Memory mechanisms. Photographic memory in flies.
A new study of olfactory memory formation in Drosophila shows that a delicate balance of CREB transcription factor activity may play a decisive role in triggering long-term memory.
Animals↗
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Results for “Memory”
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Event memory: the effects of processing objectives and time delay on memory for action sequences.
The memorial representations of events that result from different types of goal-directed cognition are conceptualized on the basis of the general model of information processing proposed by Wyer and Srull (1980, 1984). In a test of this conceptualization, subjects read a passage describing the events that took place at a cocktail party. They were told either (a) to form an impression of the party and the events that occurred, (b) to empathize with the person from whose perspective the passage was written, or (c) to remember the information presented in a way that would allow them to reproduce it. The stimulus passage contained two target events, each consisting of actions that were either described chronologically or in reverse order, and were either presented together or were separated by other unrelated material. After either a short or a long delay, subjects recalled the information they read in the order it came to mind. Finally, subjects were given the individual event actions and told to place them in the order they were presented. The actions comprising target events were generally more likely to be recalled together and in chronological order when subjects had learned about them with either an impression formation or an empathy objective than when they had read about them with the goal of remembering them. However, orderings of these actions were affected by task objectives only after a long delay. The effect of task objectives on the order of recalling the events themselves showed a quite different pattern; for example, subjects with an empathy objective were most likely to recall the last target event presented before the first one after a long delay, whereas subjects with an impression objective were least likely to do so. The proposed model provided a reasonable account of these and other effects of task objectives on memory for events and the actions comprising them.
Cognition↗
Trait memory and behavior memory: the effects of alternative pathways on impression judgment response times.
Carlston (1980a) and Lingle (1983) argued that remembered behaviors, previous trait inferences, or both may be accessed and used in making new trait inferences, depending on a variety of factors. In this article we relate this argument to a spreading activation model of memory and suggest factors that should affect the relative accessibility of inferences and behaviors during trait judgment processes. In our study we varied several of these factors and assessed accessibility, using response-time methods. The results of this study strongly support the model's prediction that prompting inference formation facilitates subsequent trait judgment response times, but only when relevant behavior memories have not been recently primed. We theorize that the inference manipulations used in this study strengthened the direct pathway to a relevant trait concept, but that the strength of this pathway was immaterial to judgment response times when a "proximal prime" directed retrieval efforts along an alternative "behavioral" route to the trait information. The results also suggest that the proximal behavior prime facilitated trait responses among subjects who had not been induced to make trait inferences, but slowed trait responses among subjects who had previously been induced to make trait inferences.
Adult↗
The role of long-term-memory and short-term-memory links in the Simon effect.
In Experiment 1, children performed a Simon task after a spatially compatible or incompatible task. Results showed a Simon effect after the spatially compatible task and a reversed Simon effect after the spatially incompatible task. In Experiments 2-5, an identical procedure was adopted with adult participants, who performed the Simon task immediately after, a day after, or a week after the spatial compatibility task. Experiment 6 established a baseline for the Simon effect. Results showed a Simon effect after the spatially compatible task and no Simon effect or a reversed Simon effect after the spatially incompatible task. A modified version of the computational model of M. Zorzi and C. Umiltà (1995) was used to compare possible accounts of the findings. The best account exploits 2 types of short-term-memory links between stimulus and response and their interaction with long-term-memory links.
Adult↗
Semantic memory content in permastore: fifty years of memory for Spanish learned in school.
Retention of Spanish learned in school was tested over a 50-year period for 733 individuals. Tests of reading comprehension, recall, and recognition vocabulary and grammar were administered together with a questionnaire to determine the level of original training, the grades received, and rehearsals during the retention interval in the form of reading, writing, speaking, or listening to Spanish. Multiple regression analysis shows that retention throughout the 50-year period is predictable on the basis of the level of original training. The great majority of subjects rehearse so little that the data reveal no significant rehearsal effects. The analysis yields memory curves which decline exponentially for the first 3-6 years of the retention interval. After that retention remains unchanged for periods of up to 30 years before showing a final decline. Large portions of the originally acquired information remain accessible for over 50 years in spite of the fact the information is not used or rehearsed. This portion of the information in a "permastore" state is a function of the level of original training, the grades received in Spanish courses, and the method of testing (recall vs. recognition), but it appears to be unaffected by ordinary conditions of interference. The life-span frequency distribution of learned responses is discontinuous; one portion of the response distribution has life spans of 0-6 years, the other portion, life spans in excess of 25 years, and no responses have life spans of 6-25 years. This suggests a discrete transition into a permastore state during the extended period of original training. Analysis of successive relearning processes over extended time periods is deemed essential for an understanding of the acquisition of permanent semantic memory content.
