Partial Report Performance Research Articles

Hydrocortisone Counteracts Adverse Stress Effects on Dual-Task Performance by Improving Visual Sensory Processes

The impact of acute stress on executive processes is commonly attributed to glucocorticoid-induced disruptions of the pFC. However, the occipital cortex seems to express a higher density of glucocorticoid receptors. Consequently, acute stress effects on executive processes could as well be mediated by glucocorticoid (e.g., cortisol)-induced alterations of visual sensory processes. To investigate this alternative route of stress action by demarcating the effects of acute stress and cortisol on executive from those on visual sensory processes, 40 healthy young men completed a standardized stress induction (i.e., the Trier Social Stress Test) and control protocol in two consecutive sessions. In addition, they received either a placebo or hydrocortisone (0.12-mg/kg bodyweight) pill and processed a dual and a partial report task to assess their executive and visual sensory processing abilities, respectively. Hydrocortisone administration improved both partial report and dual-task performance as indicated by increased response accuracies and/or decreased RTs. Intriguingly, the hydrocortisone-induced increase in dual-task performance was completely mediated by its impact on partial report performance (i.e., visual sensory processes). Moreover, RT measures in both tasks shared approximately 26% of variance, which was only in part attributable to hydrocortisone administration (ΔR2 = 8%). By contrast, acute stress selectively impaired dual-task performance (i.e., executive processes), presumably through an alternative route of action. In summary, the present results suggest that cortisol secretion (as mimicked by hydrocortisone administration) may counteract adverse residual stress effects on executive processes by improving visual sensory processes (e.g., the maintenance and amplification of task-relevant sensory information).

Comments on how Mack et al. (2015) (do not) see iconic memory.

In a recent paper (Mack et al., 2015) the effect of attentional manipulations on partial report performance was investigated. The results were interpreted in favor of the stance that an attention-free phenomenal iconic store does not exist. Therefore, the authors argue that consciousness requires attention. Here we question their conclusions both on the methodological and conceptual grounds.

Action video game playing is associated with improved visual sensitivity, but not alterations in visual sensory memory

Action video game playing has been experimentally linked to a number of perceptual and cognitive improvements. These benefits are captured through a wide range of psychometric tasks and have led to the proposition that action video game experience may promote the ability to extract statistical evidence from sensory stimuli. Such an advantage could arise from a number of possible mechanisms: improvements in visual sensitivity, enhancements in the capacity or duration for which information is retained in visual memory, or higher-level strategic use of information for decision making. The present study measured the capacity and time course of visual sensory memory using a partial report performance task as a means to distinguish between these three possible mechanisms. Sensitivity measures and parameter estimates that describe sensory memory capacity and the rate of memory decay were compared between individuals who reported high evels and low levels of action video game experience. Our results revealed a uniform increase in partial report accuracy at all stimulus-to-cue delays for action video game players but no difference in the rate or time course of the memory decay. The present findings suggest that action video game playing may be related to enhancements in the initial sensitivity to visual stimuli, but not to a greater retention of information in iconic memory buffers.

Disengaging attention: on the locus of the cue-duration effect in partial report.

Increasing cue duration impairs performance in bar-probe partial report when cues are presented peripherally, but not centrally (P. Dixon, R. Gordon, A. Leung, & V. Di Lollo, 1997). Three experiments examined whether this cue-duration effect reflects processes of exogenous attention. The effect of cue duration on partial report performance with peripheral, but not central, cues was replicated (Experiment 1). Further experiments manipulated the degree that exogenous versus endogenous modes of selection were favored and found that the cue-duration effect for peripheral cues was reduced (a) when blocks contained a high proportion of central cues (Experiment 2) and (b) when the color of the cue indicated the location of the target (Experiment 3). These findings challenge the view that the cue-duration effect is restricted to exogenous attention and are discussed in terms of the process of disengaging attention from the cue to reallocate attention to the target representation.

