Position and order information in recognition memory.

In three experiments we examined short-term recognition memory for order information. In each, a target string of letters was followed by a test string to which the subject responded "same" or "different." The test string either was identical to the target, or it included a transposition of a single pair of letters. Results were consistent in showing that the closer two transposed letters were to another in the target string, the poorer was the recognition of transposition. A probed recall procedure introduced in Experiment 3 required subjects to identify the serial position in the target string held by the probe letter. This procedure showed that memory for a letter's serial position was distributed over a number of serial positions and that the overlap of such positional uncertainty functions for individual pairs of adjacent items predicted recognition memory for transposition. Uncertainty about position of occurrence appears to determine order information, at least in part, and constitutes a neglected aspect of current theories of serial-position phenomena. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotion-attention interactions in recognition memory for distractor faces.

Effective filtering of distractor information has been shown to be dependent on perceptual load. Given the salience of emotional information and the presence of emotion-attention interactions, we wanted to explore the recognition memory for emotional distractors especially as a function of focused attention and distributed attention by manipulating load and the spatial spread of attention. We performed two experiments to study emotion-attention interactions by measuring recognition memory performance for distractor neutral and emotional faces. Participants performed a color discrimination task (low-load) or letter identification task (high-load) with a letter string display in Experiment 1 and a high-load letter identification task with letters presented in a circular array in Experiment 2. The stimuli were presented against a distractor face background. The recognition memory results show that happy faces were recognized better than sad faces under conditions of less focused or distributed attention. When attention is more spatially focused, sad faces were recognized better than happy faces. The study provides evidence for emotion-attention interactions in which specific emotional information like sad or happy is associated with focused or distributed attention respectively. Distractor processing with emotional information also has implications for theories of attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Initiation latency and advanced planning in rapid recitation and oral reading.

12 university students and staff persons translated arrays of 1–8 letters into spoken letter names as rapidly as possible. Initial visual encoding was investigated by comparing a reading condition in which naming was direct from the display with a retrieval condition in which naming was from memory of an immediately preceding display. In both conditions, a preparatory process was revealed in which Ss delayed their initiation of naming for a time dependent on the number of letters to be named. This delay was briefer in the retrieval condition and was reduced in both conditions by orthographic structure in the letter array. The time taken to complete naming was a linear function of array size in the reading task; however, in the retrieval task the completion-time function was positively accelerated. For arrays of up to 5 letters speech was faster in the retrieval than in the reading condition, suggesting that preparation in the reading task had resulted in a lesser degree of response planning. The diminished speech rate with longer arrays in the retrieval task was partly attributable to discrete hesitations ascribed to difficulties in retrieving response information from short-term memory. This slowing was almost eliminated by structure in the letter arrays. (French abstract) (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison requirements and attention in identical-nonidentical stimulus discriminations.

Perceptual matching data show several puzzling effects. Particularly problematic are the disparities between the processing rates for same and different stimuli—the fast–same effect—and between the processing rates for two same–different judgment tasks that are related as mirror images—the task effect. Current models have difficulty accounting simultaneously for both effects. Central to these models is a stimulus comparison process that derives relative judgments of sameness and difference from tests of the congruence of stimulus representations. A contrasting view holds that same–different judgments can be modeled as absolute, rather than relative, judgments. This latter view is shown to be supported by experimental data. Reaction times (RTs) for judgments of identical letter strings increase with string length at the same rate whether judgments are based on all the information in the strings or just the information in a single pair of component letters. The data show that stimulus comparisons of the sort described by previous models are not involved in these judgments. An attentional model accounts for the data and for the fast–same and task effects as well. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Priming by numb3r5 does not involve top-down feedback.

