Strategic adaptation to performance objectives in a dual-task setting

How do people interleave attention when multitasking? One dominant account is that the completion of a subtask serves as a cue to switch tasks. But what happens if switching solely at subtask boundaries led to poor performance? We report a study in which participants manually dialed a UK‐style telephone number while driving a simulated vehicle. If the driver were to exclusively return his or her attention to driving after completing a subtask (i.e., using the single break in the xxxxx‐xxxxxx representational structure of the number), then we would expect to see a relatively poor driving performance. In contrast, our results show that drivers choose to return attention to steering control before the natural subtask boundary. A computational modeling analysis shows that drivers had to adopt this strategy to meet the required performance objective of maintaining an acceptable lateral position in the road while dialing. Taken together these results support the idea that people can strategically control the allocation of attention in multitask settings to meet specific performance criteria.     

Intra-female aggression in the mouse (Mus musculus domesticus) is linked to the estrous cycle regularity but not to ovulation

Intraspecific communication between mice takes place mainly via urinary chemosignals or "pheromones". Pheromones can influence aggressive and reproductive behavior as well as the neuroendocrine condition of the recipient female mice via their olfactory system. In this study, reproductively cyclic mice in the estrus phase were used to test intraspecific agonistic aggressive behavior. Data were obtained also on the count of the eggs shed in the oviducts. The results showed that (i) individually housed female mice are more aggressive toward an intruder female mouse than grouped mice, (ii) mice in which the vomeronasal organ was removed show aggressive behavior intermediate between individually housed and grouped mice, and (iii) a within group analysis did not show a positive correlation between aggression and presence of shed eggs in the oviducts.     

Beyond Therapy and Enhancement: The Alteration of Human Nature

With the rapid progress and considerable promise of nanobiotechnology/neurosciences there is the potential of transforming the very nature of human beings and of how humans can conceive of themselves as rational animals through technological innovations. The interface between humans and machines (neuro-digital interface), can potentially alter what it means to be human, i.e., the very idea of human nature and of normal functioning will be changed. In this paper, I argue that we are potentially on the verge of a paradigm shift in terms of the ends and goals of techno-science and its applications in the biomedical sciences. In particular, the development of brain-computer interfaces could reconceptualize the very notion of what it means to be human. Hence, we should not limit our reflections of applications in terms of therapy and enhancement but also include an examination of applications aiming at the alteration of human nature. To this end I will first delineate the potential paradigm shift and then map out four distinct clusters of concerns in relation to the brain-computer interface. Finally, I argue that our moral and philosophical reflections should follow a procedural model based on managed consensus due to our pluralistic context.

Using real-time visual feedback to improve posture at computer workstations

The purpose of the current study was to examine the effects of a multicomponent intervention that included discrimination training, real-time visual feedback, and self-monitoring on postural behavior at a computer workstation in a simulated office environment. Using a nonconcurrent multiple baseline design across 8 participants, the study assessed the effects of the intervention across three postural variables. Following an information phase, the intervention started for the lowest stable postural variable. The intervention led to substantial improvements in safety behavior for most targeted postural variables. A reversal to the information phase for 2 participants did not lead to decreases in safety. Postures self-monitored with high accuracy improved to a greater degree than postures self-monitored with low accuracy.     

Audience-contingent variation in action demonstrations for humans and computers

People may exhibit two kinds of modifications when demonstrating action for others: modifications to facilitate bottom-up, or sensory-based processing; and modifications to facilitate top-down, or knowledge-based processing. The current study examined actors' production of such modifications in action demonstrations for audiences that differed in their capacity for intentional reasoning. Actors' demonstrations of complex actions for a non-anthropomorphic computer system and for people (adult and toddler) were compared. Evidence was found for greater highlighting of top-down modifications in the demonstrations for the human audiences versus the computer audience. Conversely, participants highlighted simple perceptual modifications for the computer audience, producing more punctuated and wider ranging motions. This study suggests that people consider differences in their audiences when demonstrating action.     

