Psychology

The use of tactile pictures for the blind
The purpose of this paper is to evaluate the relevance of using tactile pictures in the cognitive development of the blind. This paper examines two experiments, the first evaluates the cognitive development of congenitally totally blind children using tactile-based tests and the second experiment examines the neural activity triggered by exposure to tactile pictures for both sighted and blind subjects.

Cognitive Patterning in Congenitally Totally Blind Children

Introduction and hypothesis
The aim of the study is to explore whether the absence of vision impairs the cognitive development of totally blind children. The hypotheses of the study are 1. The global-articulated cognitive style observed in sighted subjects is also manifested by the congenitally totally blind subjects 2. Visual impairment slows down the development of articulation of congenitally totally blind children and result to lower cognitive performance and, 3. Articulation and comprehension have no relationship with each other (Witkin, Birnbaum, Lomonaco, Lehr,  Herman, 1968, p.770). These were all explored using a series of tests given to the subjects.

Method
The subjects considered for the study, the various tests given to evaluate cognitive skills of the subjects and the procedures followed in conducting the experiment is provided below.

Subjects
For this experiment, 25 participants (13 boys and 12 girls) who are totally blind since birth made up the experimental group. All of them had no visual or light visions. The age of the participants ranged from 12 to 18 with the mean age of 14. Their IQ ranged from 92 to 153 with a mean of 114.8.
The control group on the other hand consists of 28 sighted children (15 boys and 13 girls). Their age ranged from 12 to 19 with mean age of 14 which is equivalent to that of the experimental group. Both groups were also equated in their average grade which is 8.7 and 8.8 for blind and sighted children respectively.

Tests and materials
The different tests conducted for this experiment are tactile embedded-figures, auditory embedded-figures, tactile design, matchsticks test and body concept test. The materials used in these tests include simple and complex objects made of plastic, matchsticks, textured blocks, musical note recordings and modeling clay.

Procedure
To test the analytical ability in perception of the subjects, the tactile embedded-figures test developed by Axelrod and Cohen (1961) was used (cited in Witkin, et al, 1968, p. 771). The test was conducted for both the control and experimental group. The participants were asked to examine a complex and simple object made of 4-inch-square sheet of plastic. For each trial, the participants were given 15 seconds to examine and describe a complex object. The figure is then removed and replaced by a simple figure embedded in it which the participant again examines for 10 seconds. The participants are then told that the simple object is embedded in the complex object. Then, the complex object is returned and the subjects were asked to find the simple object within it.  The maximum time provided was 300 seconds. Subjects who gave the wrong answers were allowed to continue until they find the right answer within the allotted time. Subjects who failed to give the right answer after 300 seconds automatically get the maximum score which is 300. Three practice trials were given before the actual test. The test consists of 14 trials. Sighted participants were asked to examine the objects behind a rectangular screen with a curtain to prevent visual exposure of the materials.

The next test conducted for the experiment is the auditory embedded-figures test developed by White (1953). It is an auditory version of the embedded test. For this method, 50 pairs of simple and complex tunes were played for the subjects. Subjects were asked to listen to each pair of tune and identify whether the short note is present in the complex tune. If the subjects are not sure of their answers, they were asked to guess.

Analytical ability of the participants in problem solving was measured using the tactile block design test. In this test, the subjects were asked to duplicate a reference design using a set of blocks. Instead of using colors, the blocks used were differentiated by their textures.  The process is timed and participants were given three points if they finish the reproduction within 30 seconds, 2 points if they finish it between 31 to 60 seconds, and one point if the time is between 61 and 180 seconds. Each subject was given eight trials.

The last tactile test was the matchsticks test. This is developed by Guilford, Frick, Christensen, and Merrifield (1957) and adapted from the visual test. Subjects were asked to reduce the number of squares in the lattice by removing specified number of matchsticks.

Another test given to the subjects is the body concept evaluation. The authors used a modified version of the body concept for this method. Instead of asking the subjects to draw a human figure, they used clay modeling. Subjects were asked to make a representation of a human figure. Models were rated based on their resemblance to the human figure. Lastly, subjects were tested for intelligence using the verbal section of the Wechsler test.

