Visual-word identification thresholds for the 260 fragmented words of the Snodgrass and Vanderwart pictures in Spanish

Word difficulty varies from language to language; therefore, normative data of verbal stimuli cannot be imported directly from another language. We present mean identification thresholds for the 260 screen-fragmented words corresponding to the total set of Snodgrass and Vanderwart (1980) pictures. Individual words were fragmented in eight levels using Turbo Pascal, and the resulting program was implemented on a PC microcomputer. The words were presented individually to a group of 40 Spanish observers, using a controlled time procedure. An unspecific learning effect was found showing that performance improved due to practice with the task. Finally, of the 11 psycholinguistic variables that previous researchers have shown to affect word identification, only imagery accounted for a significant amount of variance in the threshold values.     

Perceptual identification thresholds for 150 fragmented pictures from the Snodgrass and Vanderwart picture set

This paper reports perceptual identification thresholds for 150 pictures from the 1980 Snodgrass and Vanderwart picture set. These pictures were fragmented and presented on the Apple Macintosh microcomputer in a picture-fragment completion task in which identification thresholds were obtained at three phases of learning: Train (initial presentation), New (initial presentation after training on a different set), and Old (repeated presentation of the Train set). Pictures were divided into five sets of two subsets of 15 pictures each, which served alternately as the Train and New sets. A total of 100 subjects participated in the task, with 10 subjects assigned to each subset. Individual thresholds for each picture at each phase of learning are presented, along with the fragmented pictures identified by 35% of the subjects across the Train and New learning phases. This set of fragmented pictures is provided for use in experiments in which a single level of fragmented image is presented for identification after a priming phase. Correlations between the Snodgrass and Vanderwart norms and identification thresholds at the three phases of learning are also reported.     

Imagery ability and the identification of hands: A chronometric analysis

In a replication of Cooper and Shepard's (1975) study of hand recognition, it was found that individual differences in imagery ability had a significant influence on reaction times to such stimuli (Experiment 1). However, it was found (Experiment 2) that individual difference effects were only seen if prior instructions to use imagery were given to the subjects.     

Interhemispheric categorization of pictures and words

Earlier studies suggest that interhemispheric processing increases the processing power of the brain in cognitively complex tasks as it allows the brain to divide the processing load between the hemispheres. We report two experiments suggesting that this finding does not generalize to word-picture pairs: they are processed at least as efficiently when processed by a single hemisphere as compared to processing occurring between the two hemispheres. We examined whether dividing the stimuli between the visual fields/hemispheres would be more advantageous than unilateral stimulus displays in the semantic categorization of simultaneously presented pictures, words, and word-picture pairs. The results revealed that within-domain stimuli (semantically related picture pairs or word pairs) were categorized faster in bilateral than in unilateral displays, whereas cross-domain stimuli (word-picture pairs) were not categorized faster in bilateral than in unilateral displays. It is suggested that interhemispheric sharing of word-picture stimuli is not advantageous as compared to unilateral processing conditions because words and pictures use different access routes, and therefore, it may be possible to process in parallel simultaneously displayed word-picture stimuli within a single hemisphere.     

Semantic classification of pictures and words

We provide new behavioural norms for semantic classification of pictures and words. The picture stimuli are 288 black and white line drawings from the International Picture Naming Project ([Székely, A., Jacobsen, T., D'Amico, S., Devescovi, A., Andonova, E., Herron, D., et al. (2004). A new on-line resource for psycholinguistic studies. Journal of Memory & Language, 51, 247–250]). We presented these pictures for classification in a living/nonliving decision, and in a separate version of the task presented the corresponding word labels for classification. We analyzed behavioural responses to a subset of the stimuli in order to explore questions about semantic processing. We found multiple semantic richness effects for both picture and word classification. Further, while lexical-level factors were related to semantic classification of words, they were not related to semantic classification of pictures. We argue that these results are consistent with privileged semantic access for pictures, and point to ways in which these data could be used to address other questions about picture processing and semantic memory.     

Semantic facilitation with pictures and words

The present experiments explored the role of processing level and strategic factors in cross-form (word-picture and picture-word) and within-form (picture-picture and word-word) semantic facilitation. Previous studies have produced mixed results. The findings presented in this article indicate that semantic facilitation depends on the task and on the subjects' strategies. When the task required semantic processing of both picture and word targets (e.g., category verification), equivalent facilitation was obtained across all modality combinations. When the task required name processing (e.g., name verification, naming), facilitation was obtained for the picture targets. In contrast, with word targets, facilitation was obtained only when the situation emphasized semantic processing. The results are consistent with models that propose a common semantic representation for both picture and words but that also include assumptions regarding differential order of access to semantic and phonemic features for these stimulus modalities.     

Test expectancy and encoding of pictures and words

Undergraduates were shown pictures or corresponding labels and then were tested for recognition either in the same mode or in a cross-over mode. Significantly more items were recognized in the picture-picture condition than in the picture-word and word-picture conditions. Informing subjects in advance of the change in modality significantly improved picture-word performance.     

Hunting for individual differences in cognitive processes: Verbal ability and semantic processing of pictures and words

Semantic category decisions were examined for single picture and word stimuli. Consistent with previous research, pictures yielded faster latencies than words and both showed significant taxonomic frequency effects for positive decisions. The results are interpreted in terms of general models for semantic verification, in which both pictures and words involve access to the same underlying semantic knowledge base. The latter conclusion was supported by correlation-regression analyses on individual item latencies. Variations in processing latency as a function of stimulus mode, taxonomic frequency, and type of decision were analyzed with respect to adult individual differences in verbal ability, The results uniformly failed to show a significant relationship between verbal ability and any processing speed measure. The lack of any significant relationship is discussed in light of previous results on verbal ability and processing speed, suggesting obvious qualifications of past results and possible reinterpretations of the meaning of previously obtained speed differences.     

