Journal of Experimental Psychology Human Learning and Memory

Published by American Psychological Association
Print ISSN: 0096-1515
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In Experiment 1, pictures were presented to subjects two, five, or eight times, and subjects were asked to imagine each pciture two, five, or eight times. Subsequently, subjects estimated the number of times each picture had been presented. Their estimates of the frequency of these external events were influenced by imagination trials; this effect was greater for good imagers than for poor imagers. Experiment 2 involved a similar design in which subjects were asked either to imagine the same referent for a word or to imagine a different referent for a word on successive imagination trials. Consistency (same referent) did not increase the influence of imaginations on immediate judgments of external frequency. Thus, the results of Experiment 1 were attributed to the greater accuracy (as opposed to greater consistency) of good imagers' internal generations of the stimuli. Furthermore, variation (imagining different referents), like greater accuracy, increased the effects of imagination trials on immediate but not on delayed judgments of frequency. Possible mechanisms underlying these effects are discussed. In general, the two studies show that qualitative characteristics of completely covert generations influence their impact on estimates of the frequency of external events.
 
In this article we present a standardized set of 260 pictures for use in experiments investigating differences and similarities in the processing of pictures and words. The pictures are black-and-white line drawings executed according to a set of rules that provide consistency of pictorial representation. The pictures have been standardized on four variables of central relevance to memory and cognitive processing: name agreement, image agreement, familiarity, and visual complexity. The intercorrelations among the four measures were low, suggesting that they are indices of different attributes of the pictures. The concepts were selected to provide exemplars from several widely studied semantic categories. Sources of naming variance, and mean familiarity and complexity of the exemplars, differed significantly across the set of categories investigated. The potential significance of each of the normative variables to a number of semantic and episodic memory tasks is discussed.
 
Two paired-associate (PA) learning studies observed the acquisition performance of 85 college students with either odors or abstract figures as stimuli and numbers as responses. In both studies visual PA acquisition was reliably superior to olfactory learning. Since the second study was designed to maximize the learning of associations to the odors and minimize the learning of associations to the figures, it appears that the sense of smell is not as well suited to the PA task as vision when essentially naive subjects are involved. In a third experiment, the familiarity of odors and figures was judged and reported as a graphic magnitude estimation response. These judged stimulus familiarities were used to select stimuli for the PA task. Subsequently, PA acquisition was facilitated by the use of highly familiar odors.
 
The similarity among a set of stimuli used in a paired-associate (PA) task was controlled by psychological scaling. Three lists of odorants and two lists of abstract figures (forms) with six stimuli in each list were constructed to have varying degrees of intralist similarity. Independent groups learned to associate digit responses with one stimulus list in a PA training session. Recognition of training stimuli presented among 12 distractor stimuli and recall of the associations was tested after 7 days. Within each modality, increased intralist similarity impaired PA acquisition. Between modalities, acquisition was inferior with the odor stimuli. During recognition testing, the olfactory modality supported inferior performance. In recall testing, equivalently learned responses in the two modalities were equally well retained. There appears to be a perceptual limitation in olfaction relative to vision that influences stimulus encoding and stimulus retrieval processes but that does not affect retrieval of associated responses.
 
The primary purpose of this study was to investigate whether preverbal infants, when presented with exemplars of an artificially constructed category, would abstract a prototypical representation of the category, and if so, whether this representation was formed by either "counting" or "averaging" the features that were varying among category members. Two experiments are reported. In Experiment 1, a set of stimuli was developed and tested for which it was demonstrated that adult subjects would readily abstruct either a modal or an average prototypical representation. The type of representation abstracted was found to be dependent on the discriminability of the feature values. In Experiment 2, 10-mo.-old infants were tested using a habituation paradigm with the stimuli developed in the first experiment. The results of this study indicated that the infants were also able to abstract the featural information that was varying among the exemplars of the category, and the infants formed an internal represenatation of the category by averaging feature values. Thus, the results clearly imply that infants are able to constructively process visual information and hence take a more active role in category formation than had been previously believed.
 
Memory for sequences of briefly presented letters was examined to discover the effects of intraserial repetition and acoustic contrast on recall of a critical letter pair. The critical pairs were either repeated or nonrepeated letters presented in an acoustically contrasting or noncontrasting sequence. The hypothesis was tested that recall of repeated letters and contrasting nonrepeated letter pairs would depend on the lag between their presentations. Immediate recall of both letters (but not recall of at least one letter) of a critical pair was enhanced when the pair was a repetition or acoustically contrasting but only when the letters of the pair were adjacent. Recall of pairs separated by a lag of two intervening letters was not affected by repetition or contrast. When recall was delayed by a retention interval of eight random digits, the contrast effects disappeared and only the repetition effect remained. The findings are discussed in terms of the coding of attribute tags as cues for retrieval from short-term memory.
 
