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Subjects in Experiment 1 studied a list of words under varying presentation conditions (visual or auditory) and in two typographies within the visual condition (typed or hand printed) and then received a word-fragment completion test (e.g., _YS_E _ Y for mystery) in which the test cues also varied in typography. The main findings were that (1) priming occurred for all study items, relative to nonstudied items, but greater priming occurred for visual than for auditory presentation, and (2)performance in the visual conditions was better when typographies matched between study and test than when the typographies mismatched, but only for words studied in hand-printed form. These findings were generally replicated when the test was delayed 1 week, although priming declined across this retention interval (Experiment 2). In Experiment 3 subjects studied words that were either in focus or blurred and showed greater priming when test fragments were presented in the same manner as at study. Priming in the word-fragment completion task depends on matching surface characteristics of items between study and test and exemplifies the requirement of performing similar mental operations at study and test for maximizing performance (transfer-appropriate processing).In the present series of experiments, we explored a task for investigating memory that was introduced by Tulving, Schacter, and Stark (1982). Following presentation of a list of words, their subjects received two forms of test either 1 h or I week later. One test was a standard yeslno recognition test in which previously studied target words were intermixed with an equal number of new words, and the subjects' task was to identify the target words. In the novel task, subjects were presented with fragmented versions of the words (half studied, half not) and told to complete them with the first word that came to mind. The fragmented words constituted word frames that permitted only a single completion (e.g., A __A __IN for assassin). This fragment completion task represents a variant of other tasks in which subjects receive various parts of words and attempt to complete them (Warrington & Weiskrantz, 1970), although the more usual forms of the task involve perceptually degrading all letters in the word or presenting only the first few letters of the word (e.g., dre-for dream). This last type of test has been most frequently studied (e.g., Graf, Squire, & Mandler, 1984); relative to words in the fragment completion task under study here, target words in This research was supported by Grant ROI HD-15054 from the Nationallnstitute of Child Health and Human Development. We thank Bradford Challis, Alice Healy, Neal Johnson, James Neely, Douglas Nelson, and Endel Tulving for their comments on previous versions of this paper. A preliminary report of these results was presented at the meeting ofthe Psychonomic Society in San Diego in November, 1983 that task are typically of higher frequency (at least 10 completions are possible) and subjects respond more rapidly. The measure of ...

By several accounts, reading single words may be accomplished either by sequentially transcribing orthographic units into their corresponding sounds (an indirect route), or by directly associating a visual word form to the semantic or articulatory representation (a direct route). By contrast, the similar task of naming objects must rely only on a direct route, since objects cannot be "sounded out." To study the localization of cognitive processes specific to reading, we used positron emission tomography (PET) to measure regional cerebral blood flow while subjects named words and pictures of objects silently or aloud. Group averages of blood flow changes were obtained for experimental vs. control tasks. Object and word presentations elicited similar blood flow increases in extra-striate visual cortices compared with a visual noise control. Silent reading invoked a neural network very similar to that seen when subjects named objects silently, consistent with a "direct" route. Naming objects aloud produced the addition of motor output regions to this network. By contrast, oral reading produced a markedly different pattern of activated regions, suggesting reliance on a separate phonological pathway. These results provide support for the dual coding hypothesis in reading and challenge the use of strict hierarchical models of cognitive operations in PET activation studies.

Deficits in conceptual transfer on both implicit and explicit memory tests were obtained for memory-impaired temporal lobe epileptic (TLE) subjects in three studies. In Experiment 1, in which a generate-read paradigm was employed, memory-impaired TLEs failed to show normal generation effects on conceptually driven tests of semantic cued recall and general knowledge questions, although their data-driven memory as measured by word-fragment completion and graphemic cued recall tasks was normal. In Experiment 2, memory-impaired patients having left temporal lobe seizure foci were tested on these four tasks and compared with nonimpaired TLEs having right temporal foci. The left TLEs showed deficits on conceptually driven tasks and normal memory for data-driven tests. These findings were extended in Experiment 3, in which left TLE patients failed to show any benefit from blocked study, as compared with random study, on category production and semantic cued-recall tests, although right TLEs and normal controls showed blocking effects on both tasks. These findings may be accommodated by a processing framework of memory in which memory-impaired patients are characterized as having deficits in conceptual, but not in data-driven, processing capabilities.

The phenomenon of inhibition from generating successive items within a category, reported by A. S. Brown (1981), was examined in two experiments. Subjects responded on target trials by either generating targets (e.g., generating BASS to B when it followed the category name FISH, Experiment 1) or reading them (reading BASS when it followed the category name FISH, Experiment 2). Prior to target trials, all subjects received priming trials consisting of either one or four exemplars from a single semantic category, which could be either the same category as the target's category (related priming condition) or an unrelated category (unrelated priming condition). In both experiments, different groups of subjects either read or generated primes. When primes were read, target response times (RTs) were always facilitated in the related priming condition compared with in the unrelated priming condition. However, when primes were generated, this facilitation from related primes was eliminated, except in the one-prime condition, when targets were also generated. When primes and targets were both generated, RTs in the related priming condition were slower following four primes than following one prime. Thus, category-specific inhibition from multiple related primes is greatest when both primes and targets must be actively retrieved.Recent presentation of material semantically related to target information typically facilitates the processing or retrieval of that target information. For example, in a lexical (word-nonword) decision task, subjects are faster to respond that the letter string "nurse" is a word when it has been primed by a semantically related word such as "doctor" rather than by an unrelated word such as "butter" (

Findings implicate dysfunction of posterior brain areas that mediate visual perceptual processing and the prefrontal areas involved in the active maintenance of information during delay intervals. However, the systems that govern object and spatial visual perception and working memory appear to be affected differentially by schizophrenia.

Regional cerebral blood flow (rCBF) was measured using positron emission tomography during eyeblink conditioning in young adults. Subjects were scanned in three experimental conditions: delay conditioning, in which binaural tones preceded air puffs to the right eye by 400 msec; pseudoconditioning, in which presentations of tone and air puff stimuli were not correlated in time; and fixation rest, which served as a baseline control. Compared with fixation, pseudoconditioning produced rCBF increases in frontal and temporal cortex, basal ganglia, left hippocampal formation, and pons. Learning-specific activations were observed in conditioning as compared with pseudoconditioning in bilateral frontal cortex, left thalamus, right medial hippocampal formation, left lingual gyrus, pons, and bilateral cerebellum; decreases in rCBF were observed for bilateral temporal cortex, and in the right hemisphere in putamen, cerebellum, and the lateral aspect of hippocampal formation. Blood flow increased as the level of learning increased in the left hemisphere in caudate, hippocampal formation, fusiform gyrus, and cerebellum, and in right temporal cortex and pons. In contrast, activation in left frontal cortex decreased as learning increased. These functional imaging results implicate many of the same structures identified by previous lesion and recording studies of eyeblink conditioning in animals and humans and suggest that the same brain regions in animals and humans mediate multiple forms of associative learning that give meaning to a previously neutral stimulus.

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