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 changes in neural activity to familiar words and gestures

Infants younger than 20 months of age interpret both words and symbolic gestures as object names. Later in development words and gestures take on divergent communicative functions. Here, we examined patterns of brain activity to words and gestures in typically developing infants at 18 and 26 months of age. Event-related potentials (ERPs) were recorded during a match/mismatch task. At 18 months, an N400 mismatch effect was observed for pictures preceded by both words and gestures. At 26 months the N400 effect was limited to words. The results provide the first neurobiological evidence showing developmental changes in semantic processing of gestures.     

Developmental changes in the recognition of faces and facial features

The view that, as children get older, there is a decline in the use of feature‐based forms of face processing to more configurational forms of processing was examined by asking 6‐year‐old and 9‐year‐old children to judge which of two photographs matches an identical probe photograph. The probe and test stimuli were either photographs of whole faces or photographs of isolated facial features. Within this standard method, the stimuli also systematically varied in terms of the familiarity of the faces shown and in the orientation of presentation, both factors that have been interpreted as effecting configurational encoding. A number of age‐related effects are observed: (a) older children are better at recognizing whole faces than younger children, (b) older children exhibit a clear face inversion effect with whole faces while the younger children are equally adept at identifying upright and inverted whole faces, and (c) analysis of the recognition rates associated with the individual features reveals that younger children are better than older children when asked to recognize eye regions. It is argued that the data support the view that as children get older there is a change in the forms of piecemeal encoding employed and an increase in configurational processing. Copyright © 2000 John Wiley & Sons, Ltd.     

Developmental changes in word recognition: An information-processing account

Two experiments examining developmental changes in the use of context in single word reading are reported. The first experiment investigated how effectively children can access conceptual knowledge and use this to help their word recognition. The results indicated that young readers can on demand direct their attention to semantic information, and this allows them to reap a relatively greater benefit from context than older more skilful readers. The second experiment attempted to clarify the way such use of contextual information might help in the specific case when a child attempts to decode a new word for the first time. Skilled and unskilled readers pronounced pseudohomophonic nonwords faster when they were primed by a semantic context, and the context effect was greater for unskilled readers. The nonword's graphemic similarity to a lexical item was also important.

In general, the results were consistent with Stanovich's (1980) interactive-compensatory model of reading, and they suggest that in learning to read, several already existing stores of information (e.g. auditory, visual and conceptual) are integrated in order to achieve a solution to the word recognition problem.     

Developmental bias for number words in the intraparietal sulcus

Children and adults show behavioral evidence of psychological overlap between their early, non‐symbolic numerical concepts and their later‐developing symbolic numerical concepts. An open question is to what extent the common cognitive signatures observed between different numerical notations are coupled with physical overlap in neural processes. We show that from 8 years of age, regions of the intraparietal sulcus (IPS) that exhibit a numerical ratio effect during non‐symbolic numerical judgments also show a semantic distance effect for symbolic number words. In both children and adults, the IPS showed a semantic distance effect during magnitude judgments of number words (i.e. larger/smaller number) but not for magnitude judgments of object words (i.e. larger/smaller object size). The results provide novel evidence of conceptual overlap between neural representations of symbolic and non‐symbolic numerical values that cannot be explained by a general process, and present the first demonstration of an early‐developing dissociation between number words and object words in the human brain.     

Developmental changes in visual object recognition between 18 and 24 months of age

Two experiments examined developmental changes in children's visual recognition of common objects during the period of 18 to 24 months. Experiment 1 examined children's ability to recognize common category instances that presented three different kinds of information: (1) richly detailed and prototypical instances that presented both local and global shape information, color, textural and featural information, (2) the same rich and prototypical shapes but no color, texture or surface featural information, or (3) that presented only abstract and global representations of object shape in terms of geometric volumes. Significant developmental differences were observed only for the abstract shape representations in terms of geometric volumes, the kind of shape representation that has been hypothesized to underlie mature object recognition. Further, these differences were strongly linked in individual children to the number of object names in their productive vocabulary. Experiment 2 replicated these results and showed further that the less advanced children's object recognition was based on the piecemeal use of individual features and parts, rather than overall shape. The results provide further evidence for significant and rapid developmental changes in object recognition during the same period children first learn object names. The implications of the results for theories of visual object recognition, the relation of object recognition to category learning, and underlying developmental processes are discussed.     