Two studies were conducted on a face--name mnemonic containing several components: a prominent facial feature; a concrete, high imagery transformation of the person's name (e.g., "Bryant" became "bride ant"); and an interactive visual image of these two components. In the first experiment subjects were given one of six strategies for learning face--name associations; the strategies differed with respect to which of the three or combination of the three components were incorporated. Results indicated that all three components of the face--name mnemonic were essential for its effectiveness. The second experiment showed that the cue effectiveness of a facial feature decreased with the frequency of its usage and varied directly with the feature's distinctiveness among all faces in the list.
 
In the present study we examined the hypothesis that electrodermal responses conditioned to fear-relevant stimuli are insensitive to verbal instructions. In the first experiment, different groups of subjects were conditioned to fear-relevant and fear-irrelevant control stimuli in a long interstimulus interval differential paradigm with shock as the unconditioned stimulus. Then half of the subjects were informed that no more shocks would be presented, and a number of extinction trials followed. The instruction completely abolished responding to fear-irrelevant stimuli, while leaving responses to the fear-relevant stimuli unaffected. In the second experiment, subjects were "conditioned" to fear-relevant or irrelevant stimuli by an instruction involving threat of shock. This manipulation potentiated potentiated responses to fear-relevant stimuli significantly more than responses to fear-irrelevant stimuli. Thus, instruction had a symmetrical effect on acquisition and extinction to fear-irrelevant stimuli, whereas it facilitated acquisition but was ineffective in reducing responding to the other class of stimuli. These results are related to a preparedness theory, and their relevance for an understanding of phobias is discussed.
 
In a study of paired-associate learning and retention, the mode of presentation (pictures versus words) of the stimuli and the responses was varied factorially. The numbers of acquisition trials were adjusted to control degree of learning, and recall was tested 1 week after the end of acquisition. Learning was substantially retarded when pictures rather than words were used as responses. Rate of improvement over trials was faster with pictorial than with verbal stimuli, but these effects were less pronounced than those on the response side. The differences in long-term retention were relatively small. The stimulus mode had no effect; the picture-response ggroups showed some advantage over the word-response groups. Some of the results pose difficulties for current interpretations of picture--word differences.
 
Two experiments tested the applicability to human beings of findings with animals that the number of performances required for the reinforcement of one behavior affects the subsequent effort expended in other instrumental behaviors. In the first experiment, adult depressed psychiatric patients worked on a sorting task for the approval of a staff psychologist. The time spent and the work completed were increased by prior approval from a ward attendant for each completion of several custodial tasks, as compared to the ward attendant's approval for each completion of a single task or a no-pretreatment control condition. In the second experiment, preadolescent learning-disabled students who were required to read and spell correctly a greater number of words per reward token later spent more time and completed more work for reward tokens in mathematics, and handwriting. Two alternative interpretations of these results are evaluated: (a) The degree of accustomed effort per reinforcer becomes a learned component of behavior, or (b) high effort increases the habituation of frustration-produced disruptive responses. The results suggest that individual differences in general persistence may arise, in part, from an accumulation of effort training in the natural environment.
 
Seidenberg and Tanenhaus reported that orthographically similar rhymes were detected more rapidly than dissimilar rhymes in a rhyme monitoring task with auditory stimulus presentation. The present experiments investigated the hypothesis that these results were due to a rhyme production-frequency bias in favor of similar rhymes that was present in their materials. In three experiments, subjects monitored short word lists for the word that rhymed with a cue presented prior to each list. All stimuli were presented auditorily. Cue-target rhyme production frequency was equated for orthographically similar and dissimilar rhymes. Similar rhymes were detected more rapidly in all three experiments, indicating that orthographic information was accessed in auditory word recognition. The results suggest that multiple codes are automatically accessed in word recognition. This entails a reinterpretation of phonological "recording" in visual word recognition.
 
Subjects low or high in activation, as measured by Thayer's Activation-Deactivation Adjective Check List, participated in two semantic memory tasks, one involving speed of recall and the other speed of recognition. White noise at 80 db. re 20 muN/m-2 was presented on half the trials. There was an interaction between noise and activation under the recall condition only. High activation facilitated recall performance with high dominance items, but had a detrimental effect with low dominance items. The differential effect of arousal on recall and recognition was interpreted as indicating that arousal affected the retrieval component of recall. The findings with the dominance variable were interpreted in light of D.E. Broadbent's hypothesis that high arousal enhances the probability of sampling information from dominant sources.
 
