Learning by Looking. The Case for Visual-Perceptual Repetition Priming

 

Annalisa Banzi (1), Raffaella Folgieri (2)

(1) Institute of Communication and Behaviour “Giampaolo Fabris” IULM University, via Carlo Bo, 8, 20143 Milan – Italy

(2) Dipartimento di Scienze Economiche, Aziendali e Statistiche Università degli Studi di Milano, via Conservatorio, 7, 20123 Milan – Italy

 

 

Abstract.

Sometimes scholars complain that students and lay public are not able to watch an artistic exhibit displayed in a museum of fine arts. Watching is a learned skill that is neither innate nor spontaneous. Onlookers would benefit from a method that may enhance their visual skills. The goal of this paper is to assess whether a model based on visual-perceptual priming, a kind of implicit memory, may improve the methodology of looking. In this work we also present some preliminary results of a new promising approach consisting in analysing subjects’ brain signals collected by an EEG-based device during the verification phase of the performed experiment.

 

Keywords.

Education, Implicit Memory, Learning, Museum Visitor, Museum of Fine Arts, Museum Studies, Priming, Lay Public, EEG, Brain Computer Interface, BCI device.

We all look at the same things, yet see different things.

Claude Monet

 

The structure of the forthcoming paper is divided into three main parts. The first part provides an introduction to visual skills and visual literacy in order to select the major features required. A few methodologies used in the museum environment to improve observational skills are outlined. The second part investigates what is priming and why priming may be useful in the museum environment. Finally, we discuss how visual-perceptual priming may enhance the museum experience. The purpose of this paper is to focus on visual-perceptual priming as a means to promote visual skills development.

 

1. Visual Literacy and Visual Skills 

Visual Literacy, as first devised by John Debes (one of the most important figures in the history of the International Visual Literacy Association), refers to:

 

A group of vision-competencies a human being can develop by seeing and at the same time having and integrating other sensory experiences. The development of these competencies is fundamental to normal human learning. When developed, they enable a visually literate person to discriminate and interpret the visible actions, objects, symbols, natural or man-made, that he encounters in his environment. Through the creative use of these competencies, he is able to communicate with others. Through the appreciative use of these competencies, he is able to comprehend and enjoy the masterworks of visual communication. (Debes, 1969)

Sinatra (1986) states that Visual Literacy is “the active reconstruction of past visual experience with incoming visual messages to obtain meaning” (p. 5). He stresses the learner role in creating recognition.

Visual Literacy, according to Wileman (1993), is “the ability to read, interpret, and understand information presented in pictorial or graphic images” (p. 114). Visual Thinking is “the ability to turn information of all types into pictures, graphics, or forms that help communicate the information” (p. 114). Visual Literacy is “the learned ability to interpret visual messages accurately and to create such messages” (Heinich et Al., 1999, p. 64).

Kleinman and Dwyer (1999) analyse specific visual skills effects to facilitate learning. For instance, the use of colour graphics in instructional modules, as opposed to black and white graphics, improve learning.

Visual skills are not to be confused with vision, colour vision, disease, and various anomalies. Visual perceptual motor skills and ocular motor skills are the main visual skills categories. These skills are developed after birth. Visual perceptual motor skills process visual information and affect eye/body movements. They encompass abilities such as visual memory, visual-spatial (e.g., mapping locations), visual analysis (e.g., discriminating), visual-motor coordination, visual-auditory integration (e.g., matching sound and image), and visualization. Ocular motor skills involve eye movements control and focus control.

Rueschoff and Swart (1969) single out the major visual skills that children should develop by means of educational program:

 

• the ability to see the individual art elements and application of principle;
• the ability to see the art elements and principles, as applied, within the context of the image or environment;
• the ability to assign meaning to the elements and principles within the context of the thing seen;
• the ability to see conflicts between and among the elements and principles, and to understand the inherent meaning;
• the ability to separate subject matter from content.

