Richard D. Sperber

Words, pictures, and priming: on semantic activation, conscious identification, and the automaticity of information processing.

We investigated the encoding mechanisms involved in the perceptual recognition of words and pictures. Latencies in naming word and picture targets were analyzed as a function of several characteristics of a preceding prime, including whether it was a word or a picture, its duration of exposure, the interval between the prime and target onset, and whether or not the prime was consciously identified and reported by the subject. Results indicated that a common semantic code is available that can represent the meaning of either a word or a picture. This semantic representation, however, appears to be more easily activated by picture primes than by word primes and seems to benefit the naming of picture targets more than the naming of word targets. Despite the advantage for pictures with respect to semantic activation, overall processing in the naming task was slower and more attention demanding for pictures than for words. Comparison of our data with data on classification, in which an opposite pattern occurs (overall processing appears to be slower and more attention demanding for words than for pictures), suggests that, on the average, pictures have faster and more automatic access to their meanings than to their names but that words have faster and more automatic access to their names than to their meanings. This conclusion concerning the relative ability of stimuli to activate different kinds of internal representations has implications for a theory of the basis and development of automaticity.

Semantic priming effects on picture and word processing

The effects of semantic priming on picture and word processing were assessed under conditions in which subjects were required simply to identify stimuli (label pictures or read words) as rapidly as possible. Stimuli were presented in pairs (a prime followed by a target), with half of the pairs containing members of the same semantic category and half containing unrelated concepts. Semantic relatedness was found to facilitate the identification of both pictures (Experiment 1) and words (Experiment 2), and obtained interactions of semantic relatedness and stimulus quality in both experiments suggested that semantic priming affects the initial encoding of both types of stimuli. In Experiment 3, subjects received pairs of pictures, pairs of words, and mixed pairs composed of a picture and a word or of a word and a picture. Significant priming effects were obtained on mixed as well as unmixed pairs, supporting the assumption that pictures and words access semantic information from a common semantic store. Of primary interest was the significantly greater priming obtained in picture-picture pairs than in word-word or mixed pairs. This suggests that, in addition to priming that is mediated by the semantic system, priming may occur in picture-picture pairs that results from the overlap in visual features common to the pictorial representations of objects from the same semantic category.

Early extraction of meaning from pictures and its relation to conscious identification.

Two experiments were conducted in which subjects labeled target pictures preceded by either semantically related or unrelated prime pictures. The exposure duration of each prime was varied around a threshold value, established separately for each subject, that represented the minimum viewing time necessary to identify the prime picture with 100% accuracy. The results of the first study indicated that semantic-priming effects can be obtained with pictures at prime exposure durations too brief for conscious identification of the prime to occur. Data from the second experiment provided an estimate of the minimum exposure time necessary for priming under these conditions. There was evidence from both experiments that attaching a name to a picture is an attended operation that can interfere with naming a subsequent picture, independent of any semantic priming that might occur. This indicates that extracting the meaning from a picture and consciously identifying it may be separate processes. The results are discussed in terms of current models of picture perception.

Differences in semantic encoding as a function of reading comprehension skill

Using a modified Stroop procedure, we examined the extent to which the semantic encoding of a word is governed by the context within which that word appears. Good and poor comprehenders named the color of target words following their reading of either sentences or single words representing the object nouns of the sentences. Target words represented contextually emphasized (appropriate) attributes of the object nouns, nonemphasized (inappropriate) attributes of these nouns, or object attributes not related to these nouns (neutral). For single-word contexts, all subjects exhibited equal semantic interference to appropriate and inappropriate targets, relative to neutral targets. For sentence contexts, however, good comprehenders exhibited semantic interference only to appropriate targets, whereas poor comprehenders again exhibited equal interference to appropriate and inappropriate targets. These findings suggest that differences in comprehension skill may be attributable, at least in part, to fundamental differences in the way in which sentences are semantically encoded.

The Development of Memory Structure as Reflected by Semantic-Priming Effects.

