Attentional blink for color.

Colored letters were presented by means of rapid serial visual presentation (RSVP). Two letters (T1 and T2) were targets that required a speeded (T1) or delayed (T2) response. T1 was shown on half of the trials. Two tasks were performed in the experimental conditions. Task1 required a discrimination between 2 letters (when T1 was shown) or an indication that T1 was absent. In Experiment 1, Task2 was to detect the presence of a unique color in the RSVP stream (e.g., green in a stream of alternating red and gray). In Experiment 2, Task2 was to report the color of the first colored letter to appear in the RSVP stream. The lag between T1 and T2 in the RSVP stream was manipulated. Accuracy of color reports in Task2 was poor at shorter lags and improved as the lag was lengthened in both experiments, demonstrating an attentional blink for chromatic information. Theoretical implications of the results are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attention to orientation, size, luminance, and color: Attentional failure within the form domain.

Whether Ss can attend to physical dimensions of objects without access to semantic information about them was examined. Ss decided which of 2 laterally presented pictures, a target and a distractor, had the same orientation (Exp 1), size (Exp 2), luminance (Exp 3), or color (Exp 4) as a reference picture. In each experiment, the matching stimuli were either physically identical, semantically related, or semantically unrelated. The reference stimulus and the distractor were either semantically related or unrelated. When matching was based on orientation or on size, performance was facilitated when the matching stimuli were semantically related, and it was disrupted when the distractor was semantically related to the reference stimulus. Semantic effects were eliminated when matching was based on luminance or color. The results are discussed in terms of physiological data, form and surface information, and global and local processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional processing and the subjective contour illusion.

To distinguish between bottom–up and top–down (TD) accounts of subjective contour (SC) perception, the present investigation used a dual-task paradigm to test the relative attentional demands of real SC perception. In the primary task, 16 undergraduates made speeded same–different discriminations of either paired SC forms or their real contour analogs. Half the Ss performed this primary task in conjunction with a 6-digit short-term memory load secondary task. If subjective forms impose a greater limited-capacity processing load than real forms, then the need to share processing capacity with a secondary task was expected to produce a greater increment in RT for subjective relative to real forms. Results indicate that the expected enhanced RT increment for subjective relative to real forms with the addition of a concurrent memory load was limited to same trials. This result implies that the nature of response indicators must be considered in assessing capacity requirements with the sort of dual-task paradigm used in the present investigation. Nevertheless, the fact that the increment in same RT with the addition of a concurrent memory load was greater for subjective relative to real forms accords with expectations derived from the notion that the perception of SCs is more attention-demanding than that of real contours. A comprehensive theory of SC perception will most likely be formulated within the TD perspective of conceptually driven visual information processing. (90 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional capture by irrelevant color singletons.

Four experiments investigated attentional capture by a color singleton in visual search for a nonsingleton target. B. S. Gibson and E. M. Kelsey (1998) found that a color singleton in a precuing array facilitated target discrimination at that location if the same color also signaled the target array onset. The authors found similar cuing effects regardless of whether the singleton color matched the target array and regardless of whether subjects could anticipate the singleton or target-array color. In Experiment 4, a color singleton captured attention when it appeared in the precuing array but not when it appeared in the target array. The results indicate that attentional control settings for displaywide attributes are imprecise: Although subjects may anticipate a specific color, they cannot avoid attentional capture by other irrelevant colors. In addition, the effect of irrelevant singletons depends on whether a target is simultaneously present in the array. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional requirements of automatic and controlled processing.

The attentional demands of automatic and controlled processing were investigated in a dual task paradigm. Ss performed consistent and varied mapping versions of an S. Sternberg (see record 1966-10810-001) memory search task, both separately and together with a recognition running-memory task. In different conditions, Ss were instructed to maximize their performance on either the Sternberg or running memory tasks or to emphasize the tasks equally. Processing priority and memory load had large effects on performance when the variably mapped version of the Sternberg task was paired with the running memory task. Performance decrements in these conditions were accompanied by trade-offs in the amplitude of the P300 component of the event-related brain potential, presumably reflecting the distribution of attention between the tasks. Performance in the consistently mapped version of the Sternberg task was relatively unaffected by memory load or dual task demands. Large P300s, which were insensitive to manipulations of memory load and priority, were elicited in the consistently mapped conditions. These P300s appear to reflect the obligatory allocation of attention to task-relevant events during automatic processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional control in children's metalinguistic performance and measures of field independence.

Examined the relation between the cognitive style construct of field dependence–independence (FDI) and 2 processing components. These components, control of linguistic processing and analysis of knowledge, have been identified in previous research as part of metalinguistic ability. Children between the ages of 7 and 9 years were given a number of metalinguistic tasks and 2 measures of FDI. The results showed a common basis for FDI and metalinguistic problems requiring high levels of control but not for FDI and metalinguistic problems requiring high levels of analysis. These results shed light on the underlying cognitive basis of metalinguistic performance and established the role for 1 of the 2 processing components across domains. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the statistical independence of color and shape in object identification.