 

Lay public should develop or foster these visual skills. Rountree, Wong and Hannah (2002) are correct when they explain that learning to look  involves developing the skill of Visual Literacy. Namely, the modality of looking at objects and understanding the effect of what we see. Beholders should learn to set aside personal and cultural preconceptions and to share the meaning of visual forms “at some level of universality” (DeLong, 1987, p. 3).

 

1. 1.1    Learning to Look. Gathering Meanings through Observation

Michael Baxandall in the introduction of Patterns of intention: on the historical explanation of picture (Baxandall, 1986) explains how we look at an artwork:

When scanning a picture we get a first general sense of a whole very quickly, but this is imprecise; and since vision is clearest and sharpest on the foveal axis of vision, we move the eye over the picture, scanning it with a succession of rapid fixation. The gait of the eye, in fact changes in the course of inspecting the object. At first, while we are getting our bearing, it moves not only more quickly, but more widely; presently it settles down to movements at a rate of something like four or five a second and shifts of something like three to five degrees – this offering the overlap of effective vision that enables coherence of registration.

A work of art is composed by visual clues employed to express its meaning. How can we achieve this meaning? How does the artist set the scene or sketch out his characters in order to “create” this meaning?

Some strategies for helping people to develop Visual Literacy in looking at subject matter (objects and incidents represented) and expressive content (combined effect of subject matter and visual form) of different forms of visual art are here considered.

Taylor (1981) investigates how to approach drawings, paintings, graphic arts, sculptures, and architecture. He begins the artwork analysis describing what is represented through different visual forms. He picks over composition as a dominant contributor to the expressive content of a painting.

He discriminates lines (e.g., vertical, horizontal, and diagonal), shapes, colours (hue, saturation, and value), symmetry, objects arrangement, proportion, and space. He stresses that the choice of material and technique is paired with the artwork character. In order to improve the understanding of an artwork, Taylor compares different artworks representing the same subject but using different expressive contents.

Museum educators often adopt the inquiry-method in order to explore an exhibit with the lay public.

GRAM (Grand Rapids Art Museum) staff has provided a methodology based on a inquiry-based tour of the museum (2011). They stress the importance of encouraging the development of viewers oral and written communication skills in relation to Visual Arts. GRAM docents are trained to exploit specific questioning techniques in the course of the tour. Such questionnaires aims at encouraging students response. After a periods of time spent observing an exhibit, students are asked to answer some questions, suggested by teachers, such as: What is going on in this picture? What is the mood of this image? How do you feel about having to spend time with this artwork? Has your first impression changed now that you have spent time with it? All these questions are followed by another question: What do you see that makes you say that? This question, as stated by GRAM practitioners, helps people beginning to look at an image separate from their own past life experiences and to find evidence for their response within the artwork itself.

The inquiry-based method is used to analyse the formal elements (shape/composition, line, colour, pattern/texture, light, subject/function, and interpretation) as well. The interpretation level, for example, is examined through questions like: Why do you think the artist created this work? Do you feel certain emotions associated with each artwork? What effect do you think the artist’s time period had on his work?

Knowing about the artist’s education, partnerships and ideas about art, GRAM staff uphold, may help the viewer to see a work from a new perspective and to catch novel meanings. The artist weltanschauung is a key part of the artwork meaning.

Another guideline, developed by the National Park Service (http://www.nps.gov/museum/), specifically designed for students, is based on four basic steps. The Close observation of the visual elements – first part of this method – begins with broad open-ended questions (e.g., What do you see?). subsequently people focus on details (e.g., How would you describe the clothing?), sometimes it is possible to identify artistic processes and materials. Preliminary analysis is composed by simple analytic questions that will deepen viewer understanding of a work of art. Each question is followed by another question: How can you tell? This question chain pushes students to seek answers in the work of art rather than veering off into speculation. Research is the third step required to comprehend artworks (additional information on the historical, political, economical, and social artist’s environment). Lastly, interpretation involves assembling observation details, analyses, and information gathered about an art object in order to understand the exhibit meaning. The analyses is completed by comparing exhibits. A sample query is: How are these sculpture similar or dissimilar?

