Is entry-level recognition viewpoint invariant or viewpoint dependent?

Subjects decided whether an object drawing matched the entry-level name that immediately preceded it in a name-object sequence. When objects in the stimulus set were visually similar with respect to global shape and configuration of parts, response time increased linearly from 0° to 120° for both match and mismatch trials. Similar effects of orientation were found on match trials when objects in the stimulus set were visually dissimilar. No effects of orientation were observed when name and drawing did not match in the visually dissimilar condition. The results are consistent with the view that, in a variety of viewing situations, the initial identification of an object at the entry level is accomplished by viewpoint-dependent mechanisms.     

A visual object stimulus database with standardized similarity information

Although many visual stimulus databases exist, none has data on item similarity levels for multiple items of each kind of stimulus. We present such data for 50 sets of grayscale object photographs. Similarity measures between pictures in each set (e.g., 25 different buttons) were collected using a similarity-sorting method (Goldstone, Behavior Research Methods Instruments & Computers, 26(4):381–386, 1994). A validation experiment used data from 1 picture set and compared responses from standard pairwise measures. This showed close agreement. The similarity-sorting measures were then standardized across picture sets, using pairwise ratings. Finally, the standardized similarity distances were validated in a recognition memory experiment; false alarms increased when targets and foils were more similar. These data will facilitate memory and perception research that needs to make comparisons between stimuli with a range of known target–foil similarities.     

Semantic distance effects on object and action naming

Graded interference effects were tested in a naming task, in parallel for objects and actions. Participants named either object or action pictures presented in the context of other pictures (blocks) that were either semantically very similar, or somewhat semantically similar or semantically dissimilar. We found that naming latencies for both object and action words were modulated by the semantic similarity between the exemplars in each block, providing evidence in both domains of graded semantic effects.     

Revisiting the looking at nothing phenomenon: Visual and semantic biases in memory search

When visual stimuli remain present during search, people spend more time fixating objects that are semantically or visually related to the target instruction than looking at unrelated objects. Are these semantic and visual biases also observable when participants search within memory? We removed the visual display prior to search while continuously measuring eye movements towards locations previously occupied by objects. The target absent trials contained objects that were either visually or semantically related to the target instruction. When the overall mean proportion of fixation time was considered, we found biases towards the location previously occupied by the target, but failed to find biases towards visually or semantically related objects. However, in two experiments the pattern of biases towards the target over time provided a reliable predictor for biases towards the visually and semantically related objects. We therefore conclude that visual and semantic representations alone can guide eye movements in memory search, but that orienting biases are weak when the stimuli are no longer present.     

Recognition thresholds for plane-rotated pictures of familiar objects

We investigated picture plane rotation effects on the minimum stimulus duration required to recognise pictures of familiar objects in a picture-word verification task. Participants made unspeeded responses, selecting from 126 written alternatives. Longer stimulus durations were needed to identify plane-misoriented views. These orientation effects were non-linear, arguing against a simple mental rotation account of compensation for plane misorientation in identification tasks. Orientation effects were found for almost all items, in particular including those labelled at the basic level (cf. Hamm, McMullen, 1998, Journal of Experimental Psychology: Human Perception and Performance 24, 413-426). We suggest that plane misorientation increases the difficulty of basic level as well as subordinate level identification unless only a small, visually dissimilar set of stimuli are presented. Errors in the task were analysed to provide an alternative, objective measure of perceived visual similarity, by assessing the number and nature of mistaken identifications made to a given target object. We propose that misorientation effects are best understood in terms of the effects of the perceived visual similarity of a target to its set of response alternatives rather than in terms of the level (basic or subordinate) at which the target is to be identified.     

Imagery effects and semantic similarity in sentence recognition memory

The idea that subjects often use imagery to discriminate semantically similar sentences was tested in three experiments. In the first experiment, subjects heard subject-verb-object sentences in the context of either a comprehension task or an image-generation task. Their memory for the sentences was tested using a two-alternative forced-choice recognition test in which different types of distractor sentence were used. A sentence semantically similar to the target sentence was one type; a sentence with the same subject and object nouns as the target sentence, but dissimilar in meaning, was another type; and a sentence similar in meaning to one of the stimulus sentences, but not to the target sentence, was a third type. The results showed that the image-generation instructions enhanced later recognition performance, but only for semantically similar test items. A second experiment showed that this finding only holds for high-imagery sentences containing concrete noun concepts. A third experiment demonstrated that the enhanced recognition performance could not be accounted for in terms of a semantic model of test-item discrimination. Collectively, the results were interpreted as providing evidence for the notion that subjects discriminate the semantically similar test items by elaborating the sentence encoding through image processing.     