M. J. Nissen (1985) showed that color and shape are processed independently. M. A. Monheit and J. C. Johnston (1994) argued that dependence of color and shape in these experiments was reduced due to random guessing. They conducted 4 experiments in which they attempted to reduce the effect of random guessing. A strong dependence of color and shape reports was observed. In this article the effects that random guessing can have on statistical (in)dependence are analyzed. The authors argue that Monheit and Johnston's analysis is incorrect and inconsistent with the data they report and that random guessing can be the cause of statistical dependence of color and shape reports. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evidence of visual processing negativity with attention to orientation and color in central space

The aim of this study was to determine whether the visual frontal processing negativity reported in our earlier paper (Karayanidis, F. and Michie, P.T. Electroenceph. clin. Neurophysiol., 1996, 99: 38-56) is related to selection of spatial location, or occurs regardless of the stimulus features used to define the target. Subjects were instructed to respond to infrequent target stimuli of a particular combination of orientation, color and size. All stimuli were presented at central fixation. Posteriorly, orientation selection enhanced P125 amplitude over the right hemisphere but neither orientation nor color selection had an effect on N190. Posterior selection negativities emerged for orientation, color and their conjunction. At anterior sites, widespread effects of orientation and color processing were evident. The effect of location selection on the anterior N1 seen in our previous study was not evident with orientation selection. Instead, selection of orientation, color and their conjunction resulted in P145-250 frontally. Two later anterior negativities emerged. The early negativity (vPNe) was affected independently by orientation and color selection while the late negativity (vPNl) was affected only by selection of feature conjunction. Thus, the present results show that, like its auditory counterpart, the visual processing negativity occurs with a variety of stimulus classification features and is not exclusively related to spatial selection.     

Attentional modulation of central odor processing

As long ago as 1931 Fisher outlined the reasons for the accumulation of male 'benefit genes' (e.g. male fertility factors) on the Y chromosome, but it was over four decades later that a study of men with partial Y chromosome deletions revealed that a factor essential for male fertility was present on the human Y. Today, the Y deletion interval containing this 'Azoospermia Factor' (AZF) has been subdivided into three subintervals associated with different degrees of spermatogenic impairment. Furthermore, three deletion intervals have been identified on the mouse Y that impact on the spermatogenic process. This review examines these deletion intervals in mouse and man and summarises progress towards identifying candidate genes for their respective spermatogenic functions.     

Attentional versus absorptive processing in hypnotic time estimation.

Tested the absorption hypothesis of hypnotic time estimation by giving instructions designed to induce either an absorptive or an attentional listening set to 40 Ss. All Ss listened to an involving short story embedded in an administration of the Stanford Hypnotic Susceptibility Scale—Form C and provided retrospective estimates of the story's duration. Ss in the attention condition, but not those in the absorption condition, significantly underestimated the duration. However, instructional set did not influence Ss' ratings of absorption in the story. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional capture by emotional stimuli is modulated by semantic processing.

The attentional blink paradigm was used to examine whether emotional stimuli always capture attention. The processing requirement for emotional stimuli in a rapid sequential visual presentation stream was manipulated to investigate the circumstances under which emotional distractors capture attention, as reflected in an enhanced attentional blink effect. Emotional distractors did not cause more interference than neutral distractors on target identification when perceptual or phonological processing of stimuli was required, showing that emotional processing is not as automatic as previously hypothesized. Only when semantic processing of stimuli was required did emotional distractors capture more attention than neutral distractors and increase attentional blink magnitude. Combining the results from 5 experiments, the authors conclude that semantic processing can modulate the attentional capture effect of emotional stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Delayed Attentional Engagement in the Attentional Blink.

Observers often miss the 2nd of 2 visual targets (first target [T1] and second target [T2]) when these targets are presented closely in time; the attentional blink (AB). The authors hypothesized that the AB occurs because the attentional response to T2 is delayed by T1 processing, causing T2 to lose a competition for attention to the item that follows it. The authors investigated this hypothesis by determining whether the AB is attenuated when T2 is precued. The results from 4 experiments showed that the duration and magnitude of the AB were substantially reduced when T2 was precued. The observed improvement in T2 report did not occur at the expense of T1 report, suggesting that processing of T1 was already completed or was at least protected when the cue was presented. The authors conclude that, during the AB, there is a delay between detection and the selection of target candidates for consolidation in short-term memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional capture by salient color singleton distractors is modulated by top-down dimensional set.

Three experiments examined whether salient color singleton distractors automatically interfere with the detection singleton form targets in visual search (e.g., J. Theeuwes, 1992), or whether the degree of interference is top-down modulable. In Experiments 1 and 2, observers started with a pure block of trials, which contained either never a distractor or always a distractor (0% or 100% distractors)--varying the opportunity to learn distractor suppression. In the subsequent trial blocks, the proportion of distractors was systematically varied (within-subjects factor in Experiment 1, between-subjects factor in Experiment 2)--varying the incentive to use distractor suppression. In Experiment 3, observers started with 100% distractors in the first block and were presented with "rare" color or luminance distractors, in addition to "frequent" color distractors, in the second block. The results revealed distractor interference to vary as a function of both the initial experience with distractors and the incentive to suppress them: the interference was larger without relevant practice and with a lesser incentive to apply suppression (Experiments 1-3). This set of findings suggests that distractor interference is top-down modulable. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Expecting a break in time estimation: Attentional time-sharing without concurrent processing.