Using the same–different task, Perea, Du?abeitia, Pollatsek, and Carreiras (2009) showed that digits resembling letters (“leet digits”; e.g., 1 = I, 4 = A) primed pseudoword strings (e.g., V35Z3D–VESZED), but letters resembling digits (“leet letters”) did not prime digit strings (e.g., 9ES7E2–935732), and suggested that this is due to top-down feedback available for letter, but not digit, strings. Here we show that (a) single letters show as much leet priming as 3-letter words (Experiment 1); (b) leet priming is equally robust for digit strings and pseudowords when the string is 4 items long but not when 6 items long (Experiment 2); and (c) with 6-item strings, orthotactically illegal letter strings (e.g., OIAUEQ) behave just like digit strings (Experiment 3). These results indicate that the asymmetry in leet priming is not due to top-down feedback available selectively for letter strings. We offer an alternative explanation based on the Bayesian reader account of masked priming proposed by Norris and Kinoshita (2008), and the role played by the orthotactic knowledge used to extend the functional capacity of visual working memory involved in performing the same–different task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Effect of Perceptual Distinctiveness on the Prospective and Retrospective Components of Prospective Memory in Young and Old Adults.

In two experiments, the effect of perceptual distinctiveness of cues on prospective memory performance was examined. Young and older adults completed a visual search task with embedded prospective memory instructions. On each trial, participants were asked to indicate the position of a target letter in a letter string, unless either of two letters previously identified as prospective memory cues was presented. Each prospective cue was associated with a specific response. Perceptual distinctiveness was manipulated by spatially displacing a single letter. The prospective component (successful detection of the cue) and the retrospective memory component (recalling the correct response when a cue is detected) were measured separately. Perceptual displacement of cues modulated performance of the prospective component but not the retrospective component. Young adults successfully detected a larger proportion of cues (prospective component) than older adults. However, there were minimal effects of age and no effect of cue displacement on participants' ability to recall the intention once they detected a cue (retrospective component performance). Results are discussed within the context of current theoretical models of prospective memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Frequency discrimination: Assessing global-level and element-level units in memory.

Assessed the retention of memory units for word-like strings of letters using the perceptions of 120 undergraduates in 2 experiments in determining how frequently various letters appeared. A series of strings was presented at 1 of 3 exposure durations. Within the series, the frequencies of occurrence of different strings and of the letters composing the strings were varied orthogonally. Results indicate that, at relatively long exposure durations, Ss could discriminate the frequency of occurrence for both strings and their constituent letters. The formation of global-level (string) memory units was indicated by judgments of string frequency being unaffected by either the frequencies of their component letters or experimental conditions (brief exposures) that prohibited accurate judgment of letter frequency. Although judgments of letter frequency were sometimes biased by the frequency of the strings containing the letters, the success with which the judgments discriminated different levels of letter frequency did not depend on the activation of string-level memory units. Furthermore, Ss' frequency judgments for letters were not predictable from their recall of the strings containing the letters. Results provide evidence for the formation of element-level (letter) memory units. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of structural and naming factors of letters upon the recognition of tachistoscopic letters (author''s transl)

To determine the nature of effects of a preceding letter stimulus upon the recognition of a following letter stimulus, 20 subjects were sequentially and tachistoscopically presented pairs of letters of pairs of random patterns, which consist of the same number of elements, and asked to judge whether they were "same" or "different" in form. Four variable interstimulus intervals (ISI) between the 1st stimuli and the 2nd stimuli were employed as parameters. Results obtained were as follows: (a) percentages of correct responses for the letters were not significantly different from those for the random patterns, and (b) percentages of correct responses for the "same" matching tasks were significantly higher than those for the "different" matching tasks, but, differences in number of correct responses between the two tasks diminished as ISI increased. These results reveal structural, rather than naming, effects of preceding letters in the information processing of matching single letters.     

Blank characters in tachistoscopic recognition: Space has both a symbolic and a sensory role.