Abstract This study was designed to investigate the development of knowledge about categorical and associative relationships as reflected by the presence or absence of semantic priming effects. Kindergarteners and second-graders were shown pairs of pictures, one picture at a time, and asked to name each picture as rapidly and accurately as possible. Picture pairs were of four types which reflected the factorial combination of associative relatedness (high and low) with categorial relatedness (high and low). An analysis of naming times revealed a significant main effect of associative relatedness, i.e., second pictures or “target” pictures in high-associative pairs were named faster than those in low-associative pairs. This reduction in naming latency, or priming effect, was independent of developmental level. However, the effects of category relatedness varied with developmental level, i.e., target pictures in high-categorical pairs were named significantly faster than those in low pairs by second-graders, but not by kindergarteners. These findings are discussed in terms of previous estimates of childrens semantic competence.

Intelligence-related differences in semantic processing speed

Abstract Educable mentally retarded and nonretarded adolescents verified superordinate and basic level descriptions of common objects. Obtained category decision times, as measured by superordinate-basic level difference scores, were longer for retarded than for nonretarded subjects, indicating fundamental group differences in semantic processing speed. Additional data were interpreted as indicating that retarded adolescents may be slower in making basic level as well as superordinate level decisions, suggesting that they have difficulty in making semantic classification decisions in general. Other results, from a semantic priming task performed by the same subjects, suggested that the obtained group differences in semantic processing speed were related to the active (deliberate) processes required for verification, rather than to category knowledge per se or more passive processes associated with the activation of stored semantic knowledge.

Picture encoding speed and mental retardation

Abstract Using a modified Posner “encoding function” methodology, we assessed group differences in semantic encoding speed under conditions in which subjects encoded pictures of common objects to determine physical identity (PI) matches, name identity (NI) matches, and superordinate identity (SI) matches. Mildly retarded adults; Chronological Age (CA)-matched, nonretarded adults; and Mental Age (MA)-matched, nonretarded children were presented pairs of stimuli in which the two stimuli within the pairs were separated by a variable stimulus onset asyncrony (SOA). Subjects were required to determine as rapidly as possible whether or not the two stimuli matched. A subjects encoding time corresponded to the shortest SOA at which optimal response time performance on the matching task was achieved. The results of primary interest revealed group differences in basic encoding speed and indicated that the magnitude of the group differences increased with increases in the degree to which accessing semantic knowledge was necessary to encode the stimuli. In addition, our data suggested that differences in basic encoding speed are IQ rather than MA related, whereas the degree to which accessing semantic knowledge increases encoding times is related to MA.

Autoshaping And Maintenance Of A Lever-Press Response In Mentally Retarded Children

Three autoshaping paradigms were used to train a lever-press response in mentally retarded children. It was found that subjects undergoing autoshaping (forward stimulus-reinforcement pairings) required fewer acquisition trials than those in a control condition (reverse pairings), indicating that retarded subjects can acquire a lever-press response when only stimulus-reinforcement contingencies are in effect. In addition, the effects of stimulus-reinforcement and response-reinforcement contingencies on the level of maintenance responding were examined by comparing post-acquisition performance in the three autoshaping conditions. The results of this comparison indicated that the maintenance level of an autoshaped response in retarded subjects is determined by both respondent and operant principles.

Facilitative Effects of Forgetting from Short-Term Memory on Growth of Long-Term Memory in Retardates.

Abstract Competing explanations of the beneficial effect of spacing in retardate discrimination learning were tested. Three-trial multidimensional (“junk”) problems were presented concurrently to educable retardates with MAs over 8 years. The spacing interval spearating Trials 1 and 2 was filled with either zero, four, or eight interpolations, the interpolations being either trials on similar junk problems or repetitions of a single, well-learned dot-pattern discrimination. The principal findings were that: (1) while short-term retention of junk problems (as measured by Trial 2 performance) suffered greater interference from similar junk interpolations than from dot-pattern interpolations, long-term learning (as measured by a delayed Trial 3) was superior following the highly interfering junk problems; and (2) spacing facilitated learning only following highly interfering interpolations. These results are inconsistent with consolidation and rehearsal theories but support the prediction of the Sperber. Greenfield, and House ( Journal of Experimental Psychology , 1973 , 99 ) spacing model that forgetting from short-term memory facilitates retardate learning.