The interference from nontemporal processing on concurrent time estimation is usually attributed to disruption in timing caused by attentional requirements of nontemporal processing. Here, we examined interruption in timing without concurrent nontemporal processing. Empty breaks of various durations, during time-interval production, lengthened produced intervals. Moreover, an effect of break location was observed: Intervals lengthened proportionally to prebreak duration. When cued and uncued uninterrupted trials were introduced, the lengthening was proportional to the duration for which a break was expected. It was concluded that attentional time-sharing between time estimation and expectation of its interruption contributed to the interference effect in time-estimation research, independently of any concurrent processing requirements during time estimation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional difficulties in hyperactive and conduct-disordered children: a processing deficit

A random population sample of 1479 Chinese boys from Hong Kong was screened and diagnosed in a two-stage epidemiological study. Four groups, age 7-8, were distinguished: (1) a pure hyperactive group (HA), (2) a mixed hyperactive/conduct-disordered group (HA+CD), (3) a pure conduct-disordered group (CD), and (4) a normal control group (N). On a visual search task, only the HA children showed a specific processing deficit in performance. This confirms the diagnostic value of such a deficit for hyperactivity, differentiating it from conduct disorder. The failure to find a similar deficit in the HA+CD group raises questions concerning the clinical identity of these children. Each group showed a performance decrement over time in the visual search task but the decrement did not differ between the four groups. This observation is not congruent with the reports of a short attention span in hyperactive children; explanations of this apparent contradiction are considered.     

Featural guidance in conjunction search: The contrast between orientation and color.

Four experiments examined the effects of precues on visual search for targets defined by a color-orientation conjunction. Experiment 1 showed that cueing the identity of targets enhanced the efficiency of search. Cueing effects were stronger with color than with orientation cues, but this advantage was additive across array size. Experiment 2 demonstrated that cueing effects interacted with bottom-up segmentation processes, whereas Experiment 3 showed the stronger effects of color cues remained in a compound task. Experiment 4 confirmed the enhanced effect of color cueing even when verbal rather than visual cues were used. The targets used were balanced for search efficiency within both orientation and color dimensions. We suggest search benefits from the top-down cueing of color compared with orientation because color cueing enhances the segmentation of displays into color groups more efficiently. This enables search to an appropriate color group to be initiated earlier. We discuss how top-down segmentation processes interact with differences in bottom-up segmentation to further improve target detection. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interactions between color and word processing in a flanker task.

To examine interactions between color and word attributes, participants responded, either manually or vocally, to a central target (color patch or word) flanked by a Stroop stimulus. Color and word attributes of the flanker affected both vocal and manual responding to color patches. Color and word flankers also affected manual responding to word targets, but only word flanker affected vocal responding to word targets. These results are not consistent with models (e.g., translational models) of Stroop tasks, which posit that interactions between colors and words occur only when vocal responding is required. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional modulation of visual motion processing in cortical areas MT and MST

The visual system is constantly inundated with information received by the eyes, only a fraction of which seems to reach visual awareness. This selection process is one of the functions ascribed to visual attention. Although many studies have investigated the role of attention in shaping neuronal representations in the visual cortex, few have focused on attentional modulation of neuronal signals related to visual motion. Here we report that the responses of direction-selective neurons in monkey visual cortex are greatly influenced by attention, and that this modulation occurs as early in the cortical hierarchy as the level of the middle temporal visual area (MT). Our finding demonstrates a stronger and earlier influence of attention on motion processing along the dorsal visual pathway than previously recognized.     

Attentional and ocular movements.

The relationship between eye movements and movements of attention was examined in a series of 6 experiments. A temporal order judgment technique was used to index attentional allocation. The results showed that endogenous movements of attention were slower than movements of the eyes and that the participants were able to hold attention at one location while executing an eye movement to another location. Under conditions of exogenous cueing, attention moved rapidly to the cued location, in advance of the eyes. These findings challenge the prevailing view that ocular movements must necessarily be preceded by a movement of attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional demands of processing shape in three-dimensional space: Evidence from visual search and precuing paradigms.

The hypothesis that representation of projective shape is preattentive whereas representation of objective shape in 3-dimensional space requires allocation of attention was tested in 2 visual search and 2 precuing experiments. In the visual search experiments, the slope for projective shape search was expected to approach 0 and that for objective shape search was expected to be a positive monotonic function of set size. In the precuing experiments, the effects of precuing were expected to be largely limited to the task requiring representation of objective shape. The overall pattern of results conformed to expectations. The findings are interpreted in the context of a model of shape-at-a-slant processing set out by W. Epstein and B. Lovitts (1985) and Epstein and T. Babler (1989, 1990). (PsycINFO Database Record (c) 2010 APA, all rights reserved)