On finding negative priming from distractors

Negative priming from distractors has attracted considerable interest because it appears to reveal a fundamental mechanism of selective attention. Recently, the phenomenon has become muddled because it can be explained in far too many ways. This may partly be because the empirical foundation for the phenomenon has been handicapped by an overreliance on a simplistic comparison of a single experimental condition with control. A sounder approach requires that we collect data that can rule out alternatives to the hypothesis we might favor or test. Regardless of the paradigm used, we propose collecting data from a much fuller set of conditions than is typical. Despite the variety of underlying explanations, we show that the various theories that attribute negative priming to ignoring the distractor predict a common pattern of results across the full set of related conditions. Theories, such as inhibition of return, that do not attribute the cost in performance to ignoring the distractor do not predict this pattern.     

Inattentional blindness for ignored words: Comparison of explicit and implicit memory tasks

Inattentional blindness is described as the failure to perceive a supra-threshold stimulus when attention is directed away from that stimulus. Based on performance on an explicit recognition memory test and concurrent functional imaging data Rees, Russell, Frith, and Driver [Rees, G., Russell, C., Frith, C. D., & Driver, J. (1999). Inattentional blindness versus inattentional amnesia for fixated but ignored words. Science, 286, 2504–2507] reported inattentional blindness for word stimuli that were fixated but ignored. The present study examined both explicit and implicit memory for fixated but ignored words using a selective-attention task in which overlapping picture/word stimuli were presented at fixation. No explicit awareness of the unattended words was apparent on a recognition memory test. Analysis of an implicit memory task, however, indicated that unattended words were perceived at a perceptual level. Thus, the selective-attention task did not result in perfect filtering as suggested by Rees et al. While there was no evidence of conscious perception, subjects were not blind to the implicit perceptual properties of fixated but ignored words.     

The configuration and relaxation of motor task sets

Often the performance of a task does not only require the processing of certain stimuli in certain ways, but also certain patterns of interlimb coordination. We studied shifts between different tasks involving different patterns of intermanual coupling by means of the timed-response procedure, which allows to trace state variables related to task sets. The tasks required the production of rapid bimanual reversal movements with symmetric or parallel directions. Symmetric movements are associated with symmetric coupling, as indicated by positive intermanual correlations between the directions of left-hand and right-hand movements, whereas parallel movements are associated with parallel coupling, as indicated by negative intermanual correlations. Task switches were associated with gradual changes of the intermanual correlations, which indicate the state of intermanual coupling as a major ingredient of a task set, in the course of action preparation. At short preparation intervals intermanual correlations were those appropriate for the preceding trial; with increasing preparation time they were replaced by those appropriate for the current trial, but the influence of the preceding trial did not disappear completely. In-between trials, intermanual coupling drifted toward a symmetric coupling, but not to uncoupled limbs. After a change of the task the specification of movement directions was slowed, but its initiation was not delayed. According to these results, task sets relax toward attractors which can be different from the absence of task sets. They are gradually configured during task preparation with a persistent influence of the preceding task, and the specification of response characteristics does not wait until the configuration of the new task set is completed. The research reported in this paper was supported by grant He 1187/14-1 of the Deutsche Forschungsgemeinschaft. We thank Barbara Herbst, Holger Küper, Kevin Schepers, and Elisei Rotaro for their support in running the experiment.     

Repeated cocaine experience facilitates sucrose-reinforced operant responding in enriched and isolated rats

The purpose of the present experiment was to determine whether repeated cocaine exposure differentially affects sucrose-reinforced operant responding in rats raised in an enriched condition (EC) or an isolated condition (IC). Specifically, the performance of EC and IC rats pressing a lever for sucrose under a high fixed-ratio schedule (FR 30) prior to and after 10 days of exposure to cocaine (15 mg/kg, i.p.) or saline was compared. Regardless of rearing condition, rats repeatedly exposed to cocaine had shorter reacquisition latencies to complete a sucrose-reinforced FR 30 task than saline controls. The results suggest that cocaine exposure may have cross-sensitized both EC and IC rats to the reinforcing effects of sucrose or sucrose-associated cues, thus facilitating reacquisition of operant responding.     

Eye movements as direct tests of the GO model for the missing-letter effect

When asked to detect target letters while reading a text, participants miss more letters in frequently occurring function words than in less frequent content words. To account for this pattern of results, known as the missing-letter effect, Greenberg, Healy, Koriat, and Kreiner proposed the guidance-organization (GO) model, which integrates the two leading models of the missing-letter effect while incorporating innovative assumptions based on the literature on eye movements during reading. The GO model was evaluated by monitoring the eye movements of participants while they searched for a target letter in a continuous text display. Results revealed the usual missing-letter effect, and many empirical benchmark effects in eye movement literature were observed. However, contrary to the predictions of the GO model, response latencies were longer for function words than for content words. Alternative models are discussed that can accommodate both error and response latency data for the missing-letter effect.     

