The dual role of vision in sequential aiming movements

Previous research has demonstrated that movement times to the first target in sequential aiming movements are influenced by the properties of subsequent segments. Based on this finding, it has been proposed that individual segments are not controlled independently. The purpose of the current study was to investigate the role of visual feedback in the interaction between movement segments. In contrast to past research in which participants were instructed to minimize movement time, participants were set a criterion movement time and the resulting errors and limb trajectory kinematics were examined under vision and no vision conditions. Similar to single target movements, the results indicated that vision was used within each movement segment to correct errors in the limb trajectory. In mediating the transition between segments, visual feedback from the first movement segment was used to adjust the parameters of the second segment. Hence, increases in variability that occurred from the first to the second target in the no vision condition were curtailed when visual feedback was available. These results are discussed along the lines of the movement constraint and movement integration hypotheses.     

Mind-wandering: phenomenology and function as assessed with a novel experience sampling method

Mind-wandering refers to the occurrence of thoughts whose content is both decoupled from stimuli present in the current environment and unrelated to the task being carried out at the moment of their occurrence. The core of this phenomenon is therefore stimulus-independent and task-unrelated thoughts (SITUTs). In the present study, we designed a novel experience sampling method which permitted to isolate SITUTs from other kinds of distractions (i.e., irrelevant interoceptive/exteroceptive sensory perceptions and interfering thoughts related to the appraisal of the current task). In Experiment 1, we examined the impact of SITUTs on the performance of the Sustained Attention to Response Task (SART; a Go/No-Go task). Analyses demonstrated that SITUTs impair SART performance to the same extent as irrelevant sensory perceptions. In Experiment 2, we further examined SITUTs in order to assess the possible functions of mind-wandering. We observed that the content of most of reported SITUTs refers to the anticipation and planning of future events. Furthermore, this “prospective bias” was increased when participants' attention had been oriented toward their personal goals before performing the SART. These data support the view that an important function of mind-wandering relates to the anticipation and planning of the future.     

The influence of motor simulations on language comprehension

This study investigates the influence of activating specific motor codes on the comprehension of passages that describe the use of an object requiring similar motor manipulations. In three experiments, participants either imagined or pantomimed performing an action involving a common object. Participants then held the action in memory while reading a brief story, which described another object that required similar or different motor behaviors. Reading times were collected on the complementary actions. Finally, participants acted out the original action. In Exp. 1 and 2, reading slowed to the verbs. Exp. 2 revealed the slowing to be true interference, which disappeared in Exp. 3 when the action did not need to be recalled. The results suggest that readers activate motor codes when reading story actions, which supports an embodied view. The results also indicate that activated codes bound to an action will, at least briefly, impair reading about a complementary action requiring the same codes, consistent with Hommel's (2009) theory of event coding.     

Intra-individual stability of neuromotor tasks from 6 to 18 years: a longitudinal study

This study investigates the intra-individual stability of the speed of several motor tasks and the intensity of associated movements in 256 children (131 girls, 125 boys) from the Zurich generational study using the Zurich neuromotor assessment battery (ZNA) over a 12-year period from the age of 6 to 18 years. The stability was assessed by correlograms of standard deviation scores calculated from age- and gender-adjusted normative values and compared with standing height and full scale intelligence quotient (IQ). While motor tasks of hand, finger and foot (HFT) and contralateral associated movements (CAM) exhibited a moderate stability (summary measure as correlation coefficients between two measurements made 4 years apart: .61 and .60), other tasks (dynamic balance, static balance and pegboard) were only weakly stable (.46, .47 and .49). IQ and height were more stable than neuromotor components (.72 and .86). We conclude that the moderately stable HFT and CAM may reflect “motor traits”, while the stability of the pegboard and balance tasks is weaker because these skills are more experience related and state-dependent.     

Temporal preparation and inhibitory deficit in fibromyalgia syndrome

Cognitive deficits in fibromyalgia may be specifically related to controlled processes, such as those measured by working memory or executive function tasks. This hypothesis was tested here by measuring controlled temporal preparation (temporal orienting) during a response inhibition (go no-go) task. Temporal orienting effects (faster reaction times for targets appearing at temporally attended vs. unattended moments) and response inhibition were impaired in fibromyalgia compared to the control group. It is concluded that frontal networks underlying attentional control (temporal orienting and response inhibition) can be a dysfunctional neurocognitive mechanism in fibromyalgia.     

Search asymmetry, sustained attention, and response inhibition

In the present experiment, we used search asymmetry to test whether the sustained attention to response task is a better measure of response inhibition or sustained attention. Participants performed feature present and feature absent target detection tasks using either a sustained attention to response task (SART; high Go low No-Go) or a traditionally formatted task (TFT; high No-Go low Go) response format. In addition to performance, we employed functional near infrared spectroscopy (fNIRS) to measure lateral cerebral oxygenation levels and self-reports of Tense Arousal, Energetic Arousal, task related and unrelated thoughts occurring during the tasks. Detections were lower and reaction times longer in the feature absent search than the feature present search regardless of response format. Detections were lower, but reaction times shorter in the SART than the TFT regardless of feature search. Greater right than left frontal hemisphere activation occurred in the SART than the TFT. In addition, the SART was more fatiguing based on self-reports than the TFT, but there were no differences in Task-Unrelated Thoughts across task conditions. Overall, the results suggest the SART places high response inhibition, not necessarily sustained attention, demands on participants.     

