Search

Child-directed speech has long been known to influence children's vocabulary learning. However, while we know that caregiver utterances differ from those directed at adults in various ways, little is known about any differences in the lexical properties of child-directed and adult-directed utterances. We compare over half a million word tokens from adult speech directed at children (from caregiver–child transcriptions) to the same quantity directed at adults. We show that child-directed speech contains greater numbers of words that are lower in phonemic length, higher in frequency, lower in phonotactic probability, and higher in neighborhood density than adult-directed speech; furthermore, child-directed speech explains over twice the variability of children's productive noun vocabularies than adult-directed speech. These findings indicate that children's word production is clearly influenced by the characteristics of the words spoken directly to them and that researchers need to be wary of using adult-directed language corpora when calculating lexical measures. [ABSTRACT FROM AUTHOR]

Experience is positively related to performance, but it is less clear whether experience might also minimise the deleterious effects of anxiety and arousal in stressful situations. One hundred and twenty-seven UK firearms officers of different experience levels participated in an experiment examining the extent to which anxiety affects performance during a bi-annual qualification shoot. Performance and anxiety were compared on a low-arousal development shoot and a high-arousal qualification shoot; qualification shoot failure would result in removal from operational duties. Heart rate and responses to the State-Trait Anxiety questionnaire were examined in relation to shooting performance. Less experienced officers demonstrated significantly higher baseline corrected mean heart rates, higher anxiety levels and lower accuracy than their more experienced counterparts, who maintained accuracy, despite a significant increase in heart rate during the qualification compared to the development shoot. The results, some of the first to examine British firearms officers in their natural training environment, suggest experience reduces the physiological impact of arousal on performance in pressurised situations. We discuss options for reducing the impact on performance in less experienced officers. [ABSTRACT FROM AUTHOR]

We present optical photometry of six intermediate polars that exhibit transitions to a low-flux state. For four of these systems, DW Cnc, V515 And, V1223 Sgr, and RX J2133.7+5107, we are able to perform timing analysis in and out of the low states. We find that, for DW Cnc and V515 And, the dominant periodicities in the light curves change as the flux decreases, indicating a change in the sources’ accretion properties as they transition to the low state. For V1223 Sgr, we find that the variability is almost completely quenched at the lowest flux, but we do not find evidence for a changing accretion geometry. For RX J2133.7+5107, the temporal properties do not change in the low state, but we do see a period of enhanced accretion that is coincident with increased variability on the beat frequency, which we do not associate with a change in the accretion mechanisms in the system. [ABSTRACT FROM AUTHOR]

Simultaneous search for one of two targets is slower and less accurate than search for a single target. Within the Signal Detection Theoretic (SDT) framework, this can be attributed to the division of resources during the comparison of visual input against independently cued targets. The current study used one or two cues to elicit single- and dual-target searches for orientation targets among similar and dissimilar distractors. In Experiment 1, the accuracy of target discrimination in brief displays was compared at setsizes of 1, 2 and 4. Results revealed a reduction in accuracy that scaled with the product of set size and the number of cued targets. In Experiment 2, the accuracy and latency of observers' saccadic targeting were compared. Fixations on single-target searches were highly selective towards the target. On dual-target searches, the requirement to detect one of two targets produced a significant reduction in target fixations and equivalent rates of fixations to distractors with opposite orientations. For most observers, the dual-target cost was predicted by an SDT model that simulated increases in decision-noise and the distribution of capacity-limited resources during the comparison of selected input against independently cued targets. For others, search accuracy was consistent with a single-item limit on perceptual decisions and saccadic targeting during search. These findings support a flexible account of the dual-target cost based on different strategies to resolve competition between independently cued targets. [ABSTRACT FROM AUTHOR]

We investigated how dimension-based attention influences visual short-term memory (VSTM). This was done through examining the effects of cueing a feature dimension in two perceptual comparison tasks (change detection and sameness detection). In both tasks, a memory array and a test array consisting of a number of colored shapes were presented successively, interleaved by a blank interstimulus interval (ISI). In Experiment 1 (change detection), the critical event was a feature change in one item across the memory and test arrays. In Experiment 2 (sameness detection), the critical event was the absence of a feature change in one item across the two arrays. Auditory cues indicated the feature dimension (color or shape) of the critical event with 80 % validity; the cues were presented either prior to the memory array, during the ISI, or simultaneously with the test array. In Experiment 1, the cue validity influenced sensitivity only when the cue was given at the earliest position; in Experiment 2, the cue validity influenced sensitivity at all three cue positions. We attributed the greater effectiveness of top-down guidance by cues in the sameness detection task to the more active nature of the comparison process required to detect sameness events (Hyun, Woodman, Vogel, Hollingworth, & Luck, Journal of Experimental Psychology: Human Perception and Performance, 35; 1140-1160, ). [ABSTRACT FROM AUTHOR]

A number of studies have shown that training on action video games improves various aspects of visual cognition including selective attention and inhibitory control. Here, we demonstrate that action video game play can also reduce the Simon Effect, and, hence, may have the potential to improve response selection during the planning and execution of goal-directed action. Non-game-players were randomly assigned to one of four groups; two trained on a first-person-shooter game (Call of Duty) on either Microsoft Xbox or Nintendo DS, one trained on a visual training game for Nintendo DS, and a control group who received no training. Response times were used to contrast performance before and after training on a behavioral assay designed to manipulate stimulus-response compatibility (the Simon Task). The results revealed significantly faster response times and a reduced cost of stimulus-response incompatibility in the groups trained on the first-person-shooter game. No benefit of training was observed in the control group or the group trained on the visual training game. These findings are consistent with previous evidence that action game play elicits plastic changes in the neural circuits that serve attentional control, and suggest training may facilitate goal-directed action by improving players' ability to resolve conflict during response selection and execution. [ABSTRACT FROM AUTHOR]

