Long-term proactive interference and novelty enhancement effects in monkey list memory.

Serial-probe-recognition (SPR) performance by 2 monkeys deteriorated over several months of training. Three hundred and twenty different items were presented without repetition within a session (trial unique) but were repeated between sessions. The cause of the deterioration was identified as proactive interference (PI) due to repetitive use of items from day to day. Introduction of novel stimuli across days improved performance from 63% to 82% correct (Experiment 1). Tests with only probe items and no list items (Experiment 2) revealed that the monkeys were using a familiar/novel response strategy in combination with a relational strategy (relating the probe item to the list items) to further improve their SPR performance. Intermixing familiar baseline trials and novel transfer trials within a session (Experiment 3) encouraged the subjects to use a relational strategy, and it improved performance on baseline trials as well as on transfer trials. Possible qualitative similarity between the relational strategy and the familiar/novel response strategy is discussed along with theoretical implications of these findings for experiments which have used small number of repeating stimuli within a session. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual list memory in capuchin monkeys (Cebus apella).

Memory of 3 capuchin monkeys, Cebus apella, was tested with lists of 4 travel-slide pictures and different retention intervals. They touched different areas of a video monitor to indicate whether a test picture was in a list. At short retention intervals (0 s, 1 s, 2 s), memory was good for the last list items (recency effect). At a 10-s retention interval, memory improved for 1st list items (primacy effect). At long retention intervals (20 s and 30 s), primacy effects were strong and recency effects had dissipated. The pattern of retention-interval changes was similar to rhesus monkeys, humans, and pigeons. The time course of recency dissipation was similar to rhesus monkeys. The capuchin's superior tool-use ability was discussed in relation to whether it reflects a superior general cognitive ability, such as memory. In terms of visual memory, capuchin monkeys were not shown to be superior to rhesus monkeys. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Picture memory in monkeys.

Three squirrel monkeys were shown lists of 3 items drawn from a pool of 150 slides containing colored pictures of natural objects and scenes. A delayed matching technique was used to probe recognition memory for each serial position on different trials. Four experiments on the effects of picture-exposure time and off time were conducted. In agreement with human picture memory experiments, accuracy improved as exposure duration increased from 0.3 to 6 sec. In contrast to research on humans, off time after picture exposure did not improve accuracy relative to a condition with no off time. Further, a comparison of different off-time conditions showed no difference between off times spent in darkness and off times filled either with filler pictures or white light. This finding differs from the well-known observation that illumination interpolated between sample and comparison stimuli interferes with delayed matching. ( French abstract) (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Auditory memory for timbre.

Psychophysical studies are reported examining how the context of recent auditory stimulation may modulate the processing of new sounds. The question posed is how recent tone stimulation may affect ongoing performance in a discrimination task. In the task, two complex sounds occurred in successive intervals. A single target component of one complex was decreased (Experiments 1 and 2) or increased (Experiments 3, 4, and 5) in intensity on half of trials: The task was simply to identify those trials. Prior to each trial, a pure tone inducer was introduced either at the same frequency as the target component or at the frequency of a different component of the complex. Consistent with a frequency-specific form of disruption, discrimination performance was impaired when the inducing tone matched the frequency of the following decrement or increment. A timbre memory model (TMM) is proposed incorporating channel-specific interference allied to inhibition of attending in the coding of sounds in the context of memory traces of recent sounds. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dissociations of processes in recognition memory: Effects of interference and of response speed.

Examined effects on 2 bases for recognition-memory judgments using a process dissociation procedure and variation in the length of study lists in 3 experiments with 62 undergraduates. Exp 1 defined recollection (RCL) and examined the influence of list length on RCL and familiarity. Exp 2 redefined RCL, and Exp 3 examined differences in the speed of the 2 bases for recognition using a response-signal procedure. It was found that increasing the length of a study list interfered with conscious RCL, but left familiarity in place. An examination of reaction time (RT) distributions, as well as results from a response-signal procedure, showed that familiarity was faster as a basis for recognition judgments than was conscious RCL. Findings indicate that both bases contributed to performance on the fastest as well as the slowest responses, suggesting that the 2 processes were acting in parallel. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Output interference in long-term memory.

