Journal of Experimental Psychology Human Learning & Memory

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.

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.

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.

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.

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.

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.

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.

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.

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.