Buildup and release from proactive interference in a rhesus monkey

The potential of the buildup and release from proactive interference (PI) technique in the study of animal categorization was demonstrated with a rhesus monkey. A serial probe recognition task was used with a list of 4 consecutive slide pictures (upper screen) followed by a single probe picture (lower screen). The monkey moved a lever to indicate whether or not the probe was contained in the list. PI built over 40 consecutive trials tested with either flowers or primate faces. PI was released on category change and then built during 40 trials with the second category. The first 2 serial positions showed somewhat greater PI buildup and release, supporting conclusions from human studies that the effects occur primarily in secondary memory. A second experiment provided 2 replications of the main effect and showed through color border changes and elimination of color differences that color was not a critical feature.     

High and low gender schematic children's release from proactive interference

Thirty-seven 4–5 year-old predominantly white children from moderate SES households, identified as high and low gender schematic, completed a Release from Proactive Interference task (RPI) comprised of drawings of same-sex gender-typed toys and animals. The RPI task assesses spontaneous comprehension, encoding, and short-term recall of items from two categories of information. As predicted, high gender schematic children demonstrated significantly greater patterns of release from proactive interference than low schematic children. Specifically, high and low schematic children's patterns of recall following a shift from same-sex gender-typed toys to animals differed significantly, suggesting that gender roles are a more salient and influential information processing dimension to high than low gender schematic children. Results add to data validating the present measure of gender schematicity and its ability to differentiate individual differences in the salience of gender roles to young children. Results also corroborate and expand on theory and research describing the impact and consequences of individual differences in the salience of the gender role dimension on the information processing of high and low gender schematic children.Completion of this project was facilitated, in part, by an Academic Challenge Award from the University of Toledo. This support is gratefully acknowledged. Special thanks to Narina Nightingale for her comments and suggestions on earlier drafts of this article, and to Stephanie Sellers at the University of Toledo, and to Ashley Lyster at the University of Wyoming for their data collection efforts and to the faculty, children, and parents of the Loving Tree Preschool and the Gateway School, both of Toledo, Ohio, and the University of Wyoming Child Care Center, and especially to Director Mark Bittner for his assistance with this research. A shorter version of this article was presented at the annual meetings of the Western Psychological Association, Phoenix, Arizona, April 1993.To whom reprint requests should be addressed at Department of Psychology, University of Wyoming, P. O. Box 3415, Room 135 Biological Sciences Bldg, Laramie, WY 82071-3415.     

Testing during study insulates against the buildup of proactive interference

Recent interest in the benefits of retrieval practice on long-term retention--the testing effect--has spawned a considerable amount of research toward understanding the underlying nature of this ubiquitous memory phenomenon. Taking a test may benefit retention through both direct means (engaging appropriate retrieval processes) and indirect means (fostering directed study). Here the authors report 4 experiments demonstrating a novel benefit of testing. Extended study sessions cause a buildup of proactive interference, but interpolating tests during the study sequence insulates against this negative influence. These findings highlight a unique benefit of testing and have important implications for study strategies.     

The effects of proactive interference (PI) and release from PI on judgments of learning

In three experiments, we investigated metacognitive monitoring in a variant of an A–B A–C learning paradigm in which the repetition of cues, but not targets, led to increasing proactive interference (PI) across trials. Judgments of learning (JOLs) correctly predicted decreases across trials in this paradigm but incorrectly continued to predict decreases on a final release trial in which new cues were introduced and performance consequently increased. Experience with the paradigm did not ameliorate this metacognitive failure (Experiment 3). In addition, JOLs decreased equally for pairs with repeated and with novel cue terms, even though recall of the latter group of items did not decrease across trials (Experiment 2). These results suggest that metacognizers’ naïve theories of remembering and forgetting include a role for global, but not cue-specific, interference.     

Pupillary measurement and release from proactive inhibition.

One of the explanations of release from proactive inhibition in short-term memory is that the subjects re-attend to the items on the release trial because the items are different from the previous ones. It is further assumed that this increase in attention causes the relase items to be learned better than the preceding items. This experiment measured the pupils of the subjects' eyes while they were participating in a proactive-inhibition release-type task. The results showed no increase in attention, as indexed by pupil size, on the release trial. This did not support the attentional explanation of the proactive-inhibition release phenomenon.     

Testing improves true recall and protects against the build-up of proactive interference without increasing false recall

Retrieval practice has been shown to protect against the negative effects of previously learned information on the learning of subsequent information, while increasing retention of new information. We report three experiments investigating the impact of retrieval practice on false recall in a multiple list paradigm. In three different experimental designs participants studied blocks of interrelated words that converged on non-presented associates. Participants were tested either after every study block or only after the fifth study block, and both groups received a cumulative test on all five study blocks. Overall the results from all three different experimental designs point to a benefit of testing in increasing long-term veridical recall on the cumulative test. More importantly, this improvement in veridical recall did not come at a cost: False recall on the cumulative test did not increase from retrieval practice.     