Reports 2 experiments, with 70 and 140 undergraduates, concerning the role of output interference on the recall of organized material. Groups of Ss received blocked presentation of a 49-item list consisting of 7 items in each of 7 categories. At recall, the category name served as the retrieval cue. In Exp. I, a 20-sec recall interval was allowed for each category and 10 Ss were assigned to each group. In Exp. II, this interval was increased to 90 sec. and 20 Ss were assigned to each group. Results of both studies indicate that the number of words recalled from a category is dependent on the position of the category in the output sequence. In general, the earlier a category appears in the output sequence, the greater the number of words recalled from that category. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Memory integration and memory interference.

S. D. Moesser (see PA, Vol 56:3437; 1977) found that Ss presented with a nonsequential order of interrelating sentences did not show any evidence of having integrated these sentences into composite units. This type of presentation procedure also produces an interference effect that lessens the probability of retrieving information from the presented sentences. However, J. Bransford and J. Franks (see record 1972-24191-001) reported that Ss presented with a nonsequential order of interrelating sentences automatically integrate the partial ideas into holistic units. Bransford and Franks based their conclusions on the facts that (1) Ss were unable to identify the exact exemplars that were presented, and (2) Ss showed a bias in choosing more complex sentences as having been part of the acquisition corpus. Two experiments are reported here, which were conducted with 124 Newfoundland college students who participated in 1 of 2 encoding conditions while performing forced-choice or confidence recognition tasks. Results show that both the failure to identify presented exemplars and the tendency to choose more complex sentences in the test corpus were products of the retrieval interference effect. Findings fail to support the proposal that Ss will automatically integrate related ideas into composite units. (French abstract) (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Imagery and interference in sequential short-term memory.

Conducted an experiment with 132 college students to compare the disruptive effects of irrelevant information (names of colors) superimposed on relevant information (bands of colors) with the effects of irrelevant information occupying the interval between stimuli. Irrelevant information disrupted performance only when it occupied the interval between stimuli, suggesting that interference was primarily with the rehearsal process and not with the perceptual process. It made no difference whether the names of colors were the same as or different from the bands of colors. Analysis of control conditions suggests that Ss can better "keep track" of colors than color names. Results are discussed in terms of visual imagery and the spatial window model of "keeping-track" performance. (French summary) (16 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging and interference in verbal working memory.

According to inhibitory views of working memory, old adults should have particular problems deleting irrelevant information from working memory, leading to greater interference effects compared with young adults. The authors investigated this hypothesis by using variations of an A-B, C-D retroactive interference paradigm in working memory with young and old adults. They used a recognition measure of memory, assessing both accuracy and reaction time. The primary finding was that senior adults consistently exhibited proportionally greater retroactive interference effects compared with young adults when interfering word pairs that had been read aloud had to be rejected. Patterns of recognition and reaction time data suggested that old adults' activation of target material is similar to young adults, but they experience sustained activation of irrelevation material that has entered working memory. Theoretical implications of these findings for inhibitory deficit (R.T. Zacks & L. Hasher, 1998) and source memory deficit accounts of cognitive aging are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Retrieval cues and short-term memory in capuchin monkeys.

Conducted 2 experiments, each with 3 adult female monkeys, dealing with the relationship between retrieval cues and delayed matching to sample (DMTS) performance. Exp I compared 2-choice and Yes-No DMTS to determine whether delayed matching performance was impeded by reducing the number of differential retrieval cues from 2 to 1. In Exp II, with 3 other Ss, all differential retrieval cues were eliminated by employing a delayed conditional matching task (DCM), which was compared to a corresponding 2-choice DMTS task. Exp I produced only a small, unreliable difference in favor of 2-choice DMTS, while in Exp II delayed matching behavior was equally effective with DCM and DMTS, provided that the conditional discriminations were well learned. Rather than attributing the retention evidenced in delayed matching tasks to underlying storage processes, it is suggested that the results may be an extension of discrimination behavior in which the major discriminative dimensions were temporal in nature. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Auditory–verbal short-term memory effects of retention interval on proactive inhibition when interpolated interference is eliminated.

