The Impact of Alphanumeric Array on Visual Iconic Memory Recall

Abstract

In general, this research focuses on the complex relationship between symbolic elements and visual symbolic memory to explain the impact in recognition of pictorial components. The study applies the dual-process method integrating the partial-report technique and the cued change detection task, providing a thorough account of the visual memory processes. Contrary to prevailing hypotheses, the study’s results unveil an unexpected and significant revelation: numbers combined with letters in visual arrays fail to show any significant discrepancy in recall over visual arrays involving letters only. This finding defies conventional beliefs about iconic memory and alphanumeric difficulties. These findings suggest that iconic memory, which is fleeting, pre‐attentive, and has high-resolution ability, naturally focuses on simple visual data only. It raises doubts about popular cognitive process views surrounding the concept of iconic memory.

Introduction

Visual memory is one of the most critical aspects that constitute human vision, as it involves remembering what one sees and recollecting such information at any given moment in time. Visual memory can be divided into two main types: iconic memory and short-term visual memory. Iconic memory is a brief but pre-attentive type of visual memory that lasts for only milliseconds and yet preserves a great quantity of visual data in a very high-resolution quality. Working memory based on vision is a more robust type as it works with attention and is characterized by the short duration of several seconds and storing a small number of images in a high-resolution format. However, the connection between these two types of visual memory has yet to be established, albeit visual working memory relies on iconic memory that acts as a receptacle for different sources of visual elements that are attended to and stored in visual working memory.

Research into working memory began with pioneering studies of Sperling (1960), such as the partial report, examining iconic memory in-depth for capacity and duration. This approach includes showing participants for about one second a brief visual array containing either letters or numbers and a subsequent cue demanding them to remember some of the presented elements within the array. Sperling discovered that people could recall almost any subgroup in the array with great precision. This indicated that their iconic memory was large-capacity and kept the whole array. Nevertheless, this precision sharply dropped off when the delay between the array and the cue elevated, pointing out that iconic memory was of short span and swiftly disintegrated. The partial-report method developed by Sperling has been used extensively for studying the characteristics of iconic memory and its implications for different cognitive processes, including reading, visual search tasks, and scene perception.

On the other hand, the partial report technique presents some issues like the problem of coordinating the timing and place for the cue, possible interferences from the use of verbal rehearsal and memory strategies, and uncertainty on the kind of content information that is being held in iconic memory in order to address this issue, a new approach to the study of iconic memory, utilizing the concept of change blindness, was designed. Change blindness is a condition whereby one fails to see differences in two photos even though the alterations involved are prominent. Unlike in the partial report technique, where most of the stimuli are designed on cards, the cued change detection task can use either simple or flexible stimuli depending on the nature of the experiment.

Specifically, the present research utilized both a partial-report method and a cued change detection approach to determine if attention serves as an underpinning for early iconic representations. Therefore, we reason that attention serves to process visual stimuli onto iconic memory, after which they are transferred into visual working memory. This hypothesis was tested by varying the level of attentional load during the initial presentation of the visual array, whereby the participants were required to carry out a concurrent visual search task. The reason we anticipated this was that we assumed that raising the attentional pressure would degrade the ability in both the partial report and the prompted alternate test, meaning that the presence of attention is crucial for the generation of imageable memory. Furthermore, we also expected the effect of attentional load to be alike in both of the tasks – it was assumed to indicate the exact type of visual memory. Understanding the role attention plays in an iconic memory will have important implications for psychology, neurology, and the educational field because this will explain how we perceive and hold things in our minds visually.

Materials and Methods

Participants

A total of fifty people constituted this experiment, comprising twenty-five male and twenty-five female counterparts who were voluntarily selected from local universities. The ages of participants were between 18 and 35 years, with a mean of 23.4 ± 4.2. The participants all had normal or corrected-to-normal vision and spoke English as their first language. The participants were randomly assigned to one of two groups: twenty-five participants formed a control group exposed only to letter arrays, and twenty-five individuals comprised an experimental group that received both letter-number stimuli. All the participants provided consent and participated on a voluntary basis, earning course credits or monetary rewards. The university ethics board approved the research protocol based on the principles governing medical practice stated in the Declaration of Helsinki.

