Visual Similarity Effects Research Articles

Is nevtral NEUTRAL? Visual similarity effects in the early phases of written-word recognition.

For simplicity, contemporary models of written-word recognition and reading have unspecified feature/letter levels-they predict that the visually similar substituted-letter nonword PEQPLE is as effective at activating the word PEOPLE as the visually dissimilar substituted-letter nonword PEYPLE. Previous empirical evidence on the effects of visual similarly across letters during written-word recognition is scarce and nonconclusive. To examine whether visual similarity across letters plays a role early in word processing, we conducted two masked priming lexical decision experiments (stimulus-onset asynchrony = 50ms). The substituted-letter primes were visually very similar to the target letters (u/v in Experiment 1 and i/j in Experiment 2; e.g., nevtral-NEUTRAL). For comparison purposes, we included an identity prime condition (neutral-NEUTRAL) and a dissimilar-letter prime condition (neztral-NEUTRAL). Results showed that the similar-letter prime condition produced faster word identification times than the dissimilar-letter prime condition. We discuss how models of written-word recognition should be amended to capture visual similarity effects across letters.

The effect of spatial frequency information and visual similarity in threat detection

ABSTRACTIn the current research, we sought to examine the role of spatial frequency on the detection of threat using a speeded visual search paradigm. Participants searched for threat-relevant (snakes or spiders) or non-threat-relevant (frogs or cockroaches) targets in an array of neutral (flowers or mushrooms) distracters, and we measured search performance with images filtered to contain different levels (high and low) of spatial frequency information. The results replicate previous work demonstrating more rapid detection of threatening versus non-threatening stimuli [e.g. LoBue, V. & DeLoache, J. S. (2008). Detecting the snake in the grass: Attention to fear-relevant stimuli by adults and young children. Psychological Science, 19, 284–289. doi:10.1111/j.1467-9280.2008.02081.x]. Most importantly, the results suggest that low spatial frequency or relatively coarse levels of visual information is sufficient for the rapid and accurate detection of threatening stimuli. Furthermore, the results also suggest that visual similarity between the stimuli used in the search tasks plays a significant role in speeded detection. The results are discussed in terms of the theoretical implications for the rapid detection of threat and methodological implications for properly accounting for similarity between the stimuli in visual search studies.

Verbal Short-Term Memory Deficits in Chinese Children with Dyslexia may not be a Problem with the Activation of Phonological Representations.

This study explored the underlying mechanism of the verbal short-term memory deficit in Chinese children with developmental dyslexia. Twenty-four children with dyslexia and 28 age-matched normal readers participated in the study. They were required to memorize a visually presented series of six Chinese characters and identify them from a list also including code-specific distracters and non-code-specific distracters. Error rates were recorded and were higher for code-specific distracters in all three conditions, revealing phonological, visual, and semantic similarity effects respectively. Group comparisons showed a stronger phonological similarity effect in dyslexic group, suggesting intact activation of phonological representations of target characters. Children with dyslexia also exhibited a greater semantic similarity effect, revealing stronger activation of semantic representations, while visual similarity effects were equivalent to controls. These results suggest that the verbal short-term memory deficit in Chinese dyslexics might not stem from insufficient activation of phonological information. Based the semantic activation of target characters in dyslexics is greater than in controls, it is possible that the memory deficit of dyslexia is related with deficient inhibition of target semantic representations in short-term memory.

Context-dependent similarity effects in letter recognition.

In visual word recognition tasks, digit primes that are visually similar to letter string targets (e.g., 4/A, 8/B) are known to facilitate letter identification relative to visually dissimilar digits (e.g., 6/A, 7/B); in contrast, with letter primes, visual similarity effects have been elusive. In the present study we show that the visual similarity effect with letter primes can be made to come and go, depending on whether it is necessary to discriminate between visually similar letters. The results support a Bayesian view which regards letter recognition not as a passive activation process driven by the fixed stimulus properties, but as a dynamic evidence accumulation process for a decision that is guided by the task context.Electronic supplementary materialThe online version of this article (doi:10.3758/s13423-015-0826-3) contains supplementary material, which is available to authorized users.