Semantic and visual relatedness of distractors impairs episodic retrieval of pictures in a divided attention paradigm

We used a divided attention (DA) paradigm to infer the representational codes needed to support episodic retrieval of pictures, by measuring susceptibility to memory interference from different distracting tasks. Participants made recognition memory decisions to semantically categorized sets of pictures while simultaneously making size judgments to a set of visually-presented distractor pictures. Recognition accuracy was worse and response times were slower under DA conditions relative to full attention (FA), regardless of semantic relatedness of distractors to targets (Experiment 1). Similarly, we found no differential memory interference under DA relative to FA when distractor pictures were either visually (but not semantically), semantically (but not visually), or unrelated to the targets (Experiment 2). In Experiment 3, memory interference was significantly larger under DA at retrieval when distractors were both semantically and visually similar to the targets. Findings suggest episodic memory for pictures requires access to either visually- or semantically-based representations for optimal performance.     

Perceptual differentiation as a source of category effects in object processing: Evidence from naming and object decision

The locus of category effects in picture recognition and naming was examined in two experiments with normal subjects. Subjects carried out object decision (deciding whether the stimulus is a “real” object or not) and naming tasks with pictures of clothing, furniture, fruit, and vegetables. These categories are distinguished by containing either relatively many exemplars with similar perceptual structures (fruit and vegetables;structurally similar categories), or relatively few exemplars with similar perceptual structures (clothing and furniture;structurally dissimilar categories). In Experiment 1, responses to the stimuli from the structurally similar categories were slower than responses to stimuli from the structurally dissimilar categories, and this effect was larger in the naming than in the object decision task. Further, prior object decisions to stimuli from structurally similar categories facilitated their subsequent naming. In Experiment 2, we orthogonally manipulated object decision and naming as prime and target tasks, again with stimuli from the four categories. Category effects, with responses slower to objects from structurally similar categories, were again larger in naming than in object decision, and these category effects in naming were reduced by priming with both naming and object decision. We interpret the data to indicate that category effects in object naming can reflect visually based competition which is reduced by the preactivation of stored structural knowledge for objects.     

Visual effects in picture and word categorization

Two experiments are reported in which participants categorized stimuli as belonging or not belonging to the category of fruits. Blocks of pictures and words were used, with items referring to exemplars having either high or low intercategory visual similarity and/or semantic relatedness. For both pictures and words, response time was longer in the semantically related conditions than in the unrelated condition. Furthermore, there was a strong effect of visual similarity for pictures but not for words when semantic relatedness was held constant: Participants took longer to classify pictures of fruits when these were mixed with visually similar vegetables than when they were mixed with visually dissimilar vegetables. Reducing the stimulus visibility by adding a dot pattern had an additive effect for words but an interactive effect for pictures. The results are explained in terms of a unique locus for category decisions about pictures and words.     

The role of similarity in inattentional blindness: Selective enhancement,selective suppression,or both?†

When people selectively pay attention to one set of objects and ignore another, unexpected stimuli often go unnoticed. Noticing rates are higher when the unexpected object matches the features of the attended items and lower when it matches those of the ignored items. No prior studies have fully disentangled these aspects of similarity; in previous work, the unexpected object fell on a continuum between the attended and ignored objects, so increasing the similarity to one set of objects necessarily decreased it to the other. We designed an inattentional blindness task in which we held similarity to the attended set constant and varied it with respect only to the ignored set, or vice versa. In Experiment 1, objects that were more similar to the attended set were noticed more often and objects that were more similar to the ignored set were noticed less often. Experiment 2, using a different set of unexpected objects, replicated the result that similarity to the ignored set affected noticing, but showed no effect of similarity to the attended set. In both experiments, the pattern of noticing rates differed for similarity with respect to the attended and ignored items, suggesting that suppression of ignored objects functions independently of enhancement of attended objects.     