Selective disruption of hypermnesia for pictures and words

In this study, we investigated the effects of various interpolated tasks on hypermnesia (improved recall across repeated tests) for pictures and words. In five experiments, subjects studied either pictures or words and then completed two free-recall tests, with varying activities interpolated between the tests. The tasks performed between tests were varied to test several hypotheses concerning the possible factor(s) responsible for disruption of the hypermnesic effect. In each experiment, hypermnesia was obtained in a control condition in which there was no interpolated task between tests. The remaining conditions showed that the effect of the interpolated tasks was related to the overlap of the cognitive processes involved in encoding the target items and performing the interpolated tasks. When pictures were used as the target items, no hypermnesia was obtained when subjects engaged in imaginal processing interpolated tasks, even when these tasks involved materials that were very distinct from the target items. When words were used as the target items, no hypermnesia was obtained when the interpolated tasks required verbal/linguistic processing, even when the items used in these tasks were auditorily presented. The results are discussed in terms of a strength-based model of associative memory.     

Recalling pictures and words: Reversing the generation effect

Blind and sighted children’s memory for words and raised shape pictures was tested. The investigation compared performance with items when they were studied under neutral conditions (naming words and pictures) and when they were self-generated in response to cues (cue: hot ?: response: cold). The blind children could identify and name the raised shape pictures with the same apparent ease as blind-folded sighted children (as long as a cue was provided). The sighted children showed the generation effect (Slamecka and Graf, 1978) for both words and pictures, namely that self-generated items were far better recalled than neutral ones. The pattern of results for the blind children was markedly different. Although the level of memory performance overall was the same as that of the sighted controls, the congenitally blind children showed areverse generation effect. A stem completion study indicated that these results couldnot be accounted for by a relatively greater reliance on data-driven processing by the blind.     

Developmental changes in the semantic processing of pictures and words

Second- and fifth-graders' semantic decision times for pictures and words were analyzed relative to the predictions derived from unitary- and dual-memory models. At both grade levels, word-word response latencies were greater than picture-word latencies which, in turn, were greater than picture-picture latencies. An interaction between Grade and Condition indicated that verbal access times decreased more than pictorial access times. The data fit the predictions of a memory model postulating category storage in a single memory system as opposed to simultaneous representation in verbal and nonverbal memory systems. It was concluded that with increasing experience verbal access to this single semantic system is more rapid.     

Developmental differences in frequency judgments of words and pictures

Children in kindergarten, third, and fifth grades were presented a list of either pictures or words (with items presented for varying numbers of times on the study trial). In both picture and word conditions, half of the Ss estimated how many times each item had been presented (absolute judgments) and the other half judged which of two items had occurred more often on the study trial (relative judgments). The primary finding was that while frequency judgment performance improved with age for both pictures and words, there was relatively greater improvement for pictures (i.e., the picture-word difference increased with age). These results lend strong support to the frequency theory of discrimination learning and, in particular, may be useful in accounting for effects associated with age and with age by stimulus mode interactions.     

Classifying pictures and words: Implications for the dual-coding hypothesis

In deciding that two items come from the same category, subjects were delayed if the items were presented as a word and a picture, as compared with two words or two pictures. Subjects were not delayed if the items were not to be compared. Hence, the delay appears to occur during the retrieval and comparison of know ledge about the items, not during their perceptual analysis. The results suggest that there are two distinct codes involved in the categorization of words and pictures, rather than a single code.     

An enquiry into the process of categorization of pictures and words

This paper reports a series of experiments conducted to study the categorization of pictures and words. Whereas some studies reported in the past have found a picture advantage in categorization, other studies have yielded no differences between pictures and words. This paper used an experimental paradigm designed to overcome some methodological problems to examine picture-word categorization. The results of one experiment were consistent with an advantage for pictures in categorization. To identify the source of the picture advantage in categorization, two more experiments were conducted. Findings suggest that semantic relatedness may play an important role in the categorization of both pictures and words. We explain these findings by suggesting that pictures simultaneously access both their concept and visually salient features whereas words may initially access their concept and may subsequently activate features. Therefore, pictures have an advantage in categorization by offering multiple routes to semantic processing.     

Situation models and retrieval interference: pictures and words

Previous studies have found that interference in long-term memory retrieval occurs when information cannot be integrated into a single situation model, but this interference is greatly reduced or absent when the information can be so integrated. The current study looked at the influence of presentation format-sentences or pictures-on this observed pattern. When sentences were used at memorisation and recognition, a spatial organisation was observed. In contrast, when pictures were used, a different pattern of results was observed. Specifically, there was an overall speed-up in response times, and consistent evidence of interference. Possible explanations for this difference were examined in a third experiment using pictures during learning, but sentences during recognition. The results from Experiment 3 were consistent with the organisation of information into situation models in long-term memory, even from pictures. This suggests that people do create situation models when learning pictures, but their recognition memory may be oriented around more "verbatim", surface-form memories of the pictures.     

Effects of semantic context in the naming of pictures and words

Two experiments investigated whether lexical retrieval for speaking can be characterized as a competitive process by assessing the effects of semantic context on picture and word naming in German. In Experiment 1 we demonstrated that pictures are named slower in the context of same-category items than in the context of items from various semantic categories, replicating findings by Kroll and Stewart (Journal of Memory and Language, 33 (1994) 149). In Experiment 2 we used words instead of pictures. Participants either named the words in the context of same- or different-category items, or produced the words together with their corresponding determiner. While in the former condition words were named faster in the context of same-category items than of different-category items, the opposite pattern was obtained for the latter condition. These findings confirm the claim that the interfering effect of semantic context reflects competition in the retrieval of lexical entries in speaking.