Inhibition of return along the path of attention.

Investigated inhibition of return (IOR) at 4 target locations (a near and a far location in each visual hemifield). Exp 1 was conducted to determine if IOR extends over a cued visual hemifield. 12 Ss indicated when they visually detected a cross after being instructed to keep their eyes fixed on a specific point. The target locations were aligned horizontally and IOR was observed at the near locations when cues were presented at the far locations but not at the far locations when cues were presented at the near locations. In Exp 2, the target locations were not horizontally aligned and IOR was not observed for near locations when the far locations were cued. Otherwise, the same procedure and apparatus as in Exp 1 were used by 12 different Ss. The authors conclude that IOR may be an attentional phenomenon and that attention may operate in an analog fashion such that locations in the path of the attentional movement may be attended to. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Monocular asymmetries in vision: A phenomenal basis for eye signature.

Explored the conditions under which observers with known sighting dominance characteristics could discriminate eye-of-origin information in 3 experiments with 59 Ss. The nature of phenomenal differences between the 2 monocular channels was also investigated. All Ss were required to have uncorrected visual acuity of 20/30 or better in each eye with no differences between eyes and to show strong sighting dominance (i.e., the consistent use of the same eye for sighting). Exps I and II required Ss to identify the eye receiving visual information under conditions in which the stimuli were presented covertly to only 1 eye or, in some instances, to both eyes (an utrocular discrimination paradigm). Ss could distinguish between monocular stimulation and discriminate binocular from monocular exposures only after feedback on the accuracy of the original responses was given. Exp III investigated the type of information differentiating the 2 monocular images used by the Ss during the feedback training. Ss assigned different ratings of image quality to the 2 monocular images when they were given the opportunity to compare them directly. Findings suggest that the phenomenal difference between the monocular images demonstrated in Exp III may have been the discriminative cue learned by Ss in the previous 2 experiments to improve their utrocular discrimination. (French abstract) (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Socially mediated learning in male Betta splendens..

Showed, in 7 experiments, that in the absence of social stimulation male Siamese fighting fish would approach any of several visual and spatial cues that had previously been paired with the Ss' mirror images. Findings demonstrate that learned modifications of swimming mediated by social stimuli are possible in Bettas. Results suggest that Ss learned to exhibit conditioned gill-cover erection as part of a pattern of locomotion that could effectively maintain territories. Nearly all Ss learned to swim in proximity to visual and spatial cues previously presented with conspecific images. Results also suggest that territorial defense in some teleosts may be mediated by the association of social cues with visual and spatial stimuli. (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Directed attention prolongs the perceived duration of a brief stimulus

Stelmach, Herdman, and McNeil (1994) suggested recently that the perceived duration for attended stimuli is shorter than that for unattended ones. In contrast, the attenuation hypothesis (Thomas & Weaver, 1975) suggests the reverse relation between directed attention and perceived duration. We conducted six experiments to test the validity of the two contradictory hypotheses. In all the experiments, attention was directed to one of two possible stimulus sources. Experiments 1 and 2 employed stimulus durations from 70 to 270 msec. A stimulus appeared in either the visual or the auditory modality. Stimuli in the attended modality were rated as longer than stimuli in the unattended modality. Experiment 3 replicated this finding using a different psychophysical procedure. Experiments 4-6 showed that the finding applies not only to stimuli from different sensory modalities but also to stimuli appearing at different locations within the visual field. The results of all six experiments support the assumption that directed attention prolongs the perceived duration of a stimulus.     

Laboratory observations of aggregative behavior of garter snakes, Thamnophis sirtalis: Roles of the visual, olfactory, and vomeronasal senses.

Two experiments determined (a) whether male garter snakes require a functional vomeronasal or olfactory system to return to previously preferred shelter locations and (b) the sensory modalities used to aggregate in the absence of previously deposited chemical cues. In Exp I, 22 male garter snakes with vomeronasal nerve lesions did not return to previously preferred shelter locations when tested individually. However, when tested with a group that included 9 control Ss, they returned to previously preferred shelters. The shelter-selection behavior of Ss with olfactory nerve lesions improved postoperatively, whereas the behavior of Ss with sham lesions was unchanged. In Exp II, 32 Ss were tested for aggregation in aquaria in which the substrate and other contents were cleaned between trials. After blindfolding or olfactory nerve cuts, Ss aggregated at normal levels. When Ss' vomeronasal ducts were sutured closed, aggregation scores were significantly depressed, although 2 of the 3 groups with vomeronasal duct sutures did aggregate just above change levels. Results from both studies indicate that use of chemical signals by garter snakes in shelter selection and aggregation is mediated by the vomeronasal system and that neither the olfactory nor the visual system is critical for these behaviors. (30 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of orienting to locations and objects in human infants.

