Olfactory self-recognition in a cichlid fish

Animal self-cognizance might be of importance in different contexts like territoriality, self-referent mate-choice or kin recognition. We investigated whether the cichlid fish Pelvicachromis taeniatus is able to recognize own olfactory cues. P. taeniatus is a cave breeding fish with pronounced brood care and social behavior. In the experiments we gave male cave owners the choice between two caves in which we introduced scented water. In a first experiment males preferred caves with their own odor over caves with the odor of an unfamiliar, unrelated male. To examine whether self-recognition is based rather on individual or on family cues we conducted two further experiments in which males could choose between their own odor and the odor of a familiar brother and between the odor of a familiar brother and an unfamiliar, unrelated male, respectively. Males preferred their own odor over that of a familiar brother suggesting individual self-referencing. Interestingly, males (at least outbred ones) preferred the odor of an unfamiliar, unrelated male over that of a familiar brother, maybe to avoid competition with kin. We discuss the results in the context of animal self-cognizance. All experiments were conducted with in- and outbred fish. Inbreeding did not negatively affect self-recognition.     

Predictors of time-based prospective memory in children

This study identified age differences in time-based prospective memory performance in school-aged children and explored possible cognitive correlates of age-related performance. A total of 56 7- to 12-year-olds performed a prospective memory task in which prospective memory accuracy, ongoing task performance, and time monitoring were assessed. Additional tests of time estimation, working memory, task switching, and planning were performed. Results showed a robust relationship between age and prospective memory performance even after controlling for ongoing task performance. Developmental differences in time monitoring were also observed, with older children generally adopting a more strategic monitoring strategy than younger children. The majority of age-related variance in prospective memory task performance could be explained by cognitive resources, in particular planning and task switching. In contrast, no further independent contribution of time estimation was observed. Findings are in line with the development of strategic behavior, as well as executive functioning, in school-aged children.     

Privileged detection of conspecifics: Evidence from inversion effects during continuous flash suppression

The rapid visual detection of other people in our environment is an important first step in social cognition. Here we provide evidence for selective sensitivity of the human visual system to upright depictions of conspecifics. In a series of seven experiments, we assessed the impact of stimulus inversion on the detection of person silhouettes, headless bodies, faces and other objects from a wide range of animate and inanimate control categories. We used continuous flash suppression (CFS), a variant of binocular rivalry, to render stimuli invisible at the beginning of each trial and measured the time upright and inverted stimuli needed to overcome such interocular suppression. Inversion strongly interfered with access to awareness for human faces, headless human bodies, person silhouettes, and even highly variable body postures, while suppression durations for control objects were not (inanimate objects) or only mildly (animal faces and bodies) affected by inversion. Furthermore, inversion effects were eliminated when the normal body configuration was distorted. The absence of strong inversion effects in a binocular control condition not involving interocular suppression suggests that non-conscious mechanisms mediated the effect of inversion on body and face detection during CFS. These results indicate that perceptual mechanisms that govern access to visual awareness are highly sensitive to the presence of conspecifics.     

Sleep normalization and decrease in dissociative experiences: evaluation in an inpatient sample

We conducted a longitudinal study to investigate the relation between sleep experiences and dissociative symptoms in a mixed inpatient sample at a private clinic evaluated on arrival and at discharge 6 to 8 weeks later. Using hierarchical regression analyses and structural equation modeling, we found a link between sleep experiences and dissociative symptoms and determined that specifically decreases in narcoleptic experiences rather than insomnia accompany a reduction in dissociative symptoms. Although sleep improvements were associated with a general reduction in psychopathology, this reduction could not fully account for the substantial and specific effect that we found for dissociation. Our findings are consistent with Watson's (2001) hypothesis that disruptions in the sleep-wake cycle lead to intrusions of sleep phenomena into waking consciousness, resulting in dissociative experiences. Accordingly, sleep hygiene may contribute to the treatment or prevention of dissociative symptoms.     

Gaze control and recollective experience in face recognition

In two experiments, we examined the relation between gaze control and recollective experience in the context of face recognition. In Experiment 1, participants studied a series of faces, while their eye movements were eliminated either during study or test, or both. Subsequently, they made remember/know judgements for each recognized test face. The preclusion of eye movements impaired explicit recollection without affecting familiarity-based recognition. In Experiment 2, participants examined unfamiliar faces under two study conditions (similarity vs. difference judgements), while their eye movements were registered. Similarity vs. difference judgements produced the opposite effects on remember/know responses, with no systematic effects on eye movements. However, face recollection was related to eye movements, so that remember responses were associated with more frequent refixations than know responses. These findings suggest that saccadic eye movements mediate the nature of recollective experience, and that explicit recollection reflects a greater consistency between study and test fixations than familiarity-based face recognition.     

The effect of fearful faces on the attentional blink is task dependent

In a set of three rapid serial visual presentation experiments, we investigated the effect of fearful and neutral face stimuli on the report of trailing scene targets. When the emotional expression of the face stimuli had to be indicated, fearful faces induced a stronger attentional blink (AB) than did neutral faces. However, with identical physical stimulation, the enhancement of the AB by fearful faces disappeared when participants had to judge the faces’ gender. If faces did not have to be reported, no AB was observed. Thus, fearful faces exhibited an effect on the AB that crucially depended on the observer’s attentional set. Hence, the AB can be influenced by an emotional T1 when T1 has to be reported, but this influence is modulated by task context. This result indicates a close connection between temporal attention and emotional processing that is modulated by task context.     

From Semantic Games to Provability: The Case of Gödel Logic

Studia Logica - We present a semantic game for Gödel logic and its extensions, where the players’ interaction stepwise reduces arbitrary claims about the relative order of truth degrees...     

Psychological effects of (non)employment: A cross‐national comparison of the United States and Japan

The involuntary loss of employment has been shown to deteriorate subjective well‐being. Adopting a cross‐cultural perspective on Jahoda's ( 1982 ) deprivation model this study examines several latent and manifest benefits of work that were expected to mediate the effects of employment status on well‐being. It was hypothesized that in more collectivistic societies the decline in subjective well‐being would be a consequence of a diminished sense of collective purpose for the non‐employed, whereas in individualistic societies the crucial factors would be a loss of social status and financial benefits. The findings from two representative national surveys conducted in the United States (N = 1,093) and Japan (N = 647) provided partial support for these hypotheses. Cultural differences moderated the effects of employment status on the benefits of work. As a consequence, different processes mediated the decline in well‐being for the non‐employed in the two countries. These results are embedded within the wider discourse on culture and its effect on unemployment.