Effects of cross-modal and intramodal division of attention on perceptual implicit memory.

Extant results motivate 3 hypotheses on the role of attention in perceptual implicit memory. The first proposes that only intramodal manipulations of attention reduce perceptual priming. The second attributes reduced priming to the effects of distractor selection operating in a central bottleneck process. The third proposes that manipulations of attention only affect priming via disrupted stimulus identification. In Experiment 1, a standard cross-modal manipulation did not disrupt priming in perceptual identification. However, when study words and distractors were presented synchronously, cross-modal and intramodal distraction reduced priming. Increasing response frequency in the distractor task produced effects of attention regardless of target-distractor synchrony. These effects generalized to a different category of distractors arguing against domain-specific interference. The results support the distractor-selection hypothesis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Failures to ignore entirely irrelevant distractors: The role of load.

In daily life (e.g., in the work environment) people are often distracted by stimuli that are clearly irrelevant to the current task and should be ignored. In contrast, much applied distraction research has focused on task interruptions by information that requires a response and therefore cannot be ignored. Moreover, the most commonly used laboratory measures of distractibility (e.g., in the response-competition and attentional-capture paradigms), typically involve distractors that are task relevant (e.g., through response associations or location). A series of experiments assessed interference effects from stimuli that are entirely unrelated to the current task, comparing the effects of perceptual load on task-irrelevant and task-relevant (response competing) distractors. The results showed that an entirely irrelevant distractor can interfere with task performance to the same extent as a response-competing distractor and that, as with other types of distractors, the interfering effects of the irrelevant distractors can be eliminated with high perceptual load in the relevant task. These findings establish a new laboratory measure of a form of distractibility common to everyday life and highlight load as an important determinant of such distractibility. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The spatial focus of attention is controlled at perceptual and cognitive levels.

Selective attention has been hypothesized to reduce distractor interference at both perceptual and postperceptual levels (Lavie, 2005), respectively, by focusing perceptual resources on the attended location and by blocking at postperceptual levels distractors that survive perceptual selection. This study measured the impact of load on these selection mechanisms using a flanker paradigm (Eriksen & St. James, 1986) and indexing distractor interference as a function of separation. It distinguished changes in the extent of focus of the distractor-interference function of separation (reflecting perceptual selection) from changes in the amplitude of distractor interference not accompanied by changes in focus (reflecting postperceptual selection). It showed that: (1) the spatial profile of perceptual resources is shaped like a “Mexican hat” (Müller et al., 2005); (2) increasing perceptual load focuses perceptual resources (Caparos & Linnell, 2009); (3) increasing cognitive load defocuses perceptual resources; and (4) participants with reduced working-memory span show reduced postperceptual blocking of distractors. While these findings are consistent with two levels of selective attention, they show that the first perceptual level is affected not only by perceptual but also by cognitive-control mechanisms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The influence of temporal selection on spatial selection and distractor interference: An attentional blink study.

Both spatial and temporal selection require focused attention. The authors examine how temporal attention affects spatial selection. In a dual-task rapid serial visual presentation paradigm, temporal selection of a target (T1) impairs processing of a second target (T2) that follows T1 within 500 ms. This process is the attentional blink (AB). To test the effects of withdrawing temporal attention, the authors measured concurrent distractor interference on T2 when the distractors were presented during and outside of the AB. Perceptual interference was manipulated by the similarity in color between T2 and concurrent distractors, and response interference was manipulated by the flanker congruency task. Results showed that perceptual interference was larger during the AB. Response interference also increased during the AB, but only when perceptual interference was high. The authors conclude that temporal selection and spatial selection rely on a common attentional process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Processing capacity under perceptual and cognitive load: A closer look at load theory.