Category similarity effects in children's semantic memory retrieval

Fourth-, sixth-, and eighth-grade students were required to indicate whether or not a stimulus word belonged in either of two semantic categories that were held in memory. Each category pair was either semantically similar or semantically dissimilar. The results indicated that even for the youngest children, similar categories required less search time than dissimilar categories. It was suggested that while dissimilar categories had to be accessed successively prior to search, subjects were able to consolidate similar categories into a superordinate group which eliminated the time to shift from one category to another during search. The results were contrasted with clustering studies which have demonstrated a minimal amount of memory facilitation in children for conceptually related items over unrelated items.     

Visuo-haptic integration in object identification using novel objects

Although some studies have shown that haptic and visual identification seem to rely on similar processes, few studies have directly compared the two. We investigated haptic and visual object identification by asking participants to learn to recognize (Experiments 1, and 3), or to match (Experiment 2) novel objects that varied only in shape. Participants explored objects haptically, visually, or bimodally, and were then asked to identify objects haptically and/or visually. We demonstrated that patterns of identification errors were similar across identification modality, independently of learning and testing condition, suggesting that the haptic and visual representations in memory were similar. We also demonstrated that identification performance depended on both learning and testing conditions: visual identification surpassed haptic identification only when participants explored the objects visually or bimodally. When participants explored the objects haptically, haptic and visual identification were equivalent. Interestingly, when participants were simultaneously presented with two objects (one was presented haptically, and one was presented visually), object similarity only influenced performance when participants were asked to indicate whether the two objects were the same, or when participants had learned about the objects visually—without any haptic input. The results suggest that haptic and visual object representations rely on similar processes, that they may be shared, and that visual processing may not always lead to the best performance.     

Guidance of attention by information held in working memory

Information held in working memory (WM) can guide attention during visual search. The authors of recent studies have interpreted the effect of holding verbal labels in WM as guidance of visual attention by semantic information. In a series of experiments, we tested how attention is influenced by visual features versus category-level information about complex objects held in WM. Participants either memorized an object’s image or its category. While holding this information in memory, they searched for a target in a four-object search display. On exact-match trials, the memorized item reappeared as a distractor in the search display. On category-match trials, another exemplar of the memorized item appeared as a distractor. On neutral trials, none of the distractors were related to the memorized object. We found attentional guidance in visual search on both exact-match and category-match trials in Experiment 1, in which the exemplars were visually similar. When we controlled for visual similarity among the exemplars by using four possible exemplars (Exp. 2) or by using two exemplars rated as being visually dissimilar (Exp. 3), we found attentional guidance only on exact-match trials when participants memorized the object’s image. The same pattern of results held when the target was invariant (Exps. 2–3) and when the target was defined semantically and varied in visual features (Exp. 4). The findings of these experiments suggest that attentional guidance by WM requires active visual information.     

Comparison and the development of knowledge

This paper considers the role of comparison in the development of knowledge. Results show that comparing similar objects makes them appear more similar. Comparing dissimilar objects, on the other hand does not make them appear more similar, and in some circumstances may make them appear less similar. The effect of comparison on similar items was especially striking since participants judged items to be more similar after comparison even if the comparison task was to list differences between the two items. Further, this effect appears specific to comparison and does not appear to be simply due to a "fleshing out" of object representations (listing properties of two objects without comparing the objects themselves served to increase the objects' similarity regardless of whether the objects were similar or dissimilar to start). This suggests that comparison may play a special role in partitioning bits of experience into categories, sharpening categorical boundaries, and otherwise helping us create conceptual structure above and beyond that offered by the world.     

Memory coding in individuals with Down syndrome

Previous research has identified a deficit in phonological short-term memory in individuals with Down syndrome.

The present work aimed to analyze how a group of 30 individuals with Down syndrome performed in a picture span task compared with 30 typically developing children of the same mental age. The task involved four conditions (i.e., dissimilar, phonologically similar, visually similar, and long-name items) chosen to analyze the strategy used by individuals with Down syndrome to code visually presented nameable items.

Individuals with Down syndrome performed less well than typically developing children. Both groups showed the visual similarity effect.

Taken together, our results confirm that individuals with Down syndrome have a verbal working memory deficit, even when nameable items are presented visually. Mental age appears to be an important determinant of memory coding stage in individuals with Down syndrome.     

