Sleep deprivation impairs object recognition in mice

Many studies in animals and humans suggest that sleep facilitates learning, memory consolidation, and retrieval. Moreover, sleep deprivation (SD) incurred after learning, impaired memory in humans, mice, rats, and hamsters. We investigated the importance of sleep and its timing in an object recognition task in OF1 mice subjected to 6h SD either immediately after the acquisition phase (0-6 SD) or 6h later (7-12 SD), and in corresponding undisturbed controls. Motor activity was continuously recorded with infrared sensors. All groups explored two familiar, previously encountered objects to a similar extent, both at the end of the acquisition phase and 24h later during the test phase, indicating intact familiarity detection. During the test phase 0-6 SD mice failed to discriminate between the single novel and the two familiar objects. In contrast, the 7-12 SD group and the two control groups explored the novel object significantly longer than the two familiar objects. Plasma corticosterone levels determined after SD did not differ from time-matched undisturbed controls, but were significantly below the level measured after learning alone. ACTH did not differ between the groups. Therefore, it is unlikely that stress contributed to the memory impairment. We conclude that the loss of sleep and the activities the mice engaged in during the SD, impaired recognition memory retrieval, when they occurred immediately after acquisition. The delayed SD enabled memory consolidation during the 6h when the mice were allowed to sleep, and had no detrimental effect on memory. Neither SD schedule impaired object familiarity processing, suggesting that only specific cognitive abilities were sensitive to the intervention. Sleep may either actively promote memory formation, or alternatively, sleep may provide optimal conditions of non-interference for consolidation.     

Structure-based modulation of inhibition of return is triggered by object-internal but not occluding shape features

When attention is oriented to an object it is inhibited from returning to the same object following a short delay. This inhibition-of-return (IOR) effect is modulated by an edge discontinuity presented between cue and target—an effect referred to as structure-based modulation of IOR. Here we examined two alternative accounts for the structure-based modulation effect. On one account the modulation is caused by the presence of any intervening feature between cue and target. On another account the modulation is caused by edge-bounded (i.e., closed) regions of space, on which space-based selection mechanisms operate. We presented cues and targets on unsegmented and internally or externally segmented rectangles to examine the two alternative accounts for the effect. Contrary to the predictions of the two alternative accounts, structure-based modulation of IOR was found with the internally but not with the externally segmented displays. This supports our hypothesis that object-based IOR arises from perceptually complete and internally structured object representations.     

What the voice reveals: within- and between-category stereotyping on the basis of voice

The authors report research that attempts to shift the traditional focus of visual cues to auditory cues as a basis for stereotyping. Moreover, their approach examines whether gender-signaling vocal cues lead not only to between-category but also to within-category gender stereotyping. Study 1 showed that both men and women vary within category in how feminine their voices sound and that perceptions of vocal femininity are highly consensual. Furthermore, the measured acoustic characteristics that differed between gender were also related to perceptions of within-gender femininity. Subsequent studies demonstrated that variability in vocal femininity affects gender stereotyping when the targets are all of the same gender (Study 2) and when the targets are of different genders (Study 3). In the latter case, evidence of both category-based and feature-based stereotyping was found. Mediation analyses showed that the relationship between acoustics and stereotyping was in part due to femininity.     

Recognition memory and awareness: A high-frequency advantage in the accuracy of knowing

The well-established advantage of low-frequency words over high-frequency words in recognition memory has been found to occur in remembering and not knowing. Two experiments employed remember and know judgements, and divided attention to investigate the possibility of an effect of word frequency on know responses given appropriate study conditions. With undivided attention at study, the usual low-frequency advantage in the accuracy of remember responses, but no effect on know responses, was obtained. Under a demanding divided attention task at encoding, a high-frequency advantage in the accuracy of know responses was obtained. The results are discussed in relation to theories of knowing, particularly those incorporating perceptual and conceptual fluency.     

Recognition memory and awareness: A high-frequency advantage in the accuracy of knowing

The well-established advantage of low-frequency words over high-frequency words in recognition memory has been found to occur in remembering and not knowing. Two experiments employed remember and know judgements, and divided attention to investigate the possibility of an effect of word frequency on know responses given appropriate study conditions. With undivided attention at study, the usual low-frequency advantage in the accuracy of remember responses, but no effect on know responses, was obtained. Under a demanding divided attention task at encoding, a high-frequency advantage in the accuracy of know responses was obtained. The results are discussed in relation to theories of knowing, particularly those incorporating perceptual and conceptual fluency.     

Sometimes it's easier to forgive my transgressor than your transgressor: effects of subjective temporal distance on forgiveness for harm to self or close other

The present research extended previous work on the third‐party (un)forgiveness effect—the tendency to be more forgiving for transgressions committed against the self than a close other—by testing how subjective temporal distance of first‐ and third‐party transgressions might influence the forgiveness process. Participants recalled a time in which they or a close other was harmed by another person, and was then made to feel either distant from or close to the transgression. As predicted, third‐party (un)forgiveness was observed when transgressions felt distant, but not when transgressions felt recent. Implications for restoring and maintaining positive relationships are discussed.     

A Test of Order-Constrained Hypotheses for Circular Data With Applications to Human Movement Science

Researchers studying the movements of the human body often encounter data measured in angles (e.g., angular displacements of joints). The evaluation of these circular data requires special statistical methods. The authors introduce a new test for the analysis of order-constrained hypotheses for circular data. Through this test, researchers can evaluate their expectations regarding the outcome of an experiment directly by representing their ideas in the form of a hypothesis containing inequality constraints. The resulting data analysis is generally more powerful than one using standard null hypothesis testing. Two examples of circular data from human movement science are presented to illustrate the use of the test. Results from a simulation study show that the test performs well.     

The Sense of Being Dead and of Dying: Some Perspectives

The present communication is made in response to a published study (Lester and Schumacher, 1969) which found no support for hypotheses that schizophrenic women might usefully be conceptualized as dying women, and that schizophrenics (men and women) would have more death themes in their TAT stories than non-schizophrenics. The present authors argue that there is no reason to expect schizophrenic women to feel like dying women, do present empirical data strongly supporting the notion of a relation between feelings of unreality and of deadness, and suggest reasons for Lester and Schumacher's failure to find schizophrenic-nonschizophrenic differences in TAT themes of death.