C. Results
For the tactile embedded test, the mean score obtained for the sighted was 64.5 while the blind subjects got a mean score of 134.5. This shows that they it took the blind group longer to find the simple object from the complex object. For the matchsticks test, the sighted obtained a score of 5.3 while the blind got 4.8. In the tactile block design, the scores were 10.9 and 12.3 for blind and sighted respectively which shows a more advanced development in the sighted subjects in terms of analytical ability. In terms of the body concept, the sighted subjects obtained a higher rating of 3.4 compared with the 2.6 rating obtained by the blind subjects. In the auditory-embedded test, the blind group scored 84.9 while the sighted group only scored 66.7.

Discussion
The test for consistency in cognitive functioning of the visually impaired shows intercorrelation among the scores obtained in the tactile embedded test, matchsticks test and tactile block design. The result shows that the performance of the blind subjects in the different tactile tests is consistent with the expectations of the experiment. The correlation scores from the three tests are high and significant ((Witkin, et al, 1968, p. 775). This suggests that blind people have different tactile skills and result varies from one individual to the next.  This confirms the first hypothesis that the global-articulated dimension observed in sighted individuals is also evident in the congenitally blind.

In the case of the auditory embedded test however, the scores obtained are not significant. This contradicts the expectation of the experiment. The authors believe that the inconsistency could be a factor of the nature of the test. Although the embedded factor is present, the fact that the test is more auditory rather than tactile-based could account for the unexpected results.

For the next hypothesis, the performance of the two groups was compared. Based on their mean scores, it is notable that the sighted subjects got higher scores in the tactile tests (tactile embedded test, matchsticks test and tactile block design) and body concept. The analysis of variance shows that the differences between the scores in the tactile tests and clay modeling test are significant. These results are also consistent with the expectations of the experiment.

For the third hypothesis, the articulation and comprehension of the blind subjects were tested for correlation. Using their verbal-comprehension factor IQ obtained from the Wechsler scales and the result of the five tests, the correlation obtained were all low and not significant. This confirms the hypothesis that comprehension and articulation are not related.

The contribution of the study is that the blind show less articulation in their cognitive development than the sighted subjects. The authors noted that this could be a function of their developmental history (p. 779). The sighted subjects had more exposure to the objects due to their visual advantage than the blind subjects. However, the authors noted that the difference in the result obtained from the congenitally totally blind subjects and the sighted subjects is not as great as expected given the circumstances. They also added that some of the blind participants even have more advanced cognitive functioning than their sighted counterparts. According to the study, this shows that blindness is not a hurdle to the development of the children, despite the inconveniences the blind children can learn these skills with time and practice.

The result for the blind and the sighted show that both groups have comparable verbal-comprehension ability as evidenced by their comprehension factor IQs of 115.5 and 113.7, respectively. The sighted group performed better in the tactile tests but the blind group have higher mean attention-concentration factor IQ compared with the sighted children, 124.0 and 110.9. The blind group has lower scores in terms of articulation but this is not correlated with comprehension. The authors believe that these differences maybe factor of their different experiences and that the field can be leveled up if the blind subjects are given more chances to develop these skills.

The next experiment deals with the neural examination of blind and sighted subjects. This examines whether there are differences in the brain activities of sighted and blind subjects exposed to tactile tests.

Object-Based Representation in the Human Ventral Pathway

Introduction and hypothesis
The paper investigated whether neural responses in the ventral visual pathway depend on sensory images or not. The experiment, by Pietrini,. et al (2004) was conducted to test the hypothesis that representations of objects in the  ventral temporal cortex are abstract rather than visual.

Method

Subject
For the experiment, five sighted and four blind subjects were tested. Among the sighted subjects, two are females and three are males and the average age was 336 years. Among the blind subjects, two are congenitally blind and the other two had no recollection of any visual experience, two females and two males with an average age of 5314 years. The subjects went through medical, neurological and psychiatric evaluations and structural MRI to rule out other causes affecting brain function.