实物形状的知觉相似性对视觉隐喻加工的影响

视觉隐喻是众多研究者比较关注的领域, 当前多以物体简笔画、漫画及广告等方面的研究为主, 但对与生活密切相关的实物的视觉隐喻研究甚少。因此研究采用掩蔽启动范式、李克特9点量表及语音生成等研究方法, 在物体概念类型(概念相同、概念相异)及形状类型(形状相似、形状相异)条件下, 针对实物图片的形状知觉相似性是否对视觉隐喻加工产生影响进行探讨。结果发现无论物体概念是否相同, 形状相似性对个体的物体识别具有“促进”作用, 并有利于视觉隐喻加工; 在物体识别中, 当两个物体概念不同时, 个体会试图建立一个特设类别来对形状相似的物体进行归类, 从而实现了视觉隐喻的加工。因此研究进一步证明了实物形状的知觉相似性有利于视觉隐喻的加工。     

Is naming faces different from naming objects? Semantic interference in a face- and object-naming task

A current debate regarding face and object naming concerns whether they are equally vulnerable to semantic interference. Although some studies have shown similar patterns of interference, others have revealed different effects for faces and objects. In Experiment 1, we compared face naming to object naming when exemplars were presented in a semantically homogeneous context (grouped by their category) or in a semantically heterogeneous context (mixed) across four cycles. The data revealed significant slowing for both face and object naming in the homogeneous context. This semantic interference was explained as being due to lexical competition from the conceptual activation of category members. When focusing on the first cycle, a facilitation effect for objects but not for faces appeared. This result permits us to explain the previously observed discrepancies between face and object naming. Experiment 2 was identical to Experiment 1, with the exception that half of the stimuli were presented as face/object names for reading. Semantic interference was present for both face and object naming, suggesting that faces and objects behave similarly during naming. Interestingly, during reading, semantic interference was observed for face names but not for object names. This pattern is consistent with previous assumptions proposing the activation of a person identity during face name reading.     

Comparison Facilitates Children's Learning of Names for Parts

Learning names for parts of objects can be challenging for children, as it requires overcoming their tendency to name whole objects. We test whether comparing items can facilitate learning names for their parts. Applying the structure-mapping theory of comparison leads to two predictions: (a) young children will find it easier to identify a common part between two very similar items than between two dissimilar items (because the similar pair is easier to align); (b) close alignments potentiate far alignments: children will be better able to extend a novel part name to a dissimilar object after having extended it to a similar object. In three studies, 227 preschool children mapped novel part terms to new animals or objects. Both predictions were confirmed. Children more accurately extended novel part terms to objects that were similar to the standard than to objects that were dissimilar (Experiments 1 and 2), and children more accurately extended novel part names to dissimilar objects after having extended them to similar objects (Experiment 3). We conclude that structure-mapping processes can support part learning.     

Constrained formation of object representations

Viewers were presented with a rapid sequence of very brief stimulus pairs, each of which consisted of a pictured object followed by a related or unrelated word. The form of relatedness between the picture and word was manipulated across experiments (identical concept, associated concept, ink color of the picture). Recognition memory for the pictures was affected not only by whether or not paired items were conceptually identical or semantically related, but also by whether or not the words named an irrelevant feature, ink color. These results show that sequential items are integrated on the basis of similarity at whatever level is available, so that the stability of the memory representation of one or both items is increased. We propose that a common mechanism may underlie integration, priming, and selective attention.     

Motion and position shifts induced by the double-drift stimulus are unaffected by attentional load

The double-drift stimulus produces a strong shift in apparent motion direction that generates large errors of perceived position. In this study, we tested the effect of attentional load on the perceptual estimates of motion direction and position for double-drift stimuli. In each trial, four objects appeared, one in each quadrant of a large screen, and they moved upward or downward on an angled trajectory. The target object whose direction or position was to be judged was either cued with a small arrow prior to object motion (low attentional load condition) or cued after the objects stopped moving and disappeared (high attentional load condition). In Experiment 1, these objects appeared 10° from the central fixation, and participants reported the perceived direction of the target’s trajectory after the stimulus disappeared by adjusting the direction of an arrow at the center of the response screen. In Experiment 2, the four double-drift objects could appear between 6 ° and 14° from the central fixation, and participants reported the location of the target object after its disappearance by moving the position of a small circle on the response screen. The errors in direction and position judgments showed little effect of the attentional manipulation—similar errors were seen in both experiments whether or not the participant knew which double-drift object would be tested. This suggests that orienting endogenous attention (i.e., by only attending to one object in the precued trials) does not interact with the strength of the motion or position shifts for the double-drift stimulus.