Visual word recognition of single-syllable words

Speeded visual word naming and lexical decision performance are reported for 2428 words for young adults and healthy older adults. Hierarchical regression techniques were used to investigate the unique predictive variance of phonological features in the onsets, lexical variables (e.g., measures of consistency, frequency, familiarity, neighborhood size, and length), and semantic variables (e.g. imageahility and semantic connectivity). The influence of most variables was highly task dependent, with the results shedding light on recent empirical controversies in the available word recognition literature. Semantic-level variables accounted for unique variance in both speeded naming and lexical decision performance, level with the latter task producing the largest semantic-level effects. Discussion focuses on the utility of large-scale regression studies in providing a complementary approach to the standard factorial designs to investigate visual word recognition.     

Developmental changes in the effect of inversion: using a picture book to investigate face recognition

A novel child-oriented procedure was used to examine the face-recognition abilities of children as young as 2 years. A recognition task was embedded in a picture book containing a story about two boys and a witch. The story and the task were designed to be entertaining for children of a wide age range. In eight trials, the children were asked to pick out one of the boys from amongst eight distractors as quickly as possible. Response-time data to both upright and inverted conditions were analysed. The results revealed that children aged 6 years onwards showed the classic inversion effect. By contrast, the youngest children, aged 2 to 4 years, were faster at recognising the target face in the inverted condition than in the upright condition. Several possible explanations for this 'inverted inversion effect' are discussed.     

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.     

Tracking recognition of spoken words by tracking looks to printed words

Eye movements of Dutch participants were tracked as they looked at arrays of four words on a computer screen and followed spoken instructions (e.g., “Klik op het woord buffel”: Click on the word buffalo). The arrays included the target (e.g., buffel), a phonological competitor (e.g., buffer, buffer), and two unrelated distractors. Targets were monosyllabic or bisyllabic, and competitors mismatched targets only on either their onset or offset phoneme and only by one distinctive feature. Participants looked at competitors more than at distractors, but this effect was much stronger for offset-mismatch than onset-mismatch competitors. Fixations to competitors started to decrease as soon as phonetic evidence disfavouring those competitors could influence behaviour. These results confirm that listeners continuously update their interpretation of words as the evidence in the speech signal unfolds and hence establish the viability of the methodology of using eye movements to arrays of printed words to track spoken-word recognition.     

Tracking recognition of spoken words by tracking looks to printed words

Eye movements of Dutch participants were tracked as they looked at arrays of four words on a computer screen and followed spoken instructions (e.g., “Klik op het woord buffel”: Click on the word buffalo). The arrays included the target (e.g., buffel), a phonological competitor (e.g., buffer, buffer), and two unrelated distractors. Targets were monosyllabic or bisyllabic, and competitors mismatched targets only on either their onset or offset phoneme and only by one distinctive feature. Participants looked at competitors more than at distractors, but this effect was much stronger for offset-mismatch than onset-mismatch competitors. Fixations to competitors started to decrease as soon as phonetic evidence disfavouring those competitors could influence behaviour. These results confirm that listeners continuously update their interpretation of words as the evidence in the speech signal unfolds and hence establish the viability of the methodology of using eye movements to arrays of printed words to track spoken-word recognition.     

Developmental changes in face recognition during childhood: Evidence from upright and inverted faces

Adults are experts at recognizing faces but there is controversy about how this ability develops with age. We assessed 6- to 12-year-olds and adults using a digitized version of the Benton Face Recognition Test, a sensitive tool for assessing face perception abilities. Children's response times for correct responses did not decrease between ages 6 and 12, for either upright or inverted faces, but were significantly longer than those of adults for both face types. Accuracy improved between ages 6 and 12, significantly more for upright than inverted faces. Inverted face recognition improved slowly until late childhood, whereas there was a large improvement in upright face recognition between ages 6 and 8, with a further enhancement after age 12. These results provide further evidence that during childhood face processing undergoes protracted development and becomes increasingly tuned to upright faces.     

Semantic neighborhood effects on the recognition of ambiguous words

The effect of semantic neighborhood on the processing of ambiguous words was examined in two lexical decision experiments. Semantic neighborhood was defined in terms of semantic set size and network connectivity. In Experiment 1, the variables of semantic set size, network connectivity, and ambiguity were crossed. An ambiguity advantage was observed only within small-set low-connectivity words. In Experiment 2, the effect of network connectivity on the processing of words of high and low meaning relatedness was examined. Participants responded more rapidly to words of high meaning relatedness, relative to words of low meaning relatedness, but only within high-connectivity words. These results are interpreted within a framework in which both semantic feedback processes and meaning-level competition can affect the recognition of semantically ambiguous words.