Strategic effects on pseudohomophone reading in phonological dyslexics with and without phonological impairment

Abstract The literature concerning reading in acquired phonological dyslexia is conflicted with regard to performance with pseudohomophones (e.g. SKOOL). While some cases are more accurate in pronouncing non-words that sound like known words than those that do not, other cases show no pseudohomophone advantage. Some cases are more successful when pseudohomophones are orthographically similar to their base words (SKOOL versus KLOO); other cases show no visual similarity effects. We collected data from two phonological dyslexics in order to examine whether pseudohomophone reading was influenced by a) the presence of a generalised phonological impairment b) whether pseudohomophones appeared alone or intermixed with non-words and c) whether the phonological dyslexic was told that pseudohomophones were included among the stimuli. Results showed that patterns of reading accuracy were different in cases with and without phonological impairment, and that altering the presentation context or providing explicit instruction affected the responses. The findings are discussed in relation to models of word reading.

Visual similarity is stronger than semantic similarity in guiding visual search for numbers

Using a visual search task, we explored how behavior is influenced by both visual and semantic information. We recorded participants' eye movements as they searched for a single target number in a search array of single-digit numbers (0-9). We examined the probability of fixating the various distractors as a function of two key dimensions: the visual similarity between the target and each distractor, and the semantic similarity (i.e., the numerical distance) between the target and each distractor. Visual similarity estimates were obtained using multidimensional scaling based on the independent observer similarity ratings. A linear mixed-effects model demonstrated that both visual and semantic similarity influenced the probability that distractors would be fixated. However, the visual similarity effect was substantially larger than the semantic similarity effect. We close by discussing the potential value of using this novel methodological approach and the implications for both simple and complex visual search displays.

Visual similarity effects on masked priming.

We investigated the role of the visual similarity of masked primes to targets in a lexical decision experiment. In the primes, some letters in the target (e.g., A in ABANDON) had either visually similar letters (e.g., H), dissimilar letters (D), visually similar digits (4), or dissimilar digits (6) substituted for them. The similarities of the digits and letters to the base letter were equated and verified in a two-alternative forced choice (2AFC) perceptual identification task. Using targets presented in lowercase (e.g., abandon) and primes presented in uppercase, visually similar digit primes (e.g., 484NDON) produced more priming than did visually dissimilar digit primes (676NDON), but little difference was found between the visually similar and dissimilar letter primes (HRHNDON vs. DWDNDON). These results were explained in terms of task-driven competition between the target letter and the visually similar letter.

Prelexical representations and processes in reading: Evidence from acquired dyslexia

We report a detailed and extensive single-case study of an acquired dyslexic patient, L.H.D., who suffered a left-hemisphere lesion as a result of a ruptured aneurysm. We present evidence that L.H.D.’s reading errors stem from a deficit in visual letter identification, and we use her deficit as a basis for exploring a variety of issues concerning prelexical representations and processes in reading. First, building on the work of other researchers, we present evidence that the prelexical reading system includes an allograph level of representation that represents each distinct visual shape of a letter (e.g., a, A, etc., for the letter A). We extend a theory proposed by Caramazza and Hillis [Caramazza, A., & Hillis, A. (1990a). Spatial representation of words in the brain implied by studies of a unilateral neglect patient. Nature, 346, 267–269] to include an allograph level, and we probe the nature of the allograph representations in some detail. Next, we explore the implications of visual similarity effects and letter perseverations in L.H.D.’s reading performance, arguing that these effects shed light on activation dynamics in the prelexical reading system and on the genesis of L.H.D.’s errors. We also probe the processing of letter case in the visual letter identification process, proposing that separate abstract letter identity and case representations are computed. Finally, we present evidence that the allograph level as well as the abstract letter identity level implement a word-based frame of reference.

The Effects of Phonological Similarity and Visual Similarity in Immediate Serial Recall of Chinese Characters

The Effects of Phonological Similarity and Visual Similarity in Immediate Serial Recall of Chinese Characters

Componentes funcionais da memória visuoespacial

O estudo da memória de trabalho está centrado no fracionamento desse sistema em subsistemas especializados na armazenagem de informação verbal, visuoespacial e multimodal. Neste artigo abordamos o fracionamento da memória visuoespacial em seus componentes visuais e espaciais. A presença de códigos visuais na memória de trabalho é sugerida pelos efeitos de similaridade visual e de informação visual irrelevante. A memória espacial parece depender fortemente de recursos da atenção e sua relação com a memória visual ainda é controversa.