Violent computer games and their effects on state hostility and physiological arousal

An experimental study was conducted to investigate the impact of violent computer games on state hostility, state anxiety and arousal. Participants were undergraduate students, aged from 18 to 25 years. Before the experimental sessions, participants filled in self‐report measures concerning their video game habits and were also pre‐tested for aggressiveness and trait anxiety. Physiological responses (heart rate and skin conductance) were measured during the experiment. After playing, information about state hostility and state anxiety was collected. The results showed that participants who played the violent game reported significantly higher state hostility, and support the assumption that an aggressive personality moderates the effect of playing a violent game on state hostility. Aggr. Behav. 32:146–158. 2006 © 2006 Wiley‐Liss, Inc.     

Violent computer games and their effects on state hostility and Physiological arousal

An experimental study was conducted to investigate the impact of violent computer games on state hostility, state anxiety and arousal. Participants were undergraduate students, aged from 18 to 25 years old. Before the experimental sessions, participants filled in self‐report measures concerning their video game habits and were also pre‐tested for aggressiveness and trait anxiety. Physiological responses (heart rate and skin conductance) were measured during the experiment. After playing, information about state hostility and state anxiety was collected. The results showed that participants who played the violent game reported significantly higher state hostility and support the assumption that an aggressive personality moderates the effect of playing a violent game on state hostility. Aggr. Behav. 32:358–371. 2006. © 2006 Wiley‐Liss, Inc.     

EFFECTS OF POINT‐LOSS PUNISHERS ON HUMAN SIGNAL‐DETECTION PERFORMANCE

Three experiments using human participants varied the distribution of point‐gain reinforcers or point‐loss punishers in two‐alternative signal‐detection procedures. Experiment 1 varied the distribution of point‐gain reinforcers for correct responses (Group A) and point‐loss punishers for errors (Group B) across conditions. Response bias varied systematically as a function of the relative reinforcer or punisher frequencies. Experiment 2 arranged two conditions — one where an unequal ratio of reinforcement (5:1 or 1:5) was presented without punishment (R‐only), and another where the same reinforcer ratio was presented with an equal distribution of point‐loss punishers (R+P). Response bias was significantly greater in the R‐only condition than the R+P condition, supporting a subtractive model of punishment. Experiment 3 varied the distribution of point‐gain reinforcers for correct responses across four unequal reinforcer ratios (5:1, 2:1, 1:2, 1:5) both without (R‐only) and with (R+P) an equal distribution of point‐loss punishers for errors. Response bias varied systematically with changes in relative reinforcer frequency for both R‐only and R+P conditions, with 5 out of 8 participants showing increases in sensitivity estimates from R‐only to R+P conditions. Overall, the results indicated that punishers have similar but opposite effects to reinforcers in detection procedures and that combined reinforcer and punisher effects might be better modeled by a subtractive punishment model than an additive punishment model, consistent with research using concurrent‐schedule choice procedures.     

Violent phenotype in SAL mice is inflexible and fixed in adulthood

Violence was shown to be qualitatively different from functional hyper‐aggression in mice selected for high aggression namely Short Attack Latency (SAL), Turku Aggressive (TA) and North Carolina (NC900) strains. This study aimed at investigating whether this adulthood violent phenotype as seen previously in the SAL mice is fixed and hence behaviorally inflexible right from day 1 of the experiment or consequential, i.e., subject to gradual change from functional aggression to violence. The functionally hyper‐aggressive strains namely TA and NC900 strains served as controls for the study. Methodologically, behavioral (in)flexibility was studied using the overall sequential structure of agonistic behavior. In particular, intra‐individual variations in the overall agonistic behavior as well as offensive, pre‐ and post‐offensive behavior transitions, directly related to the resident–intruder interactions were investigated. The SAL mice showed the least intra‐individual variation in their overall sequential agonistic structure as well as a fixed offense‐oriented agonistic behavior of highest magnitude when compared with the other strains. Additionally, the pre‐ and post‐ offensive transitions were most salient in the functionally hyper‐aggressive TA and NC900 strains, whereas virtually absent in the SAL mice. Thus, the violent behavior of the adult SAL mice is behaviorally inflexible or fixed, whereas the functionally hyper‐aggressive behavior of the adult TA and NC900 mice is behaviorally flexible and constantly adaptive to the opponent behavior, over 3 days of repeated resident–intruder interaction. Aggr. Behav. 35:430–436, 2009. © 2009 Wiley‐Liss, Inc.