Investigated the preference for orienting to novel locations and novel objects in young infants in 2 experiments, by examining the influence of visual signals on subsequent attentional orienting and eye movements. Exp 1 (n?=?12) demonstrates that 3-mo-olds show inhibition of return (IOR) for 10° target eccentricities, but not for 30° target eccentricities. In Exp 2, 14 3-mo-olds and 14 6-mo-olds oriented to 10° targets that varied in location and object identity. Ss of both ages strongly preferred orienting to novel objects at novel locations. At 3 mo, the preference for novel objects was equal to the preference for novel locations, while at 6 mo a tendency to prefer novel objects over novel locations emerged. Overall, findings support separate development of these 2 forms of novelty preference, and suggest that novel location preferences (IOR) relates closely to the eye movement system. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of selective attention in the perception of multiple-element stimulus arrays.

To access the role of attention in visual processing, we have recorded single-unit activity from area V4 of visual cortex in macaque monkeys, and the results of these experiments provide a clear demonstration of the relationship between inter-stimulus competition and attention. Specifically, attended stimuli elicit larger responses than ignored stimuli, and these attention effects are increased when: a) the total number of distracting stimuli is increased; b) both attended and ignored stimuli are located inside the neuron's receptive field; and c) the attended and ignored stimuli are presented simultaneously rather than sequentially. We have also examined the role of inter-stimulus competition in human subjects by recording event-related potentials (ERPs), which are electrophysiological responses that can be recorded noninvasively from the scalp. In these experiments, we have found that the attention-sensitive N2pc wave is present when subjects focus attention onto target stimuli when they are surrounded by competing distractor stimuli, but is absent when the competition is eliminated (e.g. by removing the distractors). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inhibition of return in discrimination tasks.

Although inhibition of return is known to affect a wide range of detection tasks, it has not been found consistently in discrimination tasks. To examine this issue, 5 experiments were conducted in which participants discriminated between a visual target and a distractor. The responses were not inhibited if, before the onset of stimuli, attention had been overtly oriented (i.e., an eye movement was made) to the future target location and the stimulus at that location was the same symbol as the upcoming target. However, if attention was covertly oriented (i.e., no eye movement was made) to the future location of the target, or if the stimulus at the earlier attended location was a symbol different from the target, responses to the target were inhibited. Overall, the findings provide insights into the relation between movements of attention and discrimination judgments and support the notion that inhibition of return is an attentional phenomenon. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

d-amphetamine-induced enhancement of inhibitory mechanisms involved in visual search.

The authors examined the effects of d-amphetamine on the ability to perform a cued target-detection task that measured inhibition of return (IOR). IOR is a reflexive inhibitory mechanism that delays attention from returning to a previously attended location and has been shown to increase the efficiency of a visual search. Adults (N=14) with a history of cocaine use performed the task under 4 doses of d-amphetamine (0, 10, 20, and 30 mg). The results showed active d-amphetamine doses increased the duration of IOR. By increasing the delay in returning attention to a previously attended location, d-amphetamine might reduce time spent searching previously attended locations, increasing the efficiency of visual searches. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reversal set formation in the visually decorticate rat.

Results of 4 experiments with 32 male black-hooded rats show that Ss given large visual cortex lesions demonstrated a simultaneous task reversal deficit previously reported by R. C. Gonzales et al (1964) to follow more extensive cortical ablation. However, no deficit appeared in an operant discrimination that deemphasized visuospatial cues, and the simultaneous task deficit vanished when translucent eye occluders were applied to eliminate spatial, but not intensity, cue use. Because the lesion Ss showed an impairment only when visuospatial cues were available and relevant to correct reversal performance, they seemed hindered by their incompetent processing of visuospatial information. Results support spatial rather than learning approaches to visual cortex function. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Chronometric analysis of apparent spotlight failure in endogenous visual orienting.