Types of Memory Codes in Immediate Serial Verbal Recall of Arabic : Investigation of Phonological and Visual Similarity Effects

Types of Memory Codes in Immediate Serial Verbal Recall of Arabic : Investigation of Phonological and Visual Similarity Effects

Does visuo-spatial working memory generally contribute to immediate serial letter recall?

This work contributes to the understanding of the visual similarity effect in verbal working memory, a finding that suggests that the visuo-spatial sketch pad—the system in Baddeley's working memory model specialised in retaining nonverbal visual information—might be involved in the retention of visually presented verbal materials. Crucially this effect is implicitly interpreted by the most influential theory of multimedia learning as evidence for an obligatory involvement of the visuo-spatial sketch pad. We claim that it is only involved when the functioning of the working memory component normally used for processing verbal material is impaired. In this article we review the studies that give rise to the idea of obligatory involvement of the visuo-spatial sketch pad and suggest that some findings can be understood with reference to orthographic rather than visual similarity. We then test an alternative explanation of the finding that is most apt to serve as evidence for obligatory involvement of the visuo-spatial sketch pad. We conclude that, in healthy adults and under normal learning conditions, the visual similarity effect can be explained within the framework of verbal working memory proposed by Baddeley (e.g., 1986, 2000) without additional premises regarding the visuo-spatial sketch.

Visual similarity effects in categorical search.

We asked how visual similarity relationships affect search guidance to categorically defined targets (no visual preview). Experiment 1 used a web-based task to collect visual similarity rankings between two target categories, teddy bears and butterflies, and random-category objects, from which we created search displays in Experiment 2 having either high-similarity distractors, low-similarity distractors, or "mixed" displays with high-, medium-, and low-similarity distractors. Analysis of target-absent trials revealed faster manual responses and fewer fixated distractors on low-similarity displays compared to high-similarity displays. On mixed displays, first fixations were more frequent on high-similarity distractors (bear = 49%; butterfly = 58%) than on low-similarity distractors (bear = 9%; butterfly = 12%). Experiment 3 used the same high/low/mixed conditions, but now these conditions were created using similarity estimates from a computer vision model that ranked objects in terms of color, texture, and shape similarity. The same patterns were found, suggesting that categorical search can indeed be guided by purely visual similarity. Experiment 4 compared cases where the model and human rankings differed and when they agreed. We found that similarity effects were best predicted by cases where the two sets of rankings agreed, suggesting that both human visual similarity rankings and the computer vision model captured features important for guiding search to categorical targets.

Phonological and visual similarity effects in Chinese and English language users: Implications for the use of cognitive resources in short-term memory

This study investigated the encoding strategies employed by Chinese and English language users when recalling sequences of pictured objects. The working memory performance of native English participants (n = 14) and Chinese speakers of English as a second language (Chinese ESL; n = 14) was compared using serial recall of visually-presented pictures of familiar objects with three conditions: (i) phonologically and visually distinct, (ii) phonologically similar and visually distinct, and (iii) phonologically distinct and visually similar. Digit span, visual pattern span and articulation rate were also measured. Results indicated that whilst English participants were affected by the phonological but not the visual similarity of items, the performance of Chinese ESL participants was comparable across all three conditions. No significant differences in digit span, visual memory or articulation rate were found between groups. These results are discussed in the light of our understanding of the use of cognitive resources in short-term memory in users of diverse orthographies.

Visual and phonological similarity effects in verbal immediate serial recall: A test with kanji materials

In a series of three experiments, native speakers of Japanese performed serial ordered written recall of visually presented Japanese kanji characters that varied systematically in visual and phonological similarity. Overall effects of phonological similarity were observed for retention of serial order under silent reading in Experiments 1 and 3 and they disappeared in articulatory suppression conditions in Experiments 2 and 3. All three experiments showed main effects of visual similarity even in articulatory suppression conditions in Experiments 2 and 3. This indicated spontaneous use of visual codes in immediate serial recall. It is suggested that any models of serial order memory should incorporate domain specificity.