Materials
Functional MRI was used to measure the activity evoked by tactile and visual recognition of objects. The images were obtained using gradient echo echoplanar imaging on a GE 3T scanner (Pietrini,. et al, 2004). According to Pietrini,. et al, for the tactile recognition test, 8 time series, each consisting of 174 brain volumes, were obtained for each subject (p. 5658). For the visual recognition, they obtained 12 time series, each consisting of 125 brain volumes for each sighted subject.

Procedure
In the tactile experiment, life masks, plastic bottles and shoes were used. Sighted subjects were blindfolded during the experiment. The subjects were made to lie on an MRI machine and the objects were presented to them using wooden pole with a Velcro. A wooden table was placed above their stomach to aid them in examining the object since they are restrained from the elbow up to avoid unnecessary movements. To even out the performances, subjects were given limited time to examine the objects. They were only given 15 seconds to examine face masks, 10 seconds for shoes and five seconds for bottles.

For the visual experiment, sighted subjects were shown photographic images. The same MRI procedure was undertaken to record their brain activities. Responses for both the tactile and visual experiment were analyzed to determine the recognition patterns.

Results
The result of the experiment showed that the tactile tasks evoked activities in the ventral extrastriate cortex in both sighted and blind subjects. Although there are some overlaps between the regions activated during visual and tactile exposure as shown by the result obtained from the sighted subjects, the authors noted that the inferior temporal activations in sighted and blind subjects were in essentially the same locations as shown in Figure 1 (p. 5660). This suggests that visual recognitions influence in the tactile reaction of the sighted subjects may be affected by their visual experiences but the degree of overlap is not that great which implies that the link is minimal.

Discussion
For this study, the goal was to test whether neural responses in the ventral visual pathway are more visual or more abstract. To evaluate this hypothesis, the study examined the patterns of activities evoked by tactile recognition of faces and other objects and compared them with the patterns of response obtained during visual recognition. Using both sighted and blind subjects enabled the authors to evaluate whether tactile recognitions are affected by sight or not. The authors concluded that although visual imagery affect the tactile representation in sighted subjects, the result obtained from the blind subjects shows that the development of the extrastriate visual cortex does not require visual experience (p. 5663). They added that sensory exposure to the objects alone is sufficient to support the development of these representation patterns in the brain. The study shows that the abstract, supramodal character of neural representation of objects in the inferior temporal cortex enables blind people to acquire normal knowledge about objects and interact effectively with their external world (p. 5663).

Although the visual experience of the sighted subjects influence their tactile reaction, it is remarkable that their brain reaction to tactile recognition mirrors that of the blind subjects. This indicates that tactile recognition evokes unique brain activities from visual recognition. Thus, even people who have never seen the object visually are able to recognize them through tactile recognition. In the same way, even sighted people who have seen the objects visually used tactile recognition rather than visual recognition under the circumstances.

Conclusion
Based on the results of these two experiments, it is evident that there are differences in the cognitive development of the blind and the sighted people. The blind subjects lack some of the development functions obtained by the sighted people or acquire them at a lower level. As shown in the first experiment, the blind subjects faced more challenges in accomplishing tactile tasks, however the results show that their performances of the blind group is not far behind that of the sighted subjects. The authors stressed that the lower scores do not indicate that the blind subjects are handicapped in terms of these skills, rather, it only shows that they have slight disadvantage compared with their sighted counterparts. Their performances also show that with more exposure they can develop these skills.

In the second experiment, it was shown that tactile skills are not visually dependent. Based on the experiment, blind people have the similar brain activities evoked in the sighted people when it comes to tactile recognition. The level of brain activity for both groups is not only equivalent but the areas of the brain functioning are almost similar, indicating that visual skills is not necessary in developing the tactile skill of an individual.

These tests both indicate the capability of the blind to perform well using tactile methods. The implication of the studies is that blindness is not a handicap in terms of cognitive development of an individual. As Witkin, et al (1968) noted, it could serve as an impetus for the individual to strive harder in developing these functions. Furthermore, to answer the question whether blind people have any sense of how objects appear by just using their sense of touch, these studies suggest that visually impaired individuals indeed have a very advanced understanding of how objects look like.