Control of Integrated Task Sequences Shapes Components of Reaching

Reaching toward an object usually consists of a sequence of elemental actions. Using a reaching task sequence, the authors investigated how task elements of that sequence affected feedforward and feedback components of the reaching phase of the movement. Nine right-handed adults performed, with their dominant and nondominant hands, 4 tasks of different complexities: a simple reaching task; a reach-to-grasp task; a reach-to-grasp and lift object task; and a reach-to-grasp, lift, and place object task. Results showed that in the reach-to-grasp and lift object task more time was allocated to the feedforward component of the reach phase, while latency between the task elements decreased. We also found between-hand differences, supporting previous findings of increased efficiency of processing planning-related information in the preferred hand. The presence of task-related modifications supports the concept of contextual effects when planning a movement.     

An Observational Study on How Situational Factors Influence Media Multitasking With TV: The Role of Genres,Dayparts, and Social Viewing

This study responds to the need for research on individuals' media multitasking behavior using observational data. Media multitasking can have a profound impact on media processing and effects. However, we have little knowledge on when people are likely to engage in media multitasking and, consequently, when these effects are likely to occur. This study examines how three important situational factors—television genres, dayparts, and social viewing—influence the amount of media multitasking. Granular observational data obtained by directly monitoring and recording media consumption behaviors of a large panel at 10-second intervals are used for the analysis. The study reveals that media multitasking with television is most prevalent when people watch sports or engage in channel surfing and less prevalent with commercials, news, and entertainment. Furthermore, the extent of media multitasking is greater in the morning and afternoon than in the evening, and also greater when individuals watch television alone than in the presence of others. Daypart differences are larger for genres associated with incidental viewing (commercials and channel surfing) than for genres associated with intentional viewing (news, entertainment, and sports). Sports is the only genre that is associated with higher amounts of media multitasking when watching television with others.     

The influence of memory on indoor environment exploration: A numerical study

Understanding human behavior in the context of exploration and navigation is an important but challenging problem. Such understanding can help in the design of safe structures and spaces that implicitly aid humans during evacuation or other emergency situations. In particular, the role that memory plays in this process is something that is crucial to understand. In this paper, we develop a novel serious game-based experimental approach to understanding the non-randomness and the impact of memory on the human exploration process. We show that a simple memory model, with a depth of between 6 and 8 steps, is sufficient to approximate a ‘human-like’ level of exploration efficiency. We also demonstrate the advantages that a game-based experimental methodology brings to these kinds of experiments in the amount of data that can be collected as compared to traditional experiments. We feel that these findings have important implications for ‘safety-by-design’ in complex infrastructural structures.     

Influencing surface plastic flow in metals using common chemical media

We demonstrate a unique mechanochemical effect – change in surface plastic flow by action of chemical media such as inks and glues – in large-strain deformation of metals. Unlike other well-known phenomena such as stress corrosion cracking and liquid metal embrittlement, the effect is not catastrophic and is largely material independent. High-speed in situ imaging shows that the media influence the flow by effecting a local ductile-to-brittle transition – from unsteady, large-amplitude, plastic folding, to repeated fracture and segmentation – with large decrease in deformation forces. The benign nature of the media offers opportunities for enhancing performance of metal cutting and deformation processes.     

The role of thought suppression in building mental blocks

This research examined the role of thought suppression in the formation of mental blocks. In Experiment 1, participants were asked to generate a series of creative associates for two target words after initially suppressing a word that was semantically related to one of the two target words. Participants produced fewer responses, and experienced a greater sensation of being mentally blocked, when attempting to produce associates for the target word that was semantically related to the suppressed word. In Experiment 2, participants either thought about or suppressed a series of words prior to completing a word fragment completion task. Each word either corresponded exactly to one of the word fragment solutions (target primes) or resembled one of the solutions but was slightly different in its orthographic properties (negative primes). Participants performed most poorly on the items for which they had initially suppressed negative primes.     