Short Article: Visual Similarity in Short-Term Recall for Where and When

Two experiments examined the effects of visual similarity on short-term recall for where and when in the visual spatial domain. A series of squares of similar or dissimilar colours were serially presented at various locations on the screen. At recall, all coloured squares were simultaneously presented in a random order at the bottom of the screen, and the locations used for presentation were indicated by white squares. Participants were asked to place the colours at their appropriate location in their presentation order. Performance for location (where) and order (when) was assessed separately. Results revealed that similarity severely hinders both memory for what was where and memory for what was when, under quiet and articulatory suppression conditions. These results provide further evidence that similarity has a major impact on processing relational information in memory.

Short-Term Memory Coding in Children With Intellectual Disabilities

To examine visual and verbal coding strategies, I asked children with intellectual disabilities and peers matched for MA and CA to perform picture memory span tasks with phonologically similar, visually similar, long, or nonsimilar named items. The CA group showed effects consistent with advanced verbal memory coding (phonological similarity and word length effects). Neither the intellectual disabilities nor MA groups showed evidence for memory coding strategies. However, children in these groups with MAs above 6 years showed significant visual similarity and word length effects, broadly consistent with an intermediate stage of dual visual and verbal coding. These results suggest that developmental progressions in memory coding strategies are independent of intellectual disabilities status and consistent with MA.

Visual similarity effects on short-term memory for order: The case of verbally labeled pictorial stimuli

Four experiments examined the effect of visual similarity on immediate memory for order. Experiments 1 and 2 used easily nameable line drawings. Following a sequential presentation in either silent or suppression conditions, participants were presented with the drawings in a new, random order and were required to remember their original serial position. In Experiment 3, participants first learned to associate a verbal label with an abstract matrix pattern. Then they completed an immediate memory task in which they had to name the matrices aloud during presentation. At recall, the task required remembering either the order of the matrices or the order of their names. In Experiment 4, participants learned to associate nonword labels with schematic line drawings of faces; the phonemic similarity of the verbal labels was also manipulated. All four experiments indicate that the representations supporting performance comprise both verbal and visual features. The results are consistent with a multiattribute encoding view.

On the time course of letter perception: a masked priming ERP investigation.

In an experiment measuring event-related brain potentials (ERPs), single-letter targets were preceded by briefly presented masked letter primes. Name and case consistency were manipulated across primes and targets so that the prime was either the same letter as the target (or not), and was presented in the same case as the target (or not). Separate analyses were performed for letters whose upper- and lowercase forms had similar features (or not). The results revealed an effect of prime-target visual similarity between 120 and 180 msec, an effect of case-specific letter identity between 180 and 220 msec, and an effect of case-independent letter identity between 220 and 300 msec. We argue that these ERP results reflect processing in a hierarchical system for letter recognition that involves both case-specific and case-independent representations of alphabetic stimuli.

Reading errors in first‐ and second‐grade readers of a shallow orthography: Evidence from Spanish

Studies focusing on reading errors can help to understand how children learn to read and to structure key components of reading instruction. However, no prior studies have examined which letters might be a greater source of difficulty for beginning readers in Spanish. First, to examine the pattern of reading errors in beginning readers in a shallow orthography like Spanish with a particular focus on both the context-dependant (c, g, r) and the visual similar (b, d, g, p, q) consonants. (The dual-route cascade model is used as a theoretical framework for predictions.) Second, to examine the effect of visual similarity on orientation reversals, using upper and lower case letters. Ninety Spanish-speaking children (45 in Grade 1 and 45 in Grade 2) participated in the study. Children were required to read aloud both words and non-words. Seven categories of errors were examined. To clarify the influence of visual similarity of easily confused consonants (b, d), upper and lower case letters were used. We found that most reading errors (as a function of opportunity) were due to context-dependant consonants (c, g, r), and a small proportion were due to the remaining consonants, or even the visually-similar consonants. Further, visual similarity of reversible letters had a significant effect on orientation reversals. Finally, there was a significant influence of factors such as syllable frequency on the number of word errors. The implications of these findings for early reading instruction and future research are discussed.