In a free-recall tachistoscopic task, increased letter spacing reduces the advantage of familiar pseudo-words over random letter strings. To explore this phenomenon, 2 ways of introducing "extra" space between letters were compared in 2 experiments involving 69 undergraduates. Using both a partial-report bar-probe task and a free-recall task, letter spacing was increased by (1) spreading normally sized material over a wider visual angle and (2) reducing letter size while holding the retinal position constant. In free recall, the space between letters relative to their height controlled performance by altering the size of the familiarity effect. In the probe task, however, accuracy of report depended on letter size, and the familiarity effect was independent of the size and spacing manipulations. Thus, in free-recall, the space between letters served as a blank character, but in the partial-report task, visual resolution controlled performance. (French abstract) (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Letter position information and printed word perception: The relative-position priming constraint.

Six experiments apply the masked priming paradigm to investigate how letter position information is computed during printed word perception. Primes formed by a subset of the target's letters facilitated target recognition as long as the relative position of letters was respected across prime and target (e.g., "arict" vs. "acirt" as primes for the target "apricot"). Priming effects were not influenced by whether or not absolute, length-dependent position was respected (e.g., "a-ric-t" vs. "arict"/"ar-i-ct"). Position of overlap of relative-position primes (e.g., apric-apricot; ricot-apricot; arict-apricot) was found to have little influence on the size of priming effects, particularly in conditions (i.e., 33 ms prime durations) where there was no evidence for phonological priming. The results constrain possible schemes for letter position coding. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Recognition by familiarity is preserved in Parkinson's without dementia and Lewy-Body disease.

Objective: The retrieval deficit hypothesis states that the lack of deficit in recognition often observed in patients with Parkinson's disease is because of the low retrieval requirements of the task, given that these patients have retrieval and not encoding deficits. To test this hypothesis we investigated recognition memory by familiarity in Parkinson's patients and in patients with Lewy Bodies disease and Parkinson with dementia. Method: We analyzed to what extent the experimental groups were able to recognize by familiarity in a typical yes/no recognition memory task. The experimental groups were patients with early nondemented Parkinson's disease, advanced nondemented Parkinson's disease, demented Parkinson's patients, and patients with dementia with Lewy Bodies. We compared their performance with a group of young and another group of old healthy participants. The estimation of familiarity was made by analyzing recognition of word targets and distractors consisting of combinations of different letters in comparison with a condition in which targets and distractors were composed of similar letters, even though subjects were unaware of the independent variable. Results: The results indicate that familiarity was used at the same level by controls, patients with early Parkinson's disease and patients with dementia with Lewy Bodies. Although late Parkinson patients also used familiarity, its effect was only marginally significant. Patients with Parkinson's disease and dementia were not capable of using familiarity in recognition memory. Conclusions: Our results support the retrieval deficit hypothesis as Parkinson's patients without dementia show no deficit in a situation in which the retrieval requirements are minimal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interaction effects in the lateral visual field: an extension of Bouma's (1970) approach

The recognizability of a letter is impaired by the presence of additional letters. This phenomenon is called lateral masking. Proceeding on the assumption of Bouma (1970) lateral masking can be described in terms of retinal eccentricity of the target letter and the distance between target and flanking stimuli. In this paper, we will address to the question if these kinds of parameters are adequate for describing lateral masking effects. For this purpose, characteristics of the string like its length and its homogenity are varied. The subject's task is to identify the central letter of a tachistoscopically presented string. The targets in the string are flanked both by only x and by different randomly selected letters. Additionally, we varied the length of the string. The data show that these variations influence the strength of the masking effect. It is concluded that a pure sensorical approach is not sufficient for an explanation of lateral masking effects.     

Choice reaction-time study assessing the verbal behavior of the minor hemisphere in normal adult humans.

Conducted 2 choice RT experiments in which a total of 12 right-handed college students scanned a memory set of 1 or 6 letters for the presence of a test letter. The memory set was presented binaurally and the test letter visually to either the right or left visual field. S indicated with his left hand whether or not the test letter was contained in the memory set. Results show the RT was shorter for the left visual field test letter when the set contained only 1 letter and for the right visual field test letter when the set contained 6 letters. The possibility that Ss matched the set and test letters visually when the set contained only 1 letter and verbally when the set contained 6 letters is discussed. Results suggest that the minor hemisphere displays little, if any, verbal abilities. (31 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Nonword Repetition Priming in Lexical Decision Reverses as a Function of Study Task and Speed Stress.