The guidelines aim at enhancing visual literacy, sharpening viewer observation, and learning to express what the viewer sees.

 – READ ON ART  –

Angela Lawler and Susan Wood (2011) select five steps that allow learning to look at art. Students first observe artworks in silence. Eventually, they take time to describe the artwork objectively. The third step analyzes contents, such as colour (e.g., What colours are important in this work? How would this work change if different colours were used? What associations/symbolic meanings might the colours in this work have?), balance (e.g., Is this image symmetrical, asymmetrical? Does the image lie within the frame, or appear to go beyond the edges?), space (e.g., How is our eye drawn through/across this work of art? Are there vanishing points? If so, do these imaginary lines draw our attention to a particular place in the work?), line (e.g., Are the lines the same throughout the work? Identify types of lines and where they are found in the work), value (e.g., Are there parts in this work emphasized by light? If so, can we identify that source?), technique (e.g., Can you see the brushstrokes? Are they thick? Smooth or heavy? Are the brushstrokes the same thickness throughout the work? Do the brushstrokes flow in the same direction throughout the work? Did the artist use slow, meticulous strokes, or paint them on quickly?). The forth step tries to interpret the works of art exploiting what students know and have seen. Finally, students make a critical judgment of the artwork. Judging art requires fair and logical consideration. Angela Lawler and Susan Wood recommend to take time, because reading art is a slow, thoughtful, and exciting process of discovery.

As we have seen, comparing and asking questions are the main methods used to analyze exhibits. In our opinion, an inquiry-style personal response approach to communicate artwork meaning can be useful in an adult (lay public) museum tour as well.

Shall we use other methodologies of looking in order to achieve the same goal? We would like to tackle this topic from a different point of view. The next section introduces the psychological phenomenon called priming that can be used to foster visual skills.

2. What is Priming?

The exposure to a visual-perceptual, semantic, or conceptual stimulus influences response to a later stimulus. Consider this case. A person reads a list of words including the word apple. Subsequently the person is asked to complete a word starting with ap. The probability that he/she will answer apple is increased because the word was previously primed. Therefore, if a stimulus is primed, later experiences of this stimulus will be processed more quickly and precisely by the brain.

Priming is a kind of implicit memory (a sort of tacit memory that is not consciously retrieved or observed). While performance of episodic memory based on explicit tasks initially improves with age and declines in advancing age, priming remains relatively stable from age 3 to 80. As stated by Wiggs and Martin (1998), perceptual priming is impervious to long retention intervals, stimulus attribute alterations (e.g., size) attentional manipulations (e.g., dividing attention), and developmental changes, all of which affect episodic memory.

It is useful to outline a taxonomy of different kinds of priming. Researchers have made a distinction between conceptual priming and perceptual priming. Tasks that involve analysis of stimulus meaning engage conceptual processes. Tasks that entail analysis of perceptual form trigger perceptual processes.

Repetition priming facilitates performance based on prior encounter with the same stimulus. Although the majority of research on perceptual repetition priming has been in the visual domain, repetition priming has also been examined in auditory domain.

Visual perceptual priming is defined by enhanced processing of previously seen visual material, relative to novel visual material. The response in terms of speed and accuracy is improved.

Semantic priming refers to an improvement in speed or accuracy to respond to a stimulus when it is preceded by a semantically related stimulus (e.g., table-chair) as McNamara (2005) states. Pure semantically related stimuli either share semantic features or belong to a common category. In associative priming, the target is associated with the prime but not necessarily related by means of semantic features. Dog is an associative prime for cat, since the words are closely associated and appear frequently together.

In affective priming, responses to a target stimulus (e.g., happiness) are faster when the stimulus is preceded by a prime stimulus with the same affective value (e.g., sun) than when the prime stimulus has a different value (e.g., war).

Positive and negative priming refer to cases in which priming affects the speed of processing. Negative priming, discovered by Dalrymple-Alford and Budayr (1966) in the contest of the Stroop effect, is an side-effect: it lowers the speed to slower than unprimed levels processing a stimulus that was previously presented but was not attended. A positive prime speeds up processing.

