Abstract
The perception of objects is reported to involve wide range of deciding factors such as light shape, color, location and motion. These factors are considered interdependent and influential in capturing the attention of objects as new or old and subsequently enable a feeling of sudden-onsets. But it is still unclear whether the changes of objects are perceived due to spatial allocation as low level or being represented at higher level as new things.
So, the main objective of this article was to distinguish between these two levels of cognitive perceptions and support the findings with the previous theories and data. For this purpose, we have undertaken a study comprising of 360 subjects with no cognitive and visual defects. They were told to locate the letters ‘E’ and ‘H’ assigned as the main target items by looking on the display screens and giving responses with the key board.
A total of 260 trials were included with no movement and movement as the main trials with respect to the display of shapes as random, square, and row. We compared the results obtained in milliseconds, noted the differences and considered p value less than 0.05 as statistically significant.
We found that the differences between the target sudden -onset and distractor sudden -onset of no movement trial are statistically significant compared to that of the movement trial.
The results may indicate that the allocation of objects in much filled blank space might have enabled their capture as new objects without any interference of distractors in the case of no movement trial. Whereas the movement trial has enabled the interference of distractors that lead to an increase in the responding time.
Therefore, it was inferred that the results of both the trials seem to agree with the earlier proposed hypotheses and findings that have emphasized their description that new objects presented in diverse forms could capture the attention.
Introduction
Human beings are presented with the gift of perceiving the world through the interaction between cognitive and visual functions. It is the brain that executes these important environmentally adapted roles. The perception levels rely on capturing the information either directly or indirectly which in turn is connected to the attentive state of the mind.
Various theories have been put forward in this context. It is well known that human eye is susceptible to distinguishing the shades of bright or light colors, their direction and magnitude of illumination, stationary or motile objects in a given space. This range of factors may play vital role in perceiving the captured images whether they are relevant or irrelevant.
Some times the attention may seem to perceive things as a whole but not as single unit. According to Gestalt theory, if a person looks at a tree he may perceive the image as a whole unit but not as distinct entity consisting of branches, leaves and the flowers or fruits. This would mean that parts identified are given secondary importance though they may have attractive features.
However, this aspect of looking at objects and their perception may change when some other things capture our attention. For example, while looking at a tree if we notice a dog passing by we may divert our attention on the dog seen as a moving object rather than looking at the tree. If a bright red colored huge kite was stuck to one of the tree branches and moves around due to wind currents, it may capture our attention when we prepared to look at the tree.
Therefore, it is reasonable to link this mode of perception to the concept of ‘Attention Capture’ in the sudden-onset form. Here, the kite may possess some luminescent characteristic features and appeared as a new object on an already familiar old tree.
This would very much coincide with the most prominent theory put forward by Yantis.
This theory says that the kind of stimulus that captures attention would be the appearance of a new visual object (Yantis, 1993).This was further strengthened by another report that described that new objects would capture the attention of the image if they create a strong local luminance or motion transient (Franconeri, Hollingworth, & Simons, 2005).
However, there are certain discrepancies indicating that the attention capture may not solely rely on luminance but may be only driven by the stimulus that the object is new (Franconeri, Hollingworth, & Simons, 2005). In another article, it was reported that some objects fail to capture the attention although they were believed to possess salient or distinctive features (Daniel, 2000). Very often, the shape of the objects may also capture our attention.
So, it may appear that an ambiguity is persisting in understanding the concept of attentional capture. Therefore an experiment was undertaken in this context with the objective of determining the attention capture of objects displayed in onset appearance in low and higher cognitive levels and studying the reaction times of individuals.
Method
We selected 366 undergraduates of the university as subjects. They were having normal vision. A total of 6 subjects were excluded from the study as the error rates were higher than 5%.
The study was designed with the goal of locating the target letters E and H in the presence of other distractors. The instruments used were place holders display screens and key boards.
The methodology of the experiment proceeds by studying the instructions on the screen, find the letters E and H and respond with the key board. The subjects were told repeatedly to focus on the speed but not the accuracy. They were also told to retard their speed if they were committing mistakes. The conditions of the experiment were classified as movement, no movement, and shapes such as random, regular square, regular row 1 and regular row 2.
The subjects were made to perform 270 trials comprising of 120 movement, 120 no movement and 30 of each shape. The trial blocks were grouped by shape. Specially arranged placeholders were presented for 1000ms for every trial. In order to note the response of subjects, the placeholders were followed immediately by the search display screens.
The letters E and H are always present in the search display screens to enable their position by the subjects with the help of pressing buttons on the key board. A beep sound and “doh” will be heard for every correct and incorrect answer, respectively. The reaction time of all trials were taken average and noted in milliseconds (ms).
Results
As depicted in the table, the trial with no movement has mixed results for all of the display shapes. The differences between the target sudden-onset and distractor sudden-onset noticed in sequence are more for row 1, random, square and row 2.