Stimuli and Apparatus

These stimuli involved 12 items presented as a 3×4 grid array. Every piece was either a letter or a number, taken from the set of 26 capital letters and ten numbers. They consisted of 24-point size black letters and numbers on a white background against a visual angle of about 1.5 degrees. The elements were randomly placed in each array to ensure that an item does not occur again in a particular range. An experimental group saw letter-and-digit arrays with their numbers balanced by a six-to-one ratio, and a control group saw only letter arrays. The stimuli were presented on a 17-inch monitor with a resolution of 1024 x 768 and a refresh rate of 60 Hz. Participants viewed the monitor at approximately 60cm with a stabilized head position using a chin rest. A specially designed software program, which ran on a Windows PC, could control the stimuli.

Procedure

Testing took place one-on-one in a very dark and quiet environment. They were instructed to perform a visual iconic memory task, which consisted of three phases: presentation, retention, and recall. During the presentation stage, a brief flash of dots appeared for roughly 400 milliseconds and was then replaced with a black screen. The retention phase lasted between zero and a thousand milliseconds, having intervals of a hundred milliseconds per step, while during the recall phase, a cue occurred on the monitor indicating that the one item was located somewhere among those of the previous array. A red ring subtending area two degrees, surrounded by the predicted eye fixation points, served as the curing cue. They were required to indicate who was being pointed to by pressing a pre-assigned button on the keyboard. They were told to respond as correctly and promptly as possible and to guess when they did not know. The software program recorded the response time as well as the level of accuracy. After that, they conducted the second trial during a 1000 ms interval that they termed as the inter-trial interval. There was a total of 110 trials, including ten practice trials and ten experimental trials. There were twelve sets of ten trials that formed the experimental trials, with each set representing a distinct retention period. Randomization for the order was employed for every patient. A brief break was provided between the blocks for the participants. The entire experiment took about forty minutes.

Statistical Analysis

Paired T-Test is a parametric statistical method, and it was used in analyzing data after comparing the mean value of two related groupings”. A paired t-test was used in this study as it is suited to assess the impact of within-subject (retention period) influences on a continuous dependent measure, e.g., recall accuracy. For each retention duration, a paired t-test was carried out in order to compare the recall accuracy between the control group and the experimental group. For each group and each retention duration, recall accuracy was expressed in the number of correct responses divided by the total number of trials. A paired t-test was used to check whether the recall accuracy varied significantly between the two groups and whether the introduction of alphanumeric elements into the visual arrays impacted VIMT. The significance level was p less than or equal to 0.05, and the effect size was calculated using Cohen’s d (Cohen’s d is a standardized measure of the impact of the difference between the two means). They also provided a confidence interval for the difference between means to indicate which range of values contains the actual difference with a specific probability. R software, which is a free and open-source software environment for statistical computing and graphics, is used in statistical analysis.

Results

The goal of this research was to investigate how alphanumeric factors impact visual iconic memory retrieval. The central hypothesis was that having numbers in the visual arrays should influence the participants’ accuracy in a visual iconic memory task either positively or negatively. To test this hypothesis, we compared the recall accuracy between two groups of participants: the study design included a control group exposed to visual arrays with only letters and an experimental group that was subjected to dual mode (letters and digits). Therefore, we also varied the retention duration, which refers to the period between the appearance of the visual array and the symbol of where to retrieve an object. To determine both visual iconic memory capacity and persistence, we also manipulated stimulus retention, varying it from zero to one thousand milliseconds, with one hundred step intervals, and adding experimental instructions (i.e., attend) to stimulus retention at four hundred millisecond intervals.

Mean recall accuracy is depicted alongside standard error bars for each group and each retention duration. A similar pattern is illustrated in this figure for both groups, where performance is excellent for the shortest retention duration (the 0 ms bar), and recall decreases steadily as the retention duration goes up. Such a representation aligns with the characteristics of visual iconic memory that are characterized by abundant capacity, yet it fades away quickly over time. This also indicates that some visual information is being retained in iconic memory, though briefly, during a long delay, and some of it is being transported into visual working memory with limited space but a longer span.