Subliminal priming has been extensively investigated by Marcel (1983 a, b). He reported a series of experiments from which he obtained robust priming effects in the absence of perception of the prime. He concluded that priming proceeds automatically and associatively without any necessity for awareness.

In structural priming speakers tend to repeat the structure of a sentence heard or spoken previously – even when the sentences differ in lexical and message-level content. The phenomenon has been study extensively by Boch and her colleagues (Bock and Griffin, 2000).

Finally, it must be considered that priming may be effected in other modalities (e.g., auditory, haptic).

 

2.1   Visual-Perceptual Priming

Wiggs and Martin (1998) review the literature as to the main visual-perceptual priming experiments. They stress that perceptual priming is sensitive to changes in physical appearance only in some instances. In general, stimulus attribute alterations – such as colour, pattern, luminance, contrast, location, left-right reflection, and size – do not influence priming. At the same time, perceptual priming can be attenuated when stimuli are changed so as to affect the ability to identify stimulus form. Specifically, it is not affected by relatively small changes in orientation (i.e., rotations in depth up to 67°) but is eliminated by large changes in orientation (i.e., rotations in depth > 80°). Furthermore, the phenomenon is diminished with changes in an object’s exemplar (e.g., a different picture of the same-named object), and with changes in a word’s typography from study to test. These results suggest that physical attributes essential to the representation of object form –such as line elements of drawings, or written word form (e.g., print typography of letters) – do influence perceptual priming.

Finally, “the degree of attention devoted to encoding typically does not affect the magnitude of priming. Thus, when attention is divided during encoding, priming is no different than when attention is focus” (Wiggs and Martin, 1998, p. 228).

3.  How to Improve the Methodology with Visual-Perceptual Repetition Priming

The purpose of the present research is to develop a priming-based model that takes into account the most relevant experimental and physiological findings and applies them to the museum environment.

Students and lay public are often unskilled visual onlookers. They do not know that an image or an artistic object may be read just as a book. They lack a proper education. To help them an education well-founded in visual language and communication is needed (Nuel, 1984). There are various ways to achieve such a goal. In this paper we focused on psychologically based techniques – priming is the most promising one.

The ability to analyze the artwork formal qualities, as we mentioned previously, is intrinsic to complete understanding of the art-making process. Therefore people need to develop or improve visual skills. Besides, museum visitors should learn a methodology, based on the knowledge of the main features contained in an artwork, to approach and comprehend an artistic object. In order to achieve these aims we have chosen to analyze and apply priming to museum environment. This phenomenon, as we described earlier, possesses some interesting characteristics: perceptual priming effects are long-lasting in normal adults and amnesic patients, priming remains relatively stable from age 3 to 80, the degree of attention devoted to encoding typically does not affect the magnitude of priming, and finally this phenomenon seems to be independent of cultural background.

Our aim is to trigger visitors visual skills showing visual stimuli related to artworks (colours, lines, shapes, and so forth).  Here is a streamlined example of a tentative priming-oriented method so as to develop artwork-related visual skills.

In the experiment we also adopted an innovative approach consisting in supporting results also with subjects’ EEG data acquired during the final test in which participants were asked to answer some questions about the experience. EEG has been chosen for its temporal resolution, because we aim to measure if and when, answering to the questions, participants present variation in EEG signals, due to stimuli recognition, frustration and change in attention levels.

3.1  Setups

The aim is to implement either technological devices and educational resources (wall and caption texts, booklet) based on priming process. Each artworks expressive content, described previously by art historians and museum practitioners, would be proposed as visual stimulus for a short period of time to the lay public, before the encounter with the real work of art. The comparison of visual stimuli possessed by different masterpieces that depict the same subject matter, as underlined by Taylor, would help understanding better the work of arts expressive contents.

