Visual orientation by motion-produced blur patterns: Detection of divergence

Blur patterns are physiological “streaks” of photochemical and neural activity that occur whenever an observer and his visual environment are in relative motion. When retinal velocities are high, the impression of visual “flow” gives way to one of a field of “blur lines” whose patterns are rich with information about the motions and the optical textures that produced them. Simulated blur patterns were produced and thresholds measured for the detection of divergence at nine retinal loci. Sensitivity was somewhat greater in the central retina. Thresh-olds remained the same despite variations in pattern velocity, number of elements, and the presence or absence of an internal velocity gradient. Observers were able to orient above-threshold patterns, but consistently underestimated the amount of slant.     

Operant conditioning of an in vitro CNS-pneumostome preparation of Lymnaea

Operant conditioning of aerial respiratory behaviour and its consolidation into long-term memory in Lymnaea has been previously studied in both intact, freely moving snails and in in vitro preparations made from previously trained snails. Here, we show in previously untrained semi-intact in vitro Lymnaea preparations that aerial respiratory behaviour can also be operantly conditioned. Neither yoked control nor 'run-down' control procedures in these in vitro preparations result in an alteration of aerial respiratory behaviour. Memory in the operantly trained semi-intact preparations persists for at least 1h after training. Intracellular recordings made from RPeD1, one of the 3-CPG neurons and the neuron that initiates CPG activity; show that there are specific changes in central excitatory input to this neuron concurrent with learning and its consolidation into memory. In addition following the acquisition of learning and its consolidation into memory the ability of RPeD1 and VI/J neurons when depolarized to cause a pneumostome opening is significantly decreased. Thus, previously untrained in vitro semi-intact preparations can be used to study changes in neuronal activity in a neuron known to be both necessary for the behaviour and for memory formation.     

Scale effects in memory for the timeof events

This study addressed the question of how people remember the time of past events. Stimuli were 10 news events that had occurred from 6 months to 20 years before the study. In contrast to previous studies of memory for time, subjects were asked to provide estimates of the stimulus events on multiple time scales, including year, month, day of the month, day of the week, and hour. If judgments are based on direct information about the age of the memory, accuracy should decrease monotonically as one moves to finer scales. Alternatively, if subjects reconstruct the time from fragmentary information associated with the event, one would expect that estimates on finer time scales would often exceed grosser scales in accuracy. Results for accuracy, confidence, and number of recall cues supported the latter position. In addition, subjects reported a variety of types of recall cues, the most common being memory for personal experiences or events that were contiguous with the news event.     

Identifying outpatients with entrenched suicidal ideation following hospitalization

The purpose of this study was to identify outpatients who experience entrenched suicidal ideation following inpatient psychiatric hospitalization. Our findings suggest that the use of a suicidal ambivalence index score was helpful at discriminating those who reported significantly greater ratings of suicidal ideation across a 1-year period of time, whereas splitting patients based upon suicide attempt history yielded nonsignificant results. Similar findings resulted from a dimensional analytic approach, as well. Application of the suicidal ambivalence index may help administrators identify patients who require more intensive clinical services to resolve their suicidal ideation.     

Effects of sleep on positive,negative and neutral valenced story and image memory

During sleep, emotional memories are preferentially strengthened. However, most studies on sleep and emotional memory focus on comparing negative valence with neutral valence stimuli. This study compared the sleep-dependent memory effects for stories and images, each comprising negative, neutral, and positive stimuli. It was hypothesized that a sleep effect would be seen for negatively and positively valenced stimuli. A novel story memory task (comprising three stories), and photographs from the Nencki Affective Picture database were presented for learning to 61 healthy adults (ages 18–25). They were tested for memory on the two tasks immediately, and then again after either a 2-hr nap (n = 31; 17 women, 14 men) or 2-hr wake period (n = 30; 13 women, 17 men). At second testing, the sleep condition had significantly better recall compared to the wake condition on both tasks. There was a relationship with valence only for the story task, with better performance for the sleep condition on the negatively and positively valenced texts, but not on the neutral text. There were no significant relationships between memory measures and sleep-stage duration and EEG power variables. The story memory findings support the hypothesis that memory consolidation prioritizes emotional memory, whether positively or negatively valenced.     

One Foot Out of the Nest: How Parents and Friends Influence Social Perceptions in Emerging Adulthood

Attachment theory proposes that representations of attachment figures are transferred between relationships, resulting in stable relational experiences. The current study used a transference paradigm to examine how parental and best friend attachment representations influence perceptions of new relationship partners in emerging adulthood. We discovered that close friendships influenced attachment anxiety and avoidance experienced specifically with friend-like others, while parental relationships affected feelings of anxiety toward a variety of people. Several relationship factors, such as the importance of the friend relationship, moderated the transference process. Our findings suggest that emerging adults’ current relationships have an impact on their reactions toward novel individuals, and emerging adults’ feelings about their existing relationship partners color their future social experiences.     

White matter maturation supports the development of reasoning ability through its influence on processing speed

The structure of the human brain changes in several ways throughout childhood and adolescence. Perhaps the most salient of these changes is the strengthening of white matter tracts that enable distal brain regions to communicate with one another more quickly and efficiently. Here, we sought to understand whether and how white matter changes contribute to improved reasoning ability over development. In particular, we sought to understand whether previously reported relationships between white matter microstructure and reasoning are mediated by processing speed. To this end, we analyzed diffusion tensor imaging data as well as data from standard psychometric tests of cognitive abilities from 103 individuals between the ages of 6 and 18. We used structural equation modeling to investigate the network of relationships between brain and behavior variables. Our analyses provide support for the hypothesis that white matter maturation (as indexed either by microstructural organization or volume) supports improved processing speed, which, in turn, supports improved reasoning ability.     

Parental grief of a perinatal loss: A comparison of individual and relationship variables

Abstract

This study focuses on the comparison of individual variables of bereavement, depression, and stress with variables associated with the couple relationship, including cohesion, adaptability, communication, satisfaction, and partner support. In total, 24 couples completed self-report instruments within 2 weeks after a miscarriage. Mothers had significantly stronger grief reactions than fathers. Fathers and mothers perceived their relationships similarly as highly functional. Except for mothers' depression and their satisfaction with the couple relationship, the correlations between individual and relationship variables were rather weak. Implications of the results for family professionals are discussed.