Brain areas sensitive to coherent visual motion

Detection of coherent motion versus noise is widely used as a measure of global visual-motion processing. To localise the human brain mechanisms involved in this performance, functional magnetic resonance imaging (fMRI) was used to compare brain activation during viewing of coherently moving random dots with that during viewing spatially and temporally comparable dynamic noise. Rates of reversal of coherent motion and coherent-motion velocities (5 versus 20 deg s-1) were also compared. Differences in local activation between conditions were analysed by statistical parametric mapping. Greater activation by coherent motion compared to noise was found in V5 and putative V3A, but not in V1. In addition there were foci of activation on the occipital ventral surface, the intraparietal sulcus, and superior temporal sulcus. Thus, coherent-motion information has distinctive effects in a number of extrastriate visual brain areas. The rate of motion reversal showed only weak effects in motion-sensitive areas. V1 was better activated by noise than by coherent motion, possibly reflecting activation of neurons with a wider range of motion selectivities. This activation was at a more anterior location in the comparison of noise with the faster velocity, suggesting that 20 deg s-1 is beyond the velocity range of the V1 representation of central visual field. These results support the use of motion-coherence tests for extrastriate as opposed to V1 function. However, sensitivity to motion coherence is not confined to V5, and may extend beyond the classically defined dorsal stream.     

Serotonin Depletion Does Not Prevent Intrinsic Sensitization in the Leech

Intrinsic sensitization is a form of behavioral facilitation that is distinct from the extrinsic sensitization normally studied. To examine whether intrinsic and extrinsic sensitization are mediated by different physiological processes, the effects of 5,7-dihydroxytryptamine-induced serotonin (5-HT) depletion on intrinsic sensitization of the leech whole-body shortening response were observed. Previous experiments have shown that 5-HT depletion disrupts dishabituation and extrinsic sensitization of this behavior in the leech. Intrinsic sensitization was observed in preparations from both control and 5-HT-depleted animals, indicating that this form of behavioral facilitation was not affected by 5-HT depletion. The differences in the effects of 5-HT depletion on intrinsic versus extrinsic sensitization suggest that there are distinct neurophysiological processes mediating these two forms of behavioral facilitation. In addition, 5-HT depletion appeared to disrupt a putative extrinsic form of habituation of the shortening reflex. These data support the hypothesis that both intrinsic and extrinsic processes of neuromodulation mediate habituation and sensitization.     

Reward Responsivity in Parenting: Development of a Novel Measure in Mothers of Young Children

The purpose of the current study was to develop and evaluate a measure of maternal reward responsivity in parenting. Deficits in reward responsivity, a common feature of depression, may contribute to maladaptive parenting behaviors. Reward responsivity is an individual difference in reactivity to pleasurable stimuli and represents a key motivational component that could contribute to the frequency and quality of mothers’ interactions with their infants. However, there is currently no measure of reward responsivity in parenting, which would be necessary to evaluate the link between mother reward responsivity, behaviors towards their infant, and infant behavior. Therefore, the current study reports on the development and initial evaluation of a self-report measure of reward responsivity in parenting, the Mother Inventory of Reward Experience (MIRE). We evaluated the MIRE among 200 mothers (M?=?28.45, SD?=?5.50) recruited from a pediatric primary care center. After item analysis, 22 items were retained and displayed high internal consistency reliability and test re-test reliability. Convergent validity was established via a significant correlation with global reward responsivity. Concurrent validity was established via significant correlations with depressive symptoms, parenting stress, and child behavior problems. Incremental validity of the MIRE over a measure of global reward responsivity was supported. These results support the reliability and validity of the MIRE as a measure of reward responsivity in parenting.     

Effects of interactive physical-activity video-game training on physical and cognitive function in older adults

The purpose of the present study was to assess the potential of exergame training based on physically simulated sport play as a mode of physical activity that could have cognitive benefits for older adults. If exergame play has the cognitive benefits of conventional physical activity and also has the intrinsic attractiveness of video games, then it might be a very effective way to induce desirable lifestyle changes in older adults. To examine this issue, the authors developed an active video game training program using a pretest-training-posttest design comparing an experimental group (24 × 1 hr of training) with a control group without treatment. Participants completed a battery of neuropsychological tests, assessing executive control, visuospatial functions, and processing speed, to measure the cognitive impact of the program. They were also given a battery of functional fitness tests to measure the physical impact of the program. The trainees improved significantly in measures of game performance. They also improved significantly more than the control participants in measures of physical function and cognitive measures of executive control and processing speed, but not on visuospatial measures. It was encouraging to observe that, engagement in physically simulated sport games yielded benefits to cognitive and physical skills that are directly involved in functional abilities older adults need in everyday living (e.g., Hultsch, Hertzog, Small, & Dixon, 1999).     

