Hemispheric asymmetries in the time course of recognition memory

Hemispheric specialization has been studied extensively within subfields ranging from perception to language comprehension. However, the study of asymmetries for basic memory functions—an area that holds promise for bridging these low- and high-level cognitive domains—has been sporadic at best. We examined each hemisphere’s tendency to retain verbal information over time, using a continuous recognition memory task with lateralized study items and central test probes. We found that the ubiquitous advantage of the left hemisphere for the processing and retention of verbal information is attenuated and perhaps even reversed over long retention intervals. This result is consistent with theories that propose differences in the degree to which the hemispheres maintain veridical versus semantically transformed representations of the input they receive.     

List length and the time course of recognition in immediate memory

The response signal method of Reed (1973) was used to study the time-course of list membership recognition after 2 sec of uncontrolled rehearsal, with lists of one, two, and four consonants. Fourteen specific hypotheses about the time course of this process were derived from various theories (Anderson, 1973; Anderson & Bower, 1973; Baddeley & Ecob, 1973; Corballis, Kirby, & Miller, 1972; Kirsner, 1972; Murdock, 1971; Sternberg, 1966, 1969; Theios, Smith, Haviland, Traupmann, & Moy, 1973; etc.) and additional assumptions about the effect of the response signal. When members of the to-be-learned lists are drawn from a small population of highly confusable items, as in the current experiment, list membership recognition appears to follow the model of Theios et al. (1973). Latency functions of signal lag appear to be particularly useful in differentiating among hypotheses which predict similar speed-accuracy tradeoff functions. The lag by positive-negative interaction for latencies of correct responses is highly significant for lists of one consonant, a result predicted by the hypothesis derived from the model of Theios et al. and incompatible with hypotheses derived from exhaustive search and single-threshold strength models.     

The mirror effect in recognition memory

The mirror effect in recognition memory refers to the fact that, with several different classes of stimuli, performance on new items from each class mirrors (is correlated with) performance on the corresponding classes of old items. Classes of stimuli that are accurately recognized as old when old are also accurately recognized as new when new; those that are poorly recognized as old when old are also poorly recognized as new when new. The statement above is shown not to be a tautology. A survey demonstrates that the effect holds for several types of variables (ways to classify stimuli)—word frequency, concreteness, meaningfulness, and others. The survey includes a total of 80 findings. The theoretical implications of the effect are considered.     

The time course of spatial memory distortions

Four experiments investigated the memory distortions for the location of a dot in relation to two horizontally aligned landmarks. In Experiment 1, participants reproduced from memory a dot location with respect to the two landmarks. Their performance showed a systematic pattern of distortion that was consistent across individual participants. The three subsequent experiments investigated the time course of spatial memory distortions. Using a visual discrimination task, we were able to map the emergence of spatial distortions within the first 800 msec of the retention interval. After retention intervals as brief as 50 msec, a distortion was already present. In all but one experiment, the distortion increased with longer retention intervals. This early onset of spatial memory distortions might reflect the almost immediate decay of detailed spatial information and the early influence of an enduring spatial memory representation, which encodes spatial information in terms of the perceived structure of space.     

The effects of elaboration on recognition memory

Two experiments were conducted to examine the effects of elaboration on recognition memory. Subjects were given either simple or complex sentences to learn and were tested for recognition of either an individual target word or the entire sentence. Complex sentences supported better recognition performance only when the test item allowed the subject to easily redintegrate the initial encoding context, either by re-presenting the encoded sentence as the test item or by constructing sentences such that the component words of the sentence could be easily redintegrated from an individual target item. It was suggested that complex, elaborate encoding established a richer trace, but that this richness can be utilized to enhance recognition only when the test conditions permit a reinstatement of the original encoding context.     

The neural correlates of everyday recognition memory

We used a novel automatic camera, SenseCam, to create a recognition memory test for real-life events. Adapting a 'Remember/Know' paradigm, we asked healthy undergraduates, who wore SenseCam for 2 days, in their everyday environments, to classify images as strongly or weakly remembered, strongly or weakly familiar or novel, while brain activation was recorded with functional MRI. Overlapping, widely distributed sets of brain regions were activated by recollected and familiar stimuli. Within the medial temporal lobes, 'Remember' responses specifically elicited greater activity in the right anterior and posterior parahippocampal gyrus than 'Know' responses. 'New' responses activated anterior parahippocampal regions. A parametric analysis, across correctly recognised items, revealed increasing activation in the right hippocampus and posterior parahippocampal gyrus (pPHG). This may reflect modulation of these regions by the degree of recollection or, alternatively, by increasing memory strength. Strong recollection elicited greater activity in the left posterior hippocampus/pPHG than weak recollection indicating that this region is specifically modulated by the degree of recollection.     