On the Relations among Different Measures of Visible and Informational Persistence

We report research designed to accomplish two goals. We first consider the question, raised by Coltheart (1980) and others, of whether three measures of visible and informational persistence—performance in temporally integrating two successively presented stimuli, subjective rating of the degree to which two successively presented stimuli appear to constitute a single or a dual temporal event, and partial-report performance—all measure the same underlying mental entity. We answer this question using a superset of dissociation logic calledstate-trace analysis(Bamber, 1979), and within the context of a systematic empirical foundation consisting of seven closely related experiments. Our second goal is to extend and apply a theory to data acquired from our seven experiments and also to data reported by other investigators. This theory, which has been confirmed in a variety of paradigms (see Busey & Loftus, 1994) assumes that (1) the initial stages of the visual system act as a low-pass linear filter which operates on a stimulus temporal waveform to produce asensory response;(2) instantaneous rate of acquiring information from the stimulus is jointly proportional to sensory-response magnitude and proportion of as-yet-to-be-acquired stimulus information; (3) partial-report performance is determined by total amount of acquired information; (4) the probability that two events are perceived as contemporaneous is determined by the temporal correlation of their respective information-acquisition rate functions (which is similar to a suggestion by Dixon & Di Lollo, 1994); and (5) temporal integration is successful to the degree that the two temporal events are perceived as contemporaneous. This theory was highly successful in accounting for our and other investigators' temporal-integration and completeness-rating data, and was moderately successful in accounting for partial-report data. We discuss the degree to which our three persistence measures can be united within the context of our theory; we comment on the distinction between objective and subjective measures of visible persistence; and we address the decades-old question: “What is persistence good for?”

Information on Location in Visual Persistence: Effects of Temporal Delay and Duration of Exposure on Report of Dot Location

This study of location information involved in information persistence used the partial-report paradigm. Six subjects were asked on 144 trials to recall positions of dots presented in a display. The subjects were instructed to maintain only information on location (but not on identity information) of the presented dots until a partial-report cue was introduced. The effects of display duration (50, 200, and 350 msec.) and cue delay (interval between the display offset and the onset of the partial-report cue: 50, 250, and 500 msec.) were examined. Analysis showed effect of cue delay on partial-report performance decreased as the duration of display increased so performance was negatively affected by the cue delay only when the subject was exposed to the presented dots for 50 msec. Contrarily, partial-report performance did not decline much for a 200-msec. duration and showed little variation in a 350-msec. duration, even though the cue delay increased. Consequently, the decay of the information on location mediating partial-report performance about dots varies with duration of display.

Is the icon's worth apples and oranges? Some fruitful thoughts on Loftus, Duncan, and Gehrig (1992).

Iconic memory, initially a unitary concept, was later reclassified into a multidimensional concept comprising several distinct processing events associated with the perception of brief stimuli. With respect to partial-report performance, multidimensionality was demanded by two findings : the interstimulus interval (ISI) effect (a progressive decrement in performance as the ISI is increased), and the inverse-duration effect (a progressive decrement in performance as stimulus duration is increased). Loftus, Duncan, and Gehrig (1992) suggested that both effects may be explained by a single set of principles. It is shown that given a stimulus of long duration, their model may be made to account for either the ISI effect or the inverse-duration effect, but not both

A major factor of the decline in partial report performance with temporal delay

The purpose is to clarify what is the primary cause of decline in partial report performance due to cue delay over a given time period. Four subjects participated in the partial report task, and their performances were compared by using two types of stimuli: mixed-character matrix (alphabet, katakana, and kanji) and single-character matrix (one of the three characters), under the tachistoscopic presentation. Both matrices are arranged in three rows by four columns. The result was that the report performance declined almost equally as the cue delay increased under the mixed- and single-character matrix stimuli, even though the location confusion would not influence on the report in the mixed-character condition. Consequently, we may conclude that the decline in partial report performance was caused by the decay of identity information rather than that of location information. Further, the error trends revealed that the earlier researches using single kind of character stimulus (almost exclusively alphabet) overestimated the location error.

Effects of display luminance, stimulus meaningfulness, and probe duration on visible and schematic persistence.

Partial report performance is conceived of as consisting of two independent sources of information: visible persistence and schematic persistence. Following the work of Di Lollo and Dixon (1988), these two sources of information were separated experimentally by varying interstimulus interval and stimulus onset asynchrony independently. In the present experiment we asked whether visible persistence and schematic persistence would be affected by display luminance, stimulus meaningfulness, or probe duration. The results were fit accurately by an extension of the Di Lollo and Dixon independent-decay model in which display luminance affected visible persistence but stimulus meaningfulness and probe duration affected neither form of persistence directly.