In a factorial experiment, 90 male and 90 female subjects were given (a) either instructions to increase heart rate (HR), decrease HR, or no instructions to change their HR; (b) either true biofeedback, false biofeedback, or no biofeedback; and (c) either instructions concerning cognitions to help them change HR or no instructions concerning cognitions. The results indicated that (a) for increasing HR, instructions to increase HR were as effective as the combination of instructions and true biofeedback; (b) for decreasing HR, neither instructions nor biofeedback nor the combination of instructions and biofeedback was more effective than simply sitting quietly; (c) although subjects instructed to increase HR showed higher HRs at the end of training than subjects instructed to decrease, the increase subjects showed a decline in HR from the initial period; (d) almost all subjects reported using cognitions to influence HR, and instructions concerning the use of cognitions did not facilitate changes in HR; and (e) women showed higher HRs, which declined more slowly than those of men, but sex did not interact with any treatment variable. It was concluded that increases (or retarded decreases) in HR were due to instructions, and decreases were due to simple adaptation, thus raising serious questions concerning the effectiveness of the biofeedback component of "biofeedback training" for altering HR.
 
Previous experiments with animals and young children have shown that discriminations based on the presence versus absence of a single feature are learned more easily when the feature appears on reinforced rather than nonreinforced displays. Six experiments demonstrated an analogous effect in college students, across a range of stimulus materials, general procedures, kinds of feedback, pacing of trials, and instructions to the subject. The results were analyzed in terms of the exceptionally strong control of behavior by events that are present on positive trials. These findings have implications for theoretical interpretations of human concept learning and decision making, and offer additional examples of the difficulty organisms experience in using "nonoccurrence" as a cue.
 
Two experiments investigated the effects of intoxication, expectation of intoxication, and state dependency on learning and relearning in male heavy social drinkers. In both studies, subjects participated in two daily sessions. On Day 1, intoxicated and sober subjects were presented with word lists for immediate free recall, followed by total free recall of all words. On Day 2, with or without a change in drug state, subjects were given a second total recall test, the same lists for immediate recall, and a third total recall test. In Experiment 1, 10 subjects served in each of four groups formed by crossing expectation with reception of alcohol on Day 1; all subjects were sober on Day 2. In Experiment 2, 12 subjects served in each of four groups formed by crossing drug state on Day 1 with drug state on Day 2 (sober-sober, sober-intoxicated, intoxicated-intoxicated, intoxicated-sober), and all expected alcohol. In both studies, intoxication produced a performance deficit, but retention loss on Day 2 was the same for change- and constant-state subjects. Expectation had no effect on performance. Results are discussed in terms of an alcohol-induced storage deficiency rather than a retrieval deficit.
 
A free-recall procedure demonstrated state-dependent learning using alcohol. Tests of long-term memory showed that both high- and low-imagery words were less likely to be recalled if stored while intoxicated rather than under sober conditions. However, information encoded and stored while intoxicated was more effectively retrieved when later tests of recall were performed while intoxicated, as compared to recall accomplished in the sober state. This dissociative recall effect was far more robust with low-imagery than with high-imagery words.
 
Three experiments were conducted to determine whether alcohol-induced impairments of memory would be reduced by providing subjects with elaborative schemas. Anomalous sentences were presented to sober or intoxicated subjects either alone or with context words to facilitate comprehension. Memory was tested immediately with a yes-no recognition task. The results consistently showed that context words did not increase the number of hits in either sober or intoxicated subjects, and sober subjects made reliably more hits whether or not context words had been provided. The accuracy of recognition of distractors, however, was consistently improved by the presentation of context words, and was much more improved for intoxicated than for sober subjects. The results indicate that alcohol intoxication disrupted the production of elaborative schemas for understanding, but that intoxicated subjects were quite successful at utilizing such schemas as long as the schemas had been provided for them.
 
Performance of 10 alcoholic Korsakoff patients was compared to that of 10 normal and 10 alcoholic control subjects on each of three different schedules of spatial probability learning (50:50, 70:30, and 30:70) using monetary reinforcement and a correction procedure. There was some evidence that the Korsakoff patients were less sensitive than normals to the effects of reward: Although on all three schedules, choice ratios by normal subjects approximated the reinforcement ratios, the choice ratios of Korsakoffs on the second and third schedules remained close to the reinforcement ratio acquired with the first schedule. In addition, the Korsakoffs made an abnormal number of perseverative errors early in training. On most measures, performance by alcoholic controls fell between that of the other two groups.
 