Three experiments examined auditory-verbal short-term memory using a visual nonverbal, high demand interpolated task, which successfully isolated modalities so as not to interfere with processing of the auditory-verbal items. Rehearsal was minimized, and errors were analyzed for evidence of proactive intrusions and intraunit interference. For 3-digit memory items, recall was excellent even after 60 sec (82%), and only 3% of all 3-digit items were forgotten for reasons other than measured interference. For 5-digit items, recall declined from 76% at 5 sec to approximately 65% at 9 sec. The only significant drop in recall after 9 sec was between 21 and 30 sec and was directly attributable to corresponding increases in proactive interference. Of all 5-digit items, only 5% were forgotten that were not accounted for by proactive intrusion or intraunit interference. The increase in proactive inhibition effects with increased retention interval is best fit by a model of short-term forgetting based on discriminability of temporal cues. (French summary) (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recognition processes in episodic memory.

In 5 series of experiments with 5th, 6th, and 10th graders and undergraduate and university students, Ss encouraged to process related sentences at the same time (integrated storage) were compared with those encouraged to process the related sentences independently of each other (independent storage). Overall results show that Ss in the integrated storage condition were better at deriving inferences based on interconnections among the related items, at identifying the sentences that had been presented, and at recalling the sentences to a word cue. There was no difference between conditions on word recognition tests. Thus, Ss in the independent condition had a more difficult time retrieving the sentences that had been presented, but not in identifying the words contained in these sentences. This finding is explained by postulating a 2-stage recognition process. It was also found that Ss were able to combine 2 related sentences presented independently of each other, if the intervening sentences did not contain concepts in common with these sentences. However, when there were several sentences containing overlapping information, each presented independently of the others, Ss were unable to combine them into a single idea. This result indicates that the presence of several episodic traces containing common concepts interferes with the retrieval of information from these traces. (French summary) (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Proactive interference and item similarity in working memory.

Proactive interference (PI) may influence the predictive utility of working memory span tasks. Participants in one experiment (N=70) completed Ravens Advanced Progressive Matrices (RAPM) and multiple versions of operation span and probed recall, modified for the type of memoranda (digits or words). Changing memoranda within- or across-trials released PI, but not doing so permitted PI buildup. Scores from PI-build trials, but not PI-release trials, correlated with RAPM and accounted for as much variance in RAPM as unmodified tasks. These results are consistent with controlled attention and inhibition accounts of working memory, and they elucidate a fundamental component of working memory span tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Memory independence and memory interference in cognitive development.

Recent experiments have established the surprising fact that age improvements in reasoning are often dissociated from improvements in memory for determinative informational inputs. Fuzzy-trace theory explains this memory-independence effect on the grounds that reasoning operations do not directly access verbatim traces of critical background information but, rather, process gist that was retrieved and edited in parallel with the encoding of such information. This explanation also envisions 2 ways in which children's memory and reasoning might be mutually interfering: (1) memory-to-reasoning interference, a tendency to process verbatim traces of background inputs on both memory probes and reasoning problems that simultaneously improves memory performance and impairs reasoning, and (2) reasoning-to-memory interference, a tendency for reasoning activities that produce problem solutions to erase or reduce the distinctiveness of verbatim traces of background inputs. Both forms of interference were detected in studies of children's story inferences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of divided attention on encoding processes in memory: Mapping the locus of interference.

Despite the detrimental effects of divided attention at encoding on later memory performance, results described in the literature do not unequivocally specify which processes are interrupted during encoding by participants' occupation with a concurrent task. Using a processing analysis framework where the encoding process is viewed as a multiphase mental activity, the current research investigated this issue using a new differential temporal interference paradigm where the study phase of single words was interrupted at different temporal segments. In two experiments, we used performance on both memory and online choice reaction time tasks to assess whether such differential interference would produce different degrees of reduction in participants' later memory performance, as well as changes in the attentional resources required to execute each of the encoding phases. Measures of memory and concurrent task performance in the two experiments converged on similar patterns, showing that all phases of encoding are affected by the concurrent task. However, the initial encoding phase, which is tentatively associated with the initial registration of information, seems especially vulnerable to interference. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Auditory signal detection and decision processes in the nervous system.