Humans↗
Working memory tasks in five-choice operant chambers: use of relative and absolute spatial memories.
Rats were trained to nose poke into illuminated holes to perform 1 of 2 different spatial working memory tasks (relative recency or reward history) in a 5-choice operant chamber. A series of experiments indicated that choice accuracy on both tasks depended on (a) the holes' spatial separation, and (b) their relative rather than absolute positions. The results suggest that accurate choice depended on using a motor mediation strategy to turn, so as to encounter the target (correct) hole before encountering the alternative (wrong) hole. The drugs administered to the rats, d-amphetamine, scopolamine, and CGP-37849 impaired choice accuracy on these tasks, even though task performance had not appeared to depend on explicit memory for the sample responses. This suggests that parallel drug effects obtained on other operant matching- or nonmatching-to-position tasks may not have reflected truly amnesic effects of the drug treatments.
2-Amino-5-phosphonovalerate↗
The generality of working memory capacity: a latent-variable approach to verbal and visuospatial memory span and reasoning.
A latent-variable study examined whether verbal and visuospatial working memory (WM) capacity measures reflect a primarily domain-general construct by testing 236 participants in 3 span tests each of verbal WM. visuospatial WM, verbal short-term memory (STM), and visuospatial STM. as well as in tests of verbal and spatial reasoning and general fluid intelligence (Gf). Confirmatory' factor analyses and structural equation models indicated that the WM tasks largely reflected a domain-general factor, whereas STM tasks, based on the same stimuli as the WM tasks, were much more domain specific. The WM construct was a strong predictor of Gf and a weaker predictor of domain-specific reasoning, and the reverse was true for the STM construct. The findings support a domain-general view of WM capacity, in which executive-attention processes drive the broad predictive utility of WM span measures, and domain-specific storage and rehearsal processes relate more strongly to domain-specific aspects of complex cognition.
Adolescent↗
When do visual and verbal memories conflict? The importance of working-memory load and retrieval.
Examinations of interference between verbal and visual materials in working memory have produced mixed results. If there is a central form of storage (e.g., the focus of attention; N. Cowan, 2001), then cross-domain interference should be obtained. The authors examined this question with a visual-array comparison task (S. J. Luck & E. K. Vogel, 1997) combined with various verbal memory load conditions. Interference between tasks occurred if there was explicit retrieval of the verbal load during maintenance of a visual array. The effect was localized in the maintenance period of the visual task and was not the result of articulation per se. Interference also occurred when especially large silent verbal and visual loads were held concurrently. These results suggest central storage along with code-specific passive storage.
Adolescent↗
Some effects of representational friction, target size, and memory averaging on memory for vertically moving targets.
Observers viewed an animated ascending or descending target that varied in size and velocity across trials and appeared either (a) in isolation, (b) to slide along one side of a single larger stationary object, or (c) to slide between two larger stationary objects. Targets vanished without warning, and displacements (i.e., differences between actual and remembered final position) along the axis of motion and orthogonal axis were measured. Forward displacement (a) decreased with increases in implied friction, (b) increased with increases in target size for descending targets, and (c) decreased with increases in target size for ascending targets. When a larger stationary object was to one side of the target, orthogonal displacement was toward that object; when no object or objects on both sides were present, orthogonal displacement was near zero. Results are consistent with previous findings and speculation on the effects of representational friction, memory averaging, and target size on memory.
Analysis of Variance↗
Effects of misleading questions and hypnotic memory suggestion on memory reports: a signal-detection analysis.