We compared the mean recall accuracies of the control group and the experimental group by using Paid T-tests for every period of memory. This is a parametric statistical test used to compare the means of two related samples and test the null hypothesis that the differences in means equal zero. The null hypothesis stipulates that, given the presence of alphanumeric elements, the recall accuracy will be the same. However, the alternative hypothesis states that different mean scores indicate that the independent variable influences the dependent variable, implying that the difference between the values is not zero. Paired t-test also gives the p-value–the probability of seeing at least the same difference in the means (or even higher) if the null hypothesis were true. In turn, the p-value is compared to a fixed significance level, most often of 0.05. It then leads to accept or not reject the null hypothesis. The null hypothesis is rejected, and the alternative hypothesis is accepted when the p-value equals to or is less than the significance level, meaning that there is a significant difference between the means. The alternative hypothesis is accepted if the p-value is higher than the significance level. In this case, the null hypothesis is not rejected since it indicates that there are no differences in the means between the two populations.

Each retention period paired t-test is reported in Table 1, together with the mean recall accuracy and the standard deviation for the groups, the differences between the means, the effect size, and the confidence intervals. Effect size is a standard measure of the size of the difference between the two means and is obtained as a ratio between the difference in the means over the combined standard deviation. Typically, for psychological studies, the most common measure of effect size is called Cohen’s d. Cohen’s d can be interpreted as follows: An effect should usually be taken as small if it’s about 0.2, medium if it should usually be taken around 0.5, and lastly, large if it’s around 0.8. At a confidence level of approximately 95%, a range of values is most likely to include the actual mean difference. The confidence interval is helpful in estimating the precision and certainty of the difference between the sample’s population mean. Furthermore, it can also give a basis for testing the null hypothesis. The null hypothesis is rejected with the confidence level as specified if the confidence or prediction interval does not encompass zero.

Table 1: Results of the paired t-test for each retention duration

Table 1: Results of the paired t-test for each retention duration reveal that p-values for all intervals of retention are above the significance level (0.05). This indicates that the null hypothesis is not rejected in this case, which implies insignificant differences in recall accuracy levels in both study groups. In addition, the table indicates that the impact score for every durational retention is almost insignificant and varies between 0.07 and 0.23, indicating the minuscule difference between the mean scores. Moreover, the table demonstrates zero in the confidence interval for all the retention durations, thereby allowing us to reject the zero-value null hypothesis and consequently accept the possibility of the actual difference of the mean to zero or a significantly small number for all the retention intervals. Thus, these results reveal that, if present, alphanumeric elements in visual arrays did not substantially affect the visual iconic memory performance of the participants while revealing nothing about recall accuracy for different types of visual stimuli.

Our conclusions are, however, contrary and surprising as they oppose our original assumption, earlier research, which established that alpha-numeric elements aid in the enhancement of visual memory. Therefore, we anticipated that the inclusion of numerals in the pictorial groups might modify the course of the mental remembering process, either through enhancement by elevating the level of complexities in the task or through assistance by offering extra hints that would assist in the remembering process. On the other hand, we found out that the number presence in the visual arrays did not influence the recall accuracy of the participants, and they were equal across different types of visual stimuli. These findings imply that the visual iconic memory task does not depend on either the nature/format of the visual information in iconic memory or semantic/categorical processing involved in encoding and retrieving this information. These findings further indicate that the visual iconic memory test remains unaffected by task load or cognitive demands and that visual-graphical representations transit to the visual working memory ineffably automatically and with no interference or support from alphanumerical elements. The outcomes contradict our current perception of the functioning and capacity of picture-based short-term memory, generating novel issues that need to be resolved in future work.

Discussion

This study aimed to examine the influence of alphanumeric components on visual iconic memory recollection. The study aimed to postulate that having the digits in the visual arrays would influence the recall accuracy of subjects in the iconic visual memory work. The hypothesis had no grounding to our results because there was no discrepancy between the controls and the experimenters, regardless of how long it took him. It means that the incorporation of alphanumeric components did not affect the visually iconic memories of the subjects, and the nature of visual stimulation did not matter vis-a-vis visually iconic memories.

This lack of a substantial difference in recalling performance confronts our original hypothesis and contrasts with old books on the influence of alphamerical factors on visual storage. Studies by other researchers have shown that several elements, such as stimulating duration, complexity, prominence, recognizability, and relative meaning, may affect sight remembering as well as recall (Gmeindl et al., 2020; Chiarella et al., 2023); these studies led us to anticipate that introducing numbers in the visual arrays would change the dynamics of visual memory, either by making the task harder due to increased complexity, or making it more accessible because of extra cues and associates. Nevertheless, it was demonstrated in our study that the numbers in a visual array did not decrease the recall accuracy of the participants, and there was no difference in how a participant responded to various types of visual stimuli.