Variations in perceptual and cognitive demands (load) play a major role in determining the efficiency of selective attention. According to load theory (Lavie, Hirst, Fockert, & Viding, 2004) these factors (a) improve or hamper selectivity by altering the way resources (e.g., processing capacity) are allocated, and (b) tap resources rather than data limitations (Norman & Bobrow, 1975). Here we provide an extensive and rigorous set of tests of these assumptions. Predictions regarding changes in processing capacity are tested using the hazard function of the response time (RT) distribution (Townsend & Ashby, 1978; Wenger & Gibson, 2004). The assumption that load taps resource rather than data limitations is examined using measures of sensitivity and bias drawn from signal detection theory (Swets, 1964). All analyses were performed at two levels: the individual and the aggregate. Hypotheses regarding changes in processing capacity were confirmed at the level of the aggregate. Hypotheses regarding resource and data limitations were not completely supported at either level of analysis. And in all of the analyses, we observed substantial individual differences. In sum, the results suggest a need to expand the theoretical vocabulary of load theory, rather than a need to discard it. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

"Selective Preference in Visual Fixation Away From Negative Images in Old Age? An Eye-Tracking Study": Correction.

Reports an error in the original article by D. M. Isaacowitz et al (Psychology and Aging, 2006[March], Vol 21[1], 40-48). Because of a printer's error, an incorrect version of Figure 2 appeared in the article. The correct version of the figure is provided. (The following abstract of this article originally appeared in record 2006-03906-005.) Recent studies have suggested that older individuals selectively forget negative information. However, findings on a positivity effect in the attention of older adults have been more mixed. In the current study, eye tracking was used to record visual fixation in nearly real-time to investigate whether older individuals show a positivity effect in their visual attention to emotional information. Young and old individuals (N = 64) viewed pairs of synthetic faces that included the same face in a nonemotional expression and in 1 of 4 emotional expressions (happiness, sadness, anger, or fear). Gaze patterns were recorded as individuals viewed the face pairs. Older adults showed an attentional preference toward happy faces and away from angry ones; the only preference shown by young adults was toward afraid faces. The age groups were not different in overall cognitive functioning, suggesting that these attentional differences are specific and motivated rather than due to general cognitive change with age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prioritization of New Objects in Real-World Scenes: Evidence From Eye Movements.

The authors examined the prioritization of abruptly appearing objects in real-world scenes by measuring the eyes' propensity to be directed to the new object. New objects were fixated more often than chance whether they appeared during fixations (transient onsets) or saccades (nontransient onsets). However, onsets that appeared during fixations were fixated sooner and more often than those coincident with saccades. Prioritization of onsets during saccades, but not fixations, were affected by manipulations of memory: Reducing scene viewing time prior to the onset eliminated prioritization, whereas prior study of the scenes increased prioritization. Transient objects draw attention quickly and do not depend on memory, but without a transient signal, new objects are prioritized over several saccades as memory is used to explicitly identify the change. These effects were not modulated by observers' expectations concerning the appearance of new objects, suggesting the prioritization of a transient is automatic and that memory-guided prioritization is implicit. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Investigating the Effects of a Set of Intercorrelated Variables on Eye Fixation Durations in Reading.

The present experiment investigated the influence of 5 intercorrelated variables on word recognition using a multiple regression analysis. The 5 variables were word frequency, subjective familiarity, word length, concreteness, and age of acquisition (AoA). Target words were embedded in sentences and eye tracking methodology was used to investigate the predictive power of these variables. All 5 variables were found to influence reading time. However, the time course of these variables differed. Both word frequency and familiarity showed an early but lasting influence on eye fixation durations. Word length only significantly predicted fixation durations after refixations on the target words were taken into account. This is the 1st experiment to demonstrate concreteness and AoA effects on eye fixations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Anterior cingulate activity and level of cognitive conflict: Explicit comparisons.

The role of anterior cingulate cortex (ACC) in attention is a matter of debate. One hypothesis suggests that its role is to monitor response-level conflict, but explicit evidence is somewhat lacking. In this study, the activation of ACC was compared in (a) color and number standard Stroop tasks in which response preparation and interference shared modality (response-level conflict) and (b) color and number matching Stroop tasks in which response preparation and interference did not share modality (non-response-level conflict). In the congruent conditions, there was no effect of task type. In the interference conditions, anterior cingulate activity in the matching tasks was less than that in the standard tasks. These results support the hypothesis that ACC specifically mediates generalized modality-independent selection processes invoked by response competition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of perceptual load on attention-induced motion blindness: The efficiency of selective inhibition.