The relationship between the depth to which a word is initially processed and its eventual probability of being recognized was investigated with amnesic (alcoholic Korsakoff) patients. Several variations of Craik and Tulving's paradigm designed to asses this relationship were used. basically, this procedure insures analysis of particular features of a word by the nature of the question the subject must answer about the word during its initial presentation. Decision-time measures demonstrated that Korsakoff patients could answer the query nearly as rapidly as normals, but the patients failed to demonstrate a normal increase in recognition as a function of the depth of analysis demanded by the query (Experiments 1--2). However, when the test procedure was extremely simplified (Experiment 3) by presenting only a small number of to-be-recognized words, the Korsakoff patients did demonstrate the normal "pattern" of recognition. It was concluded that under the appropriate circumstances, Korsakoff patients' recognition memory can be improved by instructions to analyze the more sophisticated (semantic) features of verbal information.
 
Three experiments were carried out to investigate the effects of a nondifferential warning signal on differential classical conditioning. In Experiment 1, a 500-msec warning interval was found to result in good differential conditioning performance at an interstimulus interval (ISI) of 500 msec in which differential conditioning did not otherwise occur. The second experiment demonstrated the warning effect with both visual and auditory conditioned stimuli, thus ruling out the possibility that the warning effects were due to eye movements. Experment 3 showed that a warning signal and an increased ISI were functionally equivalent, as demonstrated by conditioning performance and the similar effects obtained when the ISI and warning-interval conditions were switched from optimal to nonoptimal and vice versa.
 
Examined the influence of a stimulus suffix in yes-no recognition and probe-recall tasks with 20 and 22 college students, respectively. As with previous findings with serial recall, reliable suffix effects were obtained in probe recall. However, no suffix effects were found in the recognition task. Both serial and probe-recall tasks require the retention of order and item information, while only item information is required in recognition. An interpretation of the suffix effect based on interference with order information is presented. (23 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved).
 
A series of unordered recall tasks was administered to groups of congenitally deaf subjects for whom American Sign Language (ASL) is the principal means of communication. A suffix effect was observed when an ASL sign was suffixed to a list of ASL signs (Experiment 1), and when a line drawing of an ASL sign was suffixed to a list of line drawings of ASL signs (Experiment 3). The suffix effect was a diminished magnitude when a printed English word was suffixed to a list of printed words (Experiment 2). The findings of Experiment 1 and 3 argue conclusively against the suffix effect resulting solely from sensory store differences. Additionally, the results of Experiment 3 argue conclusively against explanation of the effect as arising solely from differences in the processing of "static" versus "changing-state" input.
 
When an outstanding item appears in an otherwise homogeneous list of items, the outstanding item is better remembered (the von Restorff effect), and items before and after it may be more poorly remembered (induced amnesia) than corresponding items in a control list. In the present experiments the outstanding item was a word presented as a loud shout among other words presented at normal conversational levels. In two experiments, large retrograde- and anterograde-induced amnesiae effects were demonstrated using a free-recall and a recognition task. In both experiments half of the subjects were told what to expect and were instructed to devise a strategy to eliminate induced amnesia. These instructions failed to eliminate the amnesiac effect. A third experiment was designed to demonstrate an empirical similarity between induced and clinical amnesia. In clinical retrograde (but not anterograde) amnesia, "lost" memories are sometimes recovered with time. Filled delays of 0, 30, or 120 sec interpolated between list presentation and recall demonstrated that induced retrograde amnesia disappeared at the longest delay but induced anterograde amnesia was unchanged. A fourth experiment eliminated some alternate interpretations of the effect.
 
Korsakoff amnesic and alcoholic control patients were asked to recall successive lists of nine nouns of the same category. The expected progressive decrease in recall was reversed by a category shift on the fifth list for controls but not for amnesics. A context shift on the fifth list (changed color of words and background) led to improved performance by amnesics but not by controls. However, amnesics did show "release from proactive interference" at category shift if it was the second shift in a sequence (on trial nine) or if they were told to expect the shift. These findings relate amnesics' known vulnerability to proactive interference to an impaired use of available cues to segregate new from old material--unless the cues are made additionally salient. This difficulty could operate both during learning and at retrieval.
 
Recognition memory for matrices of 0s and 1s was examined as a function of the number of elements (complexity) and density of those elements within the matrix. It was found that with greater density and lesser complexity, recognition performance improved. This result contradicts an earlier finding of Green and Purohit, who concluded that the more complicated matrices led to better performance. The present study suggests that their conclusion was erroneous and stemmed from failure to control the physical parameters of density and number of elements in the matrix. Implications for the general problem of recognition memory and eye movements are discussed.
 
