Bias in the priming of object decisions.

Seven experiments examined priming effects for 3-dimensional line drawings in the object decision task. One of the most important previous findings about object decisions has been that the decision about a possible object is primed by previous presentation of the object, but the decision about an impossible object is not. Through the use of manipulations that can eliminate processes that retrieve episodic information (response time deadlines, memory load, forced choice, and similarity), equal size effects on impossible and possible objects were obtained. This is interpreted to mean that priming effects reflect a bias to respond "possible," which can be opposed for impossible objects by episodic information so as to yield the approximately null priming effect for impossible objects found in past experiments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional priming and visual search in pigeons.

Advance information about a target's identity improved visual search efficiency in pigeons. Experiments 1 and 2 compared information supplied by visual cues with information supplied by trial sequences. Reaction times (RTs) were lower when visual cues signaled a single target rather than two. RTs were lower (Experiment 1) or accuracy improved (Experiment 2) when a sequence of trials presented a single target rather than a mixture of 2. Experiments 3, 4, and 5 considered the selectivity of visual priming by introducing probe trials that reversed the usual cue–target relationship. RT was higher following such miscues than following the usual 1- or 2-target cuing relationships (Experiment 3); the miscuing effect persisted over variations in the target's concealment (Experiments 4 and 5), but did not occur when the target was presented alone (Experiment 4). Findings indicate that priming modifies an attentional mechanism and suggest that this effect accounts for search images. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotional priming of pop-out in visual search.

When searching for a discrepant target along a simple dimension such as color or shape, repetition of the target feature substantially speeds search, an effect known as feature priming of pop-out (V. Maljkovic and K. Nakayama, 1994). The authors present the first report of emotional priming of pop-out. Participants had to detect the face displaying a discrepant expression of emotion in an array of four face photographs. On each trial, the target when present was either a neutral face among emotional faces (angry in Experiment 1 or happy in Experiment 2), or an emotional face among neutral faces. Target detection was faster when the target displayed the same emotion on successive trials. This effect occurred for angry and for happy faces, not for neutral faces. It was completely abolished when faces were inverted instead of upright, suggesting that emotional categories rather than physical feature properties drive emotional priming of pop-out. The implications of the present findings for theoretical accounts of intertrial priming and for the face-in-the-crowd phenomenon are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Form-specific visual priming in the right cerebral hemisphere.

Results of 4 experiments indicate that both within-modality and case-specific visual priming for words are greater when test stimuli are presented initially to the right cerebral hemisphere (RH). In contrast, neither within-modality nor case-specific explicit memory for words is greater when stimuli are presented initially to the RH. Priming is measured using word-stem completion, and explicit memory is measured using word-stem cued recall. In both cases, Ss first rate how much they like words, and then word stems are presented briefly to the RH (in the left visual field) or to the left hemisphere (in the right visual field). Results suggest that at least 2 separate systems encode the visual representations that produce priming. The system that is more effective in the RH is better at representing form-specific information, whereas another system that is not more effective in the RH does not distinguish among distinct instances of word forms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related reduction in 3-D visual motion priming.

In 3 experiments, younger and older adults judged the perceived motion of three-dimensional (3-D) figures that rotated in depth either unambiguously or ambiguously. Both groups were found to be equivalent in judging the direction of single rotations of the simulated 3-D objects (Experiment 1). In Experiments 2 and 3, a single unambiguous rotation (prime) was followed 0-3200 ms later by an ambiguous rotation (target). Motion priming was indicated by the disambiguation of the second rotation by the first rotation. 3-D motion priming was initially found to be similar in young and old, but it rapidly reduced in the older participants compared to the younger ones. Using a nonluminance depth cue—occlusion—to induce 3-D motion, diminished contrast sensitivity in the elderly was ruled out as a cause of the reduced priming. The results show that 3-D motion priming exhibits robust age-related decline. An age-related decrease in temporal persistence may account for the reduction in 3-D motion priming in older adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic interference from visual object recognition on visual imagery.

A new technique for examining the interaction between visual object recognition and visual imagery is reported. The "image-picture interference" paradigm requires participants to generate and make a response to a mental image of a previously memorized object, while ignoring a simultaneously presented picture distractor. Responses in 2 imagery tasks (making left-right higher spatial judgments and making taller-wider judgments) were longer when the simultaneous picture distractor was categorically related to the target distractor relative to unrelated and neutral target-distractor combinations. In contrast, performance was not influenced in this way when the distractor was a related word, when a semantic categorization decision was made to the target, or when distractor and target were visually but not categorically related to one another. The authors discuss these findings in terms of the semantic representations shared by visual object recognition and visual imagery that mediate performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of within-dimension singleton priming in visual search.