Recent visual marking studies have shown that the carry-over of distractor inhibition can impair the ability of singletons to capture attention if the singleton and distractors share features. The current study extends this finding to first-order motion targets and distractors, clearly separated in time by a visual cue (the letter X). Target motion discrimination was significantly impaired, a result attributed to the carry-over of distractor inhibition. Increasing the difficulty of cue detection increased the motion target impairment, as distractor inhibition is thought to increase under demanding (high load) conditions in order to maximize selection efficiency. The apparent conflict with studies reporting reduced distractor inhibition under high load conditions was resolved by distinguishing between the effects of "cognitive" and "perceptual" load. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Search, Enumeration, and Aging: Eye Movement Requirements Cause Age-Equivalent Performance in Enumeration but Not in Search Tasks.

Response time (RT) and fixation frequency were measured for young and older adults in search and enumeration tasks under high- and low-attentional competition conditions. There was an age-related decrement in search rates for single targets both for RT and fixation frequency, but there was no deficit in enumeration rates either with or without distractors even though serial enumeration rates were much slower than single target search rates. Fixation frequency per item in serial enumeration was much greater than in serial visual search for a single target. Enumerating targets with distractors produced an overall increase in RT and fixation frequency that was greater for older adults. The data are contrary to a generalized slowing account, and an alternative is proposed on the basis of the need to make eye movements in enumeration but not in search tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of selective attention: Perceptual load influences early versus late attentional selection in children and adults.

The moderating effect of perceptual load on visual selective attention was examined in 2 studies. In Study 1, children and young adults searched displays of varying set size flanked by irrelevant distractors. Children's performance was as efficient as adults' under conditions of high but not low loads, suggesting that early selection engages rapidly maturing neural systems and late selection engages later-maturing systems. In Study 2, 4 age groups were tested, and place markers were set at empty locations to examine perceptual grouping effects. Study 1's pattern was replicated in all age groups, with onset of early selection occurring at lower loads for younger children. Overall, children initiated early selection at lower loads to compensate for immature anterior-system interference control processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotion at the expense of cognition: Psychopathic individuals outperform controls on an operant response task.

The impact of emotional stimuli on a simple motor response task in individuals with psychopathy and comparison individuals was investigated. Psychopathy was assessed using the Psychopathy Checklist Revised (Hare, 1991). Participants were presented with the Emotional Interrupt Task, in which they responded with left and right button presses to shapes that were temporally bracketed by positive, negative, and neutral visual images taken from the International Affective Picture System. The comparison group showed increased response latencies if the shape was temporally bracketed by either a positive or negative emotional stimulus relative to a neutral stimulus. Individuals with psychopathy did not show this modulation of reaction time for either positive or negative emotional stimuli. Results are discussed with reference to current models regarding the modulation of attention by emotion and the emotional impairment seen in individuals with psychopathy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Effects of Frequency and Predictability on Eye Fixations in Reading: Implications for the E-Z Reader Model.

Readers read sentences containing target words varying in frequency and predictability. The observed pattern of data for fixation durations only mildly departed from additivity, with predictability effects that were slightly larger for low-frequency than for high-frequency words. The pattern of data for skipping was different as predictability affected only the probability of skipping for high-frequency target words. Simulations of these data using the E-Z Reader model indicated that a single-process model was unlikely to provide a good fit for both measures. A version of the model that assumes that (a) word-encoding time is additively affected by frequency and predictability and (b) difficulty with postlexical processing of the target word causes a double take accounted for the data while indicating that the relationship between the duration of hypothesized word-encoding stages and observed fixation durations is not likely to be transparent. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Response latencies in auditory sentence comprehension: Effects of linguistic versus perceptual challenge.

Older adults with good hearing and with mild-to-moderate hearing loss were tested for comprehension of spoken sentences that required perceptual effort (hearing speech at lower sound levels), and two degrees of cognitive load (sentences with simpler or more complex syntax). Although comprehension accuracy was equivalent for both participant groups and for young adults with good hearing, hearing loss was associated with longer response latencies to the correct comprehension judgments, especially for complex sentences heard at relatively low amplitudes. These findings demonstrate the need to take into account both sensory and cognitive demands of speech materials in older adults' language comprehension. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Working-memory capacity and the control of attention: The contributions of goal neglect, response competition, and task set to Stroop interference.

