Hemispheric dissociation of the involvement of NOS isoforms in memory for discriminated avoidance in the chick

Previous research has indicated a role for both the neuronal (nNOS) and endothelial (eNOS) nitric oxide isoforms in memory formation. In addition, two distinct periods of activity of nitric oxide activity, dissociated by hemispheric localization, are implicated following passive avoidance training in the chick. In the present study, we trained black Australorp-white Leghorn chicks on a color discrimination avoidance task. Diphenyleneiodonium chloride (1 microM) or N-propyl-l-arginine (50 microM) was administered into either the left or right hemisphere of the chick brain in an attempt to differentiate the effects of inhibiting eNOS or nNOS, respectively. The memory loss previously observed following administration of diphenyleneiodonium chloride between 10 and 20 min posttraining was found to be lateralized to the right hemisphere, although administration of this agent into the left hemisphere around the time of training was also amnestic. In contrast, N-propyl-l-arginine caused memory loss only when administered to the left hemisphere around the time of training. These findings suggest that activation of both eNOS and nNOS isoforms may be essential for long-term memory consolidation of this task. Further, these two periods of activity are defined temporally and by hemisphere localization, although confirmation with more selective inhibitors when they become available is advised.     

The relationship of self-monitored dating behaviors to level of feminist identity on the feminist identity scale

The feminist identity scale (FIS) has been used to assess level of feminist identity development in women. This study examined the relationship between dating behaviors and FIS level in college-aged students, as an attempt to further validate the FIS as a measure of the feminist identity concept. Dating behaviors displayed by women at different FIS levels were consistent with differing gender role behaviors hypothesized to accompany feminist identity development.     

“Just Carbon”: Ideas About Graphene Risks by Graphene Researchers and Innovation Advisors

Graphene is a nanomaterial with many promising and innovative applications, yet early studies indicate that graphene may pose risks to humans and the environment. According to ideas of responsible research and innovation, all relevant actors should strive to reduce risks related to technological innovations. Through semi-structured interviews, we investigated the idea of graphene as a risk (or not) held by two types of key actors: graphene researchers and innovation advisors at universities, where the latter are facilitating the movement of graphene from the laboratory to the marketplace. The most common idea found is that graphene is not a risk due to, e.g., low toxicity, low amounts produced/used, and its similarity to harmless materials (being “just carbon”). However, some researchers and advisors also say that graphene is a risk, e.g., under certain conditions or due to a lack of risk-related information. We explain the co-existence of these seemingly contradictory ideas through (1) the semantic ambiguity of the word risk and (2) a risk/no-risk rhetoric, where risks are mentioned rhetorically only to be disregarded as manageable or negligible. We suggest that some of the ideas held by the researchers and innovation advisors constitute a challenge to responsible research and innovation regarding graphene. At the same time, we acknowledge the dilemma that the discourse of responsible innovation creates for the actors: denying graphene risks makes them irresponsible due to a lack of risk awareness, while affirming graphene risks makes them irresponsible due to their everyday engagement in graphene development. We therefore recommend more research into what researchers and innovation advisors should do in practice in order to qualify as responsible.     

Sleep does not enhance motor sequence learning

Improvements in motor sequence performance have been observed after a delay involving sleep. This finding has been taken as evidence for an active sleep consolidation process that enhances subsequent performance. In a review of this literature, however, the authors observed 4 aspects of data analyses and experimental design that could lead to improved performance on the test in the absence of any sleep consolidation: (a) masking of learning effects in the averaged data, (b) masking of reactive inhibition effects in the averaged training data, (c) time-of-day and time-since-sleep confounds, and (d) a gradual buildup of fatigue over the course of massed (i.e., concentrated) training. In 2 experiments the authors show that when these factors are controlled for, or when their effects are substantially reduced, the sleep enhancement effect is eliminated. Whereas sleep may play a role in protection from forgetting of motor skills, it does not result in performance enhancement.     

Exposure to a rhythmic auditory stimulus facilitates memory formation for the passive avoidance task in the day-old chick.

Previous research regarding the beneficial effects of auditory stimuli on learning and memory in humans has been inconsistent. In the current study, day-old chicks were used to reduce the impact of individual differences on responses. Chicks were trained on a passive avoidance task and exposed to various auditory stimuli. Exposure to a complex rhythmic sequence for 1 min strongly facilitated chicks' long-term memory. The optimal time of presentation of the stimulus was between 10 min before and 20 min after training. Moreover, the enhancing effect was not generalized to the other auditory stimuli tested. It is suggested that this effect may be due to arousal because arousal hormones are critical to long-term memory formation. This study indicates that the temporal characteristics and type of stimulus may be important considerations when investigating the effects of auditory stimuli on cognitive functioning.     

Concurrent task performance enhances low-level visuomotor learning

Visuomotor association learning involves learning to make a motor response to an arbitrary visual stimulus. This learning is essential for visual search and discrimination performance and is reliant upon a well-defined neural circuit in the brain that includes the prefrontal cortex and the hippocampal formation. In the present study, we investigated the possible role of attentional processes during such learning using dual-task interference. A motor, verbal, or perceptual concurrent task was performed during the learning/training block of a simple visual discrimination task. Contrary to expectation, the dual-task groups showed improved learning and learning-dependent performance compared with untrained control and non-dual-task trained groups. A second experiment revealed that this effect did not appear to be due to increased arousal level; the inclusion of alerting tones during learning did not result in facilitation. These findings suggest that the engagement of attention, but not arousal, during the acquisition of a visuomotor association can facilitate this learning and its expression.