perception with visual input adjustment

Posted comment on ´Kicking the Kohler Habit` by C. Klein and G. Love published in website for the ´ASSC.ORG` June 24th 2006


Klein and Love in their article addressed the topic of what determines personal perception and began by exploring O`Regan and Nöe`s sensorimotor theory of consciousness where visual information and the perception of that information was linked to the perceiver`s actions in his environment. They explored strong enactivism where a subject at different times under different conditions experiences the same visual interpretation and used the work by Kohler to illustrate the view. In Kohler`s experiments the perceiver wore inverting goggles giving an upside down image. After a chaotic period, according to Kohler, readjustment to the inverted goggles image occurred and the image appeared to flip upright again. By removing the inverting goggles, another chaotic period ensued. This sequence was interpreted as the perceiver undergoing a period of learning so that he could interpret what he saw, but then the removal of the goggles meant that the subject had to re-learn again how to interpret the visual information he was getting. Klein and Love described the flipping of the image as a false observation and called this the ´Kohler habit` and their views were supported by others, eg Yoshimuro and Harris, Linden et al. To prove that the images had indeed not flipped upright in the readjustment phase, the authors described further visual experiments by Linden et al. involving colour-graded circles and squares that were perceived by inverted goggle wearers and non-goggle wearers consistently as either convex or concave. Although they argued against strong enactivism, the authors did question whether there was in fact a case for weak enactivism. If perception is only due to visual stimulation then no period of adjustment is necessary, but periods of learning and relearning are required with the use of inverting goggles which they attributed to a need for sensorimotor understanding. Klein and Love concluded by saying that perception research was concentrating on what they termed ´upstream` factors like anatomy, physiological perceptual processing and not enough on ´downstream` factors such as information binding and interaction between brain areas.


