Aging and shifts of visual spatial attention.

Three experiments examined adult age differences in the efficiency of endogenous (voluntary) and exogenous (involuntary) attention shifts. Younger and older Ss performed a spatial cuing task in which abruptly onset peripheral cues (Exp 1) or central, symbolic cues (Exps 2 and 3) were presented before a target stimulus at intervals ranging from 50 to 250 msec. With peripheral cues, the magnitude of cuing effects was at least as great for older as for younger adults and followed a similar time course. Similar results were obtained with symbolic cues, although cuing effects for older adults varied with cue difficulty. The results suggest that cue encoding may decline with advancing age but that the efficiency of the shift process is preserved. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Processing of auditory stimuli during auditory and visual attention as revealed by event-related potentials

Auditory event-related brain potentials (ERPs) were recorded during auditory and visual selective attention tasks. Auditory stimuli consisted of frequent standard tones (1000 Hz) and infrequent deviant tones (1050 Hz and 1300 Hz) delivered randomly to the left and right ears. Visual stimuli were vertical line gratings randomly presented on a video monitor at mean intervals of 6 s. During auditory attention, the subject attended to the stimuli in a designated ear and responded to the 1300-Hz deviants occurring among the attended tones. During visual attention, the subject responded to the occasional visual stimuli. ERPs for tones delivered to the attended ear were negatively displaced relative to ERPs elicited by tones delivered to the unattended ear and to ERPs elicited by auditory stimuli during visual attention. This attention effect consisted of negative difference waves with early and late components. Mismatch negativities (MMNs) were elicited by 1300-Hz and 1050-Hz deviants irrespective of whether they occurred among attended or unattended tones. MMN amplitudes were unaffected by attention, supporting the proposal that the MMN is generated by an automatic cerebral discrimination process.     

Goal-directed and stimulus-driven attention in cross-dimensional texture segregation

Goal-directed and stimulus-driven control of attention was examined in a visual texture segregation task. Recent published reports have debated the existence and efficiency of goal-directed guidance of attention. Some of this research has focused on the apparent stimulus-driven attentional priority given to salient distractors, even when they are known to be irrelevant to the task. In the present study, subjects searched a texture array for targets defined along one dimension. These displays also included distractors created by variation in an irrelevant dimension. Targets were of three different overall shapes. On each trial, distractors could be the same shape as the target or one of the other two shapes. In two experiments subjects were informed of the overall shape of the target prior to stimulus presentation. In these experiments, distractors that did not match the overall shape of the target caused less interference than distractors that matched the target's shape. In the third experiment, subjects were not informed of the overall shape of the target. In this experiment all distractors caused roughly equal interference. The results of these experiments demonstrate that if subjects are given information about the overall shape of the target, they are able to use this information to reduce interference from distractors that do not match the overall target shape. While acknowledging some stimulus-driven interference, this illustrates a previously unexplored source of goal-directed guidance that can reduce interfering effects of even salient distractors and argues against purely stimulus-driven control of attention.     

On the distinction between visual salience and stimulus-driven attentional capture.

It is often assumed that the efficient detection of salient visual objects in search reflects stimulus-driven attentional capture. Evidence for this assumption, however, comes from tasks in which the salient object is task relevant and therefore may elicit a deliberate deployment of attention. In 9 experiments, participants searched for a nonsalient target (vertical among tilted bars). In each display, 1 bar was highly salient in a different dimension (e.g., color or motion). When the target and salient elements coincided only rarely, reducing the incentive to attend deliberately to the salient stimuli, response times depended little on whether the target was salient, although some interesting exceptions were observed. It is concluded that efficient selection of an element in visual search does not constitute evidence that the element captures attention in a purely stimulus-driven fashion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The suppression of reflexive visual and auditory orienting when attention is otherwise engaged.

Two experiments were conducted to examine whether abrupt onsets are capable of reflexively capturing attention when they occur outside the current focus of spatial attention, as would be expected if exogenous orienting operates in a truly automatic fashion. The authors established a highly focused attentional state by means of the central presentation of a stream of visual or auditory characters, which participants sometimes had to monitor. No intramodal reflexive cuing effects were observed in either audition or vision when participants performed either an exogenous visual or auditory orthogonal cuing task together with the central focused attention task. These results suggest that reflexive unimodal orienting is not truly automatic. The fact that cuing effects were eliminated under both unimodal and cross-modal conditions is consistent with the view that auditory and visual reflexive spatial orienting are controlled by a common underlying neural substrate. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Human cortical mechanisms of visual attention during orienting and search

Functional anatomical studies indicate that a set of neural signals in parietal and frontal cortex mediates the covert allocation of attention to visual locations across a wide variety of visual tasks. This frontoparietal network includes areas, such as the frontal eye field and supplementary eye field. This anatomical overlap suggests that shifts of attention to visual locations of objects recruit areas involved in oculomotor programming and execution. Finally, the fronto-parietal network may be the source of spatial attentional modulations in the ventral visual system during object recognition or discrimination.     

Shifting and focusing auditory spatial attention.