The experimental setup takes advantage of visual-perceptual repetition priming. It is based on a museum tour (Pinacoteca Ambrosiana – Milan, Italy) where participants singularly watch prime stimuli on a screen under the supervision of researchers. On the whole, the experiment require three statistically sampled groups of subjects:  prime stimuli group, neutral stimuli group, and control group. Ten stimuli are showed within a controlled period of time. Subsequently the participants visit the museum without any restrictions. At the end of their tour, the participants are asked to answer some questions about the masterpieces chosen for the experiment in order to check if the prime stimuli (e.g., colour) helped them remembering the artworks main features (target). A control group of the same number of people tour the museum without any previous visual stimuli and another group is exposed to neutral stimuli. When taking the final test, all the groups of subjects have been submitted also to their EEG signal measure (Niedermeyer and Silva, 2004). To avoid influence in anxiety of participants, we chose to use a Brain Computer Interface (BCI) devices (Allison et Al., 2007)  to collect EEG signals. BCI devices are a simplification of the medical EEG equipment and currently several kind of low-cost, non-invasive BCI could be chosen for our research objective. We collected EEG data using a Neurosky Mindwave^TM BCI device, used in several commercial and research applications, consisting of a headset with an arm equipped with a single dry sensor acquiring brain signals from the forehead of the user at a sample rate of 512 Hz, transmitted via bluetooth to a host computer. Compared to other BCIs, such as, for example, Emotiv Epoc^TM, the Mindwave BCI results more comfortable for users, both for the easiness of positioning the device on the scalp, and because it uses a dry sensor instead of wet ones. Moreover brain functions interesting our work, are related to the premotor frontal cortex area, that is the area on which the Mindwave^TM sensor is positioned. In fact, the signals from the frontal lobes are linked to higher states of consciousness. Another advantage, convincing us about using Mindwave^TM, consists in the wireless communication between the BCI device and the computer during the collection of data, making comfortable wearing the BCI during the experiments.

BCIs collect several cerebral rhythms grouped by frequency. For our purpose, we concentrate on alpha, beta, theta and gamma band. In fact, activity in the alpha band (7 Hz – 14 Hz) is usually related to relaxed awareness, meditation, contemplation, etc. Beta band (14 Hz – 30 Hz) is associated to active thinking, active attention, focus on the outside world or solving concrete problems. Theta band (4 Hz – 7 Hz) is related to emotional stress (frustration & disappointment). Finally, activity in gamma band (30 Hz – 80 Hz) is considered to be related to cognitive processes involving different populations of neurons, and to the processing of multi-sensorial signals.

As to the kind of stimuli, ten prime stimuli are selected. In general the prime stimuli are related to the artistic features of the artworks located in the gallery (e.g., colour, technique, style, iconography, shapes, brushstroke, and line specific of) while the neutral ones are unrelated to the artistic features of the works of art selected. In this experiment, portions of colours, have been select from five artworks positioned in Pinacoteca Ambrosiana. In order to select the colours we followed some criteria: the colour extent, the colour saturation and value, and the repetition of the hue in the Pinacoteca collection.

Procedure. At the onset, participants read the instructions they will then paraphrase back to the experimenter. After a practice trial, participants are asked whether they have any doubts as to what they have to do. The prime group watches a session of 5 prime stimuli (colours: red, green, blue, brown, and white) related to 5 paintings features, alternated with neutral prime stimuli (objects in black and white not depicted in paintings: luggage, phone, baby’s bottle, vacuum cleaner, and headband) for a short period of time (1 minute circa). The neutral stimuli group watches a trail composed by 10 stimuli unrelated to paintings (objects pictures in black and white such as sunglasses) for a short period of time (1 minute circa). A control group visits the museum without any previous visual stimulus.

The prime stimuli alert the visitor’s brain and help remembering better the colours represented in the paintings.

After the museum exhibition tour, participants complete a questionnaire about the five selected features of the corresponding artworks and wear Mindwave in order to collect EEG signals.

