disorder (BPD) compared with avoidant personality disorder (APD) and normal controls (NCs), when responding to standardized experimental stimuli. In 24 BPD female patients, 23 APD female patients, and 27 female NCs, skin conductance response (SCR), heart rate (HR) change, and startle response were recorded while the subjects viewed slides with emotional content. Neither the self-report nor the psychophysiological data supported the hypothesis that affective responses of BPD individuals are generally stronger than those with APD. BPD patients showed no potentiation of the affective modulation of the startle reflex and their electrodermal reactivity was lower than in either the APD subjects or the NCs. The hypothesis of a general affective hyperresponsivity could not be confirmed. Low somatic arousal in BPD can interfere with the anticipation of signal stimuli and may explain the exaggerated openness borderline personalities show to stimuli, particularly in interpersonal situations.     

Unconscious facial reactions to emotional facial expressions

Studies reveal that when people are exposed to emotional facial expressions, they spontaneously react with distinct facial electromyographic (EMG) reactions in emotion-relevant facial muscles. These reactions reflect, in part, a tendency to mimic the facial stimuli. We investigated whether corresponding facial reactions can be elicited when people are unconsciously exposed to happy and angry facial expressions. Through use of the backward-masking technique, the subjects were prevented from consciously perceiving 30-ms exposures of happy, neutral, and angry target faces, which immediately were followed and masked by neutral faces. Despite the fact that exposure to happy and angry faces was unconscious, the subjects reacted with distinct facial muscle reactions that corresponded to the happy and angry stimulus faces. Our results show that both positive and negative emotional reactions can be unconsciously evoked, and particularly that important aspects of emotional face-to-face communication can occur on an unconscious level.     

The impact of MRI scanner environment on perceptual decision-making

Despite the widespread use of functional magnetic resonance imaging (fMRI), few studies have addressed scanner effects on performance. The studies that have examined this question show a wide variety of results. In this article we report analyses of three experiments in which participants performed a perceptual decision-making task both in a traditional setting as well as inside an MRI scanner. The results consistently show that response times increase inside the scanner. Error rates also increase, but to a lesser extent. To reveal the underlying mechanisms that drive the behavioral changes when performing a task inside the MRI scanner, the data were analyzed using the linear ballistic accumulator model of decision-making. These analyses show that, in the scanner, participants exhibit a slow down of the motor component of the response and have less attentional focus on the task. However, the balance between focus and motor slowing depends on the specific task requirements.     

Putting action memory to the test: testing affects subsequent restudy but not long-term forgetting of action events

Testing memory typically enhances subsequent re-encoding of information (“indirect” testing effect) and, as compared to restudy, it also benefits later long-term retention (“direct” testing effect). We investigated the effect of testing on subsequent restudy and 1-week retention of action events (e.g. “water the plant”). In addition, we investigated if the type of recall practice (noun-cued vs. verb-cued) moderates these testing benefits. The results showed an indirect testing effect that increased following noun-cued recall of verbs as compared to verb-cued recall of nouns. In contrast, a direct testing effect on the forgetting rate of performed actions was not reliably observed, neither for noun- nor verb-cued recall. Thus, to the extent that this study successfully dissociated direct and indirect testing-based enhancements, they seem to be differentially effective for performed actions, and may rely on partially different mechanisms.