Auditory spatial attention was investigated by manipulating spatial and temporal relations between an auditory spatial cue and an auditory target. The principal findings were that performance improved as time available to shift attention to a cued spatial position increased, accurate spatial cues facilitated performance more than inaccurate cues, performance was virtually identical for shifts of attention ranging from 0° and 180°, and performance declined as the distance of an unexpected target from a cued spatial location increased. The experiments provided evidence that auditory attention may be allocated to a specific location in response to an auditory spatial cue and that the time required to shift attention does not appear to depend on the distance of the shift. Furthermore, the findings suggest that the spatial distribution of auditory attention may be described most accurately by a gradient model in which attentional resources decline gradually with distance from a focal point. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Negative priming in auditory attention.

This article reports 3 experiments that demonstrate and analyze inhibitory (negative) priming in auditory shadowing. Participants shadowed words that were individually presented over headphones, but ignored words simultaneously presented in another voice or another location. The 1st experiment demonstrated negative priming. Ignored items are shadowed on the next trial more slowly than controls with no history of being rejected in the experiment. The 2nd experiment showed that the inhibition lasts for only one item after presentation, followed by facilitation 3 and 5 items later. The 3rd experiment showed that the inhibitory priming is exactly the same when both presentations are to the same ear as when they are to different ears. Inhibition thus adheres to the item and not to the position in space. Negative priming takes place in a modality—audition—that has no peripheral means of excluding unattended material, as vision does by shifting fixation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Auditory and visual capture during focused visual attention.

It is well known that auditory and visual onsets presented at a particular location can capture a person’s visual attention. However, the question of whether such attentional capture disappears when attention is focused endogenously beforehand has not yet been answered. Moreover, previous studies have not differentiated between capture by onsets presented at a nontarget (invalid) location and possible performance benefits occurring when the target location is (validly) cued. In this study, the authors modulated the degree of attentional focus by presenting endogenous cues with varying reliability and by displaying placeholders indicating the precise areas where the target stimuli could occur. By using not only valid and invalid exogenous cues but also neutral cues that provide temporal but no spatial information, they found performance benefits as well as costs when attention is not strongly focused. The benefits disappear when the attentional focus is increased. These results indicate that there is bottom-up capture of visual attention by irrelevant auditory and visual stimuli that cannot be suppressed by top-down attentional control. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related changes in processing auditory stimuli during visual attention: Evidence for deficits in inhibitory control and sensory memory.

Age-related declines in attention and cognition have been associated with a difficulty in inhibiting the processing of task-irrelevant information (i.e., the inhibitory deficit hypothesis). However, evidence supporting the inhibitory deficit hypothesis remains equivocal, in part because of complexities in examining the processing of irrelevant stimuli using purely behavioral techniques. The effects of age on the processing of task-irrelevant stimuli were examined using scalp-recorded event-related brain potentials. Participants performed a visual discrimination task while standard and deviant auditory stimuli were presented in the background. Deviant auditory stimuli generated a mismatch negativity (MMN) wave that decreased with age, in part because of an age-related enhancement in sensory-evoked responses. The age-related changes in processing task-irrelevant auditory stimuli are consistent with the inhibitory deficit hypothesis and suggest that impaired inhibitory control of sensory input may play a role in the age-related declines in performance during selective attention tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A theory of visual attention.

A unified theory of visual recognition and attentional selection is developed by integrating the biased-choice model for single-stimulus recognition (R. D. Luce, 1963; R. N. Shepard, 1957) with a choice model for selection from multielement displays (C. Bundesen et al; see record 1985-05669-001) in a race model framework. Mathematically, the theory is tractable, and it specifies the computations necessary for selection. The theory is applied to extant findings from a broad range of experimental paradigms. The findings include effects of object integrality in selective report, number and spatial position of targets in divided-attention paradigms, selection criterion and number of distracters in focused-attention paradigms, delay of selection cue in partial report, and consistent practice in search. On the whole, the quantitative fits are encouraging. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Children's memory for auditory and visual information on television.

Examined the relationship between children's cognitive processing of video and audio information on TV. 96 5-yr-olds viewed a videotaped segment of Sesame Street followed by comprehension and recognition tests. Ss viewed experimental segments in which (a) the audio and video tracks were from the same segment (A/V match), (b) the audio and video tracks were not from the same segment (A/V mismatch), (c) the video track was presented alone, or (d) the audio track was presented alone. This design allowed unconfounded comparisons of modality-specific processing. In the A/V mismatch condition, memory for audio information was reduced more than memory for video information. However, comprehension and recognition of audio information was similar in the audio-only and A/V match conditions. Results suggest that in regular TV programs, the video information does not interfere with processing the audio information but is more salient and memorable than the audio material. (13 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related decrement in auditory selective attention.

Young (n?=?30), middle-aged (n?=?32), and old (n?=?28) adults repeated (shadowed) words presented to the left ear at 60 words per minute with and without distracter words presented to the other ear. Dichotic shadowing error rate increased with age. An attempt to eliminate the age effect by adjusting for age differences in monaural shadowing errors, fluid intelligence, and pure-tone hearing loss did not succeed. When the analyses were confined to Ss who made no monaural shadowing errors, dichotic shadowing errors still increased linearly with age. These results showed that there are selective-attention deficits in older adults that cannot be accounted for by the uncertainty of the target location. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic contextual cuing and visual attention.