The effect of distinctive and equivalent verbal label training on a subsequent test of recognition memory for random shapes were assessed. Shape continua, systematically relating the labeled shapes, were used in the memory test so that gradients of recognition memory were obtained. Distinctive-nonrepresentative-label training produced symmetrical recognition gradients with a single mode at the correct target shape. Equivalent-label training produced symmetrical gradients that were as steep as the distinctive-label gradients, but the mode of the equivalent-label gradients was shifted to a distractor shape that varied from the target in the direction of the equivalent-label shape. The results offered support to a Gestalt/configurational account of the effects of verbal labels on memory for form, but the data were also consistent with an extension of Ellis' conceptual coding hypothesis. It was concluded that, rather than being a competing alternative account, the conceptual coding hypothesis may be viewed as an updated, more analytic statement of the older Gestalt view.
 
In a paired-associate paradigm using odors as stimuli and pictures for multiple-choice responses, the first of two associations to an odor was retained far better than the second over a 2-week period. The persistence of first-learned associations may be responsible for the long lasting nature of odor memories. Subjects reported constructing mediational schemes for mnemonic devices to link the odors and pictures. Latencies for a task of naming odors indicated that although naming odors is difficult, labels could be generated sufficiently fast that they could be employed as mediators in the paired-associate task. A third task investigated the phenomenon of knowing that an odor was familiar but being unable to name it. Subjects in this tip-of-the-nose state were questioned about the odor quality and the name of the odor and were given hints about the name. These subjects were found to have information available about the odor quality but none for the name as found in the tip-of-the-tongue state. However, as in the tip-of-the-tongue phenomenon, hints given to the subjects in the tip-of-the-nose state often led to the correct name.
 
Three experiments addressed the problem of isolating the effects of sensory similarity on subprocesses involved in coding paired associates. In the first, the standard recognition-recall procedure was used and stimulus similarity, concreteness, and frequency were varied. However, because of concern with the validity of this recognition procedure as a measure of functional stimulus contact, an alternative was developed. This alternative led to the second study in which only stimulus similarity was manipulated. In the third experiment, similarity was varied, and the pairs were either associatively compatible, unrelated, or incompatible. The results using the new procedure indicated that similarity consistently disrupted functional stimulus contact but not associative retrieval. By contrast, associative relatedness facilitated both subprocesses.
 
Specific and nonspecific transfer of pattern class concept information between vision and audition was examined. In Experiment 1, subjects learned visually or auditorily to distinguish between two pattern classes that were either the same as or different from the test classes. All subjects were then tested on the auditory classification of 50 patterns. Specific intramodal and cross-modal transfer was noted; subjects trained visually and auditorily on the test classes were equivalent in performance and more accurate than untrained controls. In Experiment 2, the training of Experiment 1 was repeated, but subjects were tested visually. There was no evidence of auditory-to-visual transfer but some suggestion of nonspecific transfer within the visual modality. The asymmetry of transfer is discussed in terms of the modality into which patterns are most likely translated for the cross-modal tasks and in terms of the quality of prototype formation with visual versus a,ditory patterns.
 
The paradigm producing recognition failure of recallable words was investigated in a series of three experiments. Results indicate that retrieval asymmetry: (a) exists in the recognition failure paradigm directly following list study, (b) increases significantly following a free-association task aimed at generation of the target words from the study list, and (c) can be used as a reasonably good predictor of the magnitude of recognition failure. Retrieval asymmetry and recognition failure are reliably related even when adjusted for the level of recognition probability, which has previously been shown by Tulving and Wiseman to be a good predictor of recognition failure.
 
Three experiments evaluated the effect of poststimulus distractor characteristics in altering recognition of random shapes. Experiment 1 demonstrated that when 150 msec or 300 msec were allowed for processing the initial shape stimulus, recognition was lowered only when it was followed by an attended shape or digit distractor. Unattended shapes, digits, and line grids and attended line grids left recognition essentially perfect. Attended shapes lowered recognition more than attended digits. Experiment 2 found that attended shapes, digits, and line grids all masked random shapes when presented immediately upon offset of a random shape displayed for 50 msec. As processing time increased, digit distractors became less effective than shape distractors, while line grids lost all effect. The shape distractors lowered recognition up to 1,200 msec. Experiment 3 showed that the larger recognition loss produced by the shape distractor than by the digit distractor could not be attributed to differences in response procedure. It was suggested that memory for random shapes moves from brief visual storage to a limited capacity visual short-term memory. Attended shape distractors may eliminate the stimulus shape from visual short-term memory thus preventing long-term storage.
 
