Strategic factors in a lexical-decision task: Evidence for automatic and attention-driven processes

The present study examined strategic factors in a semantic-priming, lexical-decision task. The first experiment demonstrated that the greater the proportion of related word-word pairs to unrelated word-word pairs, the greater the amount of facilitation, a result which is consistent with others reported in the literature. The second experiment demonstrated that this strategic factor apparently requires that sufficient time (at least several hundred milliseconds) be available for the processing of the priming word, and thus is probably caused by attention-driven processes. The third experiment replicated and extended the results of the first two studies by demonstrating that prime-target stimulus onset asynchrony is an important limiting factor in determining whether such proportion-induced strategic factors are involved in word-recognition processes, even when no other aspect or variable of the procedure changes. The results are discussed in the context of Posner and Snyder’s (1975a) two-process model of word recognition.     

SKED systems: Paper tape,Tennecomp, and OS/8

The SKED system has been developed at different levels of complexity and power for differing hardware configurations. The simplest of these, and the least expensive, is the paper-tape SKED system. Some of the drawbacks associated with the use of paper tape are absent in the Tennecomp magnetic tape cartridge system. Users with mass storage capabilities can make use of the OS/8 operating system (copyright DEC) to speed up all aspects of the SKED system (especially editing, compilation, and loading of programs), and take advantage of a file-oriented system structure for data storage and analysis.     

Spatiotopic and retinotopic components of iconic memory

Summary Recently, there has been considerable interest in whether information in iconic memory is stored in retinotopic or spatiotopic coordinates. The present experiment examined the issue using a masking paradigm. In one set of conditions, subjects maintained fixation while a row of four letters appeared for 19 ms, centered about three degrees to the right of fixation. After a 153 ms ISI, the letters were followed by a blank field (no mask), a mask in the same position as the letters, or a mask displaced three degrees to the right of the letters. In a second set of conditions, the stimuli were the same but subjects were asked to shift fixation from the fixation point to the middle of the letter row during the interval between the letters and the mask. Subjects' eye movements were monitored in all conditions. Accuracy of report for the letters was lowered only with the mask over the letters with the no-eye-movement conditions and in both masking conditions with the eye movements. The results suggest that the icon includes two components, one that is retinotopic and one that is spatiotopic.     

The validity of a computerized visual searching task as an indicator of brain damage

Goldstein, Rennick, Welch, and Shelly (1973) developed a visual searching task (VST) that succeeded in obtaining a hit rate of 94.1% correct classifications when comparing brain-damaged and normal subjects and a 79.4% hit rate when comparing brain-damaged and psychiatric subjects. Goldstein and Kyc (1978) reported 92.5% correct classifications for the brain-damaged vs. normal comparisons and 82.5% correct classifications for brain-damaged vs. schizophrenic comparisons. We computerized the administration of the VST and found 85.7% correct classifications for the brain-damaged vs. normal groups and 71.4% correct classifications for the brain-damaged vs. psychiatric group. These results suggest that the computerized VST (CVST) is also a potentially valid indicator of brain damage.     

Automatic and strategic effects in semantic priming: An examination of Becker’s verification model

Becker’s (1980) verification model, in conjunction with a two-strategy hypothesis, is cited as an alternative to a dual-process model (e.g., Posner & Snyder, 1975) of word recognition and semantic priming. Becket’s approach suggests that individuals can use either an “expectancy” or a “prediction” strategy in word recognition, and maintains that the verification model successfully predicts certain patterns of facilitation and inhibition in a semantic priming task that a dual-process model cannot. The present study demonstrated that when a long stimulus-onset asynchrony (SOA = 1,000 msec) is used between prime and target, support is given to Becker’s findings, and to the verification model approach. However, at a short SOA (200 msec), no evidence is found for the hypothesized difference between strategic processes. The results are consistent with other findings (e.g., Neely, 1977) in showing that strategic factors in semantic priming are largely inoperative at short prime-target SOAs, and suggests that Becker’s model is not general enough to rule out some type of dual-process model.     

Semantic priming and identification of near threshold primes in a lexical decision task

Three experiments examined both the impact of semantic analysis of 50-msec, masked visual primes on a target response and the impact of semantic analysis of the target on a prime response. The first two experiments used a prime-target interval of 1000 msec. In Experiment 1, subjects reported the identity of each prime: (a) after a lexical decision about the target, (b) both before and after a lexical decision, or (c) after a target detection response. Prime report after both types of target response showed retroactive priming in which report was facilitated by related targets and inhibited by unrelated targets. Analyses of lexical decision latency and accuracy conditionalized on prime report showed that semantic priming was restricted to reported related primes. In Experiment 2, subjects made no overt response to the primes. Priming was conditionalized on recognition of the primes on a subsequent test. The pattern was the same as Experiment 1: There was priming only for recognized primes; recognition memory showed a pattern consistent with retroactive priming. Experiment 3 also conditionalized priming on recognition performance but used a prime-target interval of only 250 msec. Again, semantic priming was found only for recognized primes, and recognition memory revealed retroactive priming. Retroactive priming indicates an interdependency between prime and target processing that needs to be incorporated into models of semantic priming.