Individual differences in working-memory (WM) capacity predicted performance on the Stroop task in 5 experiments, indicating the importance of executive control and goal maintenance to selective attention. When the Stroop task encouraged goal neglect by including large numbers of congruent trials (RED presented in red), low WM individuals committed more errors than did high WM individuals on the rare incongruent trials (BLUE in red) that required maintaining access to the "ignore-the-word" goal for accurate responding. In contrast, in tasks with no or few congruent trials, or in high-congruency tasks that followed low-congruency tasks, WM predicted response-time interference. WM was related to latency, not accuracy, in contexts that reinforced the task goal and so minimized the difficulty of actively maintaining it. The data and a literature review suggest that Stroop interference is jointly determined by 2 mechanisms, goal maintenance and competition resolution, and that the dominance of each depends on WM capacity, as well as the task set induced by current and previous contexts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Phase attraction in sensorimotor synchronization with auditory sequences: Effects of single and periodic distractors on synchronization accuracy.

Four experiments showed that both single and periodic distractor tones affected the timing of finger taps produced in synchrony with an isochronous auditory target sequence. Single distractors had only small effects, but periodic distractors occurring at various fixed or changing phase relationships exerted strong phase attraction. The attraction was asymmetric, being stronger when distractors preceded target tones than when they lagged behind. A large pitch difference between target and distractor tones (20 vs. 3 semitones) did not reduce phase attraction substantially, although in the case of continuously changing phase relationships it did prevent complete capture of the taps by the distractors. The results support the hypothesis that phase attraction is an automatic process that is sensitive primarily to event onsets. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Speeded old-new recognition of multidimensional perceptual stimuli: Modeling performance at the individual-participant and individual-item levels.

Observers made speeded old-new recognition judgments of color stimuli embedded in a multidimensional similarity space. The paradigm used multiple lists but with the underlying similarity structures repeated across lists, to allow for quantitative modeling of the data at the individual-participant and individual-item levels. Correct-rejection response times (RTs) got systematically faster as the similarity of foils to the old study items decreased. There were also intricate patterns of speed-accuracy trade-offs that varied across individual items and participants. An exemplar-based random-walk model provided a good overall quantitative account of the recognition choice probabilities, mean correct RTs, and mean error RTs associated with the individual items on the basis of their positions in multidimensional similarity space. However, the model failed to predict the very long RTs associated with correct rejections of a prototype foil. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Environmental Dependence of Behavioral Control Mechanisms: Effects of Alcohol and Information Processing Demands.

Studies show that alcohol increases a drinker's reliance on the environmental context for the maintenance of inhibitory and activational responding. The author of the present study examined additive effects of alcohol and cognitive load on the cue dependency of inhibitory and activational mechanisms of control. Adults received 0.0 g/kg, 0.45 g/kg, and 0.65 g/kg alcohol and performed a cued go/no-go task that presented simple and complex go and no-go stimuli. Results showed that cue dependency of response inhibition increased as a function of dose, and this effect was similar across low and high cognitive load conditions. These findings are consistent with a capacity limitation account of alcohol impairment that could involve central or output stages of information processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Detecting threat-related intentional actions of others: Effects of image quality, response mode, and target cuing on vigilance.

Three experiments examined the vigilance performance of participants watching videos depicting intentional actions of an individual’s hand reaching for and grasping an object—involving transporting or using either a gun or a hairdryer—in order to detect infrequent threat-related actions. Participants indicated detection of target actions either manually or by withholding response. They also rated their subjective mental workload before and after each vigilance task. Irrespective of response mode, the detection rate of intentional threats declined over time on task and subjective workload increased, but only under visually degraded viewing conditions. This vigilance decrement was attenuated by temporal cues that were 75% valid in predicting a subsequent target action and eliminated with 100% valid cues. The findings indicate that detection of biological motion targets, and threat-related intentional actions in particular, although not attention sensitive under normal viewing conditions, is subject to vigilance decrement under degraded viewing conditions. The results are compatible with the view that the decrement in detecting threat-related intentional actions reflects increasing failure of attention allocation processes over time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)