Five experiments demonstrate rehearsal of pictures. The pictures were displayed in pairs, with a "rehearsal interval" between successive pairs. At the beginning of each interval, subjects were cued to rehearse just one member of the preceding pair. Although the subjects were expecting a recognition test for just the cued pictures, they were tested on both the cued and the uncued pictures. The first four experiments all used a different type of picture (faces, scenes, random shapes, and simple line drawings), and in each case recognition was at a higher level for the cued pictures than for the uncued pictures. The fifth experiment examined the degree to which the benefit of the rehearsal interval was limited to the cued pictures and the results suggested that uncued pictures did not benefit at all from the rehearsal interval. It is argued that these findings of control exerted by the subject over the beneficial effects of a postpresentation interval provide an adequate demonstration that pictures can be effectively rehearsed.
 
Instructions to attend to the case and color in which words were presented led to improved retention of these visual attributes but depressed recognition performance. This trade-off between item and attribute memory occurred at three presentation rates (1.5, 5.5, and 10.5 sec/item), suggesting that visual attributes of verbal stimuli are rarely stored unless subjects expect that knowledge of physical form will be useful later. Visual attributes of high-imagery words were retained better than visual attributes of low imagery words by subjects instructed to attend to case and color, but not by subjects asked only to attend to word meaning. Implications of these findings for the hypothesis that visually presented verbal stimuli are stored as literal copies are discussed.
 
In two experiments, subjects were given five successive short-term memory tests. In Experiment 1, recall was not significantly facilitated when memory material in the final test was delivered to the ear opposite to the one that received the memory material in the four preceding tests. In Experiment 2, events were presented from two differentially located speakers rather than through headphones. A shift across speakers on the final test did produce proactive interference release. These findings suggest spatial location as a potential encoding dimension of verbal material.
 
Memory trigrams were presented by one of three methods: visual-concurrent (all three letters appeared simultaneously), visual-successive, and auditory-successive. During the 12-sec retention interval, subjects shadowed and reported their rehearsals and mnemonic associations via switches. On trials without associations, recall performance was interpreted as support for the hypothesis that the form of rehearsal is related to presentation modality. However, the frequency and temporal patterning of the rehearsals over the retention interval were virtually identical for all three presentation conditions, suggesting that the "control processes" were relatively independent of both method of presentation and modality of rehearsal. Most importantly, these data in combination with earlier data suggest that the efficiency of each rehearsal was also independent of those same factors, in each case quite comparable to that of a concurrent visual stimulus.
 
Letters presented rapidly to separate spatial locations were used to test the precategorical acoustic storage (PAS) model's assumptions that memory information can be stored and masked selectively at separate spatial locations in auditory space and that spatial location can act as a retrieval cue in PAS. The suffix effect was present at the end of the list, even at a presentation rate of six per second. The data from three other experiments suggested that spatial locations do not act as memory repositories and that spatial location cannot be used as a retrieval cue at fast rates of presentation.
 
In two experiments on the effects of modality on memory span for words, conventional measures of span were supplemented by analyses of serial position curves and by analyses of the principal auditory features of intrusion errors. Auditory presentation led not only to better recall of the terminal words in each stimulus list but also to better recall of word order given correct item recall. Intrusion errors were found to share a number of auditory features with the corresponding omissions, even when the lists had been presented visually. The most salient or the best-retained word features were the syllabic stress pattern and the identity of the stressed vowel phoneme. The data provide evidence for a partial retention of auditory features of stimulus words in short-term memory tasks and are taken to support attribute rather than unit models of short-term memory.
 
The effects of conditional discrimination training on human auditory frequency generalization were examined. In Experiment 1 subjects learned to press a key to one tone, but not to a higher pitched tone when presented in the left earphone, and to respond to the higher pitched tone but not to the lower tone in the right earphone. Generalization tests revealed conditional peak shifts, with subjects responding to frequencies lower than the positive stimulus (S+) for left-earphone presentations and to frequencies higher than S+ for right-earphone presentations. The shifts observed following conditional discrimination were larger than those obtained from subjects who received simple discrimination training. Experiment 2 showed that these larger shifts were not simply due to extended discrimination training. In Experiment 3 subjects were trained with conditional discriminations involving an S+ and a negative stimulus (S-) in one earphone but only a single, positive stimulus in the other earphone. These subjects also showed conditional gradient shifts with displacements in both directions. The occurrence of peak shift without an S- can only be interpreted as involving relational responding.
 