In 2002, the first author and colleagues reported data indicating that both hypnosis and misleading questions decreased the accuracy of memory reports and decreased "don't know" response rates, that the effects of misleading questions were significantly greater than those of hypnosis, and that the two effects were additive. Using a sample of 194 undergraduate students, the present study replicated the findings that misleading questions reduce accuracy and "don't know" responding but failed to replicate the negative effect of hypnosis on memory reports. Signal detection analysis indicated that misleading questioning produced decreased sensitivity accompanied by higher response bias, though affecting sensitivity more than producing a criterion shift.
Adolescent↗
Contextual effects upon text memory for young, aged-normal, and aged memory-impaired individuals.
The purpose of the study was to assess contextual effects upon text memory for young, aged-normal, and aged memory-impaired individuals. Subjects read short passages which differed in their contextual relatedness to target sentences, and then recalled those target sentences. It was found that large differences distinguished the performance of the young from the elderly on the free recall task; that cueing aided the performance of the young and the elderly-normal more than the aged-impaired; and lastly, that no differences were found in recognition performance between young and aged normals whereas the performance of the aged-impaireds was significantly poorer than either the young or the aged-normal group. The results were interpreted in light of two hypothetical mechanisms; the first is labeled "normal" aging and the second, "pathological" aging.
Adult↗
The impact of broadband noise on serial memory: changes in band-pass frequency increase disruption.
Irrelevant sound consisting of bursts of broadband noise, in which centre frequency changes with each burst, markedly impaired short-term memory for order. In contrast, a sequence of irrelevant sound in which the same band-pass noise burst was repeated did not produce significant disruption. Serial recall for both visual-verbal (Experiment 1) and visual-spatial items (Experiment 2) was sensitive to the increased disruption produced by changing irrelevant noise. The results provide evidence that sounds that are largely aperiodic can produce marked disruption of serial recall in a similar manner to periodic sounds (e.g., speech, musical streams, and tones), and thus show a changing-state effect.
Female↗
Working memory in spelling: evidence from backward typing.
Theories of spelling (Margolin, 1984; Nolan & Caramazza, 1983) propose a working memory system for storing order and identity information of letters during the spelling process. Capacity limitations related to the use of such a graphemic buffer were explored. Participants had to type words backwards. Longer pauses between key presses were assumed to signal points at which graphemic buffer contents were refreshed. Five- and six-letter words were divided by a major pause into chunks of two and three letters, partly coinciding with syllables. Articulatory suppression had no effect on performance. Increasing the length of the stimuli to seven to eight letters resulted in major pauses occurring at syllable boundaries, and performance becoming vulnerable to articulatory suppression but not foot tapping. Forward typing resulted in a similar pause pattern. The results suggest that chunks of approximately three letters can be handled at any one time. For short words the task seems to rely on non-phonological modes of coding, whereas longer words appear to require the use of a phonological code, possibly for keeping track of progress through the word.
Humans↗
Age differences in working memory tasks: the role of secondary memory and the central executive system.
Two experiments are reported in which age differences in working memory performance are explored. In the first study, young and older adults held 2, 3, 4, or 5 unrelated words in mind while verifying a single or complex sentence. An age-related decrement was found in subsequent serial recall of the words, and this decrement was larger with longer word lists. Experiment 2 confirmed the interaction between age and list length, using list lengths of 4, 6, and 8 words and a free-recall procedure. There was no interaction between age and divided attention in either experiment. Surprisingly, sentence complexity had a greater detrimental effect on recall in the younger group. The results are discussed in terms of articulatory rehearsal being augmented by using secondary memory in the case of younger subjects.
Adolescent↗
The class of surface immunoglobulin on cells carrying IgG memory in rat thoracic duct lymph: the size of the subpopulation mediating IgG memory.