The authors report a newly identified intertrial priming phenomenon, within-dimension singleton priming, by which search for a target that happens to be a singleton on the current trial is faster when the target on the previous trial had also been a singleton on the same dimension rather than a nonsingleton. This effect was replicated in 6 experiments with different procedures, with singletons on various dimensions, when the featural contrast defining the singleton remained the same or changed within a dimension from one trial to the next, and when the target was a singleton on a target-defining dimension or on an irrelevant dimension. These findings cannot be explained by previously demonstrated intertrial repetition effects such as dimension-specific priming or priming of popout. Theoretical implications of the within-dimension singleton priming phenomenon are discussed relative to the dimension-weighting hypothesis, the role of stimulus-driven salience in feature-guided search, and the roles of intertrial priming and goal-directed factors in visual search. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of foveal priming and extrafoveal preview on object identification.

The results of three different experiments suggested that the relation between an object in the fovea on fixation n and an object subsequently brought into the fovea on fixation n ?+?1 affects the time to identify the second object. In Experiment 1 we extended previous work by demonstrating that a previously seen related priming object speeded the time to name a target object even when a saccade intervened between the two objects. In Experiment 2 we replicated this result and further showed that the benefit on naming time was due to facilitation from the related object rather than inhibition from the unrelated object. In addition, naming of the target object was much slower in both experiments when there was not a peripheral preview of the target object on fixation n. However, because the effect of the foveal priming object was greater when the target was not present than when it was present, priming did not appear to make extraction of the extrafoveal information more efficient. In Experiment 3, fixation times were recorded while subjects looked at four objects in order to identify them. Fixation time on an object was shorter when a related object was fixated immediately before it, even though the four objects did not form a scene. The size of the facilitation was roughly comparable to that in several analogous experiments where scenes were used. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Getting a grip on numbers: Numerical magnitude priming in object grasping.

To investigate the functional connection between numerical cognition and action planning, the authors required participants to perform different grasping responses depending on the parity status of Arabic digits. The results show that precision grip actions were initiated faster in response to small numbers, whereas power grips were initiated faster in response to large numbers. Moreover, analyses of the grasping kinematics reveal an enlarged maximum grip aperture in the presence of large numbers. Reaction time effects remained present when controlling for the number of fingers used while grasping but disappeared when participants pointed to the object. The data indicate a priming of size-related motor features by numerals and support the idea that representations of numbers and actions share common cognitive codes within a generalized magnitude system. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of semantic priming on visual encoding of pictures.

We investigated the effects of semantic priming on initial encoding of briefly presented pictures of objects and scenes. Pictures in 4 experiments were presented for varying durations and were followed immediately by a mask. In Exps 1 and 2, pictures of simple objects were either preceded or not preceded by the object's category name (e.g., dog). In Exp 1 we measured immediate object identification; in Exp 2 we measured delayed old/new recognition in which targets and distractors were from the same categories. In Exp 3 naturalistic scenes were either preceded or not preceded by the scene's category name (e.g., supermarket). We measured delayed recognition in which targets and distractors were described by the same category names. In Exps 1–3, performance was better for primed than for unprimed pictures. Exp 4 was similar to Exp 2 in that we measured delayed recognition for simple objects. As in Exps 1–3, a prime that preceded the object improved subsequent memory performance for the object. However, a prime that followed the object did not affect subsequent performance. Together, these results imply that priming leads to more efficient information acquisition. We offer a picture-processing model that accounts for these results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Phonological mediation in visual masked priming: Evidence from phonotactic repair.

In a series of 4 experiments, the authors show that phonological repair mechanisms, known to operate in the auditory modality, are directly translated in the visual modality. This holds with the provision that printed stimuli are presented for a very brief duration and that the effect of phonological repair is tested after a delay of some 100 ms has elapsed after that presentation. The case of phonological repair chosen to exemplify the parallelism between print and speech is the prosthesis of /e/ in utterances beginning with /s/ followed by a consonant in Spanish. Native speakers of Spanish hear a prothetic /e/ in auditorily presented pseudowords such as special (/speθjal/, derived from "especial") as well as stuto (/stuto/, derived from "astuto"). It is shown here that they also hear that same vowel /e/ when presented with the printed pseudowords "special" and "stuto." This finding of a phonological repair effect in print has implications for the issue of phonological activation from print, as well as for the prelexical locus and mandatory nature of phonological repair mechanisms in general. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Size in the visual processing of faces and words.

Three experiments, with 34 right-handed university students, studied the influence of variations of stimulus size upon recognition of words and faces. Ss viewed a series of 640 slides of words of faces presented in 1 of 5 sizes and responded as to whether or not stimulus had been previously presented. Size played an important role in the recognition of faces but was irrelevant to the recognition of words. Analysis revealed that although irrelevant to recognition, size of words was nevertheless encoded, with some consequences similar to those for recognition of faces. The likelihood of recognition declined linearly with the numbers of words intervening between a word and its recurrence, while the likelihood of recognizing a face declined exponentially in the same circumstances. Results are interpreted in terms of stimulus-specific analyses, and this view is contrasted with other notions of mental representation. Variant measures are appended. (40 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Object-position binding in visual memory for natural scenes and object arrays.