A p value less than 0.05 was considered statistically significant for the expected differences.
These differences are noted statistically at p value of 0.007, 0.002, 0.001 and 0.002, respectively. Similarly, the trial with movement has mixed results for all of the display shapes. The sequence in decreasing order is row 2, square, random and row1. The p value calculated for these differences are 0.043, 0.052, 0.435 and 0.771, respectively.
From the results it is obvious that there is convincing significant difference between the target and distractor onsets of no movement trial. The values that obtained for the movement trial have not coincided with that of the no movement trial and most of them are far from achieving the statistical significance. These results seem to show good difference even in the presence of the letter distractors such as C, F, P and U. In contrast, the presence of distrators has not produced satisfactory result for the movement trial more probably for the random and row 1.
Discussion
There is a need to evaluate the concept of attention control to better understand the impact of objects that appear as sudden-onset and influenced by characteristic forms such as luminance, moving and shapes. In the present experiment, we have seen that the letters E and H were assigned as target objects adjacent to the place holders that show a series of ‘8’s. The target letters may have the potential to stimulate and drive the attention. This may be because of their appearance as new items which would be better known as sudden -onsets in the psychological jargon.
It is widely believed that people would develop their visual gaze towards sudden onsets more particularly E and H. This may be because that they would capture the attention automatically in a bottom up fashion. This may indicate that the direction of perception is playing vital role while the subjects are capturing the attention of objects. This may be in turn connected with the neuropsychology of information and memory retrieval.
According to recent neuroimaging studies, it was reported that the posterior parietal cortex of human brain was involved with the memory retrieval and contributes to the attention capture. These researchers have proposed a model and hypothesized that inferior parietal lobe (IPL) mediates the bottom-up attentional capture by retrieved memory contents and superior parietal lobe (SPL) allocates top-down attention to memory retrieval (Ciaramelli, Grady, & Moscovitch, 2008).
In addition, it is also reasonable to assume that the letters E and H may have close resemblance to ‘8’. Say, if a straight line of similar size is drawn very close to the right hand side of letter E, it may appear as ‘8’.Similarly, if two straight lines of similar size are drawn on the top and bottom of the letter H, it looks like ‘8’. But this may need further confirmation.
In some cases, the organization of objects in a given space may play important role while capturing the attention. In the present study, we observed that the number ‘8’ was represented in random, square and row manners. This is also followed by similar spatial arrangement of target letters ‘E and H’ and we found significant statistical difference.
This could be due to the impact of differences in the spatial allocation of objects. Yeshurun et al. (2008) tested a matrix of 16 black L elements in various orientations. They noticed better performance when the target appeared in the center of the object than in a different location, thus supporting the hypothesis that a perceptual object captures attention.
They have indicated that the automatic attention to the object could involve a spatial component. This could be the reason that for the objects presented in the row 2 of non movement trial of figure 1, there was good statistical difference. In addition this difference was high compared to row 1 because in row 2 the place holder displaying ‘8’ was not in square form. The other reason could be due to the availability of blank space combined with no movement that might have enabled the smooth capture of target letters. This could have enabled it to appear in a new sudden onset to the subject, thus contributing to the difference in values. Moreover, the target letter ‘E’ was displayed differently from other letters in a manner such that the subjects would easily perceive it in a bottom –up direction, thus supporting the description of Ciaramelli. Therefore, this mode of attention capture may seem to support the low level of cognitive perception.
In contrast, there was not much detectable difference for the movement trial. This could be due to the interference of letters C, F, P U. The other important reason is that these letters may also pose a new look. They may have the potential to distract the attention of subjects. In addition, the movement could also hide the actual information. This could result in more time (in milliseconds) to find the target letters. Therefore, this may seem to support much higher level of cognition.
Hence, this part of description supports prominent theory of Yantis that highlighted the importance of new visual object (Yantis, 1993). It also supports the transient hypotheses that highlighted that motion transients capture attention, whether or not they are associated with a new object (Franconeri, Hollingworth, & Simons, 2005).
In view of the above information, it can be inferred that the experiment has produced convincing findings in the light of low level and high level cognitive perceptions.
References
Yantis, S. (1993). Stimulus-driven attentional capture and attentional control settings. J Exp Psychol Hum Percept Perform, 19, 676-81.
Franconeri, S., Hollingworth, A., & Simons, D. (2005). Do new objects c capture attention? Psychological Science, 16, 275-281.
Daniel J. Simons (2000).Attentional capture and inattentional blindness. Trends in Cognitive Sciences, 4, 147-155.
Ciaramelli, E., Grady, C.L, Moscovitch, M. (2008). Top-down and bottom-up attention to memory: a hypothesis (AtoM) on the role of the posterior parietal cortex in memory retrieval. Neuropsychologia, 46, 1828-51.
Yeshurun, Y., Kimchi, R., Sha’shoua, G., Carmel, T. (2008). Perceptual objects capture attention. Vision Res. 2008. Web.