Simultaneous search for two targets has been shown to be slower and less accurate than independent searches for the same two targets. Recent research suggests this ‘dual-target cost’ may be attributable to a limit in the number of target-templates than can guide search at any one time. The current study investigated this possibility by comparing behavioural responses during single- and dual-target searches for targets defined by their orientation. The results revealed an increase in reaction times for dual- compared to single-target searches that was largely independent of the number of items in the display. Response accuracy also decreased on dual- compared to single-target searches: dual-target accuracy was higher than predicted by a model restricting search guidance to a single target-template and lower than predicted by a model simulating two independent single-target searches. These results are consistent with a parallel model of dual-target search in which attentional control is exerted by more than one target-template at a time. The requirement to maintain two target-templates simultaneously, however, appears to impose a reduction in the specificity of the memory representation that guides search for each target. [ABSTRACT FROM AUTHOR]

This study reports an experiment investigating the relative effects of intramodal, crossmodal and bimodal cues on visual and auditory temporal order judgements. Pairs of visual or auditory targets, separated by varying stimulus onset asynchronies, were presented to either side of a central fixation (±45°), and participants were asked to identify the target that had occurred first. In some of the trials, one of the targets was preceded by a short, non-predictive visual, auditory or audiovisual cue stimulus. The cue and target stimuli were presented at the exact same locations in space. The point of subjective simultaneity revealed a consistent spatiotemporal bias towards targets at the cued location. For the visual targets, the intramodal cue elicited the largest, and the crossmodal cue the smallest, bias. The bias elicited by the bimodal cue fell between the intramodal and crossmodal cue biases, with significant differences between all cue types. The pattern for the auditory targets was similar apart from a scaling factor and greater variance, so the differences between the cue conditions did not reach significance. These results provide evidence for multisensory integration in exogenous attentional cueing. The magnitude of the bimodal cueing effect was equivalent to the average of the facilitation elicited by the intramodal and crossmodal cues. Under the assumption that the visual and auditory cues were equally informative, this is consistent with the notion that exogenous attention, like perception, integrates multimodal information in an optimal way. [ABSTRACT FROM AUTHOR]

Empirical research examining the situational characteristics of gambling and their effect on gambling behaviour is limited but growing. This experimental pilot investigation reports the first ever empirical study into the combined effects of both music and light on gambling behaviour. While playing an online version of roulette, 56 participants took part in one of four experimental conditions (14 participants in each condition); (1) gambling with fast tempo music under normal (white) light, (2) gambling with fast tempo music under red light, (3) gambling with slow tempo music under normal (white) light, and (4) gambling with slow tempo music under red light. Risk (dollars spent) per spin and speed of bets were measured as indicators of gambling behaviour. Significant main effects were found for speed of bets in relation to musical tempo, but not light. No significant effects were found for risk per spin for either of the two independent variables. A significant interaction between light and music for speed of bets was shown. Planned comparisons revealed that fast tempo music under red light resulted in faster gambling. These findings are discussed along with the methodological limitations, and potential implications for various stakeholders including the gambling industry and practitioners. [ABSTRACT FROM AUTHOR]

The cost of searching for two visual targets simultaneously was compared against two separate single-target searches using exposure time and accuracy measures within a staircase procedure. Dual-target search for all stimuli (colour, shape and orientation) exhibited a loss of accuracy for one target. For orientation and shape, this dual-target cost in accuracy was extreme, with chance-level performance on one target. For colour, dual-target search exhibited an additional cost in search time, with search requiring a longer exposure than the summed time required for two single-target searches. An additional search-time cost was also found for orientation targets when irrelevant colour variation was added to the display. In conclusion, dual-target search for dissimilar targets is accompanied by an accuracy cost. Furthermore, colour variation, whether task-relevant or not, leads to an additional cost in processing speed. The results suggest that a divided-effort strategy would improve performance in search tasks such as X-ray baggage screening. Copyright © 2006 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Independent-resource models of visual short-term memory (VSTM) predict an inverse relationship between recall accuracy and the number of values for separate visual features (e.g., Wang et al., 2017). Slot models in contrast, predict all-or-none recall of separate features for objects that are encoded in VSTM (e.g., Luck & Vogel, 1997). The current study contrasted these predictions using a change detection task for objects that varied in their colour and orientation. Observers were cued to attend colour or orientation and the distribution of the attended and unattended feature was varied across objects in the display. Observers' accuracy to change on each dimension was equated using a staircase procedure. Comparisons of d' indicated change-discriminability was sensitive to the distribution of the attended but not the unattended feature. Pupil dilation during the retention period was i) larger on attend-colour than attend-orientation trials, ii) sensitive to the distribution of the attended feature across objects and iii) negatively associated with d'. These findings are consistent with independent-resource models of VSTM. The data also demonstrate dependencies between changes in pupil dilation during the retention of non-spatial features, and signal theoretic indices of change-discriminability, for objects that vary on attended and unattended features. [ABSTRACT FROM AUTHOR]