Testing improves true recall and protects against the build-up of proactive interference without increasing false recall

Retrieval practice has been shown to protect against the negative effects of previously learned information on the learning of subsequent information, while increasing retention of new information. We report three experiments investigating the impact of retrieval practice on false recall in a multiple list paradigm. In three different experimental designs participants studied blocks of interrelated words that converged on non-presented associates. Participants were tested either after every study block or only after the fifth study block, and both groups received a cumulative test on all five study blocks. Overall the results from all three different experimental designs point to a benefit of testing in increasing long-term veridical recall on the cumulative test. More importantly, this improvement in veridical recall did not come at a cost: False recall on the cumulative test did not increase from retrieval practice.     

Testing complex animal cognition: Concept learning,proactive interference,and list memory

This article describes an approach for assessing and comparing complex cognition in rhesus monkeys and pigeons by training them in a sequence of synergistic tasks, each yielding a whole function for enhanced comparisons. These species were trained in similar same/different tasks with expanding training sets (8, 16, 32, 64, 128 … 1024 pictures) followed by novel‐stimulus transfer eventually resulting in full abstract‐concept learning. Concept‐learning functions revealed better rhesus transfer throughout and full concept learning at the 128 set, versus pigeons at the 256 set. They were then tested in delayed same/different tasks for proactive interference by inserting occasional tests within trial‐unique sessions where the test stimulus matched a previous sample stimulus (1, 2, 4, 8, 16 trials prior). Proactive‐interference functions revealed time‐based interference for pigeons (1, 10 s delays), but event‐based interference for rhesus (no effect of 1, 10, 20 s delays). They were then tested in list‐memory tasks by expanding the sample to four samples in trial‐unique sessions (minimizing proactive interference). The four‐item, list‐memory functions revealed strong recency memory at short delays, gradually changing to strong primacy memory at long delays over 30 s for rhesus, and 10 s for pigeons. Other species comparisons and future directions are discussed.     

The categorical structure of semantic memory for famous people: a new approach using release from proactive interference

Memory for familiar people is essential to understand their identity and guide social interaction. Nevertheless, we know surprisingly little about the structure of such memory. Previous research has assumed that semantic memory for people has a categorical structure, but recently it was proposed that memory for people consists only of associations and lacks any categorical structure. Four experiments are reported that use a novel approach by adapting the 'release from proactive interference' (RPI) methodology for use with lists of famous names. Proactive interference occurs when items presented on successive trials are drawn from the same category. Recall can improve following a change to a different category. Sets of names were selected relating to aspects previously demonstrated, on the basis of reaction time data, to form a category (occupation) and a property (nationality) of celebrities (Johnston & Bruce, 1990). RPI was observed for a change at both levels of representation but was only present without explicitly cueing the change of set when the stimuli differed at the category level. At the property level, RPI was only evident when change of set was explicitly cued. RPI was absent at the set change in a novel, ad hoc distinction suggesting that the effect reflected the underlying memory structure.     

Tests of the generality of the principle of encoding specificity

Two empirical tests of the principle of encoding specificity are reported. In Experiment I, the normative strength of the cues presented on the input and on the recall trial was varied factorially. To lessen the emphasis on strictly associative learning, only half the items were cued in each phase of the study-recall cycle. Recall was higher when the cues remained the same than when they changed. However, regardless of the condition of input cuing, strong output cues were substantially more effective than weak ones. In Experiment II, the to-be-remembered words were shown in the presence of weak cues on the input trial. Recognition in the context of strong extralist cues was compared with recall to the original input cues. On the test of cued recognition, the target words were either generated by the subjects as free associates or presented to them as items on a test constructed by the experimenter. Contrary to previous findings, recall was not found to be superior to recognition. The phenomena of cue-dependent forgetting that have been interpreted as evidence for the principle of encoding specificity appear to have limited generality.     

Perceptual distinctiveness and proactive interference in the primacy effect

When subjects monitor a list of verbal items for one item which is to be selected and remembered, they are more likely to recall the critical item if it is the first member of the list than if it is presented towards the centre of the list. The present experiment examined the possibility that this primacy results from an accumulation of proactive interference from incidentally processed early members of the list which would cause a decrement in the recall of later members. By changing the semantic category of the list members before presentation of the critical item any accumulated interference would have been released, but this procedure produced no weakening of the primacy effect and so the interference theory of primacy was not supported. An alternative explanation of the effect was discussed in which it is assumed that the first member of a series is perceptually distinct from central members.     

On the generality of logical recoding in spatial interference tasks

‘Simon’ and ‘recoding’ affects refer to interference by irrelevant spatial stimulus positions on the efficiency of responding to a stimulus. According to the Simon effect faster response times occur if the irrelevant stimulus position is compatible with the response position. Slower response times occur if stimulus and response positions are incompatible. The recoding effect is a reversed Simon effect, which occurs if the response assignment of the relevant stimuli is reversed, e.g., a red response button to a green stimulus and a green response button to a red stimulus. For this reversed response assignment response times are faster if stimulus and response positions are incompatible, and slower if stimulus and response positions are compatible. In this study the generality of the recoding effect in spatial interference tasks is investigated by using, first, spatial stimuli with directional attributes, second, verbal stimuli with a directional meaning, and, third, geometric figures without directional information. In all cases Simon effects as well as recoding effects were obtained. According to these results recoding does not presuppose a directional symbolic or verbal stimulus code, and the relation between the stimulus and the spatial response may be either direct, symbolic or arbitrary. Whether recoding or a Simon effect will occur depends on a late response decision stage in which the response code derived from the stimulus is either inverted (recoding effect) or not (Simon effect).     

Working memory span and the role of proactive interference.

The authors investigated the possibility that working memory span tasks are influenced by interference and that interference contributes to the correlation between span and other measures. Younger and older adults received the span task either in the standard format or one designed to reduce the impact of interference with no impact on capacity demands. Participants then read and recalled a short prose passage. Reducing the amount of interference in the span task raised span scores, replicating previous results (C. P. May, L. Hasher, & M. J. Kane, 1999). The same interference-reducing manipulations that raised span substantially altered the relation between span and prose recall. These results suggest that span is influenced by interference, that age differences in span may be due to differences in the ability to overcome interference rather than to differences in capacity, and that interference plays an important role in the relation between span and other tasks.     

Type-specific proactive interference in patients with semantic and phonological STM deficits

Prior neuropsychological evidence suggests that semantic and phonological components of short-term memory (STM) are functionally and neurologically distinct. The current paper examines proactive interference (PI) from semantic and phonological information in two STM-impaired patients, DS (semantic STM deficit) and AK (phonological STM deficit). In Experiment 1 probe recognition tasks with open and closed sets of stimuli were used. Phonological PI was assessed using nonword items, and semantic and phonological PI was assessed using words. In Experiment 2 phonological and semantic PI was elicited by an item recognition probe test with stimuli that bore phonological and semantic relations to the probes. The data suggested heightened phonological PI for the semantic STM patient, and exaggerated effects of semantic PI in the phonological STM case. The findings are consistent with an account of extremely rapid decay of activated type-specific representations in cases of severely impaired phonological and semantic STM.     

Transient phonemic codes and immunity to proactive interference

Empirical data indicate that when memory for subspan lists of taxonomically related material is tested immediately after study, prior experience with lists involving the same material has no effect upon recall or recognition. In six experiments, we explored the possibility that immunity to proactive interference (PI) is related to discriminative information that is provided by transient phonemic codes. In these experiments, we manipulated the strength of phonemic codes as well as their presence or absence. Immunity to PI was found only when it was presumed that a phonemic representation of the target items existed and that information provided discriminative information. In all other cases, PI was observed. The finding that PI effects correspond with the manipulation of phonemic information in a principled fashion provides strong evidence for the role of phonemic codes in producing short-term PI effects.     

Capacity limits in list item recognition: evidence from proactive interference

Capacity limits in short-term recall were investigated using proactive interference (PI) from previous lists in a speeded-recognition task. PI was taken to indicate that the target list length surpassed working memory capacity. Unlike previous studies, words were presented either concurrently or sequentially and a new method was introduced to increase the amount of PI. On average, participants retrieved about four items without PI. We suggest an activation-based account of capacity limits.     

How to be proactive about interference: lessons from animal memory

Processes of proactive interference were explored using the pigeon as a model system of memory. This study shows that proactive interference extends back in time at least 16 trials (and as many minutes), revealing a continuum of interference and providing a framework for studying memory. Pigeons were tested in a delayed same/different task containing trial-unique pictures. On interference trials, sample pictures from previous trials reappeared as test pictures on different trials. Proactive-interference functions showed greatest interference from the most recent trial and with the longer of two delays (10 s vs. 1 s). These interference functions are accounted for by a time-estimation model based on signal detection theory. The model predicts that accuracy at test is determined solely by the ratio of the elapsed time since the offset of the current-trial sample to the elapsed time since the offset of the interfering sample. Implications for comparing memory of different species and different types of memory (e.g., familiarity vs. recollection) are discussed.     

Capacity limits in list item recognition: Evidence from proactive interference

Capacity limits in short‐term recall were investigated using proactive interference (PI) from previous lists in a speeded‐recognition task. PI was taken to indicate that the target list length surpassed working memory capacity. Unlike previous studies, words were presented either concurrently or sequentially and a new method was introduced to increase the amount of PI. On average, participants retrieved about four items without PI. We suggest an activation‐based account of capacity limits.     

Short term forgetting in the absence of proactive interference

It has been claimed that the short-term forgetting shown by the Peterson technique is entirely due to proactive interference from prior experimental items. Two experiments investigated this by studying forgetting when prior items were avoided by testing subjects only once. Both experiments showed significant forgetting, although the degree of forgetting was less than with a multitrial procedure. On the basis of this and other results it is suggested that the Peterson technique comprises two components, a primary memory component which decays within 6 sec, and a more stable secondary memory component. Forgetting with the multitrial procedure is attributed principally to the need to use temporal retrieval cues to avoid confusion between successive items; longer retention intervals are associated with reduced temporal discriminability and hence poorer recall.