The time course of recognition of novel melodies

Seven experiments explored the time course of recognition of brief novel melodies. In a continuous-running-memory task, subjects recognized melodic transpositions following delays up to 2.0 min. The delays were either empty or filled with other melodies. Test items included exact transpositions (T), same-contour lures (SC) with altered pitch intervals, and different-contour lures (DC). DCs differed from Ts in the pattern of ups and downs of pitch. With this design, we assessed subjects’ discrimination of detailed changes in pitch intervals (T/SC discrimination) as well as their discrimination of contour changes (T/DC). We used both artificial and “real” melodies. Artificial melodies differed in conformity to a musical key, being tonal or atonal. After empty delays, T/DC discrimination was superior to T/SC discrimination. Surprisingly, after filled delays, T/SC discrimination was superior to T/DC. When only filled delays were tested, T/SC discrimination did not decline over the longest delays. T/DC performance declined more than did T/SC performance across both empty and filled delays. Tonality was an important factor only for T/SC discrimination after filled delays. T/DC performance was better with rhythmically intact folk melodies than with artificial isochronous melodies. Although T/SC performance improved over filled delays, it did not overtake T/DC performance. These results suggest that (1) contour and pitch-interval information make different contributions to recognition, with contour dominating performance after brief empty delays and pitch intervals dominating after longer filled delays; (2) a coherent tonality facilitates the encoding of pitch-interval patterns of melodies; and (3) the rich melodic—rhythmic contours of real melodies facilitate T/DC discrimination. These results are discussed in terms of automatic and controlled processing of melodic information.     

The mere exposure effect and recognition memory

This investigation explores the relationship between liking ratings and recognition performance for obscure classical and Russian music melodies. Past studies have explored if awareness of stimulus presentation affects the mere exposure effect (MEE) (Bornstein, 1989; Bornstein & D'Agostino, 1992). We investigate if the type of awareness (i.e., "remembering" an actual occurrence of hearing the melody vs. "knowing" that one is familiar with the melody in a more general, less contextualised sense; Tulving, 1985) affects the MEE. In Experiment 1, we administered the liking test and the recognition test within the same test block and found that liking ratings for "remembered" melodies were on average higher than those for melodies that were merely "known". Although the recognition data replicate the findings of Gardiner, Kaminska, Dixon, and Java (1996) whereby remember and know responses to a given stimulus react differently to repetition from one to three trials, liking data did not vary with the degree of exposure. In addition, our adoption of the recognition category "guess" resulted in a pattern of results that is not only different from previous studies but illustrates the importance of judged, instead of true, old/new status in determining liking. The basic findings of Experiment 1 were replicated in Experiment 2 in which the liking test was conducted prior to the recognition test. Implications of these findings for theories of MEE are discussed.     

The long-term recency effect in recognition memory

Three classes of theories explain the recency effect: the modal model, single-store models, and the composite view, which integrates the two positions. None could explain the absence of a long-term recency effect in recognition memory in previous studies. We suggest that prior work did not obtain a recency effect because testing used a multiple-probe rather than a single-probe recognition procedure. Here we tested memory using a single-probe recognition procedure. Experimental conditions included an immediate test, a delayed test after a filled interval, and a continuous-distractor paradigm in which the same filled delay preceded the first word and followed every study word. The long-term recency effect in continuous-distractor recognition was equivalent to the recency effect in immediate recognition. Its absence in the delayed recognition condition demonstrated that it was not attributed to the use of a putative short-term memory store. Single-store models and the composite view can account for this novel finding.     

The time course of object-feature retrieval in recognition

The time course of perception and retrieval of object features was investigated. Participants completed a perceptual matching task and 2 recognition tasks under time pressure. The recognition tasks imposed different retention loads. A stochastic model of feature sampling with a Bayesian decision component was used to estimate the rate of feature perception and the rate of retrieval of feature information. The results demonstrated that retrieval rates did not differ among object features if only a single object was held in memory. If 2 objects were retained in memory, differences among retrieval rates of features emerged, indicating that features that were quickly perceived were also quickly retrieved. The results from the 2-object retention condition are compatible with process reinstatement models of retrieval.     

The time course of Braille word recognition.

Skilled blind readers read French nouns with the uniqueness point in different locations, presented in unabbreviated braille, and either pronounced each item (Experiment 1) or classified it as to gender (Experiments 1-3). As in previous studies with spoken words, effects of uniqueness point location on recognition reaction time were taken as demonstrating on-line lexical access. For braille words, significant effects were obtained in Experiment 1 in the two tasks. In Experiment 2, blind Ss demonstrated comparable relative uniqueness point effects for gender classification of braille and of spoken words, showing that on-line lexical access is not specific to speech. Experiment 3 showed that the effect of uniqueness point location is limited to the higher frequency words. Finally, mean finger scanning speed did not differ between the pre- and post-uniqueness point regions of the words.     