Visual Prior Entry

It has long been claimed that attended stimuli are perceived prior to unattended stimuli–the doctrine of prior entry. Most, if not all, studies on which such claims have been based, however, are open to a nonattentional interpretation involving response bias, leading some researchers to assert that prior entry may not exist. Given this controversy, we introduce a novel methodology to minimize the effect of response bias by manipulating attention and response demands in orthogonal dimensions. Attention was oriented to the left or right (i.e., spatially), but instead of reporting on the basis of location, observers reported the order (first or second) of vertical versus horizontal line segments. Although second-order response biases were demonstrated, effects of attention in accordance with the law of prior entry were clearly obtained following both exogenous and endogenous attentional cuing.     

Self-reported interference with academic functioning and eating disordered symptoms: associations with multiple dimensions of body image

A sample of 1583 undergraduates completed a multidimensional measure of body image (Multidimensional Body-Self Relations Questionnaire, MBSRQ) and a new scale, the Eating and Body Image Disturbances Academic Interference Scale (EBIDAIS). All five subscales of the MBSRQ were related to higher levels of self-reported interference with academic functioning in correlational analyses. For the entire sample, a regression revealed that only the appearance orientation subscale of the MBSRQ did not explain unique variance associated with EBIDAIS scores. A few gender differences emerged when separate regressions were conducted, however, overweight preoccupation was the variable that predicted the largest unique variance for both genders. The results suggest that academic interference should be considered as a possible variable when evaluating the social and occupational problems associated with body image disturbance.     

The association between attention control,anxiety, and depression: the indirect effects of repetitive negative thinking and mood recovery

Background and objectives: Attention control deficits and repetitive negative thinking (RNT; i.e., rumination) may be key factors in the development and persistence of depression and anxiety, although their role in symptom development remains poorly understood. This represents a gap in the literature, as interventions targeting attention control and associated RNT may enhance interventions and prevent costly relapse. The current study was designed to examine the serial indirect effects of transdiagnostic RNT and negative affect recovery following a lab-induced stressor on the association between attention control deficits and trait anxiety and depression.

Methods: Participants were N?=?583 university students who completed validated measures of RNT, anxiety, depression, and mood ratings pre- and post-stressor. Stress was induced using a modified version of the Trier Social Stress Test.

Results: Results of cross-sectional indirect effects models indicated that RNT and mood recovery explained the association between attention control deficits and trait anxiety and depression. Results from reversed models indicated that only the indirect effect of RNT was significant.

Conclusions: Findings suggest that RNT and mood recovery processes play an important role in explaining anxiety and depression symptoms. Additional work is needed to examine their role in symptom development and maintenance over time.     

Children's initial sleep‐associated changes in motor skill are unrelated to long‐term skill levels

Sleep is considered to support the formation of skill memory. In juvenile but not adult song birds learning a tutor's song, a stronger initial deterioration of song performance over night‐sleep predicts better song performance in the long run. This and similar observations have stimulated the view of sleep supporting skill formation during development in an unsupervised off‐line learning process that, in the absence of external feedback, can initially also enhance inaccuracies in skill performance. Here we explored whether in children learning a motor sequence task, as in song‐learning juvenile birds, changes across sleep after initial practice predict performance levels achieved in the long run. The task was a serial reaction time task (SRTT) where subjects had to press buttons which were lighted up in a repeating eight‐element sequence as fast as possible. Twenty‐five children (8–12 years) practised the task in the evening before nocturnal sleep which was recorded polysomnographically. Retrieval was tested on the following morning and again 1 week later after daily training on the SRTT. As expected, changes in response speed over the initial night of sleep were negatively correlated with final performance speed after the 1‐week training. However, unlike in song birds, this correlation was driven by the baseline speed level achieved before sleep. Baseline‐corrected changes in speed or variability over the initial sleep period did not predict final performance on the trained SRTT sequence, or on different sequences introduced to assess generalization of the trained behaviour. The lack of correlation between initial sleep‐dependent changes and long‐term performance might reflect that the children were too experienced for the simple SRTT, possibly also favouring ceiling effects in performance. A consistent association found between sleep spindle activity and explicit sequence knowledge alternatively suggests that the expected correlation was masked by explicit memory systems interacting with skill memory formation.     

Evidence for detection of one duration sample and default responding to other duration samples by pigeons may result from an artifact of retention-test ambiguity

S. C. Gaitan and J. T. Wixted (2000) proposed that when pigeons are trained on a conditional discrimination to associate 1 duration sample with 1 comparison and 2 other duration samples with a 2nd comparison, they detect only the single duration, and on trials involving either of the 2 other duration samples, they respond to the other comparison by default. In 2 experiments, the authors show instead that pigeons lend to treat the retention intervals (such as those used by Gaitan and Wixted) as intertrial intervals, and thus, they tend to treat all trials with a delay as 0-s sample trials. The authors tested this hypothesis by showing that divergent retention functions do not appear when the retention interval is discriminably different from the intertrial interval.