PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Serial Learning”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 577 records · Page 32Linked to original sources

Repetition blindness for locations: evidence for automatic spatial coding in an RSVP task.

The authors report a new phenomenon called repetition blindness (RB) for locations: When 3 or 4 letters are presented rapidly and sequentially at random locations within a spatial array, experimental participants have difficulty reporting pairs of letters appearing in the same location within 250 ms of each other. This deficit occurs both during report of letter identities and during report of the locations in which the letters appear; it can also be found using a partial report task. During letter report, the deficit is found for 4-location arrays but not for 8-location arrays. In contrast, letter RB is not found during location report even when the letters are always chosen from a set of 4. These results indicate that a small number of locations--but not letters--can be encoded automatically even when they are not explicitly reported. The authors argue that RB for locations results from a difficulty individuating 2 tokens at the same spatial location.

Adult↗

All updateable objects in working memory are updated whenever any of them are modified: evidence from the memory updating paradigm.

In a series of experiments, participants were required to keep track of 1 or 2 working memory (WM) objects, having to update their values in 80% of the trials. Updating cost, defined as the difference between update and non-update trials, was larger when 2 objects were involved compared with when there was only 1 object was involved. This finding was interpreted as evidence that the updating process encompasses both objects in WM, even though only 1 of them is actually updated. This feature of WM updating is limited to objects defined as "updateable," throughout the trial sequence. The results are explained by the need to reprogram the phonological loop when updating or the need for desynchronization followed by resynchronization of WM contents.

Adult↗

Acquiring a cognitive skill with a new repeating version of the Tower of London task.

A computerized version of the Tower of London task was used to investigate cognitive skill learning. Thirty-six healthy volunteers were assigned to either a random condition (nonrecurring problems), or to a sequence condition in which, unbeknownst to the subjects, a repeating sequence of three problems was presented. Indices of execution, planning, and total time, as well as number of moves performed, were used to measure behavioural change. Subjects' performance improved in both conditions across blocks of practice. A distinct learning effect related to the repeating sequence was also observed. This suggests that a specific skill that reflects procedural learning of the strategies, rules, and procedures pertaining to repeating problems can develop over and above a more general skill at solving cognitive planning problems with practice.

Adolescent↗

The hippocampus and memory for "what," "where," and "when".

Previous studies have indicated that nonhuman animals might have a capacity for episodic-like recall reflected in memory for "what" events that happened "where" and "when". These studies did not identify the brain structures that are critical to this capacity. Here we trained rats to remember single training episodes, each composed of a series of odors presented in different places on an open field. Additional assessments examined the individual contributions of odor and spatial cues to judgments about the order of events. The results indicated that normal rats used a combination of spatial ("where") and olfactory ("what") cues to distinguish "when" events occurred. Rats with lesions of the hippocampus failed in using combinations of spatial and olfactory cues, even as evidence from probe tests and initial sampling behavior indicated spared capacities for perception of spatial and odor cues, as well as some form of memory for those individual cues. These findings indicate that rats integrate "what," "where," and "when" information in memory for single experiences, and that the hippocampus is critical to this capacity.

Animals↗

Hearing what the eyes see: auditory encoding of visual temporal sequences.

When the senses deliver conflicting information, vision dominates spatial processing, and audition dominates temporal processing. We asked whether this sensory specialization results in cross-modal encoding of unisensory input into the task-appropriate modality. Specifically, we investigated whether visually portrayed temporal structure receives automatic, obligatory encoding in the auditory domain. In three experiments, observers judged whether the changes in two successive visual sequences followed the same or different rhythms. We assessed temporal representations by measuring the extent to which both task-irrelevant auditory information and task-irrelevant visual information interfered with rhythm discrimination. Incongruent auditory information significantly disrupted task performance, particularly when presented during encoding; by contrast, varying the nature of the rhythm-depicting visual changes had minimal impact on performance. Evidently, the perceptual system automatically and obligatorily abstracts temporal structure from its visual form and represents this structure using an auditory code, resulting in the experience of "hearing visual rhythms."

Acoustic Stimulation↗

The effects of nodality on the formation of equivalence classes.

A four-member equivalence class (A----B----C----D) can be formed by training AB, BC, and CD. The nodal stimuli, B and C, mediate all of the derivative (transitive and equivalence) relations in the class. The derivative relations AC, CA, BD, and DB are separated by one node, whereas AD and DA are separated by two nodes. How do the number of nodes that separate the stimuli in a derivative relation influence the induction of stimulus control exerted by that relation? Seven college students learned two four-member classes made up of nonsense syllables. After training, all derivative relations were presented repeatedly without informative feedback. Stimulus control exerted by each derivative relation was assessed concurrently. For the 7 subjects, control exerted by the derivative relations increased gradually with repeated presentations. With 6 of the 7 subjects, the one-node relations exerted more control than the two-node relations during the process. However, the disparity between the one- and two-node relations decreased with repeated presentations. Eventually, all derivative relations exerted complete control. The control exerted by derivative relations during induction was inversely related to the number of nodes separating the terms in the derivative relations. These results demonstrate that nodal distance is a determinant of the relatedness of stimuli in equivalence classes. The findings are discussed in terms of remote association, semantic memory networks, and the study of transitive inference.

Adult↗

The role of instructions in the transfer of ordinal functions through equivalence classes.