The key point of the Klein and Love article is that contrary to Kohler`s interpretation of his experiment with inverting goggles no apparent flipping of an image back to its original orientation occurred after a period of learning required to adjust to new hand-eye coordination instructions. The result of this is important because for example as in the case of picking up a bottle. Hand-eye coordination is required for navigation and manipulation and as touched on in the Klein and Love article, a theory for consciousness (the enactive sensorimotor theory). From a neuroscience point of view, hand-eye coordination requires multiple brain systems and areas such as visual input, memory, muscle coordination, monitoring mechanisms and repetition and learning leads to automaticity in movement. With incoming information not required to be attended and no conscious processing, such movements can be quick and the brain is freed for processing of more demanding and novel tasks. In the case of procedural memory, eg riding a bike, information relating to sequences is stored in the cerebellum, but other brain areas involved in object recognition, limb and muscle movements and monitoring are also required.
The Kohler experiment investigating orientation of an object in the visual field showed that visual information is interpreted using previously acquired knowledge and if the perceiver is presented with a change in visual conditions then readjustment to these conditions occurs by learning. In the Kohler experiment with inverting goggles this readjustment phase is heralded by a flipping of the image back to its original position. If the experiment continues and the visual condition is changed back then chaotic interpretation occurs again until the appropriate hand-eye coordination is re-learnt. Evidence from other researchers dispute the idea of the flipping image, but there could be a neuroscientific explanation.
In the experiment the perceiver sees what is there and learns to respond in the correct and expected way. Wearing the inverting goggles means that the perceiver has to relearn the situation in the new format, eg what was up is now down and vice versa. Certain visual information is given significance, hence is attended because this information is required to successfully complete hand-eye movement related response. In the relearning phase, it is assumed that the horizon, object size, object affordance and visual attentional networks all remain the same. Attention is focused during the learning phase with conscious thought and processing and therefore, what is presented is what is perceived. The perceiver is probably stressed and therefore, the effect of the negative emotional state is likely to affect the visual content with an increased amount of both relevant and irrelevant information being inputted and dealt with. Continual error monitoring means that there is increased activity in both the anterior cingulate cortex (ACC) and prefrontal cortex (PFC). After the period of learning when re-adjustment is complete, it can be expected that hand-eye coordination is accurate and appropriate to its demands. The information required is integrated and stored and activity in the ACC and PFC decreases. Researchers such as Kohler, Linden agree to these early stages of response to inverting goggles.
The dispute in views occurs at the following stage when adjustment is achieved. Here Kohler believes that the image flips back to its original orientation whereas other researchers believe that the image remains true to the position indicated by their visual changing apparatus. An explanation for Kohler`s interpretation could be linked to the enactive consciousness theories. Perception is due to a mix of what is observed and what is expected to be observed, the latter coming from stimulation of appropriate memory groupings, ie information from past experiences. The inability to see what is there in real-time, but from a previous occasion is due to lack of attention and input of the current information and a dominance of reactivated memory information. For example, didn´t see the new haircut or new paint colour. There is likely to be filling in and binding of information from previously stored memories which can cut the level of real-time input until recognition occurs. The processing of incoming information and stored information in such a way is likely to be carried out in the visual working memory which matches stimulus to response and can track objects temporarily out of sight (expected from past experience vs real-time visual input) and activity in ventral temporal P pathway for object recognition with activity reported in IT, V4, medial temporal and inferior temporal cortex is observed. In the Kohler experiment the current view is dominated by the reactivated memories of the expected view learnt from years of experience before the wearing of the goggles. As conscious awareness shifts away and the movements are automatic so could the return of the more expected orientation dominates.
A similar explanation could be given for the experiments carried out by Jan Degenaar who like Kohler experienced different perception to what was expected in his experiments using goggles that changed right and left sides. At the beginning he like Kohler`s subjects experienced a lack of coordination and nausea and found that his capabilities returned at different rates. Degenaar found it easier if he moved his head and had to process more if his head was stationary. In Degenaar`s experiments hand-eye coordination is again being investigated, but instead of up-down orientation changes in this case right-left were looked at, but an extra element was added with the perceiver either moving his head or keeping it stationary. In this case adjusting to the goggles led to different visual pathways being activated: head stationary – object recognition pathway – P Pathway, temporal, ventral; head moving – object recognition pathway (P, temporal, ventral) plus M pathway, dorsal, parietal pathway – spatial skills localizing points in space. Damage to the superior parietal area means that sufferers cannot reach for stationary space and find it difficult locating points in space, both appropriate to the situation here with Degenaars inverting goggles.
The observation that Degenaar found better adjustment if he moved head could be explained by neuroscientific hypotheses, since constant adjustment and learning in response to movement is a common situation in daily life. In this case the two visual pathways M and P are in play plus extra information on head/neck/eye movements (Richard`s corollary discharge theory). More conscious processing is undertaken during the learning phase (level of processing model) and information from seeing the item now appear on the opposite side is learnt just like in the Kohler experiment. The information relates to the object itself – content reference points (Wertheimer, Johansson, Navon), not location or size and the appropriate hand-eye coordination required for the response. As learning occurs more information is added to the built up stored memory.
In Degenaar`s experiment, he found that up to 30 days coordinating movements required effort, but then he discovered that when he moved his head the objects were located where he thought they were indicating like Kohler that the readjustment period had finished. However, when his head was stationary he experienced the visual field in the old way and not the sides where the objects actually were. He interpreted this as seeing two percepts of the same object, with one a ghostly image. This reported observation was dissimilar to that seen with the Neckar cube for example.
Some researchers attempted to explain the observation with Klein saying that it could be the result of the brain learning to extract information from an inverted internal image and Prinz that although knew that the image was reversed, skills were developed to cope with a world turned backwards. My own view on the observation is based on the role that memory and expectation plays on perception. There are many examples of incorrect reports of visual events relating to movement, eg the spinning wheel seen as complete when only a few spokes actually exist if the object is pictured stationary, or the impression of movement in a train that is still. In Degenaar`s experiment the incoming stimulus leads to the hand-eye coordinated response and although he reports two percepts there is actually only one for each different circumstance, but many of the features of the memories overlap. The percept form experienced in the moving head example relates to information taken from the environment, and the expectation from memory filling in the reference points. Therefore, after learning and readjustment Degenaar sees the object on the correct side. However, if the head is stationary then there is a resurfacing of the more expected view. In this case the readjustment phase is not complete and there is more reliance on memory and past experiences. This dominance of reactivated information could be because the perceiver was a long time keeping his head still to prevent the feelings of nausea and therefore the information is deeply ingrained. There could also be incorrect interpretation of reference points, applying laws of constancy of size and colour whereas with movement, more processing is involved and information is filled in as expected. Therefore, Degenaar`s two percepts are in fact one dominant one with many strong features overlapping from the moving and stationary conditions and lesser, more ghostly features which reflect the non-overlapping features of the two conditions. The brain interprets what it sees in relation to what it expects and what it thinks it should see. In this case there is likely to be a delay between what is observed if action was required and what was reported (conscious awareness). Just like the spinning wheel and other visual illusions, the correct interpretation of what is being observed is difficult.
Since we`re talking about the topic…….

….can we assume that language and priming could affect Degenaar`s two percept observation.
……if relaxants were used during learning with the inverting goggles that the period of readjustment may be reduced due to the increase in level of relevant information and more constructive awareness and processing.
…..if cannabinoids were administered after the readjustment phase then the roles of memory and real-time information would be clarified since the drugs would cause desynchronisation of visual input with no effect on reactivated memories.

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