Identifying facial emotions: valence specific effects and an exploration of the effects of viewer gender

The valence hypothesis suggests that the right hemisphere is specialised for negative emotions and the left hemisphere is specialised for positive emotions (Silberman & Weingartner, 1986). It is unclear to what extent valence-specific effects in facial emotion perception depend upon the gender of the perceiver. To explore this question 46 participants completed a free view lateralised emotion perception task which involved judging which of two faces expressed a particular emotion. Eye fixations of 24 of the participants were recorded using an eye tracker. A significant valence-specific laterality effect was obtained, with positive emotions more accurately identified when presented to the right of centre, and negative emotions more accurately identified when presented to the left of centre. The valence-specific laterality effect did not depend on the gender of the perceiver. Analysis of the eye tracking data showed that males made more fixations while recognising the emotions and that the left-eye was fixated substantially more than the right-eye during emotion perception. Finally, in a control condition where both faces were identical, but expressed a faint emotion, the participants were significantly more likely to select the right side when the emotion label was positive. This finding adds to evidence suggesting that valence effects in facial emotion perception are not only caused by the perception of the emotion but by other processes.     

Piéron's Law holds during stroop conflict: insights into the architecture of decision making

Piéron's Law describes the relationship between stimulus intensity and reaction time. Previously (Stafford & Gurney, 2004), we have shown that Piéron's Law is a necessary consequence of rise-to-threshold decision making and thus will arise from optimal simple decision-making algorithms (e.g., Bogacz, Brown, Moehlis, Holmes, & Cohen, 2006). Here, we manipulate the color saturation of a Stroop stimulus. Our results show that Piéron's Law holds for color intensity and color-naming reaction time, extending the domain of this law, in line with our suggestion of the generality of the processes that can give rise to Piéron's Law. In addition, we find that Stroop condition does not interact with the effect of color saturation; Stroop interference and facilitation remain constant at all levels of color saturation. An analysis demonstrates that this result cannot be accounted for by single-stage decision-making algorithms which combine all the evidence pertaining to a decision into a common metric. This shows that human decision making is not information-optimal and suggests that the generalization of current models of simple perceptual decision making to more complex decisions is not straightforward.     

Multi-attribute,multi-alternative models of choice: Choice,reaction time,and process tracing

The first aim of this research is to compare computational models of multi-alternative, multi-attribute choice when attribute values are explicit. The choice predictions of utility (standard random utility & weighted valuation), heuristic (elimination-by-aspects, lexicographic, & maximum attribute value), and dynamic (multi-alternative decision field theory, MDFT, & a version of the multi-attribute linear ballistic accumulator, MLBA) models are contrasted on both preferential and risky choice data. Using both maximum likelihood and cross-validation fit measures on choice data, the utility and dynamic models are preferred over the heuristic models for risky choice, with a slight overall advantage for the MLBA for preferential choice. The response time predictions of these models (except the MDFT) are then tested. Although the MLBA accurately predicts response time distributions, it only weakly accounts for stimulus-level differences. The other models completely fail to account for stimulus-level differences. Process tracing measures, i.e., eye and mouse tracking, were also collected. None of the qualitative predictions of the models are completely supported by that data. These results suggest that the models may not appropriately represent the interaction of attention and preference formation. To overcome this potential shortcoming, the second aim of this research is to test preference-formation assumptions, independently of attention, by developing the models of attentional sampling (MAS) model family which incorporates the empirical gaze patterns into a sequential sampling framework. An MAS variant that includes attribute values, but only updates the currently viewed alternative and does not contrast values across alternatives, performs well in both experiments. Overall, the results support the dynamic models, but point to the need to incorporate a framework that more accurately reflects the relationship between attention and the preference-formation process.     

Concurrent and longitudinal dyadic polynomial regression analyses of Big Five traits and relationship satisfaction: Does similarity matter?

Being with a well-matched partner seems essential for a happy relationship. However, past research on personality similarity in couples has reported inconsistent findings. The current study employs a dyadic polynomial regression approach to take into account linear and curvilinear associations between similarity and satisfaction. The concurrent results based on data of 237 couples suggest that beyond actor effects for neuroticism, agreeableness, and conscientiousness and partner effects for agreeableness, similarity plays a negligible role for relationship satisfaction. Longitudinally, two similarity effects emerged. First, if partners reported dissimilar neuroticism levels, male partner reported lower relationship satisfaction. Second, if both partners reported modest levels in openness, female partners reported higher relationship satisfaction. Implications for couples are discussed.