Conceptual and physical differences in the category effect.

In these experiments we tested whether physical differences between letters and digits could account for the category effect in visual detection and partial report. In our task, observers decided whether a target item matched any item in a briefly presented array. This yielded a visual detection task when the target preceded the array and a type of partial-report task when the target followed the array. In Experiment 1, the stimulus set consisted of nine digits and nine letters modified to match the digits on the basis of visual similarity. Partial-report performance was better in a mixed-category condition than in a single-category condition, but no such effect occurred in visual detection. However, the similarity of items between categories may have biased observers against using category information to perform the task. When the similarity was controlled both within and between categories in Experiment 2, a category effect emerged in visual detection as well. A third experiment, using a same-different reaction time task, verified that the stimuli were equally similar within and between categories. The results indicate that physical differences alone cannot explain the category effect.

Adult Age, Information Processing, and Partial Report Performance

Previous investigations using the partial report technique for examining adult age differences in iconic memory have suggested that older adults are less able to extract information stored in the icon than are young adults. The present study examined the hypothesis that poorer partial report performance on the part of older adults involves age-related differences in the speed of visual and auditory information processing. Elderly (M = 67 years) and young (M = 23.5 years) adults were contrasted on partial report, whole report, backward masking, and choice reaction time tasks. Results indicated that the older age group exhibited a smaller partial report advantage than did their younger counterparts. This age difference was found to be related in part to increases with age in the time required to encode and identify visual stimuli but was not related to the time required to translate auditory cues into recall instructions. In other words, the slowdown in visual information processing speed that accompanies increased age contributes to age differences in performance on tasks involving iconic memory.

Persisting arguments about visual persistence: reply to Long.

In a recent paper we investigated the effect of stimulus duration on partial report performance (Yeomans & Irwin, 1985). Two experiments showed that variations in stimulus duration from 50 to 500 msec had little or no effect on partial report accuracy, decay, or error patterns. Our results contrasted with previous research demonstrating that increasing stimulus duration decreases visible persistence duration (e.g., Bowen, Pola, & Matin, 1974; Cohene, 1975; Di Lollo, 1977, 1980; Efron, 1970a, 1970b, 1970c; Haber & Standing, 1970). We concluded that our findings provided support for the argument (Coltheart, 1980) that informational persistence (knowledge about the visual properties of a stimulus, as accessed by partial report) is a phenomenon that is separate from visible persistence (the phenomenal persistence of a stimulus), and we suggested that the traditional view of iconic memory, which conflates these two forms of persistence, is incorrect. We proposed, as a replacement to the traditional view, a two-stage model in which a brief period of visible persistence initiated at stimulus onset and sensitive to stimulus energy is followed by a longer period of informational persistence which begins at stimulus offset and is relatively insensitive to stimulus energy. In a recent note, Long (l985a) took exception to the conclusions of our study. He made two specific criticisms-first, that it is dangerous to base a model on a null effect; and second, that we overlooked substantial empirical evidence that was inconsistent with the two-stage model we proposed. We address each of these criticisms below.

Stimulus duration and partial report performance.

This paper investigates the effect of stimulus duration on partial report performance. Two experiments showed that variations in stimulus duration from 50 to 500 msec had little or no effect on partial report accuracy, decay, or error patterns. These results contrast with previous research demonstrating that increasing stimulus duration decreases visible persistence duration. Our findings thus provide support for the argument (Coltheart, 1980) that informational persistence (knowledge about the visual properties of a stimulus) is a separate phenomenon from visible persistence (the phenomenal persistence of a stimulus), and suggest that the traditional view of iconic memory, which conflates these two forms of persistence, is incorrect. Furthermore, our results indicate that informational persistence is not merely a function of unnaturally brief stimulus exposures, but exists even after exposure durations as long as 500 msec. Possible mechanisms of informational persistence, as well as its potential role in everyday perception, are discussed.

Stimulus Duration May Affect Partial Report Performance

Townsend, and Di Lollo and Moscovitch investigated the retention of item information in nearly identical variations of the partial report task. Whereas Townsend found a slight decrement in performance as the interval increased, Di Lollo and Moscovitch found a substantial increment. An experimental study of procedural differences that may have led to this discrepancy is reported. The results suggest that stimulus duration may have been responsible: Di Lollo and Moscovitch used extremely short durations (2 ms), while Townsend used longer durations (50 ms). This difference in durations may be important when the stimulus array and the partial report probe occur in close temporal contiguity.