In two experiments, adult subjects completed match-to-sample training and testing to establish four equivalence classes of four figures each. Then the subjects were taught one three-position sequence consisting of one stimulus from Class 1, one from Class 2, and one from Class 3. Inclusion of Class 4 stimuli in sequences was never reinforced, but two different stimuli from Class 4 appeared as distractors on each sequence trial. Tests assessed whether subjects would produce novel three-position sequences composed of members of Classes 1 through 3 that had not been used in sequence training. Three subjects in Experiment 1 received instructions about the match-to-sample and sequencing tasks, in addition to training contingencies. All 3 demonstrated equivalence class formation after match-to-sample training. After they were taught one sequence with one member of Classes 1 through 3, none of these subjects produced untrained sequences with other equivalence class members reliably. One additional sequence was trained directly; thereafter 1 subject showed some evidence of transfer of the trained ordinal functions across the remaining members of the equivalence classes, but the other 2 did not. Following a review of equivalence class training and testing and a review of the original sequence training, all 3 subjects produced most of the predicted, untrained sequences on tests. Experiment 2 replicated Experiment 1 with 2 adults but omitted all instructions except the minimal ones necessary to initiate responding. Unlike the subjects in Experiment 1, both of these subjects demonstrated virtually complete transfer of ordinal functions through the equivalence classes after direct training on just one sequence composed of one member of Classes 1 through 3.

Adult↗

The blocked-random effect in pictures and words.

Picture and word recall was examined in conjunction with list organization. 60 subjects studied a list of 30 items, either words or their pictorial equivalents. The 30 words/pictures, members of five conceptual categories, each represented by six exemplars, were presented either blocked by category or in a random order. While pictures were recalled better than words and a standard blocked-random effect was observed, the interaction indicated that the recall advantage of a blocked presentation was restricted to the word lists. A similar pattern emerged for clustering. These findings are discussed in terms of limitations upon the pictorial superiority effect.

Adult↗

Children's memory of an occurrence of a repeated event: effects of age, repetition, and retention interval across three question types.

Children's memory of the final occurrence of a repeated event was examined whereby each occurrence had the same underlying structure but included unpredictable variations in the specific instantiations of items across the series. The event was administered by the children's teachers at the kindergarten or school. The effects of repetition (single vs. repeated event), age (4-5 vs. 6-8-year-olds), retention interval (1 week vs. 6 weeks), and the frequency of specific instantiations of items were examined across 3 question types. Repetition increased the number of items recalled on a level that was common to all occurrences in response to general probes and reduced the likelihood that children would report details that did not occur in the event. However, repetition also reduced the number of correct responses about which instantiation was included in the occurrence and decreased the consistency of responses across repeated questioning. Most errors were intrusions of details from other occurrences; usually references to instantiations of items that had occurred frequently throughout the series. The younger children showed a poorer ability to discriminate between the occurrences than the older children, but age differences were less evident at the longer retention interval. The results are discussed in relation to current theories of memory and children's eyewitness testimony.

Association Learning↗

Repeated acquisition of behavioral chains: effects of methylphenidate and imipramine.

A method involving repeated acquistion of behavioral chain was used to assess the effects of methylphenidate and imipramine in individual animals. Pigeons obtained food for completing a 4-response chain, which was changed from session to session. Learning was defined by the decrease in errors across trials within a session; overall accuracy was measured by total errors per session. For comparison, the drug tests were also conducted under a performance condition, in which the 4-response chain was the same from session to session. In general, both drugs increased total errors per session as a function of dose under both the learning and performance conditions. The error-increasing effect was greater with imipramine than with methylphenidate and was detected at lower doses under the learning condition than under the performance condition. Under the learning condition, the higher doses of both drugs decreased the rate of within-session error reduction. Although neither drug enhanced accuracy at any of the doses tested, the lower doses of methylphenidate slightly decreased total trial time under both the learning and performance conditions.

Animals↗

The effect of diazepam and fentanyl on mental, psychomotor and electroencephalographic functions and their rate of recovery.

Ten healthy male subjects received diazepam (10 or 20 mg), fentanyl (0.1 or 0.2 mg) or a placebo intravenously at weekly intervals according to a latin square design. They were tested on a battery of psychological and electroencephalographic tests at 0.5, 2, 6, and 8 hrs following injection. Fentanyl had little effect on memory while diazepam reduced the ability to learn without increasing forgetting of material alread acquired. By the 2nd hour post injection, only the low dose of fentanyl had no residual effect. Recovery was complete by the 6th hour for all treatments according to the psychological tests except for the lagging effect of high dose of diazepam on memory. The electroencephalographic effects of diazepam persisted beyond the end of the testing sessions while those of the high dose of fentanyl recovered by the 8th hour. Thus in the dosages tested, diazepam had more intense and prolonged effects than fentanyl.

Adult↗

Parallel and sequential information processing in animals as a function of different hemispheres.

The procedure of motor-food conditioned reflexes in conjunction with unilateral decortication of the hemispheres by means of spreading depression was used in experiments on 53 rats. Differentiation of geometric figures, combined into simultaneous complexes or chain stimuli, presented simultaneously or sequentially, was developed. It was shown that lateralization of predominant disturbances of analysis depends not on the type of stimuli used, but on the nature of their presentation. In the case of simultaneous presentation, the most profound disturbances occurred after the right hemisphere was disconnected, and in the case of sequential presentation, as a result of inactivation of the left hemisphere. The presence of a simultaneous processor in the right hemisphere of the animals and a sequential processor in the left is suggested.

Animals↗