The authors argue that nonword repetition priming in lexical decision is the net result of 2 opposing processes. First, repeating nonwords in the lexical decision task results in the storage of a memory trace containing the interpretation that the letter string is a nonword; retrieval of this trace leads to an increase in performance for repeated nonwords. Second, nonword repetition results in increased familiarity, making the nonword more "wordlike," leading to a decrease in performance. Consistent with this dual-process account, Experiment 1 showed a facilitatory effect for nonwords studied in a lexical decision task but an inhibitory effect for nonwords studied in a letter-height task. Experiment 2 showed inhibitory nonword repetition priming for participants tested under speed-stress instructions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Orthographic and lexical processing of visual letter strings.

Three experiments tested whether orthographic and lexical properties of a letter string influence the time to search for a component letter. 102 Canadian undergraduates served as Ss. Orthographic redundancy, defined by single-letter position-specific frequency, facilitated the search of targets specified prior to and simultaneously with the letter string. Words were searched faster than nonwords when the target followed the letter string. Neither orthographic nor lexicality had significant effects when the position of the target within the string was certain. Results are consistent with a hierarchical-levels model of word perception in which the activation of detectors at different levels is constrained by task demands. (French abstract) (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age differences in entropy: primary versus secondary memory

We report a spatial-memory scanning experiment that was used to measure age differences in entropy. A target grid consisting of four adjacent letters followed by the presentation of a single probe letter was presented on each trial. Half of the trials presented the probe stimulus in the same spatial position was the target letter (i.e., the probe letter was always a member of the positive set), and half of the trials transposed the target letter one, two, or three spaces of the right or left of the original target display position (i.e., different trials). The experiment involved blocks of primary-memory and secondary-memory tasks. Reaction-time and error-rate data, as well as entropy analyses and the fitting of an entropy model (based on Allen, Kaufman, Smith, and Propper, in press) to the empirical data indicated that older adults showed higher entropy levels than young adults. These results are interpreted in a "computational temperature" framework in which older adults' higher computational temperatures result in less efficient spatial, episodic memory functioning.     

Different ways to cue a coherent memory system: A theory for episodic, semantic, and procedural tasks.

An associative theory of human memory is proposed, which serves as a counterexample to claims that disassociations between episodic, semantic, and procedural memory tasks necessitate separate memory systems. The theory is based on task analyses of matching (recognition and familiarity judgments), retrieval (cued recall with list associates, extralist associates, and part-word cues), and production (producing the first word that comes to mind). These analyses are then embedded in a distributed storage model, and it is shown how proactive interference from old memories can be largely eliminated by combining cue strengths interactively at study and test. A distinction between modality-specific and more central, modality independent, memory codes is also introduced. The model is extended to the performance of amnesic patients, and the general approach to human memory is then evaluated. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Memory for position and identity across eye movements.

Used a "transsaccadic" partial report procedure to measure memory for position and identity information across saccades. Delaying the partial-report cue after the eye movement had little effect on report accuracy. Mask presentation hindered recall only at the shortest delay. Accuracy was much higher when the letter array contained 6 letters than when it contained 10 letters. Intra-array errors were much more frequent than extra-array errors. These results suggest that memory across eye movements decays slowly, has a limited capacity, is maskable for a brief time, and retains identity information better than position information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Testing the role of vertical symmetry in letter matching

A series of experiments tested a recent suggestion that vertical symmetry of a stimulus display can serve as a visual diagnostic for responding "same" in a letter-matching task. The data of chief interest were same reaction times to vertically symmetric (e.g., AA) and asymmetric (e.g., LL) displays, each composed of two side-by-side uppercase letters. Overall, the data argue against subjects' use of vertical symmetry as a diagnostic in dealing with letter pairs. The results were interpreted within the context of recent work on symmetry. In particular, it was suggested that the importance of structural diagnostics in a matching task may be inversely related to the codability of the stimulus elements being compared.