Neuronal unit activity was recorded from auditory nuclei, the dorsal hippocampus, and the cerebellum in New Zealand White rabbits behaviorally detecting a threshold-level, constant intensity white noise stimulus. Results show that stimulus-evoked neuronal unit activity was present and identical on both detection and nondetection trials in auditory nuclei but was dichotomous in the hippocampus and in the cerebellum, the latter 2 systems predicting the occurrence of behavioral detection. It is concluded that the behavioral absolute threshold is not determined by differential activation of neurons in the primary auditory relay nuclei. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Explaining category interference effects in associative memory.

Two studies with 220 undergraduates investigated the effects of categorization on the acquisition and long-term retention of AB word pairs using modeling techniques that factor the contributions of various storage and retrieval factors. In Exp I, each S memorized 1 of the 4 basic types of lists: unrelated cues/unrelated targets, categorized cues/unrelated cues, unrelated cues/categorized targets, and categorized cues/categorized targets. Ss in Exp II memorized 24-item AB lists to criterion. Acquisition data showed that there was a crossover interaction such that the effects of increasing the degree of cue or target relatedness depended on the nature of the comparison items. In contrast with the results of previous studies, the effects were larger when categorization was manipulated on the target side of AB pairs than when it was manipulated on the cue side. The degree of categorization affected retrieval difficulty but not storage difficulty. Long-term retention data indicated that, contrary to the acquisition data, the effects of categorization on retention were uniformly positive. Categorization decreased the amount of forgetting primarily by reducing the rate at which traces were lost from memory (storage failure) during the retention interval. Results are discussed in terms of modern unitary-trace theories of associative memory. (French abstract) (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sources of proactive interference in animal memory.

Events occurring before each trial in delayed matching-to-sample tasks can proactively interfere with accurate matching on the trial. Matching performance by pigeons was examined in a two-alternative delayed matching-to-sample procedure that permitted analysis of performance on two-trial sequences where the relation between the Trial N and Trial N?–?1 stimuli was manipulated. In Experiment 1, temporal variables of intertrial interval, delay interval on Trial N, and delay interval on Trial N?–?1 were varied. In Experiment 2, the effects of illuminating the intertrial interval were examined. The results suggested that there are two independent sources of proactive interference in delayed matching-to-sample performance: a general effect of intertrial-interval duration and a specific intertrial-agreement effect. The intertrial-agreement effect was influenced by both the choice stimulus on Trial N?–?1, and by the sample stimulus on Trial N?–?1. We suggested that one-process theories of proactive interference in delayed matching-to-sample performance could not account for these data and that a two-process theory of memory is required. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Orienting attention in visual working memory reduces interference from memory probes.

Given a changing visual environment, and the limited capacity of visual working memory (VWM), the contents of VWM must be in constant flux. Using a change detection task, the authors show that VWM is subject to obligatory updating in the face of new information. Change detection performance is enhanced when the item that may change is retrospectively cued 1 s after memory encoding and 0.5 s before testing. The retro-cue benefit cannot be explained by memory decay or by a reduction in interference from other items held in VWM. Rather, orienting attention to a single memory item makes VWM more resistant to interference from the test probe. The authors conclude that the content of VWM is volatile unless it receives focused attention, and that the standard change detection task underestimates VWM capacity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Retrieval processes in transactive memory systems.

Two experiments examined retrieval processes in transactive memory systems (D. M. Wegner, 1987). In Experiment 1, intimate couples who worked face to face performed better on a knowledge-pooling task than strangers who worked face to face and better than intimate couples who worked via a computer conferencing system. Additional analyses indicated that intimate couples when interacting face to face were better able to determine which partner was correct on questions that only 1 member knew the answer to prior to discussion. In Experiment 2, intimate couples scored significantly better on the knowledge task when they had access to either nonverbal or paralinguistic communication cues than when they had access to neither. Taken together, the results indicate that both nonverbal and paralinguistic communication play an important role in the retrieval of knowledge in transactive memory systems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)