Ss made speeded responses to peripheral luminance increments or decrements preceded by informative central precues. In 4 experiments with 48 university students, one of these stimuli was much more likely to occur than the other. In a simple detection task, the likely and unlikely stimuli showed equivalent cuing effects. In a discrimination task (bright/dim), the likely stimuli showed cuing but the unlikely one did not (spotlight failure), and there was a tendency to make the likely response when the unlikely stimulus occurred at the cued location. In Exp 5, the 2 stimuli were equally likely, and a choice was required. Large cuing effects were observed for both stimuli with no evidence of a speed–accuracy trade-off. A logogen-activation framework is described within which criterion and sensitivity adjustments are needed to accommodate the full pattern of results. Endogenous orienting appears to enhance processing of all stimuli at attended (relative to unattended) locations, an effect that may be masked by specific stimulus or response expectancies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Extent and limits of the matching concept in monkeys (Cebus apella).

Two experiments with 11 monkeys investigated the extent and limits of the matching concept. In Exp I, 8 Ss that were experimentally naive with regard to visual stimuli were trained on identity matching with a 2-sample set based on 2-dimensional stimuli. On a subsequent test employing 2 new samples, 4 of the 8 Ss applied the matching rule to the new sample stimuli (as defined by a transfer criterion). Three of these Ss showed substantial savings in learning to match the new samples; 2 of the 3 Ss transferred the matching rule when given a 2nd test with 2 new samples, and the 3rd S showed immediate and complete transfer when tested with a 3rd pair of new stimuli. Results indicate a stronger representation of the matching concept in monkeys than has been demonstrated with pigeons, even in comparable assessment conditions. However, in Exp II, 4 Ss from Exp I failed to transfer the matching rule to steady vs flashing green samples, indicating that the matching concept did not immediately extend beyond the general class of visual stimuli with which it was developed. These and related research findings suggest that representation of the matching concept in animals varies along a specificity–abstractness dimension, reflecting the degree to which the concept is tied to the conditions and context of its development. (45 ref) (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Bidirectional grapheme-phoneme activation in a bimodal detection task.

A divided attention paradigm was used to investigate whether graphemes and phonemes can mutually activate or inhibit each other during bimodal processing. In 3 experiments, Dutch Ss reacted to visual and auditory targets in single-channel or bimodal stimuli. In some bimodal conditions, the visual and auditory targets were nominally identical or redundant (e.g., visual A and auditory /a/); in others they were not (e.g., visual U and auditory /a/). Temporal aspects of cross-modal activation were examined by varying the stimulus onset asynchrony of visual and auditory stimuli. Cross-modal facilitation, but not inhibition, occurred rapidly and automatically between phoneme and grapheme representations. Implications for current models of bimodal processing and word recognition are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Picture perception: Effects of luminance on available information and information-extraction rate.

Three experiments with 255 undergraduates and a 4th in which the author and 2 colleagues served as Ss showed that complex visual stimuli—pictures and digit arrays—were remembered better when shown at high luminance (LM) than at low LM. Evidence was found for the possibilities that lowering LM reduced the amount of available information in the stimulus and that lowering LM reduced the rate at which the information was extracted from the stimulus. When stimuli were presented at durations short enough to permit only a single eye fixation, LM affected only the rate at which information was extracted. Decreasing LM by a factor of 100 caused information to be extracted more slowly by a factor that ranged, over experiments, from 1.4 to 2.0. When pictures were presented at durations long enough to permit multiple fixations, however, LM affected the total amount of extractable information. In a 5th experiment, with 4 undergraduates, converging evidence was sought for the proposition that within the 1st eye fixation on a picture, LM affects the rate of information extraction. If this proposition is correct and the 1st eye fixation lasts until some criterion amount of information is extracted, then fixation duration should increase with decreasing LM. This prediction was confirmed. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attention misplaced: The role of diagnostic features in the face-inversion effect.

Inversion disproportionately impairs recognition of face stimuli compared to nonface stimuli arguably due to the holistic manner in which faces are processed. A qualification is put forward in which the first point fixated on is different for upright and inverted faces and this carries some of the face-inversion effect. Three experiments explored this possibility by using fixation crosses to guide attention to the eye or mouth region of the to-be-presented faces in different orientations. Recognition was better when the fixation cross appeared at the eye region than at the mouth region. The face-inversion effect was smaller when the eyes were cued than when the mouth was cued or when there was no cueing. The results suggest that the first facial feature attended to is important for accurate face recognition and this may carry some of the effects of inversion. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Examining Task Difficulty and the Time Course of Inhibition of Return: Detecting Perceptually Degraded Targets.