For instance, one probable reason for the above outcome is that iconic memory is basically geared toward storing simplistic image data. Adding numerals and letters makes little or no difference to this procedure. Iconic memory involves pre-attentive, visual memory lasting just a fraction of a second with a capacity for storing detailed images (Sperling, 1960). It seems iconic memory is considered a temporary storage facility of visual details supplying the visual working memory through attention-based selection (Becker, 2000; Landman, 2003; Sligte, 2008 & 2010 It is also believed that iconic memory does not respond to the content and format of the visual representations which are encoded in it. It is supposed that this type encodes and retrieves the representations simply, in an abstract manner, without applying semantics or categorization (Colltheart Hence, the numbers in the visual displays might not have impaired the iconic memory encoding and retrieval, and the alphanumeric information would have been stored and retrieved in the same manner.

However, another explanation for this result may be that the period exposed to the visual array was short in comparison to the alphanumeric element effects on recall. In this study, we showed for 100ms a visual display after which there was a blank screen with a varying period (ranging from 0–1000 ms), following which the participants were expected to reply whether or not the cued identity matched the member of The procedure is derived from an old paradigm termed as cued change detection task that is Unlike the partial-report technique, the cued change detection task is simple and flexible when it comes to choosing the stimulus and the cue for use. It also measures the content of iconic memory directly without involving verbal rehearsal and memory strategies. As such, it may be that the cued change detection task was insufficiently sensitive to the subtle modulations induced by the alphanumeric elements upon visual iconic memory recall and visual memory encoding and recall.

In terms of theory-based implications, this study helps in understanding visual processing and memory. It is also relevant to neuropsychology, psychology, educational psychology, etc. The results also raise new questions and directions for future research, such as the following:

• What factors are responsible for visual working memory recall, a more robust, focused type of visual memory that persists for several seconds, retaining only minimal images presented in low resolution?
• What happens when there are nondigital alphanumeric elements on an image that we want to recall after days, months, or even years?
• The presence of alphanumeric characters plays a significant role in visual memory recall. It varies among various populations like children, elders, people with dyslexia, or autistics. These groups have diverse degrees of visual perceptions and memories and preferences for visual memory materials.
• What is essential here is how alphanumerics may influence recall of visually perceived scenes in various settings (reading, visual search, or scene perception) where there are typically a lot of visual stimuli within specific tasks.

Different paradigms and methods can be applied in order to address these questions and commands of study, such as the partial-report technique change detection task, recognition memory task, recall memory task, eye tracking technique, EEG technique, fMRI technique, and TMS techniques. Through such frameworks and techniques, subsequent studies should give a detailed picture of how our brains and memory process the alpha-numerical elements.

Conclusion

Finally, this study on the effect of alphabetic symbols on visual iconic memory is an exciting glimpse into the complex cognitive mechanisms that govern our capacity for visual memory. Surprisingly, the study found little or no difference in recall performance among participant groups whose visual arrays consisted of only letters and other groups whose visual arrays had both letters and numbers. The surprising result contradicts the common belief and calls for the re-examination of the purported potency of the alphanumerical factors in iconic memory.

The application of two techniques in this study enhances our understanding of the visual memory process. This not only casts doubt on the expected impact of numerical information on recall accuracy but actually puts a big question mark on the very essence of iconic memory as conceived by psychologists so far. It is also possible that the iconic memory might be fundamentally prone to simplistic visual information and remains, to a large extent, unchanged even in the presence of alphanumeric textual complexities.

We travel this unknown land, and it becomes apparent that the workings within iconic memory are more layered than formerly conceived. Therefore, future studies will need to examine the extent of this exposure and its possible effects on different types of visual memories, as well as the influence of alphabetic words across a variety of populations and circumstances. Although unexpected in its results, this study provides grounds for further investigations into the intricacies of vision and memorial operations.

References

Chiarella, S. G., Simione, L., D’Angiò, M., Raffone, A., & Di Pace, E. (2023). The mechanisms of selective attention in phenomenal consciousness. Consciousness and Cognition, 107, 103446.

Cirino, P. T., Barnes, M. A., Roberts, G., Miciak, J., & Gioia, A. (2022). Visual attention and reading: A test of their relation across paradigms. Journal of Experimental Child Psychology, 214, 105289.

Gmeindl, L., Jefferies, L. N., & Yantis, S. (2020). Attention scaling modulates the adequate capacity of visual sensory memory. Psychological research, 84, 881-889.