The fluorescence activated cell sorter was used to determine the class of immunoglobulin on the thoracic duct lymphocytes (TDL) which carried IgG memory. Although only about 3% of all TDL carried membrane IgG these cells accounted for most, if not all, of the adoptive IgG anti-DNP response. It is concluded that both CR+ and CR- cells mediating IgG memory in rat TDL bear the same class of membrane immunoglobulin as that secreted by their differentiated progeny. The class of membrane immunoglobulin on CR+ and CR- rat TDL was also examined. It was found that IgM+ cells, which made up over 80% of all Ig+ cells, were virtually all CR+. In contrast, the few percent of IgG+ and IgA+ cells present were to be found in both subpopulations. There was no evidence of a large population of B cells bearing exclusively heavy chains other than IgA, IgG, of IgM. The observation that some IgG+ cells as well as IgM+ cells possess a receptor for C3 appears to rule out the hypothesis that this receptor is involved in blocking a switch from IgM to IgG synthesis.
Animals↗
Memory beyond memory in heart beating, a sign of a healthy physiological condition.
We describe two types of memory and illustrate each using artificial and actual heartbeat data sets. The first type of memory, yielding anomalous diffusion, implies the inverse power-law nature of the waiting time distribution and the second the correlation among distinct times, and consequently also the occurrence of many pseudoevents, namely, not genuinely random events. Using the method of diffusion entropy analysis, we establish the scaling that would be determined by the real events alone. We prove that the heart beating of healthy patients reveals the existence of many more pseudoevents than in the patients with congestive heart failure.
Computer Simulation↗
The role of the basolateral amygdala in stimulus-reward memory and extinction memory consolidation and in subsequent conditioned cued reinstatement of cocaine seeking.
The consolidation of cue-cocaine associations and extinction learning (i.e. cue-no cocaine associations) into long-term memory probably regulates the long-lasting control of conditioned stimuli (CS) over cocaine-seeking behaviour, and the basolateral amygdala (BLA) may play a role in this phenomenon. To test this hypothesis, rats previously trained to self-administer cocaine underwent a single classical conditioning (CC) session, during which they received passive pairings of cocaine infusions and a novel light + tone stimulus complex. After additional self-administration sessions in the absence of CS presentation and subsequent extinction training sessions, the ability of the CS to reinstate cocaine-seeking on five test days was assessed. Rats received intra-BLA microinfusions of vehicle or the Na+-channel blocker tetrodotoxin (TTX) immediately after CC (consolidation of CS-cocaine associations) or immediately after reinstatement testing (consolidation of extinction learning). TTX administered immediately after CC attenuated subsequent CS-induced reinstatement. In contrast, TTX administered after the first reinstatement test impaired the extinction of cocaine-seeking behaviour during a second reinstatement test by disrupting extinction memory. Overall, these findings suggest that Na+ channel-mediated mechanisms within the BLA mediate the consolidation of both cocaine-stimulus association and extinction learning, two processes that have opposite effects on subsequent cue-induced cocaine-seeking behaviour.
Amygdala↗
Methylphenidate improves working memory and set-shifting in AD/HD: relationships to baseline memory capacity.
OBJECTIVE: Catecholamine stimulant drugs are highly efficacious treatments for attention deficit/ hyperactivity disorders (AD/HD). Catecholamine modulation in humans influences performance of numerous cognitive tasks, including tests of attention and working memory (WM). Clear delineation of the effects of methylphenidate upon such cognitive functions in AD/HD would enhance understanding of the effects of drug treatment. METHOD: Here we present a double-blind, placebo-controlled study of the cognitive effects of an acute dose of methylphenidate (c. .5 mg/kg) in 14 boys aged 10.86 (+/- 1.19) years meeting criteria for DSM-IV AD/HD. Current behaviour was ascertained using Conners' teacher and parent self-report questionnaires and IQ was tested using sub-tests from WISC-III-UK. Tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB) were selected to assess visuo-spatial recognition memory, spatial WM, planning, visual-search and attentional-set shifting. RESULTS: Methylphenidate improved spatial WM, attentional-set shifting and visual-search task performance. Correlational analyses suggested possible relationships between WM capacity and spatial WM performance improvement. Also, poor performance on the attentional-set shifting task on placebo was associated with increased errors on the spatial WM task on placebo. CONCLUSIONS: Methylphenidate may selectively improve both underlying cognitive difficulties in tasks dependent on intact fronto-striatal structures, and clinical symptoms of AD/HD. Pre-treatment measures may have some predictive value in determining individual differences in drug response.
Adolescent↗