3.2 Results

Developing and training visual skills using priming is the goal of the present research. As previously mentioned, priming has interesting features, such as long-lasting effects, stability despite age, imperviousness to attention degree, and independence of cultural background, that can be exploited in museum environment. Future detailed experiments will better test how much such elementary psychological process may help museum practitioners to improve visitors’ visual skills.

Concerning data collected by EEG signals, to analyze the presence of differences in the brain activity during the final questions session, among the three groups, we calculated, using MATLAB^TM, the average Power Spectral Distribution (PSD)(Priestley, 1991) in the alpha, beta, theta and gamma wave bands (Niedermeyer and Silva, 2004; Bear, Connors and Paradiso, 2007) for all the users. PSD, in fact, describes how the power of a signal is distributed with frequency, and therefore the average values in each band can give useful information on the overall behaviour of the brain activity eventually induced by the visual stimuli. For our experiments, we calculated PSD using the Welch’s method(Welch, 1967) with Hamming window function(overlap 50%, segment length 64) (Oppenheim and Schafer, 1989) and to compensate the different data ranges for each user, due to personal variability, we have computed for each user data the ratio between the average power in each band and the average power in the frequencies interval between 0 Hz and 80 Hz.17 Finally, we have computed an average of these ratios in each band. From an analysis of these plot, it appears that in subjects who received the visual stimuli there is an increase in the attention level (Beta and Gamma bands, related to active thinking and attention). On the contrary, Theta brainwaves decrease, showing that participants did not feel frustration or disappointment.

Participants who did not receive any visual stimuli show results similar to those subjects who received a neutral one. In these cases, Beta and Gamma bands decrease, compared to the first group, while we registered an increasing of Theta band.

We also calculated the average band power in beta, Gamma, Theta and Alpha bands for the three groups of participants.

For subjects who received the visual stimuli, Gamma and Beta bands revealed an average band power significantly greater than participants who did not receive a stimulus and to whom received a neutral one. On the contrary, Alpha band, related to meditation and contemplation, and Theta band, corresponding to frustration, decrease for the first group, compared to the other two.

Of course, the application of EEG signal analysis to this kind of experiment is a challenge and we are aware that the presented experimental setups are not based on a specific task. This can affect the analysis of activity in the analyzed bands, often considered and studied in well-defined task-based experiments. We are currently considering other experimental setups, based also on ERPs, in order to investigate the actual appropriateness of the beta/alpha ratio as an index of attention in EEG based experiments on visual prime. 

4. Conclusions and future works

Developing and training visual skills using priming is the goal of the present research. As previously mentioned, priming has interesting features, such as long-lasting effects, stability despite age, imperviousness to attention degree, and independence of cultural background, that can be exploited in museum environment. In this paper we presented encouraging results obtained submitting individuals to a museum tour where participants singularly watch prime stimuli on a screen under a researcher’s supervision.

While participants were answering to the final questions, we also registered their EEG signals using a non-invasive BCI device. The presented preliminary results shows that, compared to subjects who did not received specific stimuli, in participants who received the visual stimuli, we registered an increasing of the attention level corresponding to questions related to the engagement of memory due to the visual stimuli. Also beta and gamma bands, related to active thinking and attention, presented a regular track on the same questions. Theta brainwaves did not show frustration symptoms and, correspondently,  alpha values, also related to meditation and contemplation,  confirmed the relaxed attention state of subjects.

On one hand this new approach promises future improvement in exploring priming mechanisms, while, on the other hand, results represent just a preliminary step in improve EEG use for our research aims. Future works will have mainly the objective to individuate measures more significant for our aims. We also will have to perform more experiments to validate this innovative approach, representing, at the same time, a great opportunity and a challenge.

Future experiments will test how much such elementary psychological process may help museum practitioners to improve visitors’ visual skills.

 

Acknowledgments 

We thank Riccardo Manzotti who helped us during this work. We also thank Daniele Marini and Davide Gadia for their suggestion on signal processing and analysis methods.

 

– READ ENGLISH ARTICLES – 

 – READ ON ART  –

 

 

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