A critical examination of the spectral contrast account of compensation for coarticulation

Vocal tract gestures for adjacent phones overlap temporally, rendering the acoustic speech signal highly context dependent. For example, following a segment with an anterior place of articulation, a posterior segment’s place of articulation is pulled frontward, and listeners’ category boundaries shift appropriately. Some theories assume that listeners perceptually attune or compensate for coarticulatory context. An alternative is that shifts result from spectral contrast. Indeed, shifts occur when speech precursors are replaced by pure tones, frequency matched to the formant offset at the assumed locus of contrast (Lotto & Kluender, 1998). However, tone analogues differ from natural formants in several ways, raising the possibility that conditions for contrast may not exist in natural speech. When we matched tones to natural formant intensities and trajectories, boundary shifts diminished. When we presented only the critical spectral region of natural speech tokens, no compensation was observed. These results suggest that conditions for spectral contrast do not exist in typical speech.     

Unexpected nanoscale phase separation in sputterdeposited Ni-25 at.%Al thin films

Thin films of nominal composition Ni-25at.%Al, sputter deposited from a target of the intermetallic compound Ni 3 Al on unheated substrates, exhibit an unexpected phase separation, in contrast with other intermetallic-forming systems such as Ti-Al which are deposited as compositionally homogeneous amorphous films under similar conditions. Precipitates of a novel tetragonal phase, a few nanometres in size, were formed in the matrix consisting of a fcc Ni-rich Ni(Al) phase and a hcp Ni-rich Ni(Al) phase. Ni-Al films of the same composition deposited on heated substrates exhibited the formation of a single, chemically long-range-ordered Ni 3 Al phase with the L1 2 structure, the thermodynamically stable phase for this composition.     

Health Related Quality of Life After Percutaneous Coronary Revascularisation in Patients with Previous Coronary Artery Bypass Grafts: A Two-Year Follow Up Study

Percutaneous coronary revascularisation [PCR] improves angina and health related quality of life [HRQOL] compared to standard medical therapy. It is unknown whether PCR has the same benefits for patients with a history of CABG. Over a period of 5 years, we assessed HRQOL of patients undergoing PCR using Part 1 of the Nottingham Health Profile [NHP] at baseline 3, 12 and 24 months. We compared HRQOL after PCR in 255 patients with CABG to 2680 without. There were more males [81.1% v 69.6% p = 0.002] and older patients [mean age 60.1 years v. 58.0 p = 0.03] in CABG group. Perceived HRQOL improved at 24 months for pain, energy and emotional reaction but the improvement was less in the CABG group. However, mean NHP scores at 24 months for those with CABG had returned to baseline levels for sleep [34.9] and for physical function was worse than at baseline [22.0 vs 30.7]. This relationship persisted after adjustment for male sex, history of previous MI and coronary stent usage. Patients with previous CABG had less improvement in HRQOL after PCR. Further work is needed to assess the benefits and cost effectiveness of PCR in these patients.     

Dynamics of attention in depth: evidence from multi-element tracking

We examined the allocation of attention in depth using a multi-element tracking paradigm. Observers were required to track a predefined subset of from two to eight elements in displays containing up to sixteen identical moving elements. We first show that depth cues, such as binocular disparity and occlusion through T-junctions, improve performance in a multi-element tracking task in the case where element boundaries are allowed to intersect in the depiction of motion in a single frontoparallel plane. We also show that the allocation of attention across two perceptually distinguishable planar surfaces, either frontoparallel or receding at a slanting angle and defined by coplanar elements, is easier than allocation of attention within a single surface. The same result was not found when attention was required to be deployed across items of two-color populations rather than across items of a single color. Our results suggest that, when surface information does not suffice to distinguish between targets and distractors that are embedded in these surfaces, division of attention across two surfaces aids in tracking moving targets. A final experiment with populations of elements moving within distinct volumes produced similar results, suggesting that spatial separation in three dimensions, rather than confinement to surfaces as such, may explain the improved performance for the two-surface case.     

An enquiry into the process of categorization of pictures and words

This paper reports a series of experiments conducted to study the categorization of pictures and words. Whereas some studies reported in the past have found a picture advantage in categorization, other studies have yielded no differences between pictures and words. This paper used an experimental paradigm designed to overcome some methodological problems to examine picture-word categorization. The results of one experiment were consistent with an advantage for pictures in categorization. To identify the source of the picture advantage in categorization, two more experiments were conducted. Findings suggest that semantic relatedness may play an important role in the categorization of both pictures and words. We explain these findings by suggesting that pictures simultaneously access both their concept and visually salient features whereas words may initially access their concept and may subsequently activate features. Therefore, pictures have an advantage in categorization by offering multiple routes to semantic processing.