47 research outputs found
The effect of induced sadness and moderate depression on attention networks
This study investigates how sadness and minor/moderate depression influences the three functions of attention: alerting, orienting, and executive control using the attention network test. The aim of the study is to investigate whether minor to moderate depression is more similar to sadness or clinical depression with regards to attentional processing. It was predicted that both induced sadness and minor to moderate depression will influence executive control by narrowing spatial attention and in turn this will lead to less interference from the flanker items (i.e., less effects of congruency) due to a focused attentional state. No differences were predicted for alerting or orienting functions. The results from the two experiments, the first inducing sadness (Experiment 1) and the second measuring subclinical depression (Experiment 2), show that, as expected, participants who are sad or minor to moderately depressed showed less flanker interference compared to participants who were neither sad nor depressed. This study provides strong evidence, that irrespective of its aetiology, sadness and minor/moderate depression have similar effects on spatial attention
Explaining efficient search for conjunctions of motion and form: Evidence from negative color effects
Dent, Humphreys, and Braithwaite (2011) showed substantial costs to search when a moving target shared its color with a group of ignored static distractors. The present study further explored the conditions under which such costs to performance occur. Experiment 1 tested whether the negative color-sharing effect was specific to cases in which search showed a highly serial pattern. The results showed that the negative color-sharing effect persisted in the case of a target defined as a conjunction of movement and form, even when search was highly efficient. In Experiment 2, the ease with which participants could find an odd-colored target amongst a moving group was examined. Participants searched for a moving target amongst moving and stationary distractors. In Experiment 2A, participants performed a highly serial search through a group of similarly shaped moving letters. Performance was much slower when the target shared its color with a set of ignored static distractors. The exact same displays were used in Experiment 2B; however, participants now responded "present" for targets that shared the color of the static distractors. The same targets that had previously been difficult to find were now found efficiently. The results are interpreted in a flexible framework for attentional control. Targets that are linked with irrelevant distractors by color tend to be ignored. However, this cost can be overridden by top-down control settings. © 2014 Psychonomic Society, Inc
Temporal processes in prime–mask interaction: Assessing perceptual consequences of masked information
Visual backward masking is frequently used to study the temporal dynamics of
visual perception. These dynamics may include the temporal features of conscious
percepts, as suggested, for instance, by the asynchronous–updating model (Neumann, 1982) and perceptual–retouch
theory ((Bachmann, 1994). These models
predict that the perceptual latency of a visual backward mask is shorter than
that of a like reference stimulus that was not preceded by a masked stimulus.
The prediction has been confirmed by studies using temporal–order judgments: For
certain asynchronies between mask and reference stimulus, temporal–order
reversals are quite frequent (e.g. Scharlau,
& Neumann, 2003a). However, it may be argued that these
reversals were due to a response bias in favour of the mask rather than true
temporal-perceptual effects. I introduce two measures for assessing latency
effects that (1) are not prone to such a response bias, (2) allow to quantify
the latency gain, and (3) extend the perceptual evidence from order reversals to
duration/interval perception, that is, demonstrate that the perceived interval
between a mask and a reference stimulus may be shortened as well as prolonged by
the presence of a masked stimulus. Consequences for theories of visual masking
such as asynchronous–updating, perceptual–retouch, and reentrant models are
discussed
Approaching disorder-free transport in high-mobility conjugated polymers.
Conjugated polymers enable the production of flexible semiconductor devices that can be processed from solution at low temperatures. Over the past 25 years, device performance has improved greatly as a wide variety of molecular structures have been studied. However, one major limitation has not been overcome; transport properties in polymer films are still limited by pervasive conformational and energetic disorder. This not only limits the rational design of materials with higher performance, but also prevents the study of physical phenomena associated with an extended π-electron delocalization along the polymer backbone. Here we report a comparative transport study of several high-mobility conjugated polymers by field-effect-modulated Seebeck, transistor and sub-bandgap optical absorption measurements. We show that in several of these polymers, most notably in a recently reported, indacenodithiophene-based donor-acceptor copolymer with a near-amorphous microstructure, the charge transport properties approach intrinsic disorder-free limits at which all molecular sites are thermally accessible. Molecular dynamics simulations identify the origin of this long sought-after regime as a planar, torsion-free backbone conformation that is surprisingly resilient to side-chain disorder. Our results provide molecular-design guidelines for 'disorder-free' conjugated polymers.We gratefully acknowledge financial support from the Engineering and Physical Sciences Research Council (EPSRC) through a programme grant (EP/G060738/1) and the Technology Strategy Board (TSB) (PORSCHED project). D. Venkateshvaran acknowledges financial support from the Cambridge Commonwealth Trust through a Cambridge International Scholarship. K. Broch acknowledges post-doctoral fellowship support from the German Research Foundation (DFG). Mateusz Zelazny acknowledges funding from the NanoDTC in Cambridge. The work in Mons was supported by the European Commission / Région Wallonne (FEDER – Smartfilm RF project), the Interuniversity Attraction Pole program of the Belgian Federal Science Policy Office (PAI 7/05), Programme d’Excellence de la Région Wallonne (OPTI2MAT project) and FNRS-FRFC. D.B. and J.C. are FNRS Research Fellows.This is the accepted manuscript. The final version's available from Nature at http://www.nature.com/nature/journal/vaop/ncurrent/full/nature13854.html
Motion onset does not capture attention when subsequent motion is "smooth"
Previous research on the attentional effects of moving objects has shown that motion per se does not capture attention. However, in later studies it was argued that the onset of motion does capture attention. Here, we show that this motion-onset effect critically depends on motion jerkiness—that is, the rate at which the moving stimulus is refreshed. Experiment 1 used search displays with a static, a motion-onset, and an abrupt-onset stimulus, while systematically varying the refresh rate of the moving stimulus. The results showed that motion onset only captures attention when subsequent motion is jerky (8 and 17 Hz), not when it is smooth (33 and 100 Hz). Experiment 2 replaced motion onset with continuous motion, showing that motion jerkiness does not affect how continuous motion is processed. These findings do not support accounts that assume a special role for motion onset, but they are in line with the more general unique-event account