An Analysis of Reading Proficiency and Its Relationship to Complete and Partial Report Performance

AVERAGE AND ABOVE average adult readers were visually presented sets of unrelated letters for brief durations under complete report and partial report conditions. The results showed that the highly skilled readers were superior in their performance on the complete report and the partial report delay-of-mask task. Complete report performance was facilitated by the inclusion of vowels in the letter strings, but the inclusion of vowels failed to interact with reading ability. Performance on the delay-of-mask task was dependent upon the rate at which the letters could be read from the iconic

Rod Persistence on a Partial-Report Task with Scotopic and Photopic Backgrounds

Two experiments were undertaken to demonstrate the participation of the rod system under certain stimulus conditions on the partial-report task of iconic memory. In Experiment 1, scotopically matched letter arrays of differing wavelength produced equivalent partial-report superiority but only if relatively large letters and a long cue delay were employed. In Experiment 2, variable photopic backgrounds were employed in contrast to the constant dark background used in the first experiment. For constant luminance targets, photopically matched red and blue-green backgrounds of 5 ftL (15.9 cd/m2) did not produce equivalent partial-report performance. Partial-report superiority was evident at much longer cue delays with the red background. This was attributed to the minimal stimulation of the rod system by this long wavelength background. However, if an intense adaptation field that saturated the rod system were interposed between stimulus trials, the photopically matched backgrounds then produced equivalent partial-report performance at all cue delays.

The psychophysics of iconic storage.

Some simple models of iconic storage, based on the persisting responses of photoreceptors, were tested in two experiments. Substantial changes in such physical parameters as adapting luminance, stimulus luminance, and stimulus contrast produced little or no change in the duration of partial-report performance. This is at odds with most receptoral models. It seems unlikely that any model based on receptoral persistence can accommodate the results, thus forcing one to locate the icon beyond the receptors and probably beyond the retina as a whole.

The psychophysics of iconic storage.

Some simple models of iconic storage, based on the persisting responses of photoreceptors, were tested in two experiments. Substantial changes in such physical parameters as adapting luminance, stimulus luminance, and stimulus contrast produced little or no change in the duration of partial-report performance. This is at odds with most receptoral models. It seems unlikely that any model based on receptoral persistence can accommodate the results, thus forcing one to locate the icon beyond the receptors and probably beyond the retina as a whole.

Analysis of processing demands in partial report.

Processing demands in the Sperling (1960) whole- and partial-report tasks were evaluated with the simple reaction-time probe procedure. 6 subjects responded to a buzzer probe presented at various temporal locations in the processing interval associated with performance in whole or partial report. The results showed relative increases in processing demands in partial report in the temporal vicinity (+/- 200 msec.) of the delivery of the auditory indicator cue as indicated by increases in probe reaction-time. Furthermore, reacting to the probe during this interval interfered with partial-report performance. This mutual interference was not detected when whole report was performed concurrently with the probe task. The results were interpreted in terms of an analysis of central processing capacity.

Two Visual Stores and Two Processing Operations in Tachistoscopic Partial Report

A two-stage interpretation of the processes underlying tachistoscopic partial report performance is suggested. It is assumed that partial report is mediated by two kinds of visual store (a sensory store and a short-term store) and by two processing operations (selection and naming). In Experiment I, the accuracy and latency of two types of partial report (report by location and report by colour) were compared for cue stimulus-test stimulus intervals ranging from —500 ms to + 500 ms. It was concluded that selection by colour takes longer than selection by location; an explanation in terms of differential decay of attributes in the sensory store was rejected. In Experiment II, cue stimulus delays of 0, 150 and 300 ms were employed, and a backward masking stimulus followed the cue stimulus with a delay of 200, 300, 400 or 600 ms. The amount of masking depended on the cue stimulus-masking stimulus interval, rather than on the test stimulus-masking stimulus interval. It was concluded that selection operates on the sensory store and that backward masking can affect the naming of a stimulus representation which is residing in the visual short-term store.