Since M. M. Chun and Y. Jiang's (1998) original study, a large body of research based on the contextual cuing paradigm has shown that the visuocognitive system is capable of capturing certain regularities in the environment in an implicit way. The present study investigated whether regularities based on the semantic category membership of the context can be learned implicitly and whether that learning depends on attention. The contextual cuing paradigm was used with lexical displays in which the semantic category of the contextual words either did or did not predict the target location. Experiments 1 and 2 revealed that implicit contextual cuing effects can be extended to semantic category regularities. Experiments 3 and 4 indicated an implicit contextual cuing effect when the predictive context appeared in an attended color but not when the predictive context appeared in an ignored color. However, when the previously ignored context suddenly became attended, it immediately facilitated performance. In contrast, when the previously attended context suddenly became ignored, no benefit was observed. Results suggest that the expression of implicit semantic knowledge depends on attention but that latent learning can nevertheless take place outside the attentional field. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The development of auditory strategies of attention.

Investigated focused and divided attention in right-handed children in 2 age groups: 6.5–7.5 and 10–11 yrs. Ss listened to lists of simultaneous word pairs that were monitored for the presence of designated target words. An analysis of correct and incorrect response rates showed that there was a general increase in the efficiency of both attention tasks with age, although selective listening performance improved to a greater extent than divided attention. In focused attention, selecting one input and ignoring another developed at different rates. In divided attention, there was a right ear advantage that remained constant across the 2 age groups. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sensory integration of auditory and visual information.

In exp. I with 3 male and 1 female o, the bisensory recognition of simultaneously presented auditory and visual verbal information was measured as a function of auditory and visual recognition. It is shown that bisensory performance is superior to performance predicted by a model that assumes the 2 modalities are processing the information independently. Instead integrative processing is suggested. In previous studies using theory of signal detectability (tsd), independent processing of bisensory presentations of mathematically equivalent stimuli has been shown. Present results suggest that the mathematically equated stimuli in those studies were not cognitively equivalent. Exp. Ii with 3 male os lends support to this notion by (a) using verbal information in a tsd paradigm, and (b) showing that when the stimuli are equivalent the results are consistent with a model in which bisensory processing occurs integratively on a common decision axis. However, when the stimuli to each mode are not equivalent, results are consistent with a model in which bisensory processing occurs independently on separate decision axes. (french summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The mechanisms of involuntary attention.

We tested 3 mechanisms of involuntary attention: (1) a perceptual enhancement mechanism, (2) a response-decision mechanism, and (3) a serial-search mechanism. Experiment 1 used a response deadline technique to compare the perceptual enhancement and the decision mechanisms and found evidence consistent with the decision mechanism. Experiment 2 used a multiple-targets paradigm to compare the decision and serial-search mechanisms. The results favored the decision mechanism. Experiment 3, which varied the display size and whether distractors were present in the display, found that when locating the target was easy, the results conformed to the decision mechanism. However, when locating the target was difficult, the serial-search mechanism was favored. Thus, there appears to be at least 2 mechanisms of involuntary attention. The serial-search mechanism accounts for involuntary attention when the target is difficult to locate, whereas the decision mechanism accounts for results when the target is easy to locate. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Short-term memory for the timing of auditory and visual signals.

Short-term memory for the timing of irregular sequences of signals has been said to be more accurate when the signals are auditory than when they are visual. No support for this contention was obtained when the signals were beeps vs flashes (Exps 1 and 3) nor when they were sets of spoken vs typewritten digits (Exps 4 and 5). On the other hand, support was obtained both for beeps vs flashes (Exps 2 and 5) and for repetitions of a single spoken digit vs repetitions of a single typewritten digit (Exp 6) when the Ss silently mouthed a nominally irrelevant item during sequence presentation. Also, the timing of sequences of auditory signals, whether verbal (Exp 7) or nonverbal (Exps 8 and 9), was more accurately remembered when the signals within each sequence were identical. The findings are considered from a functional perspective. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Splitting visual space with attention.

The present study aimed at showing a spatial compatibility effect (and, by implication, a right–left subdivision of space) solely attributable to the orienting of attention. Five groups of 8 normal Ss were required to give right–left discriminative responses to stimuli presented within one of 6 empty boxes arranged in a horizontal row. Reaction times and errors were recorded. A right–left grouping of the boxes occurred regardless of whether Ss' fixation was kept at the intermediate position (Exp 1) or at one extremity (Exp 2) of the row. In Exps 3 and 4, Ss' attention was not aligned with a fixed position but was moved, through peripheral cues, from trial to trial and positioned between different pairs of adjacent boxes. Results showed that the display was again subdivided into 2 regions and that the reference point for the right–left subdivision was the focus of attention. In Exp 5, eye position was instrumentally monitored, and Ss' attention was directed by central cues. The results confirmed that the focusing of attention leads to a right–left partitioning of space. Directing attention to a position in space brings about a right–left perceptual organization that predominates over that provided by the other egocentric reference axes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)