Nine experiments examined the means by which visual memory for individual objects is structured into a larger representation of a scene. Participants viewed images of natural scenes or object arrays in a change detection task requiring memory for the visual form of a single target object. In the test image, 2 properties of the stimulus were independently manipulated: the position of the target object and the spatial properties of the larger scene or array context. Memory performance was higher when the target object position remained the same from study to test. This same-position advantage was reduced or eliminated following contextual changes that disrupted the relative spatial relationships among contextual objects (context deletion, scrambling, and binding change) but was preserved following contextual change that did not disrupt relative spatial relationships (translation). Thus, episodic scene representations are formed through the binding of objects to scene locations, and object position is defined relative to a larger spatial representation coding the relative locations of contextual objects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modeling spatial integration and contrast invariance in visual pattern discrimination

PURPOSE: Human pattern discrimination performance has been reported to be largely independent of stimulus contrast but to depend on stimulus area. The authors propose a model that combines the effects of spatial integration and contrast. The model is based on the computation of similarity between pattern templates in memory and signals to be discriminated using normalized correlation. There are also two sources of additive noise, one before and one after the computation of correlation. The model was compared with human observers in an orientation discrimination task. METHODS: Orientation discrimination thresholds of human observers were measured for sinusoidal gratings of various areas, contrasts, and spatial frequencies. A two-interval, forced-choice methods was used. The performance of the model was determined by using computer simulations. RESULTS: It was found that the effects of contrast and grating area were interrelated. The decrease of orientation thresholds as a function of grating area was considerably larger at low than at high contrast. On the other hand, orientation thresholds decreased clearly as a function of contrast at the smallest grating areas but hardly at all at the largest grating areas. The model accounted well for the experimental findings. CONCLUSIONS: Because the invariance of orientation discrimination with respect to stimulus contrast depended on area, the cause of the invariance appeared to occur after spatial integration. The model explains this so that, with increasing contrast or area, the normalized correlation gradually approached a constant value. The proportion of pretemplate noise became negligible compared to the constant posttemplate noise. Thus, total noise also approached a constant value. Hence, the signal-to-noise ratio and discrimination performance became constant.     

Textons, visual pop-out effects, and object recognition in infancy.

Five experiments were conducted to determine whether primitive perceptual features, or textons, which B. Julesz (1984) identified in studies of texture segregation with adults, also affect object recognition early in development. Three-month-old infants discriminated Ts and Ls composed of overlapping line segments from +s but not from each other in a delayed-recognition test after 24 hrs; however, Ts and Ls were discriminated from each other after only 1 hr. In a priming paradigm, Ts, Ls, and +s were discriminated from one another after 2 wks. In succeeding experiments, infants exhibited adultlike visual pop-out effects in both delayed recognition and priming paradigms, detecting an L in the midst of 6 +s and vice versa; these effects were symmetrical. The pop-out effects apparently resulted from parallel search: Infants failed to detect 3 Ls among 4 +s. Clearly, some of the same primitive units that have been identified as the building blocks of adult visual perception underlie object recognition early in infancy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of object onset on the distribution of visual attention.

There now exists considerable evidence to suggest that the appearance of a new object in the visual field captures visual attention. One of the consequences of this attentional capture is that the object initiates a redistribution of attentional resources across visual space. This is classically observed in the precuing paradigm in which the onset of an abrupt cue influences the processing of a subsequently presented target. The present research describes a new phenomenon that occurs as a result of a new object appearing in the visual field. A stimulus presented in a region of space adjacent to a comer of an onsetting object receives an enhancement of processing relative to a stimulus presented adjacent to one of the object's straight edges. With the use of 2 converging methods, evidence is presented that suggests that the effect is a higher order attentional phenomenon whereby greater resources become directed to the comers of objects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related slowing and the time course of semantic priming in visual word identification.

Investigated, in 4 experiments, the time course of semantic priming effects during 2 forms of visual word identification, lexical decision and pronunciation. On each trial, a target letter string was preceded by a single-word priming context. The effects of varying the stimulus onset asynchrony between the prime and the target indicated that the time course of semantic priming was equivalent for young and older adults. There were no consistent differences between lexical decision and pronunciation in the time course of semantic priming. The age differences associated with response selection were greater than would be predicted by generalized age-related slowing. The semantic priming effects were also inconsistent with a generalized slowing model, but the reliability of these effects was substantially lower than the reliability of the other task-related variables. (PsycINFO Database Record (c) 2010 APA, all rights reserved)