Two experiments were conducted to determine whether the auditory and visual systems process simultaneously presented pairs of alphanumeric information differently. In Experiment 1, different groups of subjects were given extensive practice recalling pairs of superimposed visual or auditory digits in simultaneous order (the order of arrival) or successive order (one member of each digit pair in turn, followed by the other pair member). For auditory input, successive order of recall was more accurate, particularly for the last two of three pairs presented, whereas for visual input, simultaneous order of recall was more accurate. In Experiment 2, subjects were cued to recall in one or the other order either immediately before or after stimulus input. Recall order results were the same as for Experiment 1, and precuing did not facilitate recall in either order for both modalities. These results suggest that processing in the auditory system can only occur successively across time, whereas as in the visual system processing can only occur simultaneously in space.
 
The Peterson and Peterson short-term memory paradigm involves an interpolated task with several potential dimensions from which interference may orginate: Similarity of items and vocalization. Here we assess the relative interference potency of each on material presented either aurally or visually. Interpolated activity consisting of numbers or words was performed either vocally or silently after either aural or visual presentation of nouns, for which recall was tested after 0, 10, and 30 sec. The magnitude of the vocalization interference effect accounted for 59% and 53% of the total variance at 30 and 10 sec, respectively, whereas the variance associated with similarity was negligible. The effect of similarity emerged dramatically only in the visual presentation condition wherein the silent word task created greater interference than the silent number task. Vocal and silent activity produced differential interference, in partial accord with the dual memory hypothesis.
 
Four groups of subjects were given either 0. 100, 500, or 1,000 msec delays of the unconditioned stimulus (UCS) contingent upon the occurrence of a conditioned response (CR) and were given a UCS 515 msec after conditioned stimulus (CS) onset when a CR did not occur. A fifth group received standard classical conditioning trials with an interstimulus interval of 515 msec. Overall performance decreased as CR-contingent UCS delay increased, with the classical conditioning group approximating the performance of the group receiving the 100-msec delay. The data were analyzed with the two-phase model of conditioning and the following results were obtained: The duration of Phase 1 of the model increased with contingent delay; operator limits associated with CR trials or with combined CR-CR (CR absent) trials decreased as a function of delay; and operator limits associated exclusively with CR trials were unaffected by the delay. Subjects receiving a contingent delay of 0 msec gave the shortest latency responses and exhibited reliable latency decreases across trials, suggesting an attempt to "beat" the UCS. The results were interpreted as contrary to what would be expected from low-of-effect theories which postulate that reinforcement results from a CR-UCS interaction, although they could be subsumed under a drive or an associative strength theory in which the aversive, or CR-supportive, strength of the UCS is assumed to be negatively correlated with contingent UCS delay.
 
The study of Lichtenstein, Slovic, Fischhoff, Layman, and Combs reports several types of errors in subjects' frequency judgments of lethal events. These errors are interpreted as reflecting the operation of two types of judgment biases. In this research, the objective or actual frequency of lethal events served as a standard of comparison; any deviation from this standard was defined as a bias. Thus, the research strategy used is apparently modeled after that of a psychophysicist using illusions to study basic perceptual processes. There is one key difference, however. In the case of illusions, the subject is directly exposed to the physical stimulus object. In the present study, however, subjects were never exposed to actual stimuli. Since subjects were asked to make judgments about things they had not directly experienced, it is not surprising that they would be inaccurate. But unlike the study of illusions, such inaccuracies have not been shown to have any necessary connection to psychological mechanisms. Therefore, it seems somewhat tenuous to offer psychological interpretations of judgmental biases when the origins of those biases have not yet been identified.
 
Conditioned response (CR) rate and development of CR latency, rise time, and airpuff attenuation were examined for V- and C-form responders using two nonspecific command words, do and don't, as conditioned stimuli (CSs) in single-cue, double-cue, and differential eyelid conditioning. In both single-cue and differential conditioning, regardless of the command word used to signal the unconditioned stimulus (UCS), the Vs produced a higher response rate and learned a better UCS-attenuating response topography than the Cs. However, in a double-cue conditioning paradigm in which both command words were presented alone on different trials and reinforced, response latency was longer and puff attenuation poorer among Vs than when the UCS was signaled by a unique cue. In contrast, adding a second reinforced cue actually enhanced the development of puff-avoidant CR topographies among Cs compared to single-cue conditioning. These results and others indicate that response topography development is to some extent a labile process that can be biased toward either good or poor puff-avoidant properties and that the factors responsible for influencing CR topography differ for Vs and Cs.
 