Electrodermal responses to sources of dual-task interference

There is a response selection bottleneck that is responsible for dual-task interference. How the response selection bottleneck operates was addressed in three dual-task experiments. The overlap between two tasks (as indexed by the stimulus onset asynchrony [SOA]) was systematically manipulated, and both reaction time and electrodermal activity were measured. In addition, each experiment also manipulated some aspect of the difficulty of either task. Both increasing task overlap by reducing SOA and increasing the difficulty of either task lengthened reaction times. Electrodermal response was strongly affected by task difficulty but was only weakly affected by SOA, and in a different manner from reaction time. A fourth experiment found that the subjectively perceived difficulty of a dual-task trial was affected both by task difficulty and by SOA, but in different ways than electrodermal activity. Overall, the results were not consistent with a response selection bottleneck that involves processes of voluntary, executive attention. Instead, the results converge with findings from neural network modeling to suggest that the delay of one task while another is being processed reflects the operation of a routing mechanism that can process only one stream of information for action at a time and of a passive, structural store that temporarily holds information for the delayed task. The results suggest that conventional blocked or event-related neuroimaging designs may be inadequate to identify the mechanism of operation of the response selection bottleneck.     

Beyond the hedonic treadmill: revising the adaptation theory of well-being

According to the hedonic treadmill model, good and bad events temporarily affect happiness, but people quickly adapt back to hedonic neutrality. The theory, which has gained widespread acceptance in recent years, implies that individual and societal efforts to increase happiness are doomed to failure. The recent empirical work outlined here indicates that 5 important revisions to the treadmill model are needed. First, individuals' set points are not hedonically neutral. Second, people have different set points, which are partly dependent on their temperaments. Third, a single person may have multiple happiness set points: Different components of well-being such as pleasant emotions, unpleasant emotions, and life satisfaction can move in different directions. Fourth, and perhaps most important, well-being set points can change under some conditions. Finally, individuals differ in their adaptation to events, with some individuals changing their set point and others not changing in reaction to some external event. These revisions offer hope for psychologists and policy-makers who aim to decrease human misery and increase happiness.     

Interoceptive ability predicts aversion to losses

Emotions have been proposed to inform risky decision-making through the influence of affective physiological responses on subjective value. The ability to perceive internal body states, or “interoception” may influence this relationship. Here, we examined whether interoception predicts participants' degree of loss aversion, which has been previously linked to choice-related arousal responses. Participants performed both a heartbeat-detection task indexing interoception and a risky monetary decision-making task, from which loss aversion, risk attitudes and choice consistency were parametrically measured. Interoceptive ability correlated selectively with loss aversion and was unrelated to the other value parameters. This finding suggests that specific and separable component processes underlying valuation are shaped not only by our physiological responses, as shown in previous findings, but also by our interoceptive access to such signals.     

Emotion Dysregulation in Comorbid Posttraumatic Stress Disorder and Substance Use Disorders: A Narrative Review

Co-occurrence of substance use disorders (SUDs) and posttraumatic stress disorder (PTSD) is extremely common and is associated with elevated dropout and relapse rates. Given that PTSD/SUD co-occurrence rates among veterans have been found to be as high as 55?75%, it is important to identify mechanisms that may affect the interplay of both disorders. Emotion dysregulation (ED) presents a candidate mechanism that may underlie poor treatment response in co-occurring PTSD/SUD. This article proposes a transdiagnostic emotion regulation framework that considers ED conceptualized as a combination of low ability to tolerate emotional distress (low distress tolerance) and difficulties in the goal-directed use of emotion regulation strategies as a key risk factor in co-occurring PTSD/SUD. The authors review empirical findings from self-report and laboratory-based studies of ED in PTSD. They describe psychological explanations of the emotion-substance relationship and review studies documenting ED in SUDs and in co-occurring PTSD/SUD. The literature on ED in PTSD/SUD suggests that (a) patients with PTSD may resort to substances to cope with trauma-related symptoms due to ED, and (b) ED may maintain SUD symptoms and interfere with psychological treatment. Longitudinal studies on bidirectional relationships between ED and substance use in PTSD are needed, particularly research examining the course of ED in PTSD patients who use substances versus those who do not.     

Sales Force Activities and Marketing Strategies in Industrial Firms: Relationships and Implications

This study explores the role of the sales force in formulating and executing marketing strategies. Specifically, the relationships between sales force activities such as providing information about customer needs, hiring and training salespeople, and assessing new market segments and four marketing strategies (market penetration, product development, market development, diversification) are examined. Results indicate that the use of sales force activities is related to a firm's strategic choices, and that the relationships vary by firm size and type of offering.     

Novice motor performance: Better not to verbalize

Offline verbalization about a new motor experience is often assumed to positively influence subsequent performance. Here, we evaluated this presumed positive influence and whether it originates from declarative or from procedural knowledge using the explicit/implicit motor-learning paradigm. To this end, 80 nongolfers learned to perform a golf-putting task with high error rates (i.e., explicit motor learning), and thus relied on declarative knowledge, or low error rates (i.e., implicit motor learning), and thus relied on procedural knowledge. Afterward, they either put their memories of the previous motor experience into words or completed an irrelevant verbal task. Finally, they performed the putting task again. Verbalization did not improve novice motor performance: Putting was impaired, overall, and especially so for high-error learners. We conclude that declarative knowledge is altered by verbalization, whereas procedural knowledge is not.