The ability to efficiently direct visual attention to salient features in the environment is a critical function of the visual system. The finding that people are slower to detect a target that appears at a previously cued location is thought to reflect a mechanism known as inhibition of return (IOR). Past research has shown that difficult target discriminations result in a greater amount of time needed to inhibit previously attended locations (i.e., a delayed onset of inhibition), suggesting that task difficulty plays a critical role in the allocation of attention. In this study, IOR was measured at a wide range of SOAs while participants detected either a perceptually degraded target or a standard, high luminance target. When responses were made to a perceptually degraded target, the time course of IOR was delayed by approximately 250 ms (relative to the control group), suggesting that the difficulty in detecting targets also influences the allocation of attention. The results are consistent with the notion that IOR is not simply a reflexive subcortical mechanism but rather involves top-down attentional control settings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cross-modal equivalence in early infancy: Auditory–visual intensity matching.

To examine the hypothesis that young infants ignore differences between lights and sounds and instead respond to auditory and visual stimuli as more or less similar depending on their intensity, a cardiac habituation/dishabituation method with a test for stimulus generalization was employed. In 2 experiments, a total of 40 3-wk-old Ss were repeatedly presented with white-light followed by white-noise stimuli of different intensities. A U-shaped relationship between magnitude of cardiac response (CR) and loudness was found. In view of previous findings that without prior visual stimulation a monotonic increase in CR to the same range of auditory stimuli results, this finding of a significant quadratic relationship with loudness suggests that Ss were responding to the auditory stimuli in terms of their similarity to the previously presented visual stimulus. A separate group of 14 infants presented with a more intense visual stimulus exhibited a shift in the intensity at which a minimal CR occurred. Results of a study with 31 adults did not show any systematic relationship between CR and loudness, indicating that unlike infants, adults do not spontaneously make cross-modal matches of intensity. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Selection of moving and static objects for the control of spatially directed action.

Research studying visual selective attention has largely examined filtering tasks in which stationary targets are selected from stationary distractors by a physical cue such as location and identity is the reported attribute. During many interactions with the visual environment however, target stimuli are selected by what they are, whereas action is controlled by where the stimulus is located. This study demonstrates that the interference and negative priming effects observed in standard filtering tasks, which suggest that distractors are analyzed and subsequently inhibited during selection, are also observed when targets are selected on the basis of identity and spatial location is the reported attribute. Furthermore, experimental results suggest that inhibition associated with distracting objects in this new task is object-centered, so that if the object is moving through space, inhibition moves with it. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of cross-modal recognition in infant pigtail monkeys (Macaca nemestrina).

Examined the development of cross-modal recognition in 48 infant pigtail monkeys in 2 studies by using an adaptation of the visual preference technique. Ss were first familiarized orally with pacifiers of 1 of 2 shapes and were then tested on corresponding visual stimuli. In a cross-sectional experiment (Exp I), Ss under 200 days postconception at test (approximately 4 postnatal weeks) showed a visual preference for the orally familiar stimuli, which provided evidence for cross-modal recognition. Ss over 200 days postconception at test showed a visual preference for 1 of the test stimuli, which made their data uninterpretable with respect to cross-modal abilities. In a longitudinal experiment (Exp II), Ss were tested once when they were younger than 200 days postconception and once when they were older. When young, they showed a visual preference for the orally familiar stimuli. When older, they showed a visual preference for the same test stimuli found for the cross-sectional Ss. Results are discussed relative to human infant cross-modal data obtained by similar procedures. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the role of eye movements and saccade preparation in generating auditory inhibition of return.

Examined whether the suggestion that "the eccentricity of signals which are effective in activating inhibition of return is restricted to the eccentricity to which accurate saccades can be made" is consistent with the necessary conditions for the occurrence of location-based auditory inhibition of return in a total of 24 volunteers. In 3 experiments, listeners were required to either localize or identify the 2nd of 2 successive sounds. The 1st sound and the 2nd sound could originate from either the same or different locations, and the interval between the onsets of the 2 sounds (Stimulus Onset Asynchrony, SOA) was varied. Sounds were presented out of visual range at 135 azimuth left or right. In Exp 1, localization responses were made more quickly at 100 ms SOA when the target sounded from the same location as the cue, and at 700 ms SOA when the target and cue sounded from different locations. In Exps 2 and 3, Ss monitored visual information presented directly in front of them at the same time as the auditory cue and target were presented behind them. Results indicate that in both experiments, a transition from facilitation at a brief SOA to inhibition at a longer SOA was observed for the auditory task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)