Tested recognition memory for pictures using matrices of zeroes and ones as stimuli in 2 experiments. Ss totaled 50 undergraduates. In Exp I dimensionality of matrices was varied (5 * 5 and 10 * 10 matrices). Results show better recognition memory for 10 * 10 matrices. Exp II investigated the importance of certain areas (e.g., center or surround) using 10 * 10 matrices only. Results suggest that neither center nor surround is given unusual weight. (PsycINFO Database Record (c) 2006 APA, all rights reserved).
 
Four experiments on memory for briefly presented complex pictures showed the following: (a) Pictures shown in a sequence for 110 msec each with a blank 5,890-msec interstimulus interval (ISI) were later recognized almost as well as pictures shown for 6 sec each with no ISI; (b) when the ISI was deleted, recognition memory for the briefly presented pictures dropped almost to chance; (c) however, filling a 5-sec ISI with a to-be-ignored picture that was the same on all trials had little or no effect on memory for the briefly presented pictures; (d) when the time between 110-msec pictures was decreased from 4,890 to 1,390, 620, 385, or 0 msec, the ability to detect that they were mirror reversed in the recognition test decreased more rapidly than did recognition accuracy. Evidently, incidental visuospatial properties of a picture can be encoded for at least 1 sec after a brief presentation unless another to-be-remembered picture is presented during that time.
 
Watkins found the modality effect undiminished when four-syllable rather than one-syllable words were used, and concluded that the effect has a post-categorical origin. Nilsson replicated this result, and also found that with entirely unfamiliar words the effect was greater with one-syllable words than with four-syllable words. Nilsson considered his findings to be in support of a precategorical origin of the effect. This reply argues that, to the contrary, Nilsson's findings are not only consistent with a postcategorical interpretation, but also inconsistent with a precategorical interpretation.
 
The purpose of this experiment was to investigate the hypothesis that the discriminating and categorizing functions of a label associated with an ambiguous shape can differentially influence delayed recognition memory for the shape. The temporal course of shape recognition was measured after the subjects were trained to associate the shapes with relevant verbal labels, irrelevant verbal labels, or no verbal labels. Either immediately or after delays of 15 min or 1 wk, subjects were given a shape recognition test and both free- and aided-recall tests for retention of the associated verbal labels. Results indicated that relevant verbal labels differentially affect memory for shape and that the discriminating function of the label operates effectively at the time of stimulus encoding. The categorizing function of the label affects the changes occurring during the storage stage of memory. These results are interpreted as supporting the view that the courses of shape recognition and relevant label recall are not independent.
 
Research suggests that we process information by way of two distinct and functionallly separate coding systems. The localization of these two processing systems appears to be somewhat dependent on cerebral laterality, which has been shown to vary in right-handed and left-handed persons. To test the dual coding model, right-handed and left-handed subjects learned lists of abstract and concrete words under various conditions of visual and tactile interference. Right-handed subjects showed a significant superiority in the remembering of highly concrete items, while total recall did not differ reliably between groups.
 
In Experiment 1, normal 10-yr.-olds and 10-yr.-olds diagnosed as learning disabled (LD) were presented with items in visual and auditory modalities for free and cued recall. The LD children had deficits in auditory and/or visual memory. Recall by LD children was worse than for nonimpaired peers only on tasks in the impaired modality, and on cued recall the deficit was confined to recall given a semantic category cue: Recall given perceptual cues was unimpaired. In Experiment 2, presentation-time tasks were used to create a bias toward either perceptual or semantic encoding. The semantic-encoding task removed the modality-specific deficit between LD children and controls. We conclude that deficits in semantically cued recall for children with only one impaired modality had their origins at presentation time. The most parsimonious explanation of these results involves separate pathways linking the auditory and visual modalities to the semantic system.
 
Three experiments compared the effects of visual and tactual stimulus presentation in two-choice sequential learning situations requiring a predictive response. In Experiments 1 and 2, subjects received a five- or six-unit repeating pattern; in Experiment 3, they received a semirandom sequence. Tactual as compared to visual stimulus presentation resulted in less trials to criterion in predicting a repearing pattern and in earlier frequency matching in predicting a semirandom sequence. These results suggest an unusual tactual adeptness in binary serial learning. Additionally, a new method of analyzing conditional responding in th brobability learning paradigm is described and applied to the data in Experiment 3.
 
Top-cited authors
Baruch Fischhoff
  • Carnegie Mellon University
Peter Graf
  • University of British Columbia - Vancouver
Asher Koriat
  • University of Haifa
Paul Slovic
  • University of Oregon
John B Shea
  • Indiana University Bloomington