The effect of orienting tasks on recognition memory

The effect of orienting tasks on recognition memory for words and faces was investigated. It was found that relevant orienting tasks improved recognition memory for both classes of stimuli compared with a nonrelevant orienting task and the control condition of testing recognition memory without an orienting task. Attention is drawn to the possibility of qualitative differences between recall and recognition for the effect of orienting tasks. The findings are related to recognition theories. It is suggested that the findings lend support to those theories which hold that retrieval processes play a major role in recognition memory.     

Measuring recognition memory.

Recent years have seen an expanded interest in recognition memory tasks. This resurgence of interest has also renewed concerns with measurement problems. Comparing 4 models of recognition memory, Snodgrass and Corwin (1988) found that measures of bias from the distribution-free (nonparametric) model were inadequate. However, their analysis was based on bias measures that can be shown a priori to be nonindependent of discrimination. This article traces the history of the nonparametric model and develops a better measure of bias. The consequence of developing this better measure is that the nonparametric model deserves serious consideration.     

Stimulus-form effectsin recognition memory

In two experiments, recognition memory was tested using memorized lists of items containing from 2 to 32 nominal concepts. Stimulus form was manipulated by using the names of the items on word trials and outline drawings of the items on picture trials. In terms of an information processing stage model of recognition memory, stimulus form affected only an identification or encoding stage of processing. Subsequent memory-search, decision, and response processes were largely the same for all stimuli once the words or pictures were encoded. The results are consistent with the hypothesized role of stimulus form in processes underlying long-term recognition. However, our results are inconsistent with those of a number of studies involving stimulus-form effects in short-term recognition memory.     

The relation between recognition memory and classification learning

Two experiments investigated the relation between recognition memory and classification learning. The subjects were instructed that they would see a series of random-dot patterns and later would be asked to classify or to recognize the patterns. Following study, the subjects performed a classification task, a recognition-memory task, or both. It was found that classification-learning instructions were superior to recognition-memory instructions for the classification task, but that there was little or no effect of instructions on the recognition task. When subjects performed both recognition and classification tasks, there was no relation between saying “old” to a probe and correctly classifying it, except with old exemplars, and then only when the initial instructions had been to expect a recognition-memory test. Overall, the data show that classification and recognition can be experimentally separated. In addition, classification is often statistically independent of recognizing that items are old. These observed relations provide some constraints for the further development of models of classification learning and recognition memory.     

The bilingual L2 advantage in recognition memory

To better understand the mechanisms by which bilingual proficiency impacts memory processes, two recognition memory experiments were conducted with matched monolingual and bilingual samples. In Experiment 1, monolingual speakers of English and Spanish studied high- and low-frequency words under full attention or cognitive load conditions. In Experiment 2, Spanish–English bilingual participants studied high- and low-frequency words under full-attention conditions in each language. For both monolinguals and bilinguals, low-frequency words were better recognized than high-frequency words. The central new findings were that bilingual recognition was more accurate in the less fluent language (L2) than in the more fluent language (L1) and that bilingual L2 recognition was more accurate than monolingual recognition. The bilingual L2 advantage parallels word frequency effects in recognition and is attributed to the greater episodic distinctiveness of L2 words, relative to L1 words.     

The ambiguity of recognition memory tests of schema theories

The majority of theories about the effects of schemata (or generic knowledge structures) on information processing share two fundamental assumptions. It is assumed, first, that schema-based inferences about unobserved features of an event are generated, and, second, that such inferences are stored in long-term memory and thereby confused with traces of observed features of that event. To test these assumptions, researchers rely heavily on recognition memory measures of hit and false alarm rates. In the present paper, it is observed that schema theoretic interpretations of recognition memory measures are inconsistent with an interpretation jointly derived from the theory of signal detection and Mandler's (1980, Psychological Review, 87, 252–271) subjective familiarity theory of recognition memory; from the latter's perspective, recognition memory measures are considerably more ambiguous than schema researchers realize and do not necessarily support the typical schema theoretic interpretations. Data from four experiments are analyzed from the perspective of the theory of signal detection/ subjective familiarity model and demonstrate the ambiguity of recognition memory measures for testing hypotheses about the function and consequences of schemata for information processing.     

Short-term recognition memory of tones

Four Os participated in a recognition memory experiment for a period of 5 weeks. The task required O to judge whether two temporally sequenced tones (ISI = 0.5, 2.0, or 8.0 sec) were the “same” or “different ” Latencies and confidence ratings were obtained for each judgment. TSD analyses applied to individual O’s data indicated consistent and rapidly decreasing d’s as a function of ISI. ROC functions generated from the latencies and ratings produced comparable results, indicating the feasibility of using latency measures along with the type of judgments made to obtain sensitivity measures. Response bias, as indicated by the differences